X Input Device Extension Library

Mark Patrick

Ardent Computer

George Sachs

Hewlett-Packard

X Version 11, Release 7.7

Version 1.0

Copyright © 1989, 1990, 1991 Hewlett-Packard Company, Ardent Computer

Permission to use, copy, modify, and distribute this documentation for any
purpose and without fee is hereby granted, provided that the above copyright
notice and this permission notice appear in all copies. Ardent and
Hewlett-Packard make no representations about the suitability for any purpose
of the information in this document. It is provided "as is" without express or
implied warranty.

Copyright © 1989, 1990, 1991, 1992 X Consortium

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the ‘‘Software’’), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
of the Software, and to permit persons to whom the Software is furnished to do
so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE X
CONSORTIUM BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Except as contained in this notice, the name of the X Consortium shall not be
used in advertising or otherwise to promote the sale, use or other dealings in
this Software without prior written authorization from the X Consortium.

X Window System is a trademark of The Open Group.

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Table of Contents

1. Input Extension
    Overview
        Design Approach
        Core Input Devices
        Extension Input Devices
        Using Extension Input Devices
    Library Extension Requests
        Window Manager Functions
        Events
        Event Handling Functions
A. Input Extension Protocol Encoding

Chapter 1. Input Extension

Table of Contents

Overview
    Design Approach
    Core Input Devices
    Extension Input Devices
    Using Extension Input Devices
Library Extension Requests
    Window Manager Functions
    Events
    Event Handling Functions

Overview

This document describes an extension to the X11 server. The purpose of this
extension is to support the use of additional input devices beyond the pointer
and keyboard devices defined by the core X protocol. This first section gives
an overview of the input extension. The following sections correspond to
chapters 9, 10, and 11, ``Window and Session Manager Functions'', ``Events'',
and ``Event Handling Functions'' of the ``Xlib - C Language Interface'' manual
and describe how to use the input device extension.

Design Approach

The design approach of the extension is to define functions and events
analogous to the core functions and events. This allows extension input devices
and events to be individually distinguishable from each other and from the core
input devices and events. These functions and events make use of a device
identifier and support the reporting of n-dimensional motion data as well as
other data that is not currently reportable via the core input events.

Core Input Devices

The X server core protocol supports two input devices: a pointer and a
keyboard. The pointer device has two major functions. First, it may be used to
generate motion information that client programs can detect. Second, it may
also be used to indicate the current location and focus of the X keyboard. To
accomplish this, the server echoes a cursor at the current position of the X
pointer. Unless the X keyboard has been explicitly focused, this cursor also
shows the current location and focus of the X keyboard.

The X keyboard is used to generate input that client programs can detect.

The X keyboard and X pointer are referred to in this document as the core
devices, and the input events they generate ( KeyPress , KeyRelease ,
ButtonPress , ButtonRelease , and MotionNotify ) are known as the core input
events. All other input devices are referred to as extension input devices, and
the input events they generate are referred to as extension input events. This
input extension does not change the behavior or functionality of the core input
devices, core events, or core protocol requests, with the exception of the core
grab requests. These requests may affect the synchronization of events from
extension devices. See the explanation in the section titled ``Event
Synchronization and Core Grabs.''

Selection of the physical devices to be initially used by the server as the
core devices is left implementation dependent. Functions are defined that allow
client programs to change which physical devices are used as the core devices.

Extension Input Devices

The input extension controls access to input devices other than the X keyboard
and X pointer. It allows client programs to select input from these devices
independently from each other and independently from the core devices. Input
events from these devices are of extension types ( DeviceKeyPress ,
DeviceKeyRelease , DeviceButtonPress , DeviceButtonRelease , DeviceMotionNotify
, and so on) and contain a device identifier so that events of the same type
coming from different input devices can be distinguished.

Extension input events are not limited in size by the size of the server
32-byte wire events. Extension input events may be constructed by the server
sending as many wire-sized events as necessary to return the information
required for that event. The library event reformatting routines are
responsible for combining these into one or more client XEvents.

Any input device that generates key, button, or motion data may be used as an
extension input device. Extension input devices may have zero or more keys,
zero or more buttons, and may report zero or more axes of motion. Motion may be
reported as relative movements from a previous position or as an absolute
position. All valuators reporting motion information for a given extension
input device must report the same kind of motion information (absolute or
relative).

This extension is designed to accommodate new types of input devices that may
be added in the future. The protocol requests that refer to specific
characteristics of input devices organize that information by input device
classes. Server implementors may add new classes of input devices without
changing the protocol requests.

All extension input devices are treated like the core X keyboard in determining
their location and focus. The server does not track the location of these
devices on an individual basis and, therefore, does not echo a cursor to
indicate their current location. Instead, their location is determined by the
location of the core X pointer. Like the core X keyboard, some may be
explicitly focused. If they are not explicitly focused, their focus is
determined by the location of the core X pointer.

Input Device Classes

Some of the input extension requests divide input devices into classes based on
their functionality. This is intended to allow new classes of input devices to
be defined at a later time without changing the semantics of these functions.
The following input device classes are currently defined:

KEY       The device reports key events.

BUTTON    The device reports button events.

VALUATOR  The device reports valuator data in motion events.

PROXIMITY The device reports proximity events.

FOCUS     The device can be focused.

FEEDBACK  The device supports feedbacks.

Additional classes may be added in the future. Functions that support multiple
input classes, such as the XListInputDevices function that lists all available
input devices, organize the data they return by input class. Client programs
that use these functions should not access data unless it matches a class
defined at the time those clients were compiled. In this way, new classes can
be added without forcing existing clients that use these functions to be
recompiled.

Using Extension Input Devices

A client that wishes to access an input device does so through the library
functions defined in the following sections. A typical sequence of requests
that a client would make is as follows:

  • XListInputDevices - lists all of the available input devices. From the
    information returned by this request, determine whether the desired input
    device is attached to the server. For a description of the
    XListInputDevices request, see the section entitled ``Listing Available
    Devices.''

  • XOpenDevice - requests that the server open the device for access by this
    client. This request returns an XDevice structure that is used by most
    other input extension requests to identify the specified device. For a
    description of the XOpenDevice request, see the section entitled ``Enabling
    and Disabling Extension Devices.''

  • Determine the event types and event classes needed to select the desired
    input extension events, and identify them when they are received. This is
    done via macros whose name corresponds to the desired event, for example,
    DeviceKeyPress . For a description of these macros, see the section
    entitled ``Selecting Extension Device Events.''

  • XSelectExtensionEvent - selects the desired events from the server. For a
    description of the XSelextExtensionEvent request, see the section entitled
    ``Selecting Extension Device Events.''

  • XNextEvent - receives the next available event. This is the core XNextEvent
    function provided by the standard X library.

Other requests are defined to grab and focus extension devices, to change their
key, button, or modifier mappings, to control the propagation of input
extension events, to get motion history from an extension device, and to send
input extension events to another client. These functions are described in the
following sections.

Library Extension Requests

Extension input devices are accessed by client programs through the use of new
protocol requests. The following requests are provided as extensions to Xlib.
Constants and structures referenced by these functions may be found in the
files <X11/extensions/XI.h> and <X11/extensions/XInput.h>, which are attached
to this document as Appendix A.

The library will return NoSuchExtension if an extension request is made to a
server that does not support the input extension.

Input extension requests cannot be used to access the X keyboard and X pointer
devices.

Window Manager Functions

This section discusses the following X Input Extension Window Manager topics:

  • Changing the core devices

  • Event synchronization and core grabs

  • Extension active grabs

  • Passively grabbing a key

  • Passively grabbing a button

  • Thawing a device

  • Controlling device focus

  • Controlling device feedback

  • Ringing a bell on an input device

  • Controlling device encoding

  • Controlling button mapping

  • Obtaining the state of a device

Changing the Core Devices

These functions are provided to change which physical device is used as the X
pointer or X keyboard.

Note

Using these functions may change the characteristics of the core devices. The
new pointer device may have a different number of buttons from the old one, or
the new keyboard device may have a different number of keys or report a
different range of keycodes. Client programs may be running that depend on
those characteristics. For example, a client program could allocate an array
based on the number of buttons on the pointer device and then use the button
numbers received in button events as indices into that array. Changing the core
devices could cause such client programs to behave improperly or to terminate
abnormally if they ignore the ChangeDeviceNotify event generated by these
requests.

These functions change the X keyboard or X pointer device and generate an
XChangeDeviceNotify event and a MappingNotify event. The specified device
becomes the new X keyboard or X pointer device. The location of the core device
does not change as a result of this request.

These requests fail and return AlreadyGrabbed if either the specified device or
the core device it would replace are grabbed by some other client. They fail
and return GrabFrozen if either device is frozen by the active grab of another
client.

These requests fail with a BadDevice error if the specified device is invalid,
has not previously been opened via XOpenDevice , or is not supported as a core
device by the server implementation.

Once the device has successfully replaced one of the core devices, it is
treated as a core device until it is in turn replaced by another ChangeDevice
request or until the server terminates. The termination of the client that
changed the device will not cause it to change back. Attempts to use the
XCloseDevice request to close the new core device will fail with a BadDevice
error.

To change which physical device is used as the X keyboard, use the
XChangeKeyboardDevice function. The specified device must support input class
Keys (as reported in the ListInputDevices request) or the request will fail
with a BadMatch error.

int XChangeKeyboardDevice(Display *display, XDevice *device);

display Specifies the connection to the X server.

device  Specifies the desired device.

If no error occurs, XChangeKeyboardDevice returns Success . A
ChangeDeviceNotify event with the request field set to NewKeyboard is sent to
all clients selecting that event. A MappingNotify event with the request field
set to MappingKeyboard is sent to all clients. The requested device becomes the
X keyboard, and the old keyboard becomes available as an extension input
device. The focus state of the new keyboard is the same as the focus state of
the old X keyboard.

XChangeKeyboardDevice can generate AlreadyGrabbed , BadDevice , BadMatch , and
GrabFrozen errors.

To change which physical device is used as the X pointer, use the
XChangePointerDevice function. The specified device must support input class
Valuators (as reported in the XListInputDevices request) and report at least
two axes of motion, or the request will fail with a BadMatch error. If the
specified device reports more than two axes, the two specified in the xaxis and
yaxis arguments will be used. Data from other valuators on the device will be
ignored.

If the specified device reports absolute positional information, and the server
implementation does not allow such a device to be used as the X pointer, the
request will fail with a BadDevice error.

int XChangePointerDevice(Display *display, XDevice *device, int xaxis, int
yaxis);

display Specifies the connection to the X server.

device  Specifies the desired device.

xaxis   Specifies the zero-based index of the axis to be used as the x-axis of
        the pointer device.

yaxis   Specifies the zero-based index of the axis to be used as the y-axis of
        the pointer device.

If no error occurs, XChangePointerDevice returns Success . A ChangeDeviceNotify
event with the request field set to NewPointer is sent to all clients selecting
that event. A MappingNotify event with the request field set to MappingPointer
is sent to all clients. The requested device becomes the X pointer, and the old
pointer becomes available as an extension input device.

XChangePointerDevice can generate AlreadyGrabbed , BadDevice , BadMatch , and
GrabFrozen errors.

Event Synchronization and Core Grabs

Implementation of the input extension requires an extension of the meaning of
event synchronization for the core grab requests. This is necessary in order to
allow window managers to freeze all input devices with a single request.

The core grab requests require a pointer_mode and keyboard_mode argument. The
meaning of these modes is changed by the input extension. For the XGrabPointer
and XGrabButton requests, pointer_mode controls synchronization of the pointer
device, and keyboard_mode controls the synchronization of all other input
devices. For the XGrabKeyboard and XGrabKey requests, pointer_mode controls the
synchronization of all input devices, except the X keyboard, while
keyboard_mode controls the synchronization of the keyboard. When using one of
the core grab requests, the synchronization of extension devices is controlled
by the mode specified for the device not being grabbed.

Extension Active Grabs

Active grabs of extension devices are supported via the XGrabDevice function in
the same way that core devices are grabbed using the core XGrabKeyboard
function, except that an extension input device is passed as a function
parameter. The XUngrabDevice function allows a previous active grab for an
extension device to be released.

Passive grabs of buttons and keys on extension devices are supported via the
XGrabDeviceButton and XGrabDeviceKey functions. These passive grabs are
released via the XUngrabDeviceKey and XUngrabDeviceButton functions.

To grab an extension device, use the XGrabDevice function. The device must have
previously been opened using the XOpenDevice function.

int XGrabDevice(Display *display, XDevice *device, Window grab_window, Bool
owner_events, int event_count, XEventClass *event_list, int this_device_mode,
int other_device_mode, Time time);

"display"         Specifies the connection to the X server.

device            Specifies the desired device.

grab_window       Specifies the ID of a window associated with the device
                  specified above.

owner_events      Specifies a boolean value of either True or False .

event_count       Specifies the number of elements in the event_list array.

                  Specifies a pointer to a list of event classes that indicate
event_list        which events the client wishes to receive. These event
                  classes must have been obtained using the device being
                  grabbed.

                  Controls further processing of events from this device. You
this_device_mode  can pass one of these constants: GrabModeSync or
                  GrabModeAsync .

                  Controls further processing of events from all other devices.
other_device_mode You can pass one of these constants: GrabModeSync or
                  GrabModeAsync .

time              Specifies the time. This may be either a timestamp expressed
                  in milliseconds or CurrentTime .

XGrabDevice actively grabs an extension input device and generates
DeviceFocusIn and DeviceFocusOut events. Further input events from this device
are reported only to the grabbing client. This function overrides any previous
active grab by this client for this device.

The event_list parameter is a pointer to a list of event classes. This list
indicates which events the client wishes to receive while the grab is active.
If owner_events is False , input events from this device are reported with
respect to grab_window and are reported only if specified in event_list. If
owner_events is True , then if a generated event would normally be reported to
this client, it is reported normally. Otherwise, the event is reported with
respect to the grab_window and is only reported if specified in event_list.

The this_device_mode argument controls the further processing of events from
this device, and the other_device_mode argument controls the further processing
of input events from all other devices.

  • If the this_device_mode argument is GrabModeAsync , device event processing
    continues normally; if the device is currently frozen by this client, then
    processing of device events is resumed. If the this_device_mode argument is
    GrabModeSync , the state of the grabbed device (as seen by client
    applications) appears to freeze, and no further device events are generated
    by the server until the grabbing client issues a releasing
    XAllowDeviceEvents call or until the device grab is released. Actual device
    input events are not lost while the device is frozen; they are simply
    queued for later processing.

  • If the other_device_mode is GrabModeAsync , event processing from other
    input devices is unaffected by activation of the grab. If other_device_mode
    is GrabModeSync , the state of all devices except the grabbed device (as
    seen by client applications) appears to freeze, and no further events are
    generated by the server until the grabbing client issues a releasing 
    XAllowEvents or XAllowDeviceEvents call or until the device grab is
    released. Actual events are not lost while the other devices are frozen;
    they are simply queued for later processing.

XGrabDevice fails on the following conditions:

  • If the device is actively grabbed by some other client, it returns
    AlreadyGrabbed .

  • If grab_window is not viewable, it returns GrabNotViewable .

  • If the specified time is earlier than the last-grab-time for the specified
    device or later than the current X server time, it returns GrabInvalidTime
    . Otherwise, the last-grab-time for the specified device is set to the
    specified time and CurrentTime is replaced by the current X server time.

  • If the device is frozen by an active grab of another client, it returns
    GrabFrozen .

If a grabbed device is closed by a client while an active grab by that client
is in effect, that active grab will be released. Any passive grabs established
by that client will be released. If the device is frozen only by an active grab
of the requesting client, it is thawed.

XGrabDevice can generate BadClass , BadDevice , BadValue , and BadWindow
errors.

To release a grab of an extension device, use the XUngrabDevice function.

int XUngrabDevice(Display *display, XDevice *device, Time time);

display Specifies the connection to the X server.

device  Specifies the desired device.

time    Specifies the time. This may be either a timestamp expressed in
        milliseconds, or CurrentTime .

XUngrabDevice allows a client to release an extension input device and any
queued events if this client has it grabbed from either XGrabDevice or
XGrabDeviceKey . If any other devices are frozen by the grab, XUngrabDevice
thaws them. This function does not release the device and any queued events if
the specified time is earlier than the last-device-grab time or is later than
the current X server time. It also generates DeviceFocusIn and DeviceFocusOut
events. The X server automatically performs an XUngrabDevice if the event
window for an active device grab becomes not viewable or if the client
terminates without releasing the grab.

XUngrabDevice can generate BadDevice errors.

Passively Grabbing a Key

To passively grab a single key on an extension device, use XGrabDeviceKey .
That device must have previously been opened using the XOpenDevice function, or
the request will fail with a BadDevice error. If the specified device does not
support input class Keys , the request will fail with a BadMatch error.

int XGrabDeviceKey(Display *display, XDevice *device, int keycode, unsignedint
modifiers, XDevice *modifier_device, Window grab_window, Bool owner_events, int
event_count, XEventClass *event_list, int this_device_mode, int
other_device_mode);

display           Specifies the connection to the X server.

device            Specifies the desired device.

keycode           Specifies the keycode of the key that is to be grabbed. You
                  can pass either the keycode or AnyKey .

                  Specifies the set of keymasks. This mask is the bitwise
modifiers         inclusive OR of these keymask bits: ShiftMask , LockMask ,
                  ControlMask , Mod1Mask , Mod2Mask , Mod3Mask , Mod4Mask , and
                  Mod5Mask .

                  You can also pass AnyModifier , which is equivalent to
                  issuing the grab key request for all possible modifier
                  combinations (including the combination of no modifiers).

                  Specifies the device whose modifiers are to be used. If NULL
modifier_device   is specified, the core X keyboard is used as the
                  modifier_device.

grab_window       Specifies the ID of a window associated with the device
                  specified above.

owner_events      Specifies a boolean value of either True or False .

event_count       Specifies the number of elements in the event_list array.

event_list        Specifies a pointer to a list of event classes that indicate
                  which events the client wishes to receive.

                  Controls further processing of events from this device. You
this_device_mode  can pass one of these constants: GrabModeSync or
                  GrabModeAsync .

                  Controls further processing of events from all other devices.
other_device_mode You can pass one of these constants: GrabModeSync or
                  GrabModeAsync .

XGrabDeviceKey is analogous to the core XGrabKey function. It creates an
explicit passive grab for a key on an extension device. The XGrabDeviceKey
function establishes a passive grab on a device. Consequently, in the future,

  • IF the device is not grabbed and the specified key, which itself can be a
    modifier key, is logically pressed when the specified modifier keys
    logically are down on the specified modifier device (and no other keys are
    down),

  • AND no other modifier keys logically are down,

  • AND EITHER the grab window is an ancestor of (or is) the focus window or
    the grab window is a descendent of the focus window and contains the
    pointer,

  • AND a passive grab on the same device and key combination does not exist on
    any ancestor of the grab window,

  • THEN the device is actively grabbed, as for XGrabDevice , the
    last-device-grab time is set to the time at which the key was pressed (as
    transmitted in the DeviceKeyPress event), and the DeviceKeyPress event is
    reported.

The interpretation of the remaining arguments is as for XGrabDevice . The
active grab is terminated automatically when the logical state of the device
has the specified key released (independent of the logical state of the
modifier keys).

Note that the logical state of a device (as seen by means of the X protocol)
may lag the physical state if device event processing is frozen.

A modifier of AnyModifier is equivalent to issuing the request for all possible
modifier combinations (including the combination of no modifiers). It is not
required that all modifiers specified have currently assigned keycodes. A key
of AnyKey is equivalent to issuing the request for all possible keycodes.
Otherwise, the key must be in the range specified by min_keycode and
max_keycode in the information returned by the XListInputDevices function. If
it is not within that range, XGrabDeviceKey generates a BadValue error.

XGrabDeviceKey generates a BadAccess error if some other client has issued a
XGrabDeviceKey with the same device and key combination on the same window.
When using AnyModifier or AnyKey , the request fails completely and the X
server generates a BadAccess error, and no grabs are established if there is a
conflicting grab for any combination.

XGrabDeviceKey returns Success upon successful completion of the request.

XGrabDeviceKey can generate BadAccess , BadClass , BadDevice , BadMatch ,
BadValue , and BadWindow errors.

To release a passive grab of a single key on an extension device, use
XUngrabDeviceKey .

int XUngrabDeviceKey(Display *display, XDevice *device, int keycode,
unsignedint modifiers, XDevice *modifier_device, Window ungrab_window);

display         Specifies the connection to the X server.

device          Specifies the desired device.

keycode         Specifies the keycode of the key that is to be ungrabbed. You
                can pass either the keycode or AnyKey .

                Specifies the set of keymasks. This mask is the bitwise
modifiers       inclusive OR of these keymask bits: ShiftMask , LockMask ,
                ControlMask , Mod1Mask , Mod2Mask , Mod3Mask , Mod4Mask , and
                Mod5Mask .

                You can also pass AnyModifier , which is equivalent to issuing
                the ungrab key request for all possible modifier combinations
                (including the combination of no modifiers).

modifier_device Specifies the device whose modifiers are to be used. If NULL is
                specified, the core X keyboard is used as the modifier_device.

ungrab_window   Specifies the ID of a window associated with the device
                specified above.

XUngrabDeviceKey is analogous to the core XUngrabKey function. It releases an
explicit passive grab for a key on an extension input device.

XUngrabDeviceKey can generate BadAlloc , BadDevice , BadMatch , BadValue , and
BadWindow errors.

Passively Grabbing a Button

To establish a passive grab for a single button on an extension device, use
XGrabDeviceButton . The specified device must have previously been opened using
the XOpenDevice function, or the request will fail with a BadDevice error. If
the specified device does not support input class Buttons , the request will
fail with a BadMatch error.

int XGrabDeviceButton(Display *display, XDevice *device, unsignedint button,
unsignedint modifiers, XDevice*modifier_device , Window grab_window, Bool
owner_events, int event_count, XEventClass *event_list, int this_device_mode,
int other_device_mode);

display           Specifies the connection to the X server.

device            Specifies the desired device.

button            Specifies the code of the button that is to be grabbed. You
                  can pass either the button or AnyButton .

                  Specifies the set of keymasks. This mask is the bitwise
modifiers         inclusive OR of these keymask bits: ShiftMask , LockMask ,
                  ControlMask , Mod1Mask , Mod2Mask , Mod3Mask , Mod4Mask , and
                  Mod5Mask .

                  You can also pass AnyModifier , which is equivalent to
                  issuing the grab request for all possible modifier
                  combinations (including the combination of no modifiers).

                  Specifies the device whose modifiers are to be used. If NULL
modifier_device   is specified, the core X keyboard is used as the
                  modifier_device.

grab_window       Specifies the ID of a window associated with the device
                  specified above.

owner_events      Specifies a boolean value of either True or False .

event_count       Specifies the number of elements in the event_list array.

event_list        Specifies a list of event classes that indicates which device
                  events are to be reported to the client.

                  Controls further processing of events from this device. You
this_device_mode  can pass one of these constants: GrabModeSync or
                  GrabModeAsync .

                  Controls further processing of events from all other devices.
other_device_mode You can pass one of these constants: GrabModeSync or
                  GrabModeAsync .

XGrabDeviceButton is analogous to the core XGrabButton function. It creates an
explicit passive grab for a button on an extension input device. Because the
server does not track extension devices, no cursor is specified with this
request. For the same reason, there is no confine_to parameter. The device must
have previously been opened using the XOpenDevice function.

The XGrabDeviceButton function establishes a passive grab on a device.
Consequently, in the future,

  • IF the device is not grabbed and the specified button is logically pressed
    when the specified modifier keys logically are down (and no other buttons
    or modifier keys are down),

  • AND EITHER the grab window is an ancestor of (or is) the focus window OR
    the grab window is a descendent of the focus window and contains the
    pointer,

  • AND a passive grab on the same device and button/key combination does not
    exist on any ancestor of the grab window,

  • THEN the device is actively grabbed, as for XGrabDevice , the last-grab
    time is set to the time at which the button was pressed (as transmitted in
    the DeviceButtonPress event), and the DeviceButtonPress event is reported.

The interpretation of the remaining arguments is as for XGrabDevice . The
active grab is terminated automatically when logical state of the device has
all buttons released (independent of the logical state of the modifier keys).

Note that the logical state of a device (as seen by means of the X protocol)
may lag the physical state if device event processing is frozen.

A modifier of AnyModifier is equivalent to issuing the request for all possible
modifier combinations (including the combination of no modifiers). It is not
required that all modifiers specified have currently assigned keycodes. A
button of AnyButton is equivalent to issuing the request for all possible
buttons. Otherwise, it is not required that the specified button be assigned to
a physical button.

XGrabDeviceButton generates a BadAccess error if some other client has issued a
XGrabDeviceButton with the same device and button combination on the same
window. When using AnyModifier or AnyButton , the request fails completely and
the X server generates a BadAccess error and no grabs are established if there
is a conflicting grab for any combination.

XGrabDeviceButton can generate BadAccess , BadClass , BadDevice , BadMatch ,
BadValue , and BadWindow errors.

To release a passive grab of a button on an extension device, use
XUngrabDeviceButton .

int XUngrabDeviceButton(Display *display, XDevice *device, unsignedint button,
unsignedint modifiers, XDevice *modifier_device, Window ungrab_window);

display         Specifies the connection to the X server.

device          Specifies the desired device.

button          Specifies the code of the button that is to be ungrabbed. You
                can pass either a button or AnyButton .

                Specifies the set of keymasks. This mask is the bitwise
modifiers       inclusive OR of these keymask bits: ShiftMask , LockMask ,
                ControlMask , Mod1Mask , Mod2Mask , Mod3Mask , Mod4Mask , and
                Mod5Mask .

                You can also pass AnyModifier , which is equivalent to issuing
                the ungrab key request for all possible modifier combinations
                (including the combination of no modifiers).

modifier_device Specifies the device whose modifiers are to be used. If NULL is
                specified, the core X keyboard is used as the modifier_device.

ungrab_window   Specifies the ID of a window associated with the device
                specified above.

XUngrabDeviceButton is analogous to the core XUngrabButton function. It
releases an explicit passive grab for a button on an extension device. That
device must have previously been opened using the XOpenDevice function, or a
BadDevice error will result.

A modifier of AnyModifier is equivalent to issuing the request for all possible
modifier combinations (including the combination of no modifiers).

XUngrabDeviceButton can generate BadAlloc , BadDevice , BadMatch , BadValue ,
and BadWindow errors.

Thawing a Device

To allow further events to be processed when a device has been frozen, use
XAllowDeviceEvents .

int XAllowDeviceEvents(Display *display, XDevice *device, int event_mode, Time
time);

display    Specifies the connection to the X server.

device     Specifies the desired device.

           Specifies the event mode. You can pass one of these constants:
event_mode AsyncThisDevice , SyncThisDevice , AsyncOtherDevices ,
           ReplayThisDevice , AsyncAll , or SyncAll .

time       Specifies the time. This may be either a timestamp expressed in
           milliseconds, or CurrentTime .

XAllowDeviceEvents releases some queued events if the client has caused a
device to freeze. It has no effect if the specified time is earlier than the
last-grab time of the most recent active grab for the client and device, or if
the specified time is later than the current X server time. The following
describes the processing that occurs depending on what constant you pass to the
event_mode argument:

  • AsyncThisDevice

  • If the specified device is frozen by the client, event processing for that
    continues as usual. If the device is frozen multiple times by the client on
    behalf of multiple separate grabs, AsyncThisDevice thaws for all.
    AsyncThisDevice has no effect if the specified device is not frozen by the
    client, but the device need not be grabbed by the client.

  • SyncThisDevice

  • If the specified device is frozen and actively grabbed by the client, event
    processing for that device continues normally until the next key or button
    event is reported to the client. At this time, the specified device again
    appears to freeze. However, if the reported event causes the grab to be
    released, the specified device does not freeze. SyncThisDevice has no
    effect if the specified device is not frozen by the client or is not
    grabbed by the client.

  • ReplayThisDevice

  • If the specified device is actively grabbed by the client and is frozen as
    the result of an event having been sent to the client (either from the
    activation of a GrabDeviceButton or from a previous AllowDeviceEvents with
    mode SyncThisDevice , but not from a Grab ), the grab is released and that
    event is completely reprocessed. This time, however, the request ignores
    any passive grabs at or above (toward the root) the grab-window of the grab
    just released. The request has no effect if the specified device is not
    grabbed by the client or if it is not frozen as the result of an event.

  • AsyncOtherDevices

  • If the remaining devices are frozen by the client, event processing for
    them continues as usual. If the other devices are frozen multiple times by
    the client on behalf of multiple separate grabs, AsyncOtherDevices
    ``thaws'' for all. AsyncOtherDevices has no effect if the devices are not
    frozen by the client, but those devices need not be grabbed by the client.

  • SyncAll

  • If all devices are frozen by the client, event processing (for all devices)
    continues normally until the next button or key event is reported to the
    client for a grabbed device, at which time the devices again appear to
    freeze. However, if the reported event causes the grab to be released, then
    the devices do not freeze (but if any device is still grabbed, then a
    subsequent event for it will still cause all devices to freeze). SyncAll
    has no effect unless all devices are frozen by the client. If any device is
    frozen twice by the client on behalf of two separate grabs, SyncAll "thaws"
    for both (but a subsequent freeze for SyncAll will freeze each device only
    once).

  • AsyncAll

  • If all devices are frozen by the client, event processing (for all devices)
    continues normally. If any device is frozen multiple times by the client on
    behalf of multiple separate grabs, AsyncAll ``thaws ''for all. If any
    device is frozen twice by the client on behalf of two separate grabs,
    AsyncAll ``thaws'' for both. AsyncAll has no effect unless all devices are
    frozen by the client.

AsyncThisDevice , SyncThisDevice , and ReplayThisDevice have no effect on the
processing of events from the remaining devices. AsyncOtherDevices has no
effect on the processing of events from the specified device. When the
event_mode is SyncAll or AsyncAll , the device parameter is ignored.

It is possible for several grabs of different devices (by the same or different
clients) to be active simultaneously. If a device is frozen on behalf of any
grab, no event processing is performed for the device. It is possible for a
single device to be frozen because of several grabs. In this case, the freeze
must be released on behalf of each grab before events can again be processed.

XAllowDeviceEvents can generate BadDevice and BadValue errors.

Controlling Device Focus

The current focus window for an extension input device can be determined using
the XGetDeviceFocus function. Extension devices are focused using the
XSetDeviceFocus function in the same way that the keyboard is focused using the
core XSetInputFocus function, except that a device ID is passed as a function
parameter. One additional focus state, FollowKeyboard , is provided for
extension devices.

To get the current focus state, revert state, and focus time of an extension
device, use XGetDeviceFocus .

int XGetDeviceFocus(Display *display, XDevice *device, Window *focus_return,
int *revert_to_return, Time *focus_time_return);

display           Specifies the connection to the X server.

device            Specifies the desired device.

                  Specifies the address of a variable into which the server can
focus_return      return the ID of the window that contains the device focus or
                  one of the constants None , PointerRoot , or FollowKeyboard .

revert_to_return  Specifies the address of a variable into which the server can
                  return the current revert_to status for the device.

focus_time_return Specifies the address of a variable into which the server can
                  return the focus time last set for the device.

XGetDeviceFocus returns the focus state, the revert-to state, and the
last-focus-time for an extension input device.

XGetDeviceFocus can generate BadDevice and BadMatch errors.

To set the focus of an extension device, use XSetDeviceFocus .

int XSetDeviceFocus(Display *display, XDevice *device, Window focus, int
revert_to, Time time);

display   Specifies the connection to the X server.

device    Specifies the desired device.

          Specifies the ID of the window to which the device's focus should be
focus     set. This may be a window ID, or PointerRoot , FollowKeyboard , or
          None .

          Specifies to which window the focus of the device should revert if
revert_to the focus window becomes not viewable. One of the following constants
          may be passed: RevertToParent , RevertToPointerRoot , RevertToNone ,
          or RevertToFollowKeyboard .

time      Specifies the time. You can pass either a timestamp, expressed in
          milliseconds, or CurrentTime .

XSetDeviceFocus changes the focus for an extension input device and the
last-focus-change-time. It has no effect if the specified time is earlier than
the last-focus-change-time or is later than the current X server time.
Otherwise, the last-focus-change-time is set to the specified time. This
function causes the X server to generate DeviceFocusIn and DeviceFocusOut
events.

The action taken by the server when this function is requested depends on the
value of the focus argument:

  • If the focus argument is None , all input events from this device will be
    discarded until a new focus window is set. In this case, the revert_to
    argument is ignored.

  • If the focus argument is a window ID, it becomes the focus window of the
    device. If an input event from the device would normally be reported to
    this window or to one of its inferiors, the event is reported normally.
    Otherwise, the event is reported relative to the focus window.

  • If the focus argument is PointerRoot , the focus window is dynamically
    taken to be the root window of whatever screen the pointer is on at each
    input event. In this case, the revert_to argument is ignored.

  • If the focus argument is FollowKeyboard , the focus window is dynamically
    taken to be the same as the focus of the X keyboard at each input event.

The specified focus window must be viewable at the time XSetDeviceFocus is
called. Otherwise, it generates a BadMatch error. If the focus window later
becomes not viewable, the X server evaluates the revert_to argument to
determine the new focus window.

  • If the revert_to argument is RevertToParent , the focus reverts to the
    parent (or the closest viewable ancestor), and the new revert_to value is
    taken to be RevertToNone .

  • If the revert_to argument is RevertToPointerRoot , RevertToFollowKeyboard ,
    or RevertToNone , the focus reverts to that value.

When the focus reverts, the X server generates DeviceFocusIn and DeviceFocusOut
events, but the last-focus-change time is not affected.

XSetDeviceFocus can generate BadDevice , BadMatch , BadValue , and BadWindow
errors.

Controlling Device Feedback

To determine the current feedback settings of an extension input device, use
XGetFeedbackControl .

XFeedbackState * XGetFeedbackControl(Display *display, XDevice *device, int
*num_feedbacks_return);

display              Specifies the connection to the X server.

device               Specifies the desired device.

num_feedbacks_return Returns the number of feedbacks supported by the device.

XGetFeedbackControl returns a list of FeedbackState structures that describe
the feedbacks supported by the specified device. There is an XFeedbackState
structure for each class of feedback. These are of variable length, but the
first three members are common to all.



typedef struct {
     XID class;
     int length;
     XID id;
} XFeedbackState;

The common members are as follows:

  • The class member identifies the class of feedback. It may be compared to
    constants defined in the file < X11/extensions/XI.h >. Currently defined
    feedback constants include: KbdFeedbackClass , PtrFeedbackClass ,
    StringFeedbackClass , IntegerFeedbackClass , LedFeedbackClass , and
    BellFeedbackClass .

  • The length member specifies the length of the FeedbackState structure and
    can be used by clients to traverse the list.

  • The id member uniquely identifies a feedback for a given device and class.
    This allows a device to support more than one feedback of the same class.
    Other feedbacks of other classes or devices may have the same ID.

Those feedbacks equivalent to those supported by the core keyboard are reported
in class KbdFeedback using the XKbdFeedbackState structure, which is defined as
follows:



typedef struct {
     XID class;
     int length;
     XID id;
     int click;
     int percent;
     int pitch;
     int duration;
     int led_mask;
     int global_auto_repeat;
     char auto_repeats[32];
} XKbdFeedbackState;

The additional members of the XKbdFeedbackState structure report the current
state of the feedback:

  • The click member specifies the key-click volume and has a value in the
    range 0 (off) to 100 (loud).

  • The percent member specifies the bell volume and has a value in the range 0
    (off) to 100 (loud).

  • The pitch member specifies the bell pitch in Hz. The range of the value is
    implementation-dependent.

  • The duration member specifies the duration in milliseconds of the bell.

  • The led_mask member is a bit mask that describes the current state of up to
    32 LEDs. A value of 1 in a bit indicates that the corresponding LED is on.

  • The global_auto_repeat member has a value of AutoRepeatModeOn or
    AutoRepeatModeOff .

  • The auto_repeats member is a bit vector. Each bit set to 1 indicates that
    auto-repeat is enabled for the corresponding key. The vector is represented
    as 32 bytes. Byte N (from 0) contains the bits for keys 8N to 8N + 7, with
    the least significant bit in the byte representing key 8N.

Those feedbacks equivalent to those supported by the core pointer are reported
in class PtrFeedback using the XPtrFeedbackState structure, which is defined as
follows:



typedef struct {
     XID class;
     int length;
     XID id;
     int accelNum;
     int accelDenom;
     int threshold;
} XPtrFeedbackState;

The additional members of the XPtrFeedbackState structure report the current
state of the feedback:

  • The accelNum member returns the numerator for the acceleration multiplier.

  • The accelDenom member returns the denominator for the acceleration
    multiplier.

  • The accelDenom member returns the threshold for the acceleration.

Integer feedbacks are those capable of displaying integer numbers and reported
via the XIntegerFeedbackState structure. The minimum and maximum values that
they can display are reported.



typedef struct {
     XID class;
     int length;
     XID id;
     int resolution;
     int minVal;
     int maxVal;
} XIntegerFeedbackState;

The additional members of the XIntegerFeedbackState structure report the
capabilities of the feedback:

  • The resolution member specifies the number of digits that the feedback can
    display.

  • The minVal member specifies the minimum value that the feedback can
    display.

  • The maxVal specifies the maximum value that the feedback can display.

String feedbacks are those that can display character information and are
reported via the XStringFeedbackState structure. Clients set these feedbacks by
passing a list of KeySyms to be displayed. The XGetFeedbackControl function
returns the set of key symbols that the feedback can display, as well as the
maximum number of symbols that can be displayed. The XStringFeedbackState
structure is defined as follows:



typedef struct {
     XID class;
     int length;
     XID id;
     int max_symbols;
     int  num_syms_supported;
     KeySym *syms_supported;
} XStringFeedbackState;

The additional members of the XStringFeedbackState structure report the
capabilities of the feedback:

  • The max_symbols member specifies the maximum number of symbols that can be
    displayed.

  • The syms_supported member is a pointer to the list of supported symbols.

  • The num_syms_supported member specifies the length of the list of supported
    symbols.

Bell feedbacks are those that can generate a sound and are reported via the
XBellFeedbackState structure. Some implementations may support a bell as part
of a KbdFeedback feedback. Class BellFeedback is provided for implementations
that do not choose to do so and for devices that support multiple feedbacks
that can produce sound. The meaning of the members is the same as that of the
corresponding fields in the XKbdFeedbackState structure.



typedef struct {
     XID class;
     int length;
     XID id;
     int percent;
     int pitch;
     int duration;
} XBellFeedbackState;

Led feedbacks are those that can generate a light and are reported via the
XLedFeedbackState structure. Up to 32 lights per feedback are supported. Each
bit in led_mask corresponds to one supported light, and the corresponding bit
in led_values indicates whether that light is currently on (1) or off (0). Some
implementations may support leds as part of a KbdFeedback feedback. Class
LedFeedback is provided for implementations that do not choose to do so and for
devices that support multiple led feedbacks.



typedef struct {
     XID class;
     int length;
     XID id;
     Mask led_values;
     Mask led_mask;
} XLedFeedbackState;

XGetFeedbackControl can generate BadDevice and BadMatch errors.

To free the information returned by the XGetFeedbackControl function, use
XFreeFeedbackList .

void XFreeFeedbackList(XFeedbackState *list);

list Specifies the pointer to the XFeedbackState structure returned by a
     previous call to XGetFeedbackControl .

XFreeFeedbackList frees the list of feedback control information.

To change the settings of a feedback on an extension device, use
XChangeFeedbackControl . This function modifies the current control values of
the specified feedback using information passed in the appropriate
XFeedbackControl structure for the feedback. Which values are modified depends
on the valuemask passed.

int XChangeFeedbackControl(Display *display, XDevice *device, unsignedlong
valuemask, XFeedbackControl *value);

display   Specifies the connection to the X server.

device    Specifies the desired device.

          Specifies one value for each bit in the mask (least to most
valuemask significant bit). The values are associated with the feedbacks for
          the specified device.

value     Specifies a pointer to the XFeedbackControl structure.

XChangeFeedbackControl controls the device characteristics described by the
XFeedbackControl structure. There is an XFeedbackControl structure for each
class of feedback. These are of variable length, but the first three members
are common to all and are as follows:



typedef struct {
     XID class;
     int length;
     XID id;
} XFeedbackControl;

Feedback class KbdFeedback controls feedbacks equivalent to those provided by
the core keyboard using the KbdFeedbackControl structure, which is defined as
follows:.



typedef struct {
     XID class;
     int length;
     XID id;
     int click;
     int percent;
     int pitch;
     int duration;
     int led_mask;
     int led_value;
     int key;
     int auto_repeat_mode;
} XKbdFeedbackControl;

This class controls the device characteristics described by the
XKbdFeedbackControl structure. These include the key_click_percent,
global_auto_repeat, and individual key auto-repeat. Valid modes are
AutoRepeatModeOn , AutoRepeatModeOff , and AutoRepeatModeDefault .

Valid masks are as follows:


#define   DvKeyClickPercent           (1><<0)
#define   DvPercent                   (1><<0)
#define   DvPitch                     (1><<0)
#define   DvDuration                  (1><<0)
#define   DvLed                       (1><<0)
#define   DvLedMode                   (1><<0)
#define   DvKey                       (1><<0)
#define   DvAutoRepeatMode            (1><<0)

Feedback class PtrFeedback controls feedbacks equivalent to those provided by
the core pointer using the PtrFeedbackControl structure, which is defined as
follows:



typedef struct {
     XID class;
     int length;
     XID id;
     int accelNum;
     int accelDenom;
     int threshold;
} XPtrFeedbackControl;

Which values are modified depends on the valuemask passed.

Valid masks are as follows:

#define    DvAccelnum        (1L<<0)
#define    DvAccelDenom      (1L<<1)
#define    DvThreshold       (1L<<2)

The acceleration, expressed as a fraction, is a multiplier for movement. For
example, specifying 3/1 means that the device moves three times as fast as
normal. The fraction may be rounded arbitrarily by the X server. Acceleration
takes effect only if the device moves more than threshold pixels at once and
applies only to the amount beyond the value in the threshold argument. Setting
a value to -1 restores the default. The values of the accelNumerator and
threshold fields must be nonzero for the pointer values to be set. Otherwise,
the parameters will be unchanged. Negative values generate a BadValue error, as
does a zero value for the accelDenominator field.

This request fails with a BadMatch error if the specified device is not
currently reporting relative motion. If a device that is capable of reporting
both relative and absolute motion has its mode changed from Relative to
Absolute by an XSetDeviceMode request, valuator control values will be ignored
by the server while the device is in that mode.

Feedback class IntegerFeedback controls integer feedbacks displayed on input
devices and are reported via the IntegerFeedbackControl structure, which is
defined as follows:



typedef struct {
     XID class;
     int length;
     XID id;
     int int_to_display;
} XIntegerFeedbackControl;

Valid masks are as follows:


#define   DvInteger           (1L<<0)

Feedback class StringFeedback controls string feedbacks displayed on input
devices and reported via the StringFeedbackControl structure, which is defined
as follows:



typedef struct {
     XID class;
     int length;
     XID id;
     int num_keysyms;
     KeySym *syms_to_display;
} XStringFeedbackControl;

Valid masks are as follows:


#define   DvString           (1L<<0)

Feedback class BellFeedback controls a bell on an input device and is reported
via the BellFeedbackControl structure, which is defined as follows:



typedef struct {
     XID class;
     int length;
     XID id;
     int percent;
     int pitch;
     int duration;
} XBellFeedbackControl;

Valid masks are as follows:


#define   DvPercent                   (1L<<1)
#define   DvPitch                     (1L<<2)
#define   DvDuration                  (1L<<3)

Feedback class LedFeedback controls lights on an input device and are reported
via the LedFeedbackControl structure, which is defined as follows:



typedef struct {
     XID class;
     int length;
     XID id;
     int led_mask;
     int led_values;
} XLedFeedbackControl;

Valid masks are as follows:


#define   DvLed                       (1L<<4)
#define   DvLedMode                   (1L<<5)

XChangeFeedbackControl can generate BadDevice , BadFeedBack , BadMatch , and
BadValue errors.

Ringing a Bell on an Input Device

To ring a bell on an extension input device, use XDeviceBell .

int XDeviceBell(Display *display, XDevice *device, XIDfeedbackclass,
feedbackid, int percent);

display       Specifies the connection to the X server.

device        Specifies the desired device.

feedbackclass Specifies the feedbackclass. Valid values are KbdFeedbackClass
              and BellFeedbackClass .

feedbackid    Specifies the ID of the feedback that has the bell.

percent       Specifies the volume in the range -100 (quiet) to 100 percent
              (loud).

XDeviceBell is analogous to the core XBell function. It rings the specified
bell on the specified input device feedback, using the specified volume. The
specified volume is relative to the base volume for the feedback. If the value
for the percent argument is not in the range -100 to 100 inclusive, a BadValue
error results. The volume at which the bell rings when the percent argument is
nonnegative is:

       base - [(base * percent) / 100] + percent

The volume at which the bell rings when the percent argument is negative is:

       base + [(base * percent) / 100]

To change the base volume of the bell, use XChangeFeedbackControl .

XDeviceBell can generate BadDevice and BadValue errors.

Controlling Device Encoding

To get the key mapping of an extension device that supports input class Keys ,
use XGetDeviceKeyMapping .

KeySym * XGetDeviceKeyMapping(Display *display, XDevice *device, KeyCode
first_keycode_wanted, int keycode_count, int *keysyms_per_keycode_return);

display                    Specifies the connection to the X server.

device                     Specifies the desired device.

first_keycode_wanted       Specifies the first keycode that is to be returned.

keycode_count              Specifies the number of keycodes that are to be
                           returned.

keysyms_per_keycode_return Returns the number of keysyms per keycode.

XGetDeviceKeyMapping is analogous to the core XGetKeyboardMapping function. It
returns the symbols for the specified number of keycodes for the specified
extension device.

XGetDeviceKeyMapping returns the symbols for the specified number of keycodes
for the specified extension device, starting with the specified keycode. The
first_keycode_wanted must be greater than or equal to min-keycode as returned
by the XListInputDevices request (else a BadValue error results). The following
value:

first_keycode_wanted + keycode_count - 1

must be less than or equal to max-keycode as returned by the XListInputDevices
request (else a BadValue error results).

The number of elements in the keysyms list is as follows:

keycode_count * keysyms_per_keycode_return

And KEYSYM number N (counting from zero) for keycode K has an index (counting
from zero), in keysyms, of the following:

(K - first_keycode_wanted) * keysyms_per_keycode_return + N

The keysyms_per_keycode_return value is chosen arbitrarily by the server to be
large enough to report all requested symbols. A special KEYSYM value of
NoSymbol is used to fill in unused elements for individual keycodes.

To free the data returned by this function, use XFree.

If the specified device has not first been opened by this client via
XOpenDevice , this request will fail with a BadDevice error. If that device
does not support input class Keys , this request will fail with a BadMatch
error.

XGetDeviceKeyMapping can generate BadDevice , BadMatch , and BadValue errors.

To change the keyboard mapping of an extension device that supports input class
Keys , use XChangeDeviceKeyMapping .

int XChangeDeviceKeyMapping(Display *display, XDevice *device, int
first_keycode, int keysyms_per_keycode, KeySym *keysyms, int num_codes);

display             Specifies the connection to the X server.

device              Specifies the desired device.

first_keycode       Specifies the first keycode that is to be changed.

keysyms_per_keycode Specifies the keysyms that are to be used.

keysyms             Specifies a pointer to an array of keysyms.

num_codes           Specifies the number of keycodes that are to be changed.

XChangeDeviceKeyMapping is analogous to the core XChangeKeyboardMapping
function. It defines the symbols for the specified number of keycodes for the
specified extension keyboard device.

If the specified device has not first been opened by this client via
XOpenDevice , this request will fail with a BadDevice error. If the specified
device does not support input class Keys , this request will fail with a
BadMatch error.

The number of elements in the keysyms list must be a multiple of
keysyms_per_keycode. Otherwise, XChangeDeviceKeyMapping generates a BadLength
error. The specified first_keycode must be greater than or equal to the
min_keycode value returned by the ListInputDevices request, or this request
will fail with a BadValue error. In addition, if the following expression is
not less than the max_keycode value returned by the ListInputDevices request,
the request will fail with a BadValue error:

       first_keycode + (num_codes / keysyms_per_keycode) - 1

XChangeDeviceKeyMapping can generate BadAlloc , BadDevice , BadMatch , and
BadValue errors.

To obtain the keycodes that are used as modifiers on an extension device that
supports input class Keys , use XGetDeviceModifierMapping .

XModifierKeymap * XGetDeviceModifierMapping(Display *display, XDevice *device);

display Specifies the connection to the X server.

device  Specifies the desired device.

XGetDeviceModifierMapping is analogous to the core XGetModifierMapping
function. The XGetDeviceModifierMapping function returns a newly created
XModifierKeymap structure that contains the keys being used as modifiers for
the specified device. The structure should be freed after use with
XFreeModifierMapping . If only zero values appear in the set for any modifier,
that modifier is disabled.

XGetDeviceModifierMapping can generate BadDevice and BadMatch errors.

To set which keycodes are to be used as modifiers for an extension device, use
XSetDeviceModifierMapping .

int XSetDeviceModifierMapping(Display *display, XDevice *device,
XModifierKeymap *modmap);

display Specifies the connection to the X server.

device  Specifies the desired device.

modmap  Specifies a pointer to the XModifierKeymap structure.

XSetDeviceModifierMapping is analogous to the core XSetModifierMapping
function. The XSetDeviceModifierMapping function specifies the keycodes of the
keys, if any, that are to be used as modifiers. A zero value means that no key
should be used. No two arguments can have the same nonzero keycode value.
Otherwise, XSetDeviceModifierMapping generates a BadValue error. There are
eight modifiers, and the modifiermap member of the XModifierKeymap structure
contains eight sets of max_keypermod keycodes, one for each modifier in the
order Shift , Lock , Control , Mod1 , Mod2 , Mod3 , Mod4 , and Mod5 . Only
nonzero keycodes have meaning in each set, and zero keycodes are ignored. In
addition, all of the nonzero keycodes must be in the range specified by
min_keycode and max_keycode reported by the XListInputDevices function.
Otherwise, XSetModifierMapping generates a BadValue error. No keycode may
appear twice in the entire map. Otherwise, it generates a BadValue error.

A X server can impose restrictions on how modifiers can be changed, for
example, if certain keys do not generate up transitions in hardware or if
multiple modifier keys are not supported. If some such restriction is violated,
the status reply is MappingFailed , and none of the modifiers are changed. If
the new keycodes specified for a modifier differ from those currently defined
and any (current or new) keys for that modifier are in the logically down
state, the status reply is MappingBusy , and none of the modifiers are changed.
XSetModifierMapping generates a DeviceMappingNotify event on a MappingSuccess
status.

XSetDeviceModifierMapping can generate BadAlloc , BadDevice , BadMatch , and
BadValue errors.

Controlling Button Mapping

To set the mapping of the buttons on an extension device, use
XSetDeviceButtonMapping .

int XSetDeviceButtonMapping(Display *display, XDevice *device, unsignedchar map
[], int nmap);

display Specifies the connection to the X server.

device  Specifies the desired device.

map     Specifies the mapping list.

nmap    Specifies the number of items in the mapping list.

XSetDeviceButtonMapping sets the mapping of the buttons on an extension device.
If it succeeds, the X server generates a DeviceMappingNotify event, and
XSetDeviceButtonMapping returns MappingSuccess . Elements of the list are
indexed starting from one. The length of the list must be the same as
XGetDeviceButtonMapping would return, or a BadValue error results. The index is
a button number, and the element of the list defines the effective number. A
zero element disables a button, and elements are not restricted in value by the
number of physical buttons. However, no two elements can have the same nonzero
value, or a BadValue error results. If any of the buttons to be altered are
logically in the down state, XSetDeviceButtonMapping returns MappingBusy , and
the mapping is not changed.

XSetDeviceButtonMapping can generate BadDevice , BadMatch , and BadValue
errors.

To get the button mapping, use XGetDeviceButtonMapping .

int XGetDeviceButtonMapping(Display *display, XDevice *device, unsignedchar
map_return[], int nmap);

display    Specifies the connection to the X server.

device     Specifies the desired device.

map_return Specifies the mapping list.

nmap       Specifies the number of items in the mapping list.

XGetDeviceButtonMapping returns the current mapping of the specified extension
device. Elements of the list are indexed starting from one.
XGetDeviceButtonMapping returns the number of physical buttons actually on the
pointer. The nominal mapping for the buttons is the identity mapping: map[i]=i.
The nmap argument specifies the length of the array where the button mapping is
returned, and only the first nmap elements are returned in map_return.

XGetDeviceButtonMapping can generate BadDevice and BadMatch errors.

Obtaining the State of a Device

To obtain information that describes the state of the keys, buttons, and
valuators of an extension device, use XQueryDeviceState .

XDeviceState * XQueryDeviceState(Display *display, XDevice *device);

display Specifies the connection to the X server.

device  Specifies the desired device.

XQueryDeviceState returns a pointer to an XDeviceState structure, which points
to a list of structures that describe the state of the keys, buttons, and
valuators on the device:



typedef struct {
     XID device_id;
     int num_classes;
     XInputClass *data;
} XDeviceState;

The structures are of variable length, but the first two members are common to
all and are as follows:



typedef struct {
     unsigned char class;
     unsigned char length;
} XInputClass;

The class member contains a class identifier. This identifier can be compared
with constants defined in the file < X11/extensions/XI.h >. Currently defined
constants are: KeyClass , ButtonClass , and ValuatorClass .

The length member contains the length of the structure and can be used by
clients to traverse the list.

The XValuatorState structure describes the current state of the valuators on
the device. The num_valuators member contains the number of valuators on the
device. The mode member is a mask whose bits report the data mode and other
state information for the device. The following bits are currently defined:



     DeviceMode     1 << 0     Relative = 0, Absolute = 1
     ProximityState     1 << 1     InProximity = 0, OutOfProximity = 1

The valuators member contains a pointer to an array of integers that describe
the current value of the valuators. If the mode is Relative , these values are
undefined.



typedef struct {
     unsigned char class;
     unsigned char length;
     unsigned char num_valuators;
     unsigned char mode;
     int *valuators;
} XValuatorState;

The XKeyState structure describes the current state of the keys on the device.
Byte N (from 0) contains the bits for key 8N to 8N + 7 with the least
significant bit in the byte representing key 8N.



typedef struct {
     unsigned char class;
     unsigned char length;
     short num_keys;
     char keys[32];
} XKeyState;

The XButtonState structure describes the current state of the buttons on the
device. Byte N (from 0) contains the bits for button 8N to 8N + 7 with the
least significant bit in the byte representing button 8N.



typedef struct {
     unsigned char class;
     unsigned char length;
     short num_buttons;
     char buttons[32];
} XButtonState;

XQueryDeviceState can generate BadDevice errors.

To free the data returned by this function, use XFreeDeviceState .

void XFreeDeviceState(XDeviceState *state);

state Specifies the pointer to the XDeviceState data returned by a previous
      call to XQueryDeviceState .

XFreeDeviceState frees the device state data.

Events

The input extension creates input events analogous to the core input events.
These extension input events are generated by manipulating one of the extension
input devices. The remainder of this section discusses the following X Input
Extension event topics:

  • Event types

  • Event classes

  • Event structures

Event Types

Event types are integer numbers that a client can use to determine what kind of
event it has received. The client compares the type field of the event
structure with known event types to make this determination.

The core input event types are constants and are defined in the header file <
X11/X.h >. Extension event types are not constants. Instead, they are
dynamically allocated by the extension's request to the X server when the
extension is initialized. Because of this, extension event types must be
obtained by the client from the server.

The client program determines the event type for an extension event by using
the information returned by the XOpenDevice request. This type can then be used
for comparison with the type field of events received by the client.

Extension events propagate up the window hierarchy in the same manner as core
events. If a window is not interested in an extension event, it usually
propagates to the closest ancestor that is interested, unless the
dont_propagate list prohibits it. Grabs of extension devices may alter the set
of windows that receive a particular extension event.

The following table lists the event category and its associated event type or
types.

┌─────────────────────────┬───────────────────┐
│     Event Category      │    Event Type     │
├─────────────────────────┼───────────────────┤
│       Device key        │  DeviceKeyPress   │
├─────────────────────────┼───────────────────┤
│                         │ DeviceKeyRelease  │
├─────────────────────────┼───────────────────┤
│      Device motion      │ DeviceButtonPress │
├─────────────────────────┼───────────────────┤
│                         │DeviceButtonRelease│
├─────────────────────────┼───────────────────┤
│                         │DeviceMotionNotify │
├─────────────────────────┼───────────────────┤
│   Device input focus    │   DeviceFocusIn   │
├─────────────────────────┼───────────────────┤
│                         │  DeviceFocusOut   │
├─────────────────────────┼───────────────────┤
│Device state notification│ DeviceStateNotify │
├─────────────────────────┼───────────────────┤
│    Device proximity     │    ProximityIn    │
├─────────────────────────┼───────────────────┤
│                         │   ProximityOut    │
├─────────────────────────┼───────────────────┤
│     Device mapping      │DeviceMappingNotify│
├─────────────────────────┼───────────────────┤
│      Device change      │ChangeDeviceNotify │
└─────────────────────────┴───────────────────┘

Event Classes

Event classes are integer numbers that are used in the same way as the core
event masks. They are used by a client program to indicate to the server which
events that client program wishes to receive.

The core input event masks are constants and are defined in the header file <
X11/X.h >. Extension event classes are not constants. Instead, they are
dynamically allocated by the extension's request to the X server when the
extension is initialized. Because of this, extension event classes must be
obtained by the client from the server.

The event class for an extension event and device is obtained from information
returned by the XOpenDevice function. This class can then be used in an
XSelectExtensionEvent request to ask that events of that type from that device
be sent to the client program.

For DeviceButtonPress events, the client may specify whether or not an implicit
passive grab should be done when the button is pressed. If the client wants to
guarantee that it will receive a DeviceButtonRelease event for each
DeviceButtonPress event it receives, it should specify the
DeviceButtonPressGrab class in addition to the DeviceButtonPress class. This
restricts the client in that only one client at a time may request
DeviceButtonPress events from the same device and window if any client
specifies this class.

If any client has specified the DeviceButtonPressGrab class, any requests by
any other client that specify the same device and window and specify either
DeviceButtonPress or DeviceButtonPressGrab will cause an Access error to be
generated.

If only the DeviceButtonPress class is specified, no implicit passive grab will
be done when a button is pressed on the device. Multiple clients may use this
class to specify the same device and window combination.

The client may also select DeviceMotion events only when a button is down. It
does this by specifying the event classes DeviceButton1Motion through
DeviceButton5Motion . An input device will support only as many button motion
classes as it has buttons.

Event Structures

Each extension event type has a corresponding structure declared in < X11/
extensions/XInput.h >. All event structures have the following common members:

           Set to the event type number that uniquely identifies it. For
type       example, when the X server reports a DeviceKeyPress event to a
           client application, it sends an XDeviceKeyPressEvent structure.

serial     Set from the serial number reported in the protocol but expanded
           from the 16-bit least significant bits to a full 32-bit value.

send_event Set to True if the event came from an XSendEvent request.

display    Set to a pointer to a structure that defines the display on which
           the event was read.

Extension event structures report the current position of the X pointer. In
addition, if the device reports motion data and is reporting absolute data, the
current value of any valuators the device contains is also reported.

Device Key Events

Key events from extension devices contain all the information that is contained
in a key event from the X keyboard. In addition, they contain a device ID and
report the current value of any valuators on the device, if that device is
reporting absolute data. If data for more than six valuators is being reported,
more than one key event will be sent. The axes_count member contains the number
of axes that are being reported. The server sends as many of these events as
are needed to report the device data. Each event contains the total number of
axes reported in the axes_count member and the first axis reported in the
current event in the first_axis member. If the device supports input class
Valuators , but is not reporting absolute mode data, the axes_count member
contains zero (0).

The location reported in the x, y and x_root, y_root members is the location of
the core X pointer.

The XDeviceKeyEvent structure is defined as follows:



typedef struct {
     int type;                      /* of event */
     unsigned long serial;          /* # of last request processed */
     Bool send_event;               /* true if from SendEvent request */
     Display *display;              /* Display the event was read from */
     Window window;                 /* "event" window reported relative to */
     XID deviceid;
     Window root;                   /* root window event occurred on */
     Window subwindow;              /* child window */
     Time time;                     /* milliseconds */
     int x, y;                      /* x, y coordinates in event window */
     int x_root;                    /* coordinates relative to root */
     int y_root;                    /* coordinates relative to root */
     unsigned int state;            /* key or button mask */
     unsigned int keycode;          /* detail */
     Bool same_screen;              /* same screen flag */
     unsigned int device_state;     /* device key or button mask */
     unsigned char axes_count;
     unsigned char first_axis;
     int axis_data[6];
} XDeviceKeyEvent;

typedef XDeviceKeyEvent XDeviceKeyPressedEvent;
typedef XDeviceKeyEvent XDeviceKeyReleasedEvent;

Device Button Events

Button events from extension devices contain all the information that is
contained in a button event from the X pointer. In addition, they contain a
device ID and report the current value of any valuators on the device if that
device is reporting absolute data. If data for more than six valuators is being
reported, more than one button event may be sent. The axes_count member
contains the number of axes that are being reported. The server sends as many
of these events as are needed to report the device data. Each event contains
the total number of axes reported in the axes_count member and the first axis
reported in the current event in the first_axis member. If the device supports
input class Valuators , but is not reporting absolute mode data, the axes_count
member contains zero (0).

The location reported in the x, y and x_root, y_root members is the location of
the core X pointer.



typedef struct {
     int type;                      /* of event */
     unsigned long serial;          /* # of last request processed by server */
     Bool send_event;               /* true if from a SendEvent request */
     Display *display;              /* Display the event was read from */
     Window window;                 /* "event" window reported relative to */
     XID deviceid;
     Window root;                   /* root window that the event occurred on */
     Window subwindow;              /* child window */
     Time time;                     /* milliseconds */
     int x, y;                      /* x, y coordinates in event window */
     int x_root;                    /* coordinates relative to root */
     int y_root;                    /* coordinates relative to root */
     unsigned int state;            /* key or button mask */
     unsigned int button;           /* detail */
     Bool same_screen;              /* same screen flag */
     unsigned int device_state;     /* device key or button mask */
     unsigned char axes_count;
     unsigned char first_axis;
     int axis_data[6];
} XDeviceButtonEvent;

typedef XDeviceButtonEvent XDeviceButtonPressedEvent;
typedef XDeviceButtonEvent XDeviceButtonReleasedEvent;

Device Motion Events

Motion events from extension devices contain all the information that is
contained in a motion event from the X pointer. In addition, they contain a
device ID and report the current value of any valuators on the device.

The location reported in the x, y and x_root, y_root members is the location of
the core X pointer, and so is 2-dimensional.

Extension motion devices may report motion data for a variable number of axes.
The axes_count member contains the number of axes that are being reported. The
server sends as many of these events as are needed to report the device data.
Each event contains the total number of axes reported in the axes_count member
and the first axis reported in the current event in the first_axis member.



typedef struct {
     int type;                          /* of event */
     unsigned long serial;              /* # of last request processed by server */
     Bool send_event;                   /* true if from a SendEvent request */
     Display *display;                  /* Display the event was read from */
     Window window;                     /* "event" window reported relative to */
     XID deviceid;
     Window root;                       /* root window that the event occurred on */
     Window subwindow;                  /* child window */
     Time time;                         /* milliseconds */
     int x, y;                          /* x, y coordinates in event window */
     int x_root;                        /* coordinates relative to root */
     int y_root;                        /* coordinates relative to root */
     unsigned int state;                /* key or button mask */
     char is_hint;                      /* detail */
     Bool same_screen;                  /* same screen flag */
     unsigned int device_state;         /* device key or button mask */
     unsigned char axes_count;
     unsigned char first_axis;
     int axis_data[6];
} XDeviceMotionEvent;

Device Focus Events

These events are equivalent to the core focus events. They contain the same
information, with the addition of a device ID to identify which device has had
a focus change, and a timestamp.

DeviceFocusIn and DeviceFocusOut events are generated for focus changes of
extension devices in the same manner as core focus events are generated.



typedef struct {
     int type;                      /* of event */
     unsigned long serial;          /* # of last request processed by server */
     Bool send_event;               /* true if this came from a SendEvent request */
     Display *display;              /* Display the event was read from */
     Window window;                 /* "event" window it is reported relative to */
     XID deviceid;
     int mode;                      /* NotifyNormal, NotifyGrab, NotifyUngrab */
     int detail;
                                    /*
                                     * NotifyAncestor, NotifyVirtual, NotifyInferior,
                                     * NotifyNonLinear,NotifyNonLinearVirtual, NotifyPointer,
                                     * NotifyPointerRoot, NotifyDetailNone
                                     */
     Time time;
} XDeviceFocusChangeEvent;

typedef XDeviceFocusChangeEvent XDeviceFocusInEvent;
typedef XDeviceFocusChangeEvent XDeviceFocusOutEvent;

Device StateNotify Event

This event is analogous to the core keymap event but reports the current state
of the device for each input class that it supports. It is generated after
every DeviceFocusIn event and EnterNotify event and is delivered to clients who
have selected XDeviceStateNotify events.

If the device supports input class Valuators , the mode member in the
XValuatorStatus structure is a bitmask that reports the device mode, proximity
state, and other state information. The following bits are currently defined:



     0x01     Relative = 0, Absolute = 1
     0x02     InProximity = 0, OutOfProximity = 1

If the device supports more valuators than can be reported in a single XEvent ,
multiple XDeviceStateNotify events will be generated.



typedef struct {
     unsigned char class;
     unsigned char length;
} XInputClass;

typedef struct {
     int type;
     unsigned long serial;     /* # of last request processed by server */
     Bool send_event;          /* true if this came from a SendEvent request */
     Display *display;         /* Display the event was read from */
     Window window;
     XID deviceid;
     Time time;
     int num_classes;
     char data[64];
} XDeviceStateNotifyEvent;

typedef struct {
     unsigned char class;
     unsigned char length;
     unsigned char num_valuators;
     unsigned char mode;
     int valuators[6];
} XValuatorStatus;

typedef struct {
     unsigned char class;
     unsigned char length;
     short num_keys;
     char keys[32];
} XKeyStatus;

typedef struct {
     unsigned char class;
     unsigned char length;
     short num_buttons;
     char buttons[32];
} XButtonStatus;

Device Mapping Event

This event is equivalent to the core MappingNotify event. It notifies client
programs when the mapping of keys, modifiers, or buttons on an extension device
has changed.



typedef struct {
     int type;
     unsigned long serial;
     Bool send_event;
     Display *display;
     Window window;
     XID deviceid;
     Time time;
     int request;
     int first_keycode;
     int count;
} XDeviceMappingEvent;

ChangeDeviceNotify Event

This event has no equivalent in the core protocol. It notifies client programs
when one of the core devices has been changed.



typedef struct {
     int type;
     unsigned long serial;
     Bool send_event;
     Display *display;
     Window window;
     XID deviceid;
     Time time;
     int request;
} XChangeDeviceNotifyEvent;

Proximity Events

These events have no equivalent in the core protocol. Some input devices such
as graphics tablets or touchscreens may send these events to indicate that a
stylus has moved into or out of contact with a positional sensing surface.

The event contains the current value of any valuators on the device if that
device is reporting absolute data. If data for more than six valuators is being
reported, more than one proximity event may be sent. The axes_count member
contains the number of axes that are being reported. The server sends as many
of these events as are needed to report the device data. Each event contains
the total number of axes reported in the axes_count member and the first axis
reported in the current event in the first_axis member. If the device supports
input class Valuators , but is not reporting absolute mode data, the axes_count
member contains zero (0).



typedef struct {
     int type;                 /* ProximityIn or ProximityOut */
     unsigned long serial;     /* # of last request processed by server */
     Bool send_event;          /* true if this came from a SendEvent request */
     Display *display;         /* Display the event was read from */
     Window window;
     XID deviceid;
     Window root;
     Window subwindow;
     Time time;
     int x, y;
     int x_root, y_root;
     unsigned int state;
     Bool same_screen;
     unsigned int device_state;   /* device key or button mask */
     unsigned char axes_count;
     unsigned char first_axis;
     int axis_data[6];
} XProximityNotifyEvent;

typedef XProximityNotifyEvent XProximityInEvent;
typedef XProximityNotifyEvent XProximityOutEvent;

Event Handling Functions

This section discusses the X Input Extension event handling functions that
allow you to:

  • Determine the extension version

  • List the available devices

  • Enable and disable extension devices

  • Change the mode of a device

  • Initialize valuators on an input device

  • Get input device controls

  • Change input device controls

  • Select extension device events

  • Determine selected device events

  • Control event propagation

  • Send an event

  • Get motion history

Determining the Extension Version

XExtensionVersion * XGetExtensionVersion(Display *display, char *name);

display Specifies the connection to the X server.

name    Specifies the name of the desired extension.

XGetExtensionVersion allows a client to determine whether a server supports the
desired version of the input extension.

The XExtensionVersion structure returns information about the version of the
extension supported by the server and is defined as follows:



typedef struct {
     Bool present;
     short major_version;
     short minor_version;
} XExtensionVersion;

The major and minor versions can be compared with constants defined in the
header file < X11/extensions/XI.h >. Each version is a superset of the previous
versions.

You should use XFree. to free the data returned by this function.

Listing Available Devices

A client program that wishes to access a specific device must first determine
whether that device is connected to the X server. This is done through the
XListInputDevices function, which will return a list of all devices that can be
opened by the X server. The client program can use one of the names defined in
the < X11/extensions/XI.h > header file in an XInternAtom request to determine
the device type of the desired device. This type can then be compared with the
device types returned by the XListInputDevices request.

XDeviceInfo * XListInputDevices(Display *display, int *ndevices);

display  Specifies the connection to the X server.

ndevices Specifies the address of a variable into which the server can return
         the number of input devices available to the X server.

XListInputDevices allows a client to determine which devices are available for
X input and information about those devices. An array of XDeviceInfo structures
is returned, with one element in the array for each device. The number of
devices is returned in the ndevices argument.

The X pointer device and X keyboard device are reported, as well as all
available extension input devices. The use member of the XDeviceInfo structure
specifies the current use of the device. If the value of this member is
IsXPointer , the device is the X pointer device. If the value is IsXKeyboard ,
the device is the X keyboard device. If the value is IsXExtensionDevice , the
device is available for use as an extension input device.

Each XDeviceInfo entry contains a pointer to a list of structures that describe
the characteristics of each class of input supported by that device. The
num_classes member contains the number of entries in that list.

If the device supports input class Valuators , one of the structures pointed to
by the XDeviceInfo structure will be an XValuatorInfo structure. The axes
member of that structure contains the address of an array of XAxisInfo
structures. There is one element in this array for each axis of motion reported
by the device. The number of elements in this array is contained in the
num_axes element of the XValuatorInfo structure. The size of the motion buffer
for the device is reported in the motion_buffer member of the XValuatorInfo
structure.

The XDeviceInfo structure is defined as follows:



typedef struct _XDeviceInfo {
     XID id;
     Atom type;
     char *name;
     int num_classes;
     int use;
     XAnyClassPtr inputclassinfo;
} XDeviceInfo;

The structures pointed to by the XDeviceInfo structure are defined as follows:



typedef struct _XKeyInfo {
     XID class;
     int length;
     unsigned short min_keycode;
     unsigned short max_keycode;
     unsigned short num_keys;
} XKeyInfo;

typedef struct _XButtonInfo {
     XID class;
     int length;
     short num_buttons;
} XButtonInfo;

typedef struct _XValuatorInfo {
     XID class;
     int length;
     unsigned char num_axes;
     unsigned char mode;
     unsigned long motion_buffer;
     XAxisInfoPtr axes;
} XValuatorInfo;

The XAxisInfo structure pointed to by the XValuatorInfo structure is defined as
follows:



typedef struct _XAxisInfo {
     int resolution;
     int min_value;
     int max_value;
} XAxisInfo;

The following atom names are defined in the < X11/extensions/XI.h > header
file.



MOUSE     QUADRATURE
TABLET     SPACEBALL
KEYBOARD     DATAGLOVE
TOUCHSCREEN     EYETRACKER
TOUCHPAD     CURSORKEYS
BUTTONBOX     FOOTMOUSE
BARCODE     ID_MODULE
KNOB_BOX     ONE_KNOB
TRACKBALL     NINE_KNOB\s+1

These names can be used in an XInternAtom request to return an atom that can be
used for comparison with the type member of the XDeviceInfo structure.

XListInputDevices returns NULL if there are no input devices to list.

To free the data returned by XListInputDevices , use XFreeDeviceList .

void XFreeDeviceList(XDeviceInfo *list);

list Specifies the pointer to the XDeviceInfo array returned by a previous call
     to XListInputDevices .

XFreeDeviceList frees the list of input device information.

Enabling and Disabling Extension Devices

Each client program that wishes to access an extension device must request that
the server open that device by calling the XOpenDevice function.

XDevice * XOpenDevice(Display *display, XID device_id);

display   Specifies the connection to the X server.

device_id Specifies the ID that uniquely identifies the device to be opened.
          This ID is obtained from the XListInputDevices request.

XOpenDevice opens the device for the requesting client and, on success, returns
an XDevice structure, which is defined as follows:



typedef struct {
     XID device_id;
     int num_classes;
     XInputClassInfo *classes;
} XDevice;

The XDevice structure contains a pointer to an array of XInputClassInfo
structures. Each element in that array contains information about events of a
particular input class supported by the input device.

The XInputClassInfo structure is defined as follows:



typedef struct {
     unsigned char input_class;
     unsigned char event_type_base;
} XInputClassInfo;

A client program can determine the event type and event class for a given event
by using macros defined by the input extension. The name of the macro
corresponds to the desired event, and the macro is passed the structure that
describes the device from which input is desired, for example:



     DeviceKeyPress(XDevice *device, event_type, event_class)

The macro will fill in the values of the event class to be used in an
XSelectExtensionEvent request to select the event and the event type to be used
in comparing with the event types of events received via XNextEvent.

XOpenDevice can generate BadDevice errors.

Before terminating, the client program should request that the server close the
device by calling the XCloseDevice function.

int XCloseDevice(Display *display, XDevice *device);

display Specifies the connection to the X server.

device  Specifies the device to be closed.

XCloseDevice closes the device for the requesting client and frees the
associated XDevice structure.

A client may open the same extension device more than once. Requests after the
first successful one return an additional XDevice structure with the same
information as the first, but otherwise have no effect. A single XCloseDevice
request will terminate that client's access to the device.

Closing a device releases any active or passive grabs the requesting client has
established. If the device is frozen only by an active grab of the requesting
client, any queued events are released.

If a client program terminates without closing a device, the server will
automatically close that device on behalf of the client. This does not affect
any other clients that may be accessing that device.

XCloseDevice can generate BadDevice errors.

Changing the Mode of a Device

Some devices are capable of reporting either relative or absolute motion data.
To change the mode of a device from relative to absolute, use XSetDeviceMode .

int XSetDeviceMode(Display *display, XDevice *device, int mode);

display Specifies the connection to the X server.

device  Specifies the device whose mode should be changed.

mode    Specifies the mode. You can pass Absolute or Relative .

XSetDeviceMode allows a client to request the server to change the mode of a
device that is capable of reporting either absolute positional data or relative
motion data. If the device is invalid or if the client has not previously
requested that the server open the device via an XOpenDevice request, this
request will fail with a BadDevice error. If the device does not support input
class Valuators or if it is not capable of reporting the specified mode, the
request will fail with a BadMatch error.

This request will fail and return DeviceBusy if another client has already
opened the device and requested a different mode.

XSetDeviceMode can generate BadDevice , BadMatch , BadMode , and DeviceBusy
errors.

Initializing Valuators on an Input Device

Some devices that report absolute positional data can be initialized to a
starting value. Devices that are capable of reporting relative motion or
absolute positional data may require that their valuators be initialized to a
starting value after the mode of the device is changed to Absolute .

To initialize the valuators on such a device, use XSetDeviceValuators .

Status XSetDeviceValuators(Display *display, XDevice *device,
int*valuators,first_valuator, num_valuators);

display        Specifies the connection to the X server.

device         Specifies the device whose valuators should be initialized.

valuators      Specifies the values to which each valuator should be set.

first_valuator Specifies the first valuator to be set.

num_valuators  Specifies the number of valuators to be set.

XSetDeviceValuators initializes the specified valuators on the specified
extension input device. Valuators are numbered beginning with zero. Only the
valuators in the range specified by first_valuator and num_valuators are set. A
BadValue error results if the number of valuators supported by the device is
less than the following expression:



     first_valuator + num_valuators

If the request succeeds, Success is returned. If the specified device is
grabbed by some other client, the request will fail and a status of
AlreadyGrabbed will be returned.

XSetDeviceValuators can generate BadDevice , BadLength , BadMatch , and
BadValue errors.

Getting Input Device Controls

Some input devices support various configuration controls that can be queried
or changed by clients. The set of supported controls will vary from one input
device to another. Requests to manipulate these controls will fail if either
the target X server or the target input device does not support the requested
device control.

Each device control has a unique identifier. Information passed with each
device control varies in length and is mapped by data structures unique to that
device control.

To query a device control, use XGetDeviceControl .

XDeviceControl * XGetDeviceControl(Display *display, XDevice *device, int
control);

display Specifies the connection to the X server.

device  Specifies the device whose configuration control status is to be
        returned.

control Identifies the specific device control to be queried.

XGetDeviceControl returns the current state of the specified device control. If
the target X server does not support that device control, a BadValue error is
returned. If the specified device does not support that device control, a
BadMatch error is returned.

If the request is successful, a pointer to a generic XDeviceState structure is
returned. The information returned varies according to the specified control
and is mapped by a structure appropriate for that control. The first two
members are common to all device controls and are defined as follows:



typedef struct {
     XID control;
     int length;
} XDeviceState;
\fP

The control may be compared to constants defined in the file < X11/extensions/
XI.h >. Currently defined device controls include DEVICE_RESOLUTION.

The information returned for the DEVICE_RESOLUTION control is defined in the
XDeviceResolutionState structure, which is defined as follows:



typedef struct {
     XID control;
     int length;
     int num_valuators;
     int *resolutions;
     int *min_resolutions;
     int *max_resolutions;
} XDeviceResolutionState;

This device control returns a list of valuators and the range of valid
resolutions allowed for each. Valuators are numbered beginning with zero (0).
Resolutions for all valuators on the device are returned. For each valuator i
on the device, resolutions[i] returns the current setting of the resolution,
min_resolutions[i] returns the minimum valid setting, and max_resolutions[i]
returns the maximum valid setting.

When this control is specified, XGetDeviceControl fails with a BadMatch error
if the specified device has no valuators.

XGetDeviceControl can generate BadMatch and BadValue errors.

Changing Input Device Controls

Some input devices support various configuration controls that can be changed
by clients. Typically, this would be done to initialize the device to a known
state or configuration. The set of supported controls will vary from one input
device to another. Requests to manipulate these controls will fail if either
the target X server or the target input device does not support the requested
device control. Setting the device control will also fail if the target input
device is grabbed by another client or is open by another client and has been
set to a conflicting state.

Each device control has a unique identifier. Information passed with each
device control varies in length and is mapped by data structures unique to that
device control.

To change a device control, use XChangeDeviceControl .

Status XChangeDeviceControl(Display *display, XDevice *device, int control,
XDeviceControl *value);

display Specifies the connection to the X server.

device  Specifies the device whose configuration control status is to be
        modified.

control Identifies the specific device control to be changed.

value   Specifies a pointer to an XDeviceControl structure that describes which
        control is to be changed and how it is to be changed.

XChangeDeviceControl changes the current state of the specified device control.
If the target X server does not support that device control, a BadValue error
is returned. If the specified device does not support that device control, a
BadMatch error is returned. If another client has the target device grabbed, a
status of AlreadyGrabbed is returned. If another client has the device open and
has set it to a conflicting state, a status of DeviceBusy is returned. If the
request fails for any reason, the device control will not be changed.

If the request is successful, the device control will be changed and a status
of Success is returned. The information passed varies according to the
specified control and is mapped by a structure appropriate for that control.
The first two members are common to all device controls:



typedef struct {
     XID control;
     int length;
} XDeviceControl;

The control may be set using constants defined in the < X11/extensions/XI.h >
header file. Currently defined device controls include DEVICE_RESOLUTION.

The information that can be changed by the DEVICE_RESOLUTION control is defined
in the XDeviceResolutionControl structure, which is defined as follows:



typedef struct {
     XID control;
     int length;
     int first_valuator;
     int num_valuators;
     int *resolutions;
} XDeviceResolutionControl;

This device control changes the resolution of the specified valuators on the
specified extension input device. Valuators are numbered beginning with zero.
Only the valuators in the range specified by first_valuator and num_valuators
are set. A value of -1 in the resolutions list indicates that the resolution
for this valuator is not to be changed. The num_valuators member specifies the
number of valuators in the resolutions list.

When this control is specified, XChangeDeviceControl fails with a BadMatch
error if the specified device has no valuators. If a resolution is specified
that is not within the range of valid values (as returned by XGetDeviceControl
), XChangeDeviceControl fails with a BadValue error. A BadValue error results
if the number of valuators supported by the device is less than the following
expression:



     first_valuator + num_valuators,

XChangeDeviceControl can generate BadMatch and BadValue errors.

Selecting Extension Device Events

To select device input events, use XSelectExtensionEvent . The parameters
passed are a pointer to a list of classes that define the desired event types
and devices, a count of the number of elements in the list, and the ID of the
window from which events are desired.

int XSelectExtensionEvent(Display *display, Window window, XEventClass
*event_list, int event_count);

display     Specifies the connection to the X server.

window      Specifies the ID of the window from which the client wishes to
            receive events.

event_list  Specifies a pointer to an array of event classes that specify which
            events are desired.

event_count Specifies the number of elements in the event_list.

XSelectExtensionEvent requests the server to send events that match the events
and devices described by the event list and that come from the requested
window. The elements of the XEventClass array are the event_class values
obtained by invoking a macro with the pointer to an XDevice structure returned
by the XOpenDevice request. For example, the DeviceKeyPress macro would return
the XEventClass for DeviceKeyPress events from the specified device if it were
invoked in the following form:



     DeviceKeyPress (XDevice *device, event_type, event_class)

Macros are defined for the following event classes:

DeviceKeyPress
DeviceKeyRelease
DeviceButtonPress
DeviceButtonRelease
DeviceMotionNotify
DeviceFocusIn
DeviceFocusOut
ProximityIn
ProximityOut
DeviceStateNotify
DeviceMappingNotify
ChangeDeviceNotify
DevicePointerMotionHint
DeviceButton1Motion
DeviceButton2Motion
DeviceButton3Motion,
DeviceButton4Motion
DeviceButton5Motion
DeviceButtonMotion,
DeviceOwnerGrabButton
DeviceButtonPressGrab

To get the next available event from within a client program, use the core 
XNextEvent function. This returns the next event whether it came from a core
device or an extension device.

Succeeding XSelectExtensionEvent requests using event classes for the same
device as was specified on a previous request will replace the previous set of
selected events from that device with the new set.

XSelectExtensionEvent can generate BadAccess , BadClass , BadLength , and
BadWindow errors.

Determining Selected Device Events

To determine which extension events are currently selected from a given window,
use XGetSelectedExtensionEvents .

int XGetSelectedExtensionEvents(Display *display, Window window, int
*this_client_count, XEventClass **this_client, int *all_clients_count,
XEventClass **all_clients);

display           Specifies the connection to the X server.

window            Specifies the ID of the window from which the client wishes
                  to receive events.

this_client_count Returns the number of elements in the this_client list.

this_client       Returns a list of XEventClasses that specify which events are
                  selected by this client.

all_clients_count Returns the number of elements in the all_clients list.

all_clients       Returns a list of XEventClasses that specify which events are
                  selected by all clients.

XGetSelectedExtensionEvents returns pointers to two event class arrays. One
lists the extension events selected by this client from the specified window.
The other lists the extension events selected by all clients from the specified
window. This information is analogous to that returned in your_event_mask and
all_event_masks of the XWindowAttributes structure when an XGetWindowAttributes
request is made. To free the two arrays returned by this function, use XFree.

XGetSelectedExtensionEvents can generate BadWindow errors.

Controlling Event Propagation

Extension events propagate up the window hierarchy in the same manner as core
events. If a window is not interested in an extension event, it usually
propagates to the closest ancestor that is interested, unless the
dont_propagate list prohibits it. Grabs of extension devices may alter the set
of windows that receive a particular extension event.

Client programs may control event propagation through the use of the following
two functions: XChangeDeviceDontPropagateList and XGetDeviceDontPropagateList .

int XChangeDeviceDontPropagateList(Display *display, Window window, int
event_count, XEventClass *events, int mode);

display     Specifies the connection to the X server.

window      Specifies the desired window.

event_count Specifies the number of elements in the events list.

events      Specifies a pointer to the list of XEventClasses.

mode        Specifies the mode. You can pass AddToList or DeleteFromList .

XChangeDeviceDontPropagateList adds an event to or deletes an event from the
do_not_propagate list of extension events for the specified window. There is
one list per window, and the list remains for the life of the window. The list
is not altered if a client that changed the list terminates.

Suppression of event propagation is not allowed for all events. If a specified
XEventClass is invalid because suppression of that event is not allowed, a
BadClass error results.

XChangeDeviceDontPropagateList can generate BadClass , BadMode , and BadWindow
errors.

XEventClass * XGetDeviceDontPropagateList(Display *display, Window window, int
*event_count);

display     Specifies the connection to the X server.

window      Specifies the desired window.

event_count Returns the number of elements in the array returned by this
            function.

XGetDeviceDontPropagateList allows a client to determine the do_not_propagate
list of extension events for the specified window. It returns an array of
XEventClass , each XEventClass representing a device/event type pair. To free
the data returned by this function, use XFree.

XGetDeviceDontPropagateList can generate BadWindow errors.

Sending an Event

To send an extension event to another client, use XSendExtensionEvent .

int XSendExtensionEvent(Display *display, XDevice *device, Window window, Bool
propagate, int event_count, XEventClass *event_list, XEvent *event);

display     Specifies the connection to the X server.

device      Specifies the device whose ID is recorded in the event.

window      Specifies the destination window ID. You can pass a window ID,
            PointerWindow or InputFocus .

propagate   Specifies a boolean value that is either True or False .

event_count Specifies the number of elements in the event_list array.

event_list  Specifies a pointer to an array of XEventClass .

event       Specifies a pointer to the event that is to be sent.

XSendExtensionEvent identifies the destination window, determines which clients
should receive the specified event, and ignores any active grabs. It requires a
list of XEventClass to be specified. These are obtained by opening an input
device with the XOpenDevice request.

XSendExtensionEvent uses the window argument to identify the destination window
as follows:

  • If you pass PointerWindow , the destination window is the window that
    contains the pointer.

  • If you pass InputFocus and if the focus window contains the pointer, the
    destination window is the window that contains the pointer. If the focus
    window does not contain the pointer, the destination window is the focus
    window.

To determine which clients should receive the specified events,
XSendExtensionEvent uses the propagate argument as follows:

  • If propagate is False , the event is sent to every client selecting from
    the destination window any of the events specified in the event_list array.

  • If propagate is True and no clients have selected from the destination
    window any of the events specified in the event_list array, the destination
    is replaced with the closest ancestor of destination for which some client
    has selected one of the specified events and for which no intervening
    window has that event in its do_not_propagate mask. If no such window
    exists, or if the window is an ancestor of the focus window, and InputFocus
    was originally specified as the destination, the event is not sent to any
    clients. Otherwise, the event is reported to every client selecting on the
    final destination any of the events specified in event_list.

The event in the XEvent structure must be one of the events defined by the
input extension, so that the X server can correctly byte swap the contents as
necessary. The contents of the event are otherwise unaltered and unchecked by
the X server except to force send_event to True in the forwarded event and to
set the sequence number in the event correctly.

XSendExtensionEvent returns zero if the conversion-to-wire protocol failed;
otherwise, it returns nonzero.

XSendExtensionEvent can generate BadClass , BadDevice , BadValue , and
BadWindow errors.

Getting Motion History

XDeviceTimeCoord * XGetDeviceMotionEvents( axis_count_return), Display
*display, XDevice *device, Timestart, stop, int *nevents_return, int
*mode_return, int *axis_count_return);

display           Specifies the connection to the X server.

device            Specifies the desired device.

start             Specifies the start time.

stop              Specifies the stop time.

nevents_return    Returns the number of positions in the motion buffer returned
                  for this request.

mode_return       Returns the mode of the nevents information. The mode will be
                  one of the following: Absolute or Relative .

axis_count_return Returns the number of axes reported in each of the positions
                  returned.

XGetDeviceMotionEvents returns all positions in the device's motion history
buffer that fall between the specified start and stop times inclusive. If the
start time is in the future or is later than the stop time, no positions are
returned.

The return type for this function is an XDeviceTimeCoord structure, which is
defined as follows:



typedef struct {
     Time time;
     unsigned int *data;
} XDeviceTimeCoord;

The data member is a pointer to an array of data items. Each item is of type
int, and there is one data item per axis of motion reported by the device. The
number of axes reported by the device is returned in the axis_count variable.

The value of the data items depends on the mode of the device. The mode is
returned in the mode variable. If the mode is Absolute , the data items are the
raw values generated by the device. These may be scaled by the client program
using the maximum values that the device can generate for each axis of motion
that it reports. The maximum value for each axis is reported in the max_val
member of the XAxisInfo structure, which is part of the information returned by
the XListInputDevices request.

If the mode is Relative , the data items are the relative values generated by
the device. The client program must choose an initial position for the device
and maintain a current position by accumulating these relative values.

Consecutive calls to XGetDeviceMotionEvents can return data of different modes,
that is, if some client program has changed the mode of the device via an
XSetDeviceMode request.

XGetDeviceMotionEvents can generate BadDevice and BadMatch errors.

To free the data returned by XGetDeviceMotionEvents , use
XFreeDeviceMotionEvents .

void XFreeDeviceMotionEvents(XDeviceTimeCoord *events);

events Specifies the pointer to the XDeviceTimeCoord array returned by a
       previous call to XGetDeviceMotionEvents .

XFreeDeviceMotionEvents frees the specified array of motion information.
Appendix A

The following information is contained in the <X11/extensions/XInput.h> and
<X11/extensions/XI.h> header files:




/* Definitions used by the library and client */

#ifndef _XINPUT_H_
#define _XINPUT_H_

#ifndef _XLIB_H_
#include <X11/Xlib.h>
#endif

#ifndef _XI_H_
#include "XI.h"
#endif

#define _deviceKeyPress          0
#define _deviceKeyRelease     1

#define _deviceButtonPress     0
#define _deviceButtonRelease     1

#define _deviceMotionNotify     0

#define _deviceFocusIn          0
#define _deviceFocusOut          1

#define _proximityIn          0
#define _proximityOut          1

#define _deviceStateNotify     0
#define _deviceMappingNotify     1
#define _changeDeviceNotify     2

#define FindTypeAndClass(d, type, class, classid, offset) \
    { int i; XInputClassInfo *ip; \
    type = 0; class = 0; \
    for (i=0, ip= ((XDevice *) d)->classes; \
      i< ((XDevice *) d)->num_classes; \
      i++, ip++) \
     if (ip->input_class == classid) \
         {type =  ip->event_type_base + offset; \
          class =  ((XDevice *) d)->device_id << 8 | type;}}

#define DeviceKeyPress(d, type, class) \
    FindTypeAndClass(d, type, class, KeyClass, _deviceKeyPress)

#define DeviceKeyRelease(d, type, class) \
    FindTypeAndClass(d, type, class, KeyClass, _deviceKeyRelease)

#define DeviceButtonPress(d, type, class) \
    FindTypeAndClass(d, type, class, ButtonClass, _deviceButtonPress)

#define DeviceButtonRelease(d, type, class) \
    FindTypeAndClass(d, type, class, ButtonClass, _deviceButtonRelease)

#define DeviceMotionNotify(d, type, class) \
    FindTypeAndClass(d, type, class, ValuatorClass, _deviceMotionNotify)

#define DeviceFocusIn(d, type, class) \
    FindTypeAndClass(d, type, class, FocusClass, _deviceFocusIn)

#define DeviceFocusOut(d, type, class) \
    FindTypeAndClass(d, type, class, FocusClass, _deviceFocusOut)

#define ProximityIn(d, type, class) \
    FindTypeAndClass(d, type, class, ProximityClass, _proximityIn)

#define ProximityOut(d, type, class) \
    FindTypeAndClass(d, type, class, ProximityClass, _proximityOut)

#define DeviceStateNotify(d, type, class) \
    FindTypeAndClass(d, type, class, OtherClass, _deviceStateNotify)

#define DeviceMappingNotify(d, type, class) \
    FindTypeAndClass(d, type, class, OtherClass, _deviceMappingNotify)

#define ChangeDeviceNotify(d, type, class) \
    FindTypeAndClass(d, type, class, OtherClass, _changeDeviceNotify)

#define DevicePointerMotionHint(d, type, class) \
    { class =  ((XDevice *) d)->device_id << 8 | _devicePointerMotionHint;}

#define DeviceButton1Motion(d, type, class) \
    { class =  ((XDevice *) d)->device_id << 8 | _deviceButton1Motion;}

#define DeviceButton2Motion(d, type, class) \
    { class =  ((XDevice *) d)->device_id << 8 | _deviceButton2Motion;}

#define DeviceButton3Motion(d, type, class) \
    { class =  ((XDevice *) d)->device_id << 8 | _deviceButton3Motion;}

#define DeviceButton4Motion(d, type, class) \
    { class =  ((XDevice *) d)->device_id << 8 | _deviceButton4Motion;}

#define DeviceButton5Motion(d, type, class) \
    { class =  ((XDevice *) d)->device_id << 8 | _deviceButton5Motion;}

#define DeviceButtonMotion(d, type, class) \
    { class =  ((XDevice *) d)->device_id << 8 | _deviceButtonMotion;}

#define DeviceOwnerGrabButton(d, type, class) \
    { class =  ((XDevice *) d)->device_id << 8 | _deviceOwnerGrabButton;}

#define DeviceButtonPressGrab(d, type, class) \
    { class =  ((XDevice *) d)->device_id << 8 | _deviceButtonGrab;}

#define NoExtensionEvent(d, type, class) \
    { class =  ((XDevice *) d)->device_id << 8 | _noExtensionEvent;}

#define BadDevice(dpy, error) _xibaddevice(dpy, &error)

#define BadClass(dpy, error) _xibadclass(dpy, &error)

#define BadEvent(dpy, error) _xibadevent(dpy, &error)

#define BadMode(dpy, error) _xibadmode(dpy, &error)

#define DeviceBusy(dpy, error) _xidevicebusy(dpy, &error)

/***************************************************************
 *
 * DeviceKey events.  These events are sent by input devices that
 * support input class Keys.
 * The location of the X pointer is reported in the coordinate
 * fields of the x,y and x_root,y_root fields.
 *
 */

typedef struct
    {
    int            type;         /* of event */
    unsigned long  serial;       /* # of last request processed */
    Bool           send_event;   /* true if from SendEvent request */
    Display        *display;     /* Display the event was read from */
    Window         window;       /* "event" window reported relative to */
    XID            deviceid;
    Window         root;         /* root window event occurred on */
    Window         subwindow;    /* child window */
    Time           time;         /* milliseconds */
    int            x, y;         /* x, y coordinates in event window */
    int            x_root;       /* coordinates relative to root */
    int            y_root;       /* coordinates relative to root */
    unsigned int   state;        /* key or button mask */
    unsigned int   keycode;      /* detail */
    Bool           same_screen;  /* same screen flag */
    unsigned int   device_state; /* device key or button mask */
    unsigned char  axes_count;
    unsigned char  first_axis;
    int            axis_data[6];
    } XDeviceKeyEvent;

typedef XDeviceKeyEvent XDeviceKeyPressedEvent;
typedef XDeviceKeyEvent XDeviceKeyReleasedEvent;

/*******************************************************************
 *
 * DeviceButton events.  These events are sent by extension devices
 * that support input class Buttons.
 *
 */

typedef struct {
    int           type;         /* of event */
    unsigned long serial;       /* # of last request processed by server */
    Bool          send_event;   /* true if from a SendEvent request */
    Display       *display;     /* Display the event was read from */
    Window        window;       /* "event" window reported relative to */
    XID           deviceid;
    Window        root;         /* root window that the event occurred on */
    Window        subwindow;    /* child window */
    Time          time;         /* milliseconds */
    int           x, y;         /* x, y coordinates in event window */
    int           x_root;       /* coordinates relative to root */
    int           y_root;       /* coordinates relative to root */
    unsigned int  state;        /* key or button mask */
    unsigned int  button;       /* detail */
    Bool          same_screen;  /* same screen flag */
    unsigned int  device_state; /* device key or button mask */
    unsigned char axes_count;
    unsigned char first_axis;
    int           axis_data[6];
    } XDeviceButtonEvent;

typedef XDeviceButtonEvent XDeviceButtonPressedEvent;
typedef XDeviceButtonEvent XDeviceButtonReleasedEvent;

/*******************************************************************
 *
 * DeviceMotionNotify event.  These events are sent by extension devices
 * that support input class Valuators.
 *
 */

typedef struct
    {
    int           type;        /* of event */
    unsigned long serial;      /* # of last request processed by server */
    Bool          send_event;  /* true if from a SendEvent request */
    Display       *display;    /* Display the event was read from */
    Window        window;      /* "event" window reported relative to */
    XID           deviceid;
    Window        root;        /* root window that the event occurred on */
    Window        subwindow;   /* child window */
    Time          time;        /* milliseconds */
    int           x, y;        /* x, y coordinates in event window */
    int           x_root;      /* coordinates relative to root */
    int           y_root;      /* coordinates relative to root */
    unsigned int  state;       /* key or button mask */
    char          is_hint;     /* detail */
    Bool          same_screen; /* same screen flag */
    unsigned int  device_state; /* device key or button mask */
    unsigned char axes_count;
    unsigned char first_axis;
    int           axis_data[6];
    } XDeviceMotionEvent;

/*******************************************************************
 *
 * DeviceFocusChange events.  These events are sent when the focus
 * of an extension device that can be focused is changed.
 *
 */

typedef struct
    {
    int           type;       /* of event */
    unsigned long serial;     /* # of last request processed by server */
    Bool          send_event; /* true if from a SendEvent request */
    Display       *display;   /* Display the event was read from */
    Window        window;     /* "event" window reported relative to */
    XID           deviceid;
    int           mode;       /* NotifyNormal, NotifyGrab, NotifyUngrab */
    int           detail;
     /*
      * NotifyAncestor, NotifyVirtual, NotifyInferior,
      * NotifyNonLinear,NotifyNonLinearVirtual, NotifyPointer,
      * NotifyPointerRoot, NotifyDetailNone
      */
    Time                time;
    } XDeviceFocusChangeEvent;

typedef XDeviceFocusChangeEvent XDeviceFocusInEvent;
typedef XDeviceFocusChangeEvent XDeviceFocusOutEvent;

/*******************************************************************
 *
 * ProximityNotify events.  These events are sent by those absolute
 * positioning devices that are capable of generating proximity information.
 *
 */

typedef struct
    {
    int             type;      /* ProximityIn or ProximityOut */
    unsigned long   serial;    /* # of last request processed by server */
    Bool            send_event; /* true if this came from a SendEvent request */
    Display         *display;  /* Display the event was read from */
    Window          window;
    XID                 deviceid;
    Window          root;
    Window          subwindow;
    Time            time;
    int             x, y;
    int             x_root, y_root;
    unsigned int    state;
    Bool            same_screen;
    unsigned int    device_state; /* device key or button mask */
    unsigned char   axes_count;
    unsigned char   first_axis;
    int             axis_data[6];
    } XProximityNotifyEvent;
typedef XProximityNotifyEvent XProximityInEvent;
typedef XProximityNotifyEvent XProximityOutEvent;

/*******************************************************************
 *
 * DeviceStateNotify events are generated on EnterWindow and FocusIn
 * for those clients who have selected DeviceState.
 *
 */

typedef struct
    {
    unsigned char     class;
    unsigned char     length;
    } XInputClass;

typedef struct {
    int           type;
    unsigned long serial;       /* # of last request processed by server */
    Bool          send_event;   /* true if this came from a SendEvent request */
    Display       *display;     /* Display the event was read from */
    Window        window;
    XID           deviceid;
    Time          time;
    int           num_classes;
    char       data[64];
} XDeviceStateNotifyEvent;

typedef struct {
    unsigned char     class;
    unsigned char     length;
    unsigned char     num_valuators;
    unsigned char     mode;
    int                  valuators[6];
} XValuatorStatus;

typedef struct {
    unsigned char     class;
    unsigned char     length;
    short          num_keys;
    char             keys[32];
} XKeyStatus;

typedef struct {
    unsigned char     class;
    unsigned char     length;
    short          num_buttons;
    char             buttons[32];
} XButtonStatus;

/*******************************************************************
 *
 * DeviceMappingNotify event.  This event is sent when the key mapping,
 * modifier mapping, or button mapping of an extension device is changed.
 *
 */

typedef struct {
    int           type;
    unsigned long serial;       /* # of last request processed by server */
    Bool          send_event;   /* true if this came from a SendEvent request */
    Display       *display;     /* Display the event was read from */
    Window        window;       /* unused */
    XID           deviceid;
    Time          time;
    int           request;      /* one of MappingModifier, MappingKeyboard,
                                    MappingPointer */
    int           first_keycode;/* first keycode */
    int           count;        /* defines range of change w. first_keycode*/
} XDeviceMappingEvent;

/*******************************************************************
 *
 * ChangeDeviceNotify event.  This event is sent when an
 * XChangeKeyboard or XChangePointer request is made.
 *
 */

typedef struct {
    int           type;
    unsigned long serial;       /* # of last request processed by server */
    Bool          send_event;   /* true if this came from a SendEvent request */
    Display       *display;     /* Display the event was read from */
    Window        window;       /* unused */
    XID           deviceid;
    Time          time;
    int           request;      /* NewPointer or NewKeyboard */
} XChangeDeviceNotifyEvent;

/*******************************************************************
 *
 * Control structures for input devices that support input class
 * Feedback.  These are used by the XGetFeedbackControl and
 * XChangeFeedbackControl functions.
 *
 */

typedef struct {
     XID            class;
     int            length;
     XID            id;
} XFeedbackState;

typedef struct {
    XID     class;
    int     length;
    XID     id;
    int     click;
    int     percent;
    int     pitch;
    int     duration;
    int     led_mask;
    int     global_auto_repeat;
    char    auto_repeats[32];
} XKbdFeedbackState;

typedef struct {
    XID     class;
    int     length;
    XID     id;
    int     accelNum;
    int     accelDenom;
    int     threshold;
} XPtrFeedbackState;

typedef struct {
    XID     class;
    int     length;
    XID     id;
    int     resolution;
    int     minVal;
    int     maxVal;
} XIntegerFeedbackState;

typedef struct {
    XID     class;
    int     length;
    XID     id;
    int     max_symbols;
    int     num_syms_supported;
    KeySym  *syms_supported;
} XStringFeedbackState;

typedef struct {
    XID     class;
    int     length;
    XID     id;
    int     percent;
    int     pitch;
    int     duration;
} XBellFeedbackState;

typedef struct {
    XID     class;
    int     length;
    XID     id;
    int     led_values;
    int     led_mask;
} XLedFeedbackState;

typedef struct {
     XID            class;
     int            length;
     XID         id;
} XFeedbackControl;

typedef struct {
    XID     class;
    int     length;
    XID     id;
    int     accelNum;
    int     accelDenom;
    int     threshold;
} XPtrFeedbackControl;

typedef struct {
    XID     class;
    int     length;
    XID     id;
    int     click;
    int     percent;
    int     pitch;
    int     duration;
    int     led_mask;
    int     led_value;
    int     key;
    int     auto_repeat_mode;
} XKbdFeedbackControl;

typedef struct {
    XID     class;
    int     length;
    XID     id;
    int     num_keysyms;
    KeySym  *syms_to_display;
} XStringFeedbackControl;

typedef struct {
    XID     class;
    int     length;
    XID     id;
    int     int_to_display;
} XIntegerFeedbackControl;

typedef struct {
    XID     class;
    int     length;
    XID     id;
    int     percent;
    int     pitch;
    int     duration;
} XBellFeedbackControl;

typedef struct {
    XID     class;
    int     length;
    XID     id;
    int     led_mask;
    int     led_values;
} XLedFeedbackControl;

/*******************************************************************
 *
 * Device control structures.
 *
 */

typedef struct {
     XID            control;
     int            length;
} XDeviceControl;

typedef struct {
     XID            control;
     int            length;
     int            first_valuator;
     int            num_valuators;
     int            *resolutions;
} XDeviceResolutionControl;

typedef struct {
     XID            control;
     int            length;
     int            num_valuators;
     int            *resolutions;
     int            *min_resolutions;
     int            *max_resolutions;
} XDeviceResolutionState;

/*******************************************************************
 *
 * An array of XDeviceList structures is returned by the
 * XListInputDevices function.  Each entry contains information
 * about one input device.  Among that information is an array of
 * pointers to structures that describe the characteristics of
 * the input device.
 *
 */

typedef struct _XAnyClassinfo *XAnyClassPtr;

typedef struct _XAnyClassinfo {
    XID      class;
    int      length;
    } XAnyClassInfo;

typedef struct _XDeviceInfo *XDeviceInfoPtr;

typedef struct _XDeviceInfo
    {
    XID                 id;
    Atom                type;
    char                *name;
    int                 num_classes;
    int                 use;
    XAnyClassPtr      inputclassinfo;
    } XDeviceInfo;

typedef struct _XKeyInfo *XKeyInfoPtr;

typedef struct _XKeyInfo
    {
    XID               class;
    int               length;
    unsigned short      min_keycode;
    unsigned short      max_keycode;
    unsigned short      num_keys;
    } XKeyInfo;

typedef struct _XButtonInfo *XButtonInfoPtr;

typedef struct _XButtonInfo {
    XID          class;
    int          length;
    short      num_buttons;
    } XButtonInfo;

typedef struct _XAxisInfo *XAxisInfoPtr;

typedef struct _XAxisInfo {
    int      resolution;
    int      min_value;
    int      max_value;
    } XAxisInfo;

typedef struct _XValuatorInfo *XValuatorInfoPtr;

typedef struct     _XValuatorInfo
    {
    XID               class;
    int               length;
    unsigned char       num_axes;
    unsigned char       mode;
    unsigned long       motion_buffer;
    XAxisInfoPtr        axes;
    } XValuatorInfo;


/*******************************************************************
 *
 * An XDevice structure is returned by the XOpenDevice function.
 * It contains an array of pointers to XInputClassInfo structures.
 * Each contains information about a class of input supported by the
 * device, including a pointer to an array of data for each type of event
 * the device reports.
 *
 */


typedef struct {
        unsigned char   input_class;
        unsigned char   event_type_base;
} XInputClassInfo;

typedef struct {
        XID                    device_id;
        int                    num_classes;
        XInputClassInfo        *classes;
} XDevice;


/*******************************************************************
 *
 * The following structure is used to return information for the
 * XGetSelectedExtensionEvents function.
 *
 */

typedef struct {
        XEventClass     event_type;
        XID             device;
} XEventList;

/*******************************************************************
 *
 * The following structure is used to return motion history data from
 * an input device that supports the input class Valuators.
 * This information is returned by the XGetDeviceMotionEvents function.
 *
 */

typedef struct {
        Time   time;
        int    *data;
} XDeviceTimeCoord;


/*******************************************************************
 *
 * Device state structure.
 * This is returned by the XQueryDeviceState request.
 *
 */

typedef struct {
        XID          device_id;
        int          num_classes;
        XInputClass     *data;
} XDeviceState;

/*******************************************************************
 *
 * Note that the mode field is a bitfield that reports the Proximity
 * status of the device as well as the mode.  The mode field should
 * be OR'd with the mask DeviceMode and compared with the values
 * Absolute and Relative to determine the mode, and should be OR'd
 * with the mask ProximityState and compared with the values InProximity
 * and OutOfProximity to determine the proximity state.
 *
 */

typedef struct {
    unsigned char     class;
    unsigned char     length;
    unsigned char     num_valuators;
    unsigned char     mode;
    int                  *valuators;
} XValuatorState;

typedef struct {
    unsigned char     class;
    unsigned char     length;
    short          num_keys;
    char             keys[32];
} XKeyState;

typedef struct {
    unsigned char     class;
    unsigned char     length;
    short          num_buttons;
    char             buttons[32];
} XButtonState;

/*******************************************************************
 *
 * Function definitions.
 *
 */

_XFUNCPROTOBEGIN

extern int     XChangeKeyboardDevice(
#if NeedFunctionPrototypes
    Display*          /* display */,
    XDevice*          /* device */
#endif
);

extern int     XChangePointerDevice(
#if NeedFunctionPrototypes
    Display*          /* display */,
    XDevice*          /* device */,
    int               /* xaxis */,
    int               /* yaxis */
#endif
);

extern int     XGrabDevice(
#if NeedFunctionPrototypes
    Display*          /* display */,
    XDevice*          /* device */,
    Window          /* grab_window */,
    Bool          /* ownerEvents */,
    int               /* event count */,
    XEventClass*     /* event_list */,
    int               /* this_device_mode */,
    int               /* other_devices_mode */,
    Time          /* time */
#endif
);

extern int     XUngrabDevice(
#if NeedFunctionPrototypes
    Display*          /* display */,
    XDevice*          /* device */,
    Time           /* time */
#endif
);

extern int     XGrabDeviceKey(
#if NeedFunctionPrototypes
    Display*          /* display */,
    XDevice*          /* device */,
    unsigned int     /* key */,
    unsigned int     /* modifiers */,
    XDevice*          /* modifier_device */,
    Window          /* grab_window */,
    Bool          /* owner_events */,
    unsigned int     /* event_count */,
    XEventClass*     /* event_list */,
    int               /* this_device_mode */,
    int               /* other_devices_mode */
#endif
);

extern int     XUngrabDeviceKey(
#if NeedFunctionPrototypes
    Display*          /* display */,
    XDevice*          /* device */,
    unsigned int     /* key */,
    unsigned int     /* modifiers */,
    XDevice*          /* modifier_dev */,
    Window          /* grab_window */
#endif
);

extern int     XGrabDeviceButton(
#if NeedFunctionPrototypes
    Display*          /* display */,
    XDevice*          /* device */,
    unsigned int     /* button */,
    unsigned int     /* modifiers */,
    XDevice*          /* modifier_device */,
    Window          /* grab_window */,
    Bool          /* owner_events */,
    unsigned int     /* event_count */,
    XEventClass*     /* event_list */,
    int               /* this_device_mode */,
    int               /* other_devices_mode */
#endif
);

extern int     XUngrabDeviceButton(
#if NeedFunctionPrototypes
    Display*          /* display */,
    XDevice*          /* device */,
    unsigned int     /* button */,
    unsigned int     /* modifiers */,
    XDevice*          /* modifier_dev */,
    Window          /* grab_window */
#endif
);

extern int     XAllowDeviceEvents(
#if NeedFunctionPrototypes
    Display*          /* display */,
    XDevice*          /* device */,
    int               /* event_mode */,
    Time          /* time */
#endif
);

extern int     XGetDeviceFocus(
#if NeedFunctionPrototypes
    Display*          /* display */,
    XDevice*          /* device */,
    Window*          /* focus */,
    int*          /* revert_to */,
    Time*          /* time */
#endif
);

extern int     XSetDeviceFocus(
#if NeedFunctionPrototypes
    Display*          /* display */,
    XDevice*          /* device */,
    Window          /* focus */,
    int               /* revert_to */,
    Time          /* time */
#endif
);

extern XFeedbackState     *XGetFeedbackControl(
#if NeedFunctionPrototypes
    Display*          /* display */,
    XDevice*          /* device */,
    int*          /* num_feedbacks */
#endif
);

extern int     XFreeFeedbackList(
#if NeedFunctionPrototypes
    XFeedbackState*     /* list */
#endif
);

extern int     XChangeFeedbackControl(
#if NeedFunctionPrototypes
    Display*          /* display */,
    XDevice*          /* device */,
    unsigned long     /* mask */,
    XFeedbackControl*     /* f */
#endif
);

extern int     XDeviceBell(
#if NeedFunctionPrototypes
    Display*          /* display */,
    XDevice*          /* device */,
    XID               /* feedbackclass */,
    XID               /* feedbackid */,
    int               /* percent */
#endif
);

extern KeySym     *XGetDeviceKeyMapping(
#if NeedFunctionPrototypes
    Display*          /* display */,
    XDevice*          /* device */,
#if NeedWidePrototypes
    unsigned int     /* first */,
#else
    KeyCode          /* first */,
#endif
    int               /* keycount */,
    int*          /* syms_per_code */
#endif
);

extern int     XChangeDeviceKeyMapping(
#if NeedFunctionPrototypes
    Display*          /* display */,
    XDevice*          /* device */,
    int               /* first */,
    int               /* syms_per_code */,
    KeySym*          /* keysyms */,
    int               /* count */
#endif
);

extern XModifierKeymap     *XGetDeviceModifierMapping(
#if NeedFunctionPrototypes
    Display*          /* display */,
    XDevice*          /* device */
#endif
);

extern int     XSetDeviceModifierMapping(
#if NeedFunctionPrototypes
    Display*          /* display */,
    XDevice*          /* device */,
    XModifierKeymap*     /* modmap */
#endif
);

extern int     XSetDeviceButtonMapping(
#if NeedFunctionPrototypes
    Display*          /* display */,
    XDevice*          /* device */,
    unsigned char*     /* map[] */,
    int               /* nmap */
#endif
);

extern int     XGetDeviceButtonMapping(
#if NeedFunctionPrototypes
    Display*          /* display */,
    XDevice*          /* device */,
    unsigned char*     /* map[] */,
    unsigned int     /* nmap */
#endif
);

extern XDeviceState     *XQueryDeviceState(
#if NeedFunctionPrototypes
    Display*          /* display */,
    XDevice*          /* device */
#endif
);

extern int     XFreeDeviceState(
#if NeedFunctionPrototypes
    XDeviceState*     /* list */
#endif
);

extern XExtensionVersion *XGetExtensionVersion(
#if NeedFunctionPrototypes
    Display*          /* display */,
    _Xconst char*     /* name */
#endif
);

extern XDeviceInfo     *XListInputDevices(
#if NeedFunctionPrototypes
    Display*          /* display */,
    int*          /* ndevices */
#endif
);

extern int     XFreeDeviceList(
#if NeedFunctionPrototypes
    XDeviceInfo*     /* list */
#endif
);

extern XDevice     *XOpenDevice(
#if NeedFunctionPrototypes
    Display*          /* display */,
    XID               /* id */
#endif
);

extern int     XCloseDevice(
#if NeedFunctionPrototypes
    Display*          /* display */,
    XDevice*          /* device */
#endif
);

extern int     XSetDeviceMode(
#if NeedFunctionPrototypes
    Display*          /* display */,
    XDevice*          /* device */,
    int               /* mode */
#endif
);

extern int     XSetDeviceValuators(
#if NeedFunctionPrototypes
    Display*          /* display */,
    XDevice*          /* device */,
    int*          /* valuators */,
    int               /* first_valuator */,
    int               /* num_valuators */
#endif
);

extern XDeviceControl     *XGetDeviceControl(
#if NeedFunctionPrototypes
    Display*          /* display */,
    XDevice*          /* device */,
    int               /* control */
#endif
);

extern int     XChangeDeviceControl(
#if NeedFunctionPrototypes
    Display*          /* display */,
    XDevice*          /* device */,
    int               /* control */,
    XDeviceControl*     /* d */
#endif
);

extern int     XSelectExtensionEvent(
#if NeedFunctionPrototypes
    Display*          /* display */,
    Window          /* w */,
    XEventClass*     /* event_list */,
    int               /* count */
#endif
);

extern int     XGetSelectedExtensionEvents(
#if NeedFunctionPrototypes
    Display*          /* display */,
    Window          /* w */,
    int*          /* this_client_count */,
    XEventClass**     /* this_client_list */,
    int*          /* all_clients_count */,
    XEventClass**     /* all_clients_list */
#endif
);

extern int     XChangeDeviceDontPropagateList(
#if NeedFunctionPrototypes
    Display*          /* display */,
    Window          /* window */,
    int               /* count */,
    XEventClass*     /* events */,
    int               /* mode */
#endif
);

extern XEventClass     *XGetDeviceDontPropagateList(
#if NeedFunctionPrototypes
    Display*          /* display */,
    Window          /* window */,
    int*          /* count */
#endif
);

extern Status     XSendExtensionEvent(
#if NeedFunctionPrototypes
    Display*          /* display */,
    XDevice*          /* device */,
    Window          /* dest */,
    Bool          /* prop */,
    int               /* count */,
    XEventClass*     /* list */,
    XEvent*          /* event */
#endif
);

extern XDeviceTimeCoord     *XGetDeviceMotionEvents(
#if NeedFunctionPrototypes
    Display*          /* display */,
    XDevice*          /* device */,
    Time          /* start */,
    Time          /* stop */,
    int*          /* nEvents */,
    int*          /* mode */,
    int*          /* axis_count */
#endif
);

extern int     XFreeDeviceMotionEvents(
#if NeedFunctionPrototypes
    XDeviceTimeCoord*     /* events */
#endif
);

extern int     XFreeDeviceControl(
#if NeedFunctionPrototypes
    XDeviceControl*     /* control */
#endif
);

_XFUNCPROTOEND

#endif /* _XINPUT_H_ */

/* Definitions used by the server, library and client */

#ifndef _XI_H_

#define _XI_H_

#define sz_xGetExtensionVersionReq          8
#define sz_xGetExtensionVersionReply          32
#define sz_xListInputDevicesReq               4
#define sz_xListInputDevicesReply          32
#define sz_xOpenDeviceReq               8
#define sz_xOpenDeviceReply               32
#define sz_xCloseDeviceReq               8
#define sz_xSetDeviceModeReq               8
#define sz_xSetDeviceModeReply               32
#define sz_xSelectExtensionEventReq          12
#define sz_xGetSelectedExtensionEventsReq     8
#define sz_xGetSelectedExtensionEventsReply     32
#define sz_xChangeDeviceDontPropagateListReq     12
#define sz_xGetDeviceDontPropagateListReq     8
#define sz_xGetDeviceDontPropagateListReply     32
#define sz_xGetDeviceMotionEventsReq          16
#define sz_xGetDeviceMotionEventsReply          32
#define sz_xChangeKeyboardDeviceReq          8
#define sz_xChangeKeyboardDeviceReply          32
#define sz_xChangePointerDeviceReq          8
#define sz_xChangePointerDeviceReply          32
#define sz_xGrabDeviceReq               20
#define sz_xGrabDeviceReply               32
#define sz_xUngrabDeviceReq               12
#define sz_xGrabDeviceKeyReq               20
#define sz_xGrabDeviceKeyReply               32
#define sz_xUngrabDeviceKeyReq               16
#define sz_xGrabDeviceButtonReq               20
#define sz_xGrabDeviceButtonReply          32
#define sz_xUngrabDeviceButtonReq          16
#define sz_xAllowDeviceEventsReq          12
#define sz_xGetDeviceFocusReq               8
#define sz_xGetDeviceFocusReply               32
#define sz_xSetDeviceFocusReq               16
#define sz_xGetFeedbackControlReq          8
#define sz_xGetFeedbackControlReply          32
#define sz_xChangeFeedbackControlReq          12
#define sz_xGetDeviceKeyMappingReq          8
#define sz_xGetDeviceKeyMappingReply          32
#define sz_xChangeDeviceKeyMappingReq          8
#define sz_xGetDeviceModifierMappingReq          8
#define sz_xSetDeviceModifierMappingReq          8
#define sz_xSetDeviceModifierMappingReply     32
#define sz_xGetDeviceButtonMappingReq          8
#define sz_xGetDeviceButtonMappingReply          32
#define sz_xSetDeviceButtonMappingReq          8
#define sz_xSetDeviceButtonMappingReply          32
#define sz_xQueryDeviceStateReq               8
#define sz_xQueryDeviceStateReply          32
#define sz_xSendExtensionEventReq          16
#define sz_xDeviceBellReq               8
#define sz_xSetDeviceValuatorsReq          8
#define sz_xSetDeviceValuatorsReply          32
#define sz_xGetDeviceControlReq               8
#define sz_xGetDeviceControlReply          32
#define sz_xChangeDeviceControlReq          8
#define sz_xChangeDeviceControlReply          32

#define INAME                "XInputExtension"

#define XI_KEYBOARD     "KEYBOARD"
#define XI_MOUSE     "MOUSE"
#define XI_TABLET     "TABLET"
#define XI_TOUCHSCREEN     "TOUCHSCREEN"
#define XI_TOUCHPAD     "TOUCHPAD"
#define XI_BARCODE     "BARCODE"
#define XI_BUTTONBOX     "BUTTONBOX"
#define XI_KNOB_BOX     "KNOB_BOX"
#define XI_ONE_KNOB     "ONE_KNOB"
#define XI_NINE_KNOB     "NINE_KNOB"
#define XI_TRACKBALL     "TRACKBALL"
#define XI_QUADRATURE     "QUADRATURE"
#define XI_ID_MODULE     "ID_MODULE"
#define XI_SPACEBALL     "SPACEBALL"
#define XI_DATAGLOVE     "DATAGLOVE"
#define XI_EYETRACKER     "EYETRACKER"
#define XI_CURSORKEYS     "CURSORKEYS"
#define XI_FOOTMOUSE     "FOOTMOUSE"

#define Dont_Check               0
#define XInput_Initial_Release          1
#define XInput_Add_XDeviceBell          2
#define XInput_Add_XSetDeviceValuators     3
#define XInput_Add_XChangeDeviceControl     4

#define XI_Absent          0
#define XI_Present          1

#define XI_Initial_Release_Major          1
#define XI_Initial_Release_Minor          0

#define XI_Add_XDeviceBell_Major          1
#define XI_Add_XDeviceBell_Minor          1

#define XI_Add_XSetDeviceValuators_Major     1
#define XI_Add_XSetDeviceValuators_Minor     2

#define XI_Add_XChangeDeviceControl_Major     1
#define XI_Add_XChangeDeviceControl_Minor     3

#define DEVICE_RESOLUTION     1

#define NoSuchExtension          1

#define COUNT               0
#define CREATE               1

#define NewPointer          0
#define NewKeyboard          1

#define XPOINTER          0
#define XKEYBOARD          1

#define UseXKeyboard          0xFF

#define IsXPointer          0
#define IsXKeyboard          1
#define IsXExtensionDevice     2

#define AsyncThisDevice          0
#define SyncThisDevice          1
#define ReplayThisDevice     2
#define AsyncOtherDevices     3
#define AsyncAll          4
#define SyncAll               5

#define FollowKeyboard           3
#define RevertToFollowKeyboard      3

#define DvAccelNum              (1L << 0)
#define DvAccelDenom            (1L << 1)
#define DvThreshold             (1L << 2)

#define DvKeyClickPercent     (1L<<0)
#define DvPercent          (1L<<1)
#define DvPitch               (1L<<2)
#define DvDuration          (1L<<3)
#define DvLed               (1L<<4)
#define DvLedMode          (1L<<5)
#define DvKey               (1L<<6)
#define DvAutoRepeatMode     (1L<<7)

#define DvString                (1L << 0)

#define DvInteger               (1L << 0)

#define DeviceMode              (1L << 0)
#define Relative                0
#define Absolute                1

#define ProximityState          (1L << 1)
#define InProximity             (0L << 1)
#define OutOfProximity          (1L << 1)

#define AddToList               0
#define DeleteFromList          1

#define KeyClass            0
#define ButtonClass            1
#define ValuatorClass            2
#define FeedbackClass            3
#define ProximityClass       4
#define FocusClass            5
#define OtherClass            6

#define KbdFeedbackClass       0
#define PtrFeedbackClass       1
#define StringFeedbackClass       2
#define IntegerFeedbackClass       3
#define LedFeedbackClass       4
#define BellFeedbackClass       5

#define _devicePointerMotionHint 0
#define _deviceButton1Motion      1
#define _deviceButton2Motion      2
#define _deviceButton3Motion      3
#define _deviceButton4Motion      4
#define _deviceButton5Motion      5
#define _deviceButtonMotion      6
#define _deviceButtonGrab      7
#define _deviceOwnerGrabButton      8
#define _noExtensionEvent      9

#define XI_BadDevice     0
#define XI_BadEvent     1
#define XI_BadMode     2
#define XI_DeviceBusy     3
#define XI_BadClass     4

typedef     unsigned long     XEventClass;

/*******************************************************************
 *
 * Extension version structure.
 *
 */

typedef struct {
        int        present;
        short     major_version;
        short     minor_version;
} XExtensionVersion;

#endif /* _XI_H_ */


Appendix A. Input Extension Protocol Encoding

Syntactic Conventions

All numbers are in decimal, unless prefixed with #x, in which case they are in
hexadecimal (base 16).

The general syntax used to describe requests, replies, errors, events, and
compound types is:

NameofThing
  encode-form
  ...
  encode-form

Each encode-form describes a single component.

For components described in the protocol as:

name: TYPE

the encode-form is:



N       TYPE    name

N is the number of bytes occupied in the data stream, and TYPE is the
interpretation of those bytes. For example,



depth: CARD8

becomes:



1       CARD8   depth

For components with a static numeric value the encode-form is:



N       value   name

The value is always interpreted as an N-byte unsigned integer. For example, the
first two bytes of a Window error are always zero (indicating an error in
general) and three (indicating the Window error in particular):



1       0       Error
1       3       code

For components described in the protocol as:

name: {Name1, ..., NameI}

the encode-form is:



N               name
        value1 Name1
        ...
        valueI NameI

The value is always interpreted as an N-byte unsigned integer. Note that the
size of N is sometimes larger than that strictly required to encode the values.
For example:

class: {InputOutput, InputOnly, CopyFromParent}

becomes:



2                       class
        0       CopyFromParent
        1       InputOutput
        2       InputOnly

For components described in the protocol as:

NAME: TYPE or Alternative1 ... or AlternativeI

the encode-form is:



N       TYPE                    NAME
        value1  Alternative1
        ...
        valueI  AlternativeI

The alternative values are guaranteed not to conflict with the encoding of
TYPE. For example:

destination: WINDOW or PointerWindow or InputFocus

becomes:



4       WINDOW          destination
        0       PointerWindow
        1       InputFocus

For components described in the protocol as:



value-mask: BITMASK

the encode-form is:



N       BITMASK                 value-mask
        mask1   mask-name1
        ...
        maskI   mask-nameI

The individual bits in the mask are specified and named, and N is 2 or 4. The
most-significant bit in a BITMASK is reserved for use in defining chained
(multiword) bitmasks, as extensions augment existing core requests. The precise
interpretation of this bit is not yet defined here, although a probable
mechanism is that a 1-bit indicates that another N bytes of bitmask follows,
with bits within the overall mask still interpreted from least-significant to
most-significant with an N-byte unit, with N-byte units interpreted in stream
order, and with the overall mask being byte-swapped in individual N-byte units.

For LISTofVALUE encodings, the request is followed by a section of the form:



VALUEs
 encode-form
 ...
 encode-form

listing an encode-form for each VALUE. The NAME in each encode-form keys to the
corresponding BITMASK bit. The encoding of a VALUE always occupies four bytes,
but the number of bytes specified in the encoding-form indicates how many of
the least-significant bytes are actually used; the remaining bytes are unused
and their values do not matter.

In various cases, the number of bytes occupied by a component will be specified
by a lowercase single-letter variable name instead of a specific numeric value,
and often some other component will have its value specified as a simple
numeric expression involving these variables. Components specified with such
expressions are always interpreted as unsigned integers. The scope of such
variables is always just the enclosing request, reply, error, event, or
compound type structure. For example:



2       3+n                     request length
4n      LISTofPOINT             points

For unused bytes (the values of the bytes are undefined and do not matter), the
encode-form is:



N                       unused

If the number of unused bytes is variable, the encode-form typically is:



p                       unused, p=pad(E)

where E is some expression, and pad(E) is the number of bytes needed to round E
up to a multiple of four.



pad(E) = (4 - (E mod 4)) mod 4

Common Types

LISTofFOO

  • In this document the LISTof notation strictly means some number of
    repetitions of the FOO encoding; the actual length of the list is encoded
    elsewhere.

SETofFOO

  • A set is always represented by a bitmask, with a 1-bit indicating presence
    in the set.

BITMASK: CARD32

WINDOW: CARD32

BYTE: 8-bit value

INT8: 8-bit signed integer

INT16: 16-bit signed integer

INT32: 32-bit signed integer

CARD8: 8-bit unsigned integer

CARD16: 16-bit unsigned integer

CARD32: 32-bit unsigned integer

TIMESTAMP: CARD32

EVENTCLASS: CARD32



INPUTCLASS
        0       KeyClass
        1       ButtonClass
        2       ValuatorClass
        3       FeedbackClass
        4       ProximityClass
        5       FocusClass
        6       OtherClass



INPUTCLASS
        0       KbdFeedbackClass
        1       PtrFeedbackClass
        2       StringFeedbackClass
        3       IntegerFeedbackClass
        4       LedFeedbackClass
        5       BellFeedbackClass



INPUTINFO
        0       KEYINFO
        1       BUTTONINFO
        2       VALUATORINFO



DEVICEMODE
        0       Relative
        1       Absolute



PROXIMITYSTATE
        0       InProximity
        1       OutOfProximity



BOOL
        0       False
        1       True

KEYSYM: CARD32

KEYCODE: CARD8

BUTTON: CARD8



SETofKEYBUTMASK
        #x0001  Shift
        #x0002  Lock
        #x0004  Control
        #x0008  Mod1
        #x0010  Mod2
        #x0020  Mod3
        #x0040  Mod4
        #x0080  Mod5
        #x0100  Button1
        #x0200  Button2
        #x0400  Button3
        #x0800  Button4
        #x1000  Button5
        #xe000  unused but must be zero



SETofKEYMASK
        encodings are the same as for SETofKEYBUTMASK, except with
        #xff00          unused but must be zero

STRING8: LISTofCARD8



STR
        1       n               length of name in bytes
        n       STRING8         name

Errors



Request
        1       0               Error
        1       1               code
        2       CARD16          sequence number
        4                       unused
        2       CARD16          minor opcode
        1       CARD8           major opcode
        21                      unused



Value
        1       0               Error
        1       2               code
        2       CARD16          sequence number
        4       <32-bits>               bad value
        2       CARD16          minor opcode
        1       CARD8           major opcode
        21                      unused



Window
        1       0               Error
        1       3               code
        2       CARD16          sequence number
        4       CARD32          bad resource id
        2       CARD16          minor opcode
        1       CARD8           major opcode
        21                      unused



Match
        1       0               Error
        1       8               code
        2       CARD16          sequence number
        4                       unused
        2       CARD16          minor opcode
        1       CARD8           major opcode
        21                      unused



Access
        1       0               Error
        1       10              code
        2       CARD16          sequence number
        4                       unused
        2       CARD16          minor opcode
        1       CARD8           major opcode
        21                      unused



Alloc
        1       0               Error
        1       11              code
        2       CARD16          sequence number
        4                       unused
        2       CARD16          minor opcode
        1       CARD8           major opcode
        21                      unused



Name
        1       0               Error
        1       15              code
        2       CARD16          sequence number
        4                       unused
        2       CARD16          minor opcode
        1       CARD8           major opcode
        21                      unused



Device
        1       0               Error
        1       CARD8           code
        2       CARD16          sequence number
        4                       unused
        2       CARD16          minor opcode
        1       CARD8           major opcode
        21                      unused



Event
        1       0               Error
        1       CARD8           code
        2       CARD16          sequence number
        4                       unused
        2       CARD16          minor opcode
        1       CARD8           major opcode
        21                      unused



Mode
        1       0               Error
        1       CARD8           code
        2       CARD16          sequence number
        4                       unused
        2       CARD16          minor opcode
        1       CARD8           major opcode
        21                      unused



Class
        1       0               Error
        1       CARD8           code
        2       CARD16          sequence number
        4                       unused
        2       CARD16          minor opcode
        1       CARD8           major opcode
        21                      unused

Keyboards

KEYCODE values are always greater than 7 (and less than 256).

KEYSYM values with the bit #x10000000 set are reserved as vendor-specific.

The names and encodings of the standard KEYSYM values are contained in appendix
F.

Pointers

BUTTON values are numbered starting with one.

Requests



GetExtensionVersion
        1       CARD8           input extension opcode
        1       1               GetExtensionVersion opcode
        2       2+(n+p)/4               request length
        2       n               length of name
        2                       unused
        n       STRING8         name
        p                       unused, p=pad(n)



 =>
        1       1               Reply
        1       1               GetExtensionVersion opcode
        2       CARD16          sequence number
        4       0               reply length
        2       CARD16          major version
        2       CARD16          minor version
        1       BOOL            present
        19                      unused



ListInputDevices
        1       CARD8           input extension opcode
        1       2               ListInputDevices opcode
        2       1               request length



 =>
        1       1                       Reply
        1       2                       ListInputDevices opcode
        2       CARD16                  sequence number
        4       (n+p)/4                 reply length
        1       CARD8                   number of input devices
        23                              unused
        n       LISTofDEVICEINFO        info for each input device
        p                               unused, p=pad(n)



  DEVICEINFO
        4       CARD32          device type
        1       CARD8           device id
        1       CARD8           number of input classes this device reports
        1       CARD8           device use
                        0       IsXPointer
                        1       IsXKeyboard
                        2       IsXExtensionDevice
        1                       unused
        n       LISTofINPUTINFO                 input info for each input class
        m       STR                     name
        p                               unused, p=pad(m)



  INPUTINFO     KEYINFO or BUTTONINFO or VALUATORINFO



  KEYINFO
        1       0               class id
        1       8               length
        1       KEYCODE         minimum keycode
        1       KEYCODE         maximum keycode
        2       CARD16          number of keys
        2                       unused



BUTTONINFO
        1       1               class id
        1       4               length
        2       CARD16          number of buttons



VALUATORINFO
        1       2               class id
        1       8+12n           length
        1       n               number of axes
        1       SETofDEVICEMODE                 mode
        4       CARD32          size of motion buffer
        12n     LISTofAXISINFO          valuator limits



AXISINFO
        4       CARD32          resolution
        4       CARD32          minimum value
        4       CARD32          maximum value



OpenDevice
        1       CARD8           input extension opcode
        1       3               OpenDevice opcode
        2       2               request length
        1       CARD8           device id
        3                       unused



 =>
        1       1                       Reply
        1       3                       OpenDevice opcode
        2       CARD16                  sequence number
        4       (n+p)/4                 reply length
        1       CARD8                   number of input classes
        23                              unused
        n       LISTofINPUTCLASSINFO    input class information
        p                               unused, p=pad(n)



  INPUTCLASSINFO
        1       CARD8           input class id
                0       KEY
                1       BUTTON
                2       VALUATOR
                3       FEEDBACK
                4       PROXIMITY
                5       FOCUS
                6       OTHER
        1       CARD8           event type base code for this class



CloseDevice
        1       CARD8           input extension opcode
        1       4               CloseDevice opcode
        2       2               request length
        1       CARD8           device id
        3                       unused



SetDeviceMode
        1       CARD8           input extension opcode
        1       5               SetDeviceMode opcode
        2       2               request length
        1       CARD8           device id
        1       CARD8           mode
        2                       unused



 =>
        1       1                       Reply
        1       5                       SetDeviceMode opcode
        2       CARD16                  sequence number
        4       0                       reply length
        1       CARD8                   status
                0               Success
                        1       AlreadyGrabbed
                3 + first_error DeviceBusy
        23                              unused



SelectExtensionEvent
        1       CARD8                   input extension opcode
        1       6                       SelectExtensionEvent opcode
        2       3+n                             request length
        4       Window                  event window
        2       CARD16                  count
        2                               unused
        4n      LISTofEVENTCLASS        desired events



GetSelectedExtensionEvents
        1       CARD8           input extension opcode
        1       7               GetSelectedExtensionEvents opcode
        2       2               request length
        4       Window          event window



 =>
        1       1               Reply
        1       7               GetSelecteExtensionEvents opcode
        2       CARD16          sequence number
        4       n + m           reply length
        2       n               this client count
        2       m               all clients count
        20                      unused
        4n      LISTofEVENTCLASS        this client list
        4m      LISTofEVENTCLASS        all clients list



ChangeDeviceDontPropagateList
        1       CARD8                   input extension opcode
        1       8                       ChangeDeviceDontPropagateList opcode
        2       3+n                             request length
        4       Window                  event window
        2       n                       count of events
        1       mode
                0       AddToList
                1       DeleteFromList
        1                               unused
        4n      LISTofEVENTCLASS        desired events



GetDeviceDontPropagateList
        1       CARD8           input extension opcode
        1       9               GetDeviceDontPropagateList opcode
        2       2               request length
        4       Window          event window



 =>
        1       1                       Reply
        1       9                       GetDeviceDontPropagateList opcode
        2       CARD16                  sequence number
        4       n                       reply length
        2       n                       count of events
        22                              unused
        4n      LISTofEVENTCLASS        don't propagate list



GetDeviceMotionEvents
        1       CARD8           input extension opcode
        1       10              GetDeviceMotionEvents opcode
        2       4               request length
        4       TIMESTAMP               start
                0       CurrentTime
        4       TIMESTAMP               stop
                0       CurrentTime
        1       CARD8           device id
        3                       unused



 =>
        1               1               Reply
        1               10      GetDeviceMotionEvents opcode
        2               CARD16  sequence number
        4               (m+1)n  reply length
        4               n               number of DEVICETIMECOORDs in events
        1               m               number of valuators per event
        1               CARD8           mode of the device
                        0       Absolute
                        1       Relative
        18                              unused
        (4m+4)n LISTofDEVICETIMECOORD   events



  DEVICETIMECOORD
        4       TIMESTAMP               time
        4m      LISTofINT32             valuators



ChangeKeyboardDevice
        1       CARD8           input extension opcode
        1       11              ChangeKeyboardDevice opcode
        2       2               request length
        1       CARD8           device id
        3                       unused



 =>
        1       1               Reply
        1       11              ChangeKeyboardDevice opcode
        2       CARD16          sequence number
        4       0               reply length
        1                       status
                0       Success
                1       AlreadyGrabbed
                2       DeviceFrozen
        23                      unused



ChangePointerDevice
        1       CARD8           input extension opcode
        1       12              ChangePointerDevice opcode
        2       2               request length
        1       CARD8           x-axis
        1       CARD8           y-axis
        1       CARD8           device id
        1                       unused



 =>
        1       1               Reply
        1       12              ChangePointerDevice opcode
        2       CARD16          sequence number
        4       0               reply length
        1                       status
                0       Success
                1       AlreadyGrabbed
                2       DeviceFrozen
        23                      unused



GrabDevice
        1       CARD8           input extension opcode
        1       13              GrabDevice opcode
        2       5+n                     request length
        4       WINDOW          grab-window
        4       TIMESTAMP               time
                0       CurrentTime
        2       n               count of events
        1                       this-device-mode
                0       Synchronous
                1       Asynchronous
        1                       other-devices-mode
                0       Synchronous
                1       Asynchronous
        1       BOOL            owner-events
        1       CARD8           device id
        2                       unused
        4n      LISTofEVENTCLASS        event list



 =>
        1       1               Reply
        1       13              GrabDevice opcode
        2       CARD16          sequence number
        4       0               reply length
        1                       status
                0       Success
                1       AlreadyGrabbed
                2       InvalidTime
                3       NotViewable
                4       Frozen
        23                      unused



UngrabDevice
        1       CARD8           input extension opcode
        1       14              UngrabDevice opcode
        2       3               request length
        4       TIMESTAMP               time
                0       CurrentTime
        1       CARD8           device id
        3                       unused



GrabDeviceKey
        1       CARD8           input extension opcode
        1       15              GrabDeviceKey opcode
        2       5+n             request length
        4       WINDOW          grab-window
        2       n               count of events
        2       SETofKEYMASK            modifiers
                #x8000  AnyModifier
        1       CARD8           modifier device
                #x0FF   UseXKeyboard
        1       CARD8           grabbed device
        1       KEYCODE                 key
                0       AnyKey
        1                       this-device-mode
                0       Synchronous
                1       Asynchronous
        1                       other-devices-mode
                0       Synchronous
                1       Asynchronous
        1       BOOL            owner-events
        2                       unused
        4n      LISTofEVENTCLASS        event list



UngrabDeviceKey
        1       CARD8           input extension opcode
        1       16              UngrabDeviceKey opcode
        2       4               request length
        4       WINDOW          grab-window
        2       SETofKEYMASK            modifiers
                #x8000  AnyModifier
        1       CARD8           modifier device
                #x0FF   UseXKeyboard
        1       KEYCODE                 key
                0       AnyKey
        1       CARD8           grabbed device
        3                       unused




GrabDeviceButton
        1       CARD8           input extension opcode
        1       17              GrabDeviceButton opcode
        2       5+n             request length
        4       WINDOW          grab-window
        1       CARD8           grabbed device
        1       CARD8           modifier device
                #x0FF   UseXKeyboard
        2       n               count of desired events
        2       SETofKEYMASK            modifiers
        1                       this-device-mode
                0       Synchronous
                1       Asynchronous
        1                       other-device-mode
                0       Synchronous
                1       Asynchronous
        1       BUTTON          button
                0       AnyButton
        1       BOOL            owner-events
                #x8000  AnyModifier
        2                       unused
        4n      LISTofEVENTCLASS        event list



UngrabDeviceButton
        1       CARD8           input extension opcode
        1       18              UngrabDeviceButton opcode
        2       4               request length
        4       WINDOW          grab-window
        2       SETofKEYMASK            modifiers
                #x8000  AnyModifier
        1       CARD8           modifier device
                #x0FF   UseXKeyboard
        1       BUTTON          button
                0       AnyButton
        1       CARD8           grabbed device
        3                       unused



AllowDeviceEvents
        1       CARD8           input extension opcode
        1       19              AllowDeviceEvents opcode
        2       3               request length
        4       TIMESTAMP               time
                0       CurrentTime
        1                       mode
                0       AsyncThisDevice
                1       SyncThisDevice
                2       ReplayThisDevice
                3       AsyncOtherDevices
                4       AsyncAll
                5       SyncAll
        1       CARD8           device id
        2                       unused



GetDeviceFocus
        1       CARD8           input extension opcode
        1       20              GetDeviceFocus opcode
        2       2               request length
        1       CARD8           device
        3                       unused



 =>
        1       1               Reply
        1       20              GetDeviceFocus opcode
        2       CARD16          sequence number
        4       0               reply length
        4       WINDOW          focus
                0       None
                1       PointerRoot
                3       FollowKeyboard
        4       TIMESTAMP       focus time
        1                       revert-to
                0       None
                1       PointerRoot
                2       Parent
                3       FollowKeyboard
        15                      unused



SetDeviceFocus
        1       CARD8           input extension opcode
        1       21              SetDeviceFocus opcode
        2       4               request length
        4       WINDOW          focus
                0       None
                1       PointerRoot
                3       FollowKeyboard
        4       TIMESTAMP               time
                0       CurrentTime
        1                       revert-to
                0       None
                1       PointerRoot
                2       Parent
                3       FollowKeyboard
        1       CARD8           device
        2                       unused



GetFeedbackControl
        1       CARD8           input extension opcode
        1       22              GetFeedbackControl opcode
        2       2               request length
        1       CARD8           device id
        3                       unused



 =>
        1       1               Reply
        1       22              GetFeedbackControl opcode
        2       CARD16          sequence number
        4       m/4                     reply length
        2       n               number of feedbacks supported
        22                      unused
        m       LISTofFEEDBACKSTATE     feedbacks



  FEEDBACKSTATE KBDFEEDBACKSTATE, PTRFEEDBACKSTATE, INTEGERFEEDBACKSTATE,
  STRINGFEEDBACKSTATE, BELLFEEDBACKSTATE, or LEDFEEDBACKSTATE



  KBDFEEDBACKSTATE
        1       0               feedback class id
        1       CARD8           id of this feedback
        2       20              length
        2       CARD16          pitch
        2       CARD16          duration
        4       CARD32          led_mask
        4       CARD32          led_values
        1                       global_auto_repeat
                0       Off
                1       On
        1       CARD8           click
        1       CARD8           percent
        1                       unused
        32      LISTofCARD8     auto_repeats



  PTRFEEDBACKSTATE
        1       0               feedback class id
        1       CARD8           id of this feedback
        2       12              length
        2                       unused
        2       CARD16          acceleration-numerator
        2       CARD16          acceleration-denominator
        2       CARD16          threshold



  INTEGERFEEDBACKSTATE
        1       0               feedback class id
        1       CARD8           id of this feedback
        2       16              length
        4       CARD32          resolution
        4       INT32           minimum value
        4       INT32           maximum value



  STRINGFEEDBACKSTATE
        1       1               feedback class id
        1       CARD8           id of this feedback
        2       4n+8            length
        2       CARD16          max_symbols
        2       n               number of keysyms supported
        4n      LISTofKEYSYM            key symbols supported



  BELLFEEDBACKSTATE
        1       1               feedback class id
        1       CARD8           id of this feedback
        2       12              length
        1       CARD8           percent
        3                       unused
        2       CARD16          pitch
        2       CARD16          duration



  LEDFEEDBACKSTATE
        1       1               feedback class id
        1       CARD8           id of this feedback
        2       12              length
        4       CARD32          led_mask
        4       BITMASK         led_values
                #x0001  On
                #x0002  Off



ChangeFeedbackControl
        1       CARD8           input extension opcode
        1       23              ChangeFeedbackControl opcode
        2       3+n/4           request length
        4       BITMASK         value-mask (has n bits set to 1)
                #x0001  keyclick-percent
                #x0002  bell-percent
                #x0004  bell-pitch
                #x0008  bell-duration
                #x0010  led
                #x0020  led-mode
                #x0040  key
                #x0080  auto-repeat-mode
                #x0001  string
                #x0001  integer
                #x0001  acceleration-numerator
                #x0002  acceleration-denominator
                #x0004  acceleration-threshold
        1       CARD8           device id
        1       CARD8           feedback class id
        2                       unused
        n       FEEDBACKCLASS



  FEEDBACKCLASS KBDFEEDBACKCTL, PTRFEEDBACKCTL, INTEGERFEEDBACKCTL,
  STRINGFEEDBACKCTL, BELLFEEDBACKCTL, or LEDFEEDBACKCTL



  KBDFEEDBACKCTL
        1       0               feedback class id
        1       CARD8           id of this feedback
        2       20              length
        1       KEYCODE         key
        1                       auto-repeat-mode
                0       Off
                1       On
                2       Default
        1       INT8            key-click-percent
        1       INT8            bell-percent
        2       INT16           bell-pitch
        2       INT16           bell-duration
        4       CARD32          led_mask
        4       CARD32          led_values



  PTRFEEDBACKCTL
        1       1               feedback class id
        1       CARD8           id of this feedback
        2       12              length
        2                       unused
        2       INT16           numerator
        2       INT16           denominator
        2       INT16           threshold



  STRINGCTL
        1       2               feedback class id
        1       CARD8           id of this feedback
        2       4n+8            length
        2                       unused
        2       n               number of keysyms to display
        4n      LISTofKEYSYM            list of key symbols to display



  INTEGERCTL
        1       3               feedback class id
        1       CARD8           id of this feedback
        2       8               length
        4       INT32           integer to display



  LEDCTL
        1       4               feedback class id
        1       CARD8           id of this feedback
        2       12              length
        4       CARD32          led_mask
        4       BITMASK         led_values
                #x0001  On
                #x0002  Off



  BELLCTL
        1       5               feedback class id
        1       CARD8           id of this feedback
        2       8               length
        1       INT8            percent
        3                       unused
        2       INT16           pitch
        2       INT16           duration



GetDeviceKeyMapping
        1       CARD8           input extension opcode
        1       24              GetDeviceKeyMapping opcode
        2       2               request length
        1       CARD8           device
        1       KEYCODE         first-keycode
        1       CARD8           count
        1                       unused



 =>
        1       1               Reply
        1       24              GetDeviceKeyMapping opcode
        2       CARD16          sequence number
        4       nm              reply length (m = count field from the request)
        1       n               keysyms-per-keycode
        23                      unused
        4nm     LISTofKEYSYM            keysyms



ChangeDeviceKeyMapping
        1       CARD8           input extension opcode
        1       25              ChangeDeviceKeyMapping opcode
        2       2+nm            request length
        1       CARD8           device
        1       KEYCODE         first-keycode
        1       m               keysyms-per-keycode
        1       n               keycode-count
        4nm     LISTofKEYSYM            keysyms



GetDeviceModifierMapping
        1       CARD8           input extension opcode
        1       26              GetDeviceModifierMapping opcode
        2       2               request length
        1       CARD8           device
        3                       unused



 =>
        1       1               Reply
        1       26              GetDeviceModifierMapping opcode
        2       CARD16          sequence number
        4       2n              reply length
        1       n               keycodes-per-modifier
        23                      unused
        8n      LISTofKEYCODE           keycodes



SetDeviceModifierMapping
        1       CARD8           input extension opcode
        1       27              SetDeviceModifier opcode
        2       2+2n            request length
        1       CARD8           device
        1       n               keycodes-per-modifier
        2                       unused
        8n      LISTofKEYCODE           keycodes



 =>
        1       1               Reply
        1       27              SetDeviceModifierMapping opcode
        2       CARD16          sequence number
        4       0               reply length
        1                       status
                0       Success
                1       Busy
                2       Failed
        23                      unused



GetDeviceButtonMapping
        1       CARD8           input extension opcode
        1       28              GetDeviceButtonMapping opcode
        2       2               request length
        1       CARD8           device
        3                       unused



 =>
        1       1               Reply
        1       28              GetDeviceButtonMapping opcode
        2       CARD16          sequence number
        4       (n+p)/4         reply length
        1       n               number of elements in map list
        23                      unused
        n       LISTofCARD8                     map
        p                       unused, p=pad(n)



SetDeviceButtonMapping
        1       CARD8           input extension opcode
        1       29              SetDeviceButtonMapping opcode
        2       2+(n+p)/4               request length
        1       CARD8           device
        1       n               length of map
        2                       unused
        n       LISTofCARD8                     map
        p                       unused, p=pad(n)



 =>
        1       1               Reply
        1       29              SetDeviceButtonMapping opcode
        2       CARD16          sequence number
        4       0               reply length
        1                       status
                0       Success
                1       Busy
        23                      unused



QueryDeviceState
        1       CARD8           input extension opcode
        1       30              QueryDeviceState opcode
        2       2               request length
        1       CARD8           device
        3                       unused



 =>
        1       1                       Reply
        1       30                      QueryDeviceState opcode
        2       CARD16                  sequence number
        4       m/4                     reply length
        1       n                       number of input classes
        23                              unused
        m       LISTofINPUTSTATE



  INPUTSTATE    KEYSTATE or BUTTONSTATE or VALUATORSTATE



  KEYSTATE
        1       CARD8           key input class id
        1       36              length
        1       CARD8           num_keys
        1                       unused
        32      LISTofCARD8             status of keys



  BUTTONSTATE
        1       CARD8           button input class id
        1       36              length
        1       CARD8           num_buttons
        1                       unused
        32      LISTofCARD8                     status of buttons



  VALUATORSTATE
        1       CARD8           valuator input class id
        1       4n + 4          length
        1       n               number of valuators
        1                       mode
                #x01    DeviceMode (0 = Relative, 1 = Absolute)
                #x02    ProximityState (0 = InProximity, 1 = OutOfProximity)
        4n      LISTofCARD32            status of valuators



SendExtensionEvent
        1       CARD8                   input extension opcode
        1       31                      SendExtensionEvent opcode
        2       4 + 8n + m              request length
        4       WINDOW                  destination
        1       CARD8                   device
        1       BOOL                    propagate
        2       CARD16                  eventclass count
        1       CARD8                   num_events
        3                               unused
        32n     LISTofEVENTS            events to send
        4m      LISTofEVENTCLASS        desired events



DeviceBell
        1       CARD8           input extension opcode
        1       32              DeviceBell opcode
        2       2               request length
        1       CARD8           device id
        1       CARD8           feedback id
        1       CARD8           feedback class
        1       INT8            percent



SetDeviceValuators
        1       CARD8           input extension opcode
        1       33              SetDeviceValuators opcode
        2       2 + n           request length
        1       CARD8           device id
        1       CARD8           first valuator
        1       n               number of valuators
        1                       unused
        4n      LISTofINT32     valuator values to set



 =>
        1       1                       Reply
        1       33                      SetDeviceValuators opcode
        2       CARD16                  sequence number
        4       0                       reply length
        1       CARD8                   status
                0       Success
                1       AlreadyGrabbed
        23                              unused



GetDeviceControl
        1       CARD8           input extension opcode
        1       34              GetDeviceControl opcode
        2       2               request length
        2       CARD16          device control type
        1       CARD8           device id
        1                       unused



 =>
        1       1                       Reply
        1       34                      GetDeviceControl opcode
        2       CARD16                  sequence number
        4       n/4                     reply length
        1       CARD8                   status
                0                       Success
                1                       AlreadyGrabbed
                3 + first_error         DeviceBusy
        23                              unused
        n                               DEVICESTATE



DEVICESTATE                     DEVICERESOLUTIONSTATE



DEVICERESOLUTIONSTATE
        2       0               control type
        2       8 + 12n         length
        4       n               num_valuators
        4n      LISTOfCARD32    resolution values
        4n      LISTOfCARD32    resolution min_values
        4n      LISTOfCARD32    resolution max_values



ChangeDeviceControl
        1       CARD8           input extension opcode
        1       35              ChangeDeviceControl opcode
        2       2+n/4           request length
        2       CARD16          control type
        1       CARD8           device id
        1                       unused
        n                       DEVICECONTROL



DEVICECONTROL           DEVICERESOLUTIONCTL



DEVICERESOLUTIONCTL
        2       1               control type
        2       8 + 4n          length
        1       CARD8           first_valuator
        1       n               num_valuators
        2                       unused
        4n      LISTOfCARD32    resolution values



 =>
        1       1                       Reply
        1       35                      ChangeDeviceControl opcode
        2       CARD16                  sequence number
        4       0                       reply length
        1       CARD8                   status
                0                       Success
                1                       AlreadyGrabbed
                3 + first_error         DeviceBusy
        23                              unused

Events

DeviceKeyPress, DeviceKeyRelease, DeviceButtonPress, DeviceButtonRelease,
ProximityIn, ProximityOut, and DeviceStateNotify events may be followed by zero
or more DeviceValuator events. DeviceMotionNotify events will be followed by
one or more DeviceValuator events.



DeviceValuator
        1       CARD8           code
        1       CARD8           device id
        2       CARD16          sequence number
        2       SETofKEYBUTMASK         state
        1       n               number of valuators this device reports
        1       m               number of first valuator in this event
        24      LISTofINT32     valuators



DeviceKeyPress
        1       CARD8           code
        1       KEYCODE         detail
        2       CARD16          sequence number
        4       TIMESTAMP               time
        4       WINDOW          root
        4       WINDOW          event
        4       WINDOW          child
                0       None
        2       INT16           root-x
        2       INT16           root-y
        2       INT16           event-x
        2       INT16           event-y
        2       SETofKEYBUTMASK         state
        1       BOOL            same-screen
        1       CARD8           device id
                #x80            MORE_EVENTS follow



DeviceKeyRelease
        1       CARD8           code
        1       KEYCODE         detail
        2       CARD16          sequence number
        4       TIMESTAMP               time
        4       WINDOW          root
        4       WINDOW          event
        4       WINDOW          child
                0       None
        2       INT16           root-x
        2       INT16           root-y
        2       INT16           event-x
        2       INT16           event-y
        2       SETofKEYBUTMASK                 state
        1       BOOL            same-screen
        1       CARD8           device id
                #x80            MORE_EVENTS follow



DeviceButtonPress
        1       CARD8           code
        1       BUTTON          detail
        2       CARD16          sequence number
        4       TIMESTAMP               time
        4       WINDOW          root
        4       WINDOW          event
        4       WINDOW          child
                0       None
        2       INT16           root-x
        2       INT16           root-y
        2       INT16           event-x
        2       INT16           event-y
        2       SETofKEYBUTMASK         state
        1       BOOL            same-screen
        1       CARD8           device id
                #x80            MORE_EVENTS follow



DeviceButtonRelease
        1       CARD8           code
        1       BUTTON          detail
        2       CARD16          sequence number
        4       TIMESTAMP               time
        4       WINDOW          root
        4       WINDOW          event
        4       WINDOW          child
                0       None
        2       INT16           root-x
        2       INT16           root-y
        2       INT16           event-x
        2       INT16           event-y
        2       SETofKEYBUTMASK         state
        1       BOOL            same-screen
        1       CARD8           device id
                #x80            MORE_EVENTS follow



DeviceMotionNotify
        1       CARD8           code
        1                       detail
                0       Normal
                1       Hint
        2       CARD16          sequence number
        4       TIMESTAMP               time
        4       WINDOW          root
        4       WINDOW          event
        4       WINDOW          child
                0       None
        2       INT16           root-x
        2       INT16           root-y
        2       INT16           event-x
        2       INT16           event-y
        2       SETofKEYBUTMASK         state
        1       BOOL            same-screen
        1       CARD8           device id
                #x80            MORE_EVENTS follow



DeviceFocusIn
        1       CARD8           code
        1                       detail
                0       Ancestor
                1       Virtual
                2       Inferior
                3       Nonlinear
                4       NonlinearVirtual
                5       Pointer
                6       PointerRoot
                7       None
        2       CARD16          sequence number
        4       TIMESTAMP               time
        4       WINDOW          event
        1                       mode
                0       Normal
                1       Grab
                2       Ungrab
                3       WhileGrabbed
        1       CARD8           device id
        18                      unused



DeviceFocusOut
        1       CARD8           code
        1                       detail
                0       Ancestor
                1       Virtual
                2       Inferior
                3       Nonlinear
                4       NonlinearVirtual
                5       Pointer
                6       PointerRoot
                7       None
        2       CARD16          sequence number
        4       TIMESTAMP               time
        4       WINDOW          event
        1                       mode
                0       Normal
                1       Grab
                2       Ungrab
                3       WhileGrabbed
        1       CARD8           device id
        18                      unused



ProximityIn
        1       CARD8           code
        1                       unused
        2       CARD16          sequence number
        4       TIMESTAMP               time
        4       WINDOW          root
        4       WINDOW          event
        4       WINDOW          child
                0       None
        2       INT16           root-x
        2       INT16           root-y
        2       INT16           event-x
        2       INT16           event-y
        2       SETofKEYBUTMASK                 state
        1       BOOL            same-screen
        1       CARD8           device id
                #x80            MORE_EVENTS follow



ProximityOut
        1       CARD8           code
        1                       unused
        2       CARD16          sequence number
        4       TIMESTAMP               time
        4       WINDOW          root
        4       WINDOW          event
        4       WINDOW          child
                0       None
        2       INT16           root-x
        2       INT16           root-y
        2       INT16           event-x
        2       INT16           event-y
        2       SETofKEYBUTMASK                 state
        1       BOOL            same-screen
        1       CARD8           device id
                #x80            MORE_EVENTS follow

DeviceStateNotify events may be immediately followed by zero or one
DeviceKeyStateNotify and/ or zero or more DeviceValuator events.



DeviceStateNotify
        1       CARD8           code
        1       CARD8           device id
                #x80            MORE_EVENTS follow
        2       CARD16          sequence number
        4       TIMESTAMP               time
        1       CARD8           num_keys
        1       CARD8           num_buttons
        1       CARD8           num_valuators
        1       CARD8           valuator mode and input classes reported
                #x01    reporting keys
                #x02    reporting buttons
                #x04    reporting valuators
                #x40    device mode (0 = Relative, 1 = Absolute)
                #x80    proximity state (0 = InProximity, 1 = OutOfProximity)
        4       LISTofCARD8             first 32 keys (if reported)
        4       LISTofCARD8             first 32 buttons (if reported)
        12      LISTofCARD32            first 3 valuators (if reported)



DeviceKeyStateNotify
        1       CARD8           code
        1       CARD8           device id
                #x80            MORE_EVENTS follow
        2       CARD16          sequence number
        28      LISTofCARD8             state of keys 33-255



DeviceButtonStateNotify
        1       CARD8           code
        1       CARD8           device id
                #x80            MORE_EVENTS follow
        2       CARD16          sequence number
        28      LISTofCARD8             state of buttons 33-255



DeviceValuator
        1       CARD8           code
        1       CARD8           device id
        2       CARD16          sequence number
        2       SETofKEYBUTMASK         state
        1       n               number of valuators this device reports
        1       n               number of first valuator in this event
        24      LISTofINT32     valuators



DeviceMappingNotify
        1       CARD8           code
        1       CARD8           device id
        2       CARD16          sequence number
        1                       request
                0       MappingModifier
                1       MappingKeyboard
                2       MappingPointer
        1       KEYCODE         first-keycode
        1       CARD8           count
        1                       unused
        4       TIMESTAMP               time
        20                      unused



ChangeDeviceNotify
        1       CARD8           code
        1       CARD8           id of device specified on change request
        2       CARD16          sequence number
        4       TIMESTAMP               time
        1                       request
                0       NewPointer
                1       NewKeyboard
        23                      unused

