TransactionCommands

Transaction command types used by Socket Frontend/IMEngine/Config, Helper and Panel. More...

## Variables

const int | scim::SCIM_TRANS_CMD_UNKNOWN = 0
| Unknown command. No use.
const int | scim::SCIM_TRANS_CMD_REQUEST = 1
| It's the first command which should be put into the Transaction sending from a socket client to a socket server.
const int | scim::SCIM_TRANS_CMD_REPLY = 2
| It's the first command which should be put into the Transaction sending from a socket server to a socket client.
const int | scim::SCIM_TRANS_CMD_OK = 3
| This command is usually used in the Transaction sending from a socket server to a socket client to indicate that the request previously sent from the client was executed successfully.
const int | scim::SCIM_TRANS_CMD_FAIL = 4
| This command is usually used in the Transaction sending from a socket server to a socket client to indicate that the request previously sent from the client was failed to be executed.
const int | scim::SCIM_TRANS_CMD_OPEN_CONNECTION = 5
| This command is used internally by scim_socket_open_connection() and scim_socket_accept_connection().
const int | scim::SCIM_TRANS_CMD_CLOSE_CONNECTION = 6
| It's used to request the socket server to close the connection forcedly.
const int | scim::SCIM_TRANS_CMD_LOAD_FILE = 7
| Request the socket server to load and send a file to the client.
const int | scim::SCIM_TRANS_CMD_SAVE_FILE = 8
| Request the socket server to save a buffer into a file.
const int | scim::SCIM_TRANS_CMD_EXIT = 99
| This command should be sent from a socket server to its clients to let them exit.
const int | scim::SCIM_TRANS_CMD_PROCESS_KEY_EVENT = 100
| This command is used in SocketIMEngine to SocketFrontEnd and Panel to FrontEnd protocols to send a KeyEvent to an IMEngineInstance.
const int | scim::SCIM_TRANS_CMD_MOVE_PREEDIT_CARET = 101
const int | scim::SCIM_TRANS_CMD_SELECT_CANDIDATE = 102
const int | scim::SCIM_TRANS_CMD_UPDATE_LOOKUP_TABLE_PAGE_SIZE = 103
const int | scim::SCIM_TRANS_CMD_LOOKUP_TABLE_PAGE_UP = 104
const int | scim::SCIM_TRANS_CMD_LOOKUP_TABLE_PAGE_DOWN = 105
const int | scim::SCIM_TRANS_CMD_RESET = 106
const int | scim::SCIM_TRANS_CMD_FOCUS_IN = 107
const int | scim::SCIM_TRANS_CMD_FOCUS_OUT = 108
const int | scim::SCIM_TRANS_CMD_TRIGGER_PROPERTY = 109
const int | scim::SCIM_TRANS_CMD_PROCESS_HELPER_EVENT = 110
const int | scim::SCIM_TRANS_CMD_UPDATE_CLIENT_CAPABILITIES = 111
const int | scim::SCIM_TRANS_CMD_SHOW_PREEDIT_STRING = 150
const int | scim::SCIM_TRANS_CMD_SHOW_AUX_STRING = 151
const int | scim::SCIM_TRANS_CMD_SHOW_LOOKUP_TABLE = 152
const int | scim::SCIM_TRANS_CMD_HIDE_PREEDIT_STRING = 153
const int | scim::SCIM_TRANS_CMD_HIDE_AUX_STRING = 154
const int | scim::SCIM_TRANS_CMD_HIDE_LOOKUP_TABLE = 155
const int | scim::SCIM_TRANS_CMD_UPDATE_PREEDIT_CARET = 156
const int | scim::SCIM_TRANS_CMD_UPDATE_PREEDIT_STRING = 157
const int | scim::SCIM_TRANS_CMD_UPDATE_AUX_STRING = 158
const int | scim::SCIM_TRANS_CMD_UPDATE_LOOKUP_TABLE = 159
const int | scim::SCIM_TRANS_CMD_COMMIT_STRING = 160
const int | scim::SCIM_TRANS_CMD_FORWARD_KEY_EVENT = 161
const int | scim::SCIM_TRANS_CMD_REGISTER_PROPERTIES = 162
const int | scim::SCIM_TRANS_CMD_UPDATE_PROPERTY = 163
const int | scim::SCIM_TRANS_CMD_BEEP = 164
const int | scim::SCIM_TRANS_CMD_START_HELPER = 165
const int | scim::SCIM_TRANS_CMD_STOP_HELPER = 166
const int | scim::SCIM_TRANS_CMD_SEND_HELPER_EVENT = 167
const int | scim::SCIM_TRANS_CMD_GET_SURROUNDING_TEXT = 168
const int | scim::SCIM_TRANS_CMD_DELETE_SURROUNDING_TEXT = 169
const int | scim::SCIM_TRANS_CMD_NEW_INSTANCE = 200
const int | scim::SCIM_TRANS_CMD_DELETE_INSTANCE = 201
const int | scim::SCIM_TRANS_CMD_DELETE_ALL_INSTANCES = 202
const int | scim::SCIM_TRANS_CMD_GET_FACTORY_LIST = 203
const int | scim::SCIM_TRANS_CMD_GET_FACTORY_NAME = 204
const int | scim::SCIM_TRANS_CMD_GET_FACTORY_AUTHORS = 205
const int | scim::SCIM_TRANS_CMD_GET_FACTORY_CREDITS = 206
const int | scim::SCIM_TRANS_CMD_GET_FACTORY_HELP = 207
const int | scim::SCIM_TRANS_CMD_GET_FACTORY_LOCALES = 208
const int | scim::SCIM_TRANS_CMD_GET_FACTORY_ICON_FILE = 209
const int | scim::SCIM_TRANS_CMD_GET_FACTORY_LANGUAGE = 210
const int | scim::SCIM_TRANS_CMD_FLUSH_CONFIG = 300
const int | scim::SCIM_TRANS_CMD_ERASE_CONFIG = 301
const int | scim::SCIM_TRANS_CMD_GET_CONFIG_STRING = 302
const int | scim::SCIM_TRANS_CMD_SET_CONFIG_STRING = 303
const int | scim::SCIM_TRANS_CMD_GET_CONFIG_INT = 304
const int | scim::SCIM_TRANS_CMD_SET_CONFIG_INT = 305
const int | scim::SCIM_TRANS_CMD_GET_CONFIG_BOOL = 306
const int | scim::SCIM_TRANS_CMD_SET_CONFIG_BOOL = 307
const int | scim::SCIM_TRANS_CMD_GET_CONFIG_DOUBLE = 308
const int | scim::SCIM_TRANS_CMD_SET_CONFIG_DOUBLE = 309
const int | scim::SCIM_TRANS_CMD_GET_CONFIG_VECTOR_STRING = 310
const int | scim::SCIM_TRANS_CMD_SET_CONFIG_VECTOR_STRING = 311
const int | scim::SCIM_TRANS_CMD_GET_CONFIG_VECTOR_INT = 312
const int | scim::SCIM_TRANS_CMD_SET_CONFIG_VECTOR_INT = 313
const int | scim::SCIM_TRANS_CMD_RELOAD_CONFIG = 314
const int | scim::SCIM_TRANS_CMD_UPDATE_SCREEN = 400
const int | scim::SCIM_TRANS_CMD_UPDATE_SPOT_LOCATION = 401
const int | scim::SCIM_TRANS_CMD_PANEL_EXIT = 500
const int | scim::SCIM_TRANS_CMD_PANEL_TURN_ON = 501
const int | scim::SCIM_TRANS_CMD_PANEL_TURN_OFF = 502
const int | scim::SCIM_TRANS_CMD_PANEL_UPDATE_FACTORY_INFO = 503
const int | scim::SCIM_TRANS_CMD_PANEL_SHOW_HELP = 504
const int | scim::SCIM_TRANS_CMD_PANEL_SHOW_FACTORY_MENU = 505
const int | scim::SCIM_TRANS_CMD_PANEL_REGISTER_INPUT_CONTEXT = 506
const int | scim::SCIM_TRANS_CMD_PANEL_REMOVE_INPUT_CONTEXT = 507
const int | scim::SCIM_TRANS_CMD_PANEL_REQUEST_HELP = 520
const int | scim::SCIM_TRANS_CMD_PANEL_REQUEST_FACTORY_MENU = 521
const int | scim::SCIM_TRANS_CMD_PANEL_CHANGE_FACTORY = 522
const int | scim::SCIM_TRANS_CMD_PANEL_REGISTER_HELPER = 540
const int | scim::SCIM_TRANS_CMD_PANEL_SEND_IMENGINE_EVENT = 541
const int | scim::SCIM_TRANS_CMD_PANEL_SEND_KEY_EVENT = 542
const int | scim::SCIM_TRANS_CMD_HELPER_PROCESS_IMENGINE_EVENT = 602
const int | scim::SCIM_TRANS_CMD_HELPER_ATTACH_INPUT_CONTEXT = 603
const int | scim::SCIM_TRANS_CMD_HELPER_DETACH_INPUT_CONTEXT = 604
const int | scim::SCIM_TRANS_CMD_HELPER_MANAGER_GET_HELPER_LIST = 700
const int | scim::SCIM_TRANS_CMD_HELPER_MANAGER_RUN_HELPER = 701
const int | scim::SCIM_TRANS_CMD_CONTROLLER_REQUEST_FACTORY_MENU = 800
const int | scim::SCIM_TRANS_CMD_CONTROLLER_CHANGE_FACTORY = 801
const int | scim::SCIM_TRANS_CMD_CONTROLLER_GET_CURRENT_FACTORY = 802
const int | scim::SCIM_TRANS_CMD_CONTROLLER_GET_CURRENT_CONTEXT = 803
const int | scim::SCIM_TRANS_CMD_PANEL_RETURN_CURRENT_FACTORY_INFO = 820
const int | scim::SCIM_TRANS_CMD_PANEL_RETURN_CURRENT_CONTEXT = 821
const int | scim::SCIM_TRANS_CMD_USER_DEFINED = 10000

## Detailed Description

Transaction command types used by Socket Frontend/IMEngine/Config, Helper and Panel.

This commands are used in communication protocols of SocketFrontEnd, SocketIMEngine, SocketConfig, Helper and Panel.

There are mainly four major protocols used in the communications among each part of SCIM:

- between SocketFrontEnd and SocketIMEngine (SocketFrontEnd is server)
- between SocketFrontEnd and SocketConfig (SocketFrontEnd is server)
- between Panel and FrontEnds (eg. X11 FrontEnd, Gtk IMModule and QT IMModule. Panel is server)
- between Panel and Helper (Panel is server).

As soon as the socket to the server is established, the client must call function scim_socket_open_connection() to create the connection and get the magic key for later communication.

At the same time, the server must call function scim_socket_accept_connection() to accept the connection and get the same magic key for later client verification.

The valid types of servers are:

- "SocketFrontEnd"
  The socket FrontEnd server provides remote IMEngine and Config services. It accepts "SocketIMEngine" and "SocketConfig" clients.
- "Panel"
  The Panel server provides GUI and Helper management services. It accepts "FrontEnd" and "Helper" clients.

The valid types of clients are:

- "SocketIMEngine"
  The socket IMEngine client acts as a proxy IMEngine forwarding all requests to SocketFrontEnd. It can only connect to "SocketFrontEnd" server.
- "SocketConfig"
  The socket Config client acts as a proxy Config forwarding all request to SocketFrontEnd. It can only connect to "SocketFrontEnd" server.
- "FrontEnd"
  If a FrontEnd needs a Panel GUI services, it'll be a "FrontEnd" client of the Panel. It can only connect to "Panel" server.
- "Helper"
  All Helper objects should be "Helper" clients of a Panel. It can only connect to "Panel" server.

Then the client and the server can communicate with each other via the socket by sending transactions.

Multiple commands and their data may be put into one transaction with a restricted order. The data of a command must be put into the transaction just follow the command itself.

A transaction sent from a socket client to a socket server (eg. SocketIMEngine to SocketFrontEnd) must be started with a SCIM_TRANS_CMD_REQUEST command followed by an uint32 magic key of the client (returned by scim_socket_open_connection() function.

A transaction sent back to a socket client from a socket server must be started with a SCIM_TRANS_CMD_REPLY command.

So for example, the layout of a transaction sent from SocketIMEngine to SocketFrontEnd may look like:

- SCIM_TRANS_CMD_REQUEST
- an uint32 data (the magic key of a client)
- SCIM_TRANS_CMD_PROCESS_KEY_EVENT
- an uint32 data (the id of the IMEngineInstance object used to process the KeyEvent)
- a scim::KeyEvent data (the KeyEvent to be processed)

Some commands may be used in more than one protocols for similar purpose, but they may have different data in different protocol.

Brief introduction of communication protocols used in SCIM:

Please refer to the descriptions of each Transaction commands for details.

1. Protocol used between SocketIMEngine and SocketFrontEnd
   In this protocol, SocketFrontEnd is socket server, SocketIMEngine is client.
   - from SocketIMEngine to SocketFrontEnd:
     The Transaction sent from SocketIMEngine to SocketFrontEnd must start with SCIM_TRANS_CMD_REQUEST and followed by an uint32 magic key which was returned by scim_socket_open_connection() and scim_socket_accept_connection().
     Before parsing the Transaction, SocketFrontEnd must verify if the magic key is matched. If the magic key is not matched, then SocketFrontEnd should just discard this transaction.
     There can be one or more commands and corresponding data right after the magic key.
     The valid commands which can be used here are:
     - SCIM_TRANS_CMD_NEW_INSTANCE
     - SCIM_TRANS_CMD_DELETE_INSTANCE
     - SCIM_TRANS_CMD_DELETE_ALL_INSTANCES
     - SCIM_TRANS_CMD_GET_FACTORY_LIST
     - SCIM_TRANS_CMD_GET_FACTORY_NAME
     - SCIM_TRANS_CMD_GET_FACTORY_AUTHORS
     - SCIM_TRANS_CMD_GET_FACTORY_CREDITS
     - SCIM_TRANS_CMD_GET_FACTORY_HELP
     - SCIM_TRANS_CMD_GET_FACTORY_LOCALES
     - SCIM_TRANS_CMD_GET_FACTORY_ICON_FILE
     - SCIM_TRANS_CMD_GET_FACTORY_LANGUAGE
     - SCIM_TRANS_CMD_PROCESS_KEY_EVENT
     - SCIM_TRANS_CMD_MOVE_PREEDIT_CARET
     - SCIM_TRANS_CMD_SELECT_CANDIDATE
     - SCIM_TRANS_CMD_UPDATE_LOOKUP_TABLE_PAGE_SIZE
     - SCIM_TRANS_CMD_LOOKUP_TABLE_PAGE_UP
     - SCIM_TRANS_CMD_LOOKUP_TABLE_PAGE_DOWN
     - SCIM_TRANS_CMD_RESET
     - SCIM_TRANS_CMD_FOCUS_IN
     - SCIM_TRANS_CMD_FOCUS_OUT
     - SCIM_TRANS_CMD_TRIGGER_PROPERTY
     - SCIM_TRANS_CMD_PROCESS_HELPER_EVENT
     - SCIM_TRANS_CMD_UPDATE_CLIENT_CAPABILITIES
     - SCIM_TRANS_CMD_LOAD_FILE
     - SCIM_TRANS_CMD_CLOSE_CONNECTION
   - from SocketFrontEnd to SocketIMEngine:
     The Transaction sent back from SocketFrontEnd to SocketIMEngine must start with SCIM_TRANS_CMD_REPLY and end with SCIM_TRANS_CMD_OK or SCIM_TRANS_CMD_FAIL to indicate if the request previously sent by SocketIMEngine was executed successfully.
     For some requests, like SCIM_TRANS_CMD_GET_FACTORY_LIST, etc. only some result data will be returned between SCIM_TRANS_CMD_REPLY and SCIM_TRANS_CMD_OK.
     For some requests, like SCIM_TRANS_CMD_PROCESS_KEY_EVENT, etc. one or more following commands and corresponding data may be returned between SCIM_TRANS_CMD_REPLY and SCIM_TRANS_CMD_OK commands.
     The valid commands can be used here are:
     - SCIM_TRANS_CMD_SHOW_PREEDIT_STRING
     - SCIM_TRANS_CMD_SHOW_AUX_STRING
     - SCIM_TRANS_CMD_SHOW_LOOKUP_TABLE
     - SCIM_TRANS_CMD_HIDE_PREEDIT_STRING
     - SCIM_TRANS_CMD_HIDE_AUX_STRING
     - SCIM_TRANS_CMD_HIDE_LOOKUP_TABLE
     - SCIM_TRANS_CMD_UPDATE_PREEDIT_CARET
     - SCIM_TRANS_CMD_UPDATE_PREEDIT_STRING
     - SCIM_TRANS_CMD_UPDATE_AUX_STRING
     - SCIM_TRANS_CMD_UPDATE_LOOKUP_TABLE
     - SCIM_TRANS_CMD_COMMIT_STRING
     - SCIM_TRANS_CMD_FORWARD_KEY_EVENT
     - SCIM_TRANS_CMD_REGISTER_PROPERTIES
     - SCIM_TRANS_CMD_UPDATE_PROPERTY
     - SCIM_TRANS_CMD_BEEP
     - SCIM_TRANS_CMD_START_HELPER
     - SCIM_TRANS_CMD_STOP_HELPER
     - SCIM_TRANS_CMD_SEND_HELPER_EVENT
2. Protocol used between SocketConfig and SocketFrontEnd
   In this protocol, SocketFrontEnd is socket server, SocketConfig is client.
   - from SocketConfig to SocketFrontEnd:
     The Transaction sent from SocketConfig to SocketFrontEnd must start with SCIM_TRANS_CMD_REQUEST and followed by an uint32 magic key which was returned by scim_socket_open_connection() and scim_socket_accept_connection().
     Before parsing the Transaction, SocketFrontEnd must verify if the magic key is matched. If the magic key is not matched, then SocketFrontEnd should just discard this transaction.
     There can be one or more commands and corresponding data right after the magic key.
     The valid commands which can be used here are:
     - SCIM_TRANS_CMD_FLUSH_CONFIG
     - SCIM_TRANS_CMD_ERASE_CONFIG
     - SCIM_TRANS_CMD_GET_CONFIG_STRING
     - SCIM_TRANS_CMD_SET_CONFIG_STRING
     - SCIM_TRANS_CMD_GET_CONFIG_INT
     - SCIM_TRANS_CMD_SET_CONFIG_INT
     - SCIM_TRANS_CMD_GET_CONFIG_BOOL
     - SCIM_TRANS_CMD_SET_CONFIG_BOOL
     - SCIM_TRANS_CMD_GET_CONFIG_DOUBLE
     - SCIM_TRANS_CMD_SET_CONFIG_DOUBLE
     - SCIM_TRANS_CMD_GET_CONFIG_VECTOR_STRING
     - SCIM_TRANS_CMD_SET_CONFIG_VECTOR_STRING
     - SCIM_TRANS_CMD_GET_CONFIG_VECTOR_INT
     - SCIM_TRANS_CMD_SET_CONFIG_VECTOR_INT
     - SCIM_TRANS_CMD_RELOAD_CONFIG
     - SCIM_TRANS_CMD_LOAD_FILE
     - SCIM_TRANS_CMD_CLOSE_CONNECTION
   - from SocketFrontEnd to SocketConfig:
     The Transaction sent back from SocketFrontEnd to SocketConfig must start with SCIM_TRANS_CMD_REPLY and end with SCIM_TRANS_CMD_OK or SCIM_TRANS_CMD_FAIL to indicate if the request previously sent by SocketConfig was executed successfully.
     For some requests, like SCIM_TRANS_CMD_FLUSH_CONFIG, etc. no result data will be returned.
     For some requests, like SCIM_TRANS_CMD_GET_CONFIG_STRING, etc. the corresponding data will be returned between SCIM_TRANS_CMD_REPLY and SCIM_TRANS_CMD_OK commands.
3. Protocol used between FrontEnds and Panel
   In this protocol, Panel (eg. scim-panel-gtk or scim-panel-kde) is socket server, FrontEnds are clients.
   - from FrontEnds to Panel:
     The Transaction sent from FrontEnds to Panel must start with SCIM_TRANS_CMD_REQUEST and followed by an uint32 magic key which was returned by scim_socket_open_connection() and scim_socket_accept_connection(). Then there must be an uint32 id for current focused input context right after the magic key.
     Before parsing the Transaction, Panel must verify if the magic key is matched. If the magic key is not matched, then Panel should just discard this transaction.
     There can be one or more commands and corresponding data right after the magic key.
     The valid commands which can be used here are:
     - SCIM_TRANS_CMD_UPDATE_SCREEN
     - SCIM_TRANS_CMD_UPDATE_SPOT_LOCATION
     - SCIM_TRANS_CMD_PANEL_TURN_ON
     - SCIM_TRANS_CMD_PANEL_TURN_OFF
     - SCIM_TRANS_CMD_PANEL_UPDATE_FACTORY_INFO
     - SCIM_TRANS_CMD_PANEL_SHOW_HELP
     - SCIM_TRANS_CMD_PANEL_SHOW_FACTORY_MENU
     - SCIM_TRANS_CMD_SHOW_PREEDIT_STRING
     - SCIM_TRANS_CMD_SHOW_AUX_STRING
     - SCIM_TRANS_CMD_SHOW_LOOKUP_TABLE
     - SCIM_TRANS_CMD_HIDE_PREEDIT_STRING
     - SCIM_TRANS_CMD_HIDE_AUX_STRING
     - SCIM_TRANS_CMD_HIDE_LOOKUP_TABLE
     - SCIM_TRANS_CMD_UPDATE_PREEDIT_CARET
     - SCIM_TRANS_CMD_UPDATE_PREEDIT_STRING
     - SCIM_TRANS_CMD_UPDATE_AUX_STRING
     - SCIM_TRANS_CMD_UPDATE_LOOKUP_TABLE
     - SCIM_TRANS_CMD_REGISTER_PROPERTIES
     - SCIM_TRANS_CMD_UPDATE_PROPERTY
     - SCIM_TRANS_CMD_START_HELPER
     - SCIM_TRANS_CMD_STOP_HELPER
     - SCIM_TRANS_CMD_SEND_HELPER_EVENT
   - from Panel to FrontEnds:
     The Transaction sent from Panel to FrontEnds must start with SCIM_TRANS_CMD_REPLY. For the following commands except SCIM_TRANS_CMD_RELOAD_CONFIG and SCIM_TRANS_CMD_EXIT, there must be an uint32 id of the currently focused input context right after the SCIM_TRANS_CMD_REPLY command. Then there can be one or more commands and corresponding data following.
     The valid commands which can be used here are:
     - SCIM_TRANS_CMD_RELOAD_CONFIG
     - SCIM_TRANS_CMD_EXIT
     - SCIM_TRANS_CMD_UPDATE_LOOKUP_TABLE_PAGE_SIZE
     - SCIM_TRANS_CMD_LOOKUP_TABLE_PAGE_UP
     - SCIM_TRANS_CMD_LOOKUP_TABLE_PAGE_DOWN
     - SCIM_TRANS_CMD_PROCESS_KEY_EVENT
     - SCIM_TRANS_CMD_MOVE_PREEDIT_CARET
     - SCIM_TRANS_CMD_SELECT_CANDIDATE
     - SCIM_TRANS_CMD_TRIGGER_PROPERTY
     - SCIM_TRANS_CMD_PROCESS_HELPER_EVENT
     - SCIM_TRANS_CMD_COMMIT_STRING
     - SCIM_TRANS_CMD_FORWARD_KEY_EVENT
     - SCIM_TRANS_CMD_PANEL_REQUEST_HELP
     - SCIM_TRANS_CMD_PANEL_REQUEST_FACTORY_MENU
     - SCIM_TRANS_CMD_PANEL_CHANGE_FACTORY
4. Protocol used between Helper and Panel
   In this protocol, Panel (eg. scim-panel-gtk or scim-panel-kde) is socket server, Helper is client.
   - from Helper to Panel:
     The Transaction sent from Helper to Panel must start with SCIM_TRANS_CMD_REQUEST and followed by an uint32 magic key which was returned by scim_socket_open_connection() and scim_socket_accept_connection(). Before parsing the Transaction, Panel must verify if the magic key is matched. If the magic key is not matched, then Panel should just discard this transaction.
     There can be one or more commands and corresponding data right after the magic key.
     The valid commands which can be used here are:
     - SCIM_TRANS_CMD_PANEL_REGISTER_HELPER
     - SCIM_TRANS_CMD_PANEL_SEND_IMENGINE_EVENT
     - SCIM_TRANS_CMD_PANEL_SEND_KEY_EVENT
     - SCIM_TRANS_CMD_REGISTER_PROPERTIES
     - SCIM_TRANS_CMD_UPDATE_PROPERTY
     - SCIM_TRANS_CMD_FORWARD_KEY_EVENT
     - SCIM_TRANS_CMD_COMMIT_STRING
   - from Panel to Helper:
     The Transaction sent from Panel to Helper must start with SCIM_TRANS_CMD_REPLY and followed by an uint32 input context id and a scim::String input context UUID. Then there can be one or more commands and corresponding data just after the UUID.
     The valid commands which can be used here are:
     - SCIM_TRANS_CMD_EXIT
     - SCIM_TRANS_CMD_UPDATE_SCREEN
     - SCIM_TRANS_CMD_UPDATE_SPOT_LOCATION
     - SCIM_TRANS_CMD_TRIGGER_PROPERTY
     - SCIM_TRANS_CMD_HELPER_PROCESS_IMENGINE_EVENT

## Variable Documentation

## SCIM_TRANS_CMD_UNKNOWN

const int scim::SCIM_TRANS_CMD_UNKNOWN = 0

Unknown command. No use.

## SCIM_TRANS_CMD_REQUEST

const int scim::SCIM_TRANS_CMD_REQUEST = 1

It's the first command which should be put into the Transaction sending from a socket client to a socket server.

The corresponding data for this command is an uint32 magic key which is returned by scim_socket_open_connection() function.

## SCIM_TRANS_CMD_REPLY

const int scim::SCIM_TRANS_CMD_REPLY = 2

It's the first command which should be put into the Transaction sending from a socket server to a socket client.

The corresponding data for this command is different in each protocol. Please refer to the previous protocol notes for details.

## SCIM_TRANS_CMD_OK

const int scim::SCIM_TRANS_CMD_OK = 3

This command is usually used in the Transaction sending from a socket server to a socket client to indicate that the request previously sent from the client was executed successfully.

There is no data for this command.

## SCIM_TRANS_CMD_FAIL

const int scim::SCIM_TRANS_CMD_FAIL = 4

This command is usually used in the Transaction sending from a socket server to a socket client to indicate that the request previously sent from the client was failed to be executed.

There is no data for this command.

## SCIM_TRANS_CMD_OPEN_CONNECTION

const int scim::SCIM_TRANS_CMD_OPEN_CONNECTION = 5

This command is used internally by scim_socket_open_connection() and scim_socket_accept_connection().

It's sent from a socket client to a socket server to request the server to create the connection.

The corresponding data are:

- (scim::String) a version string (the binary version of SCIM).
- (scim::String) type of the client, eg. "SocketIMEngine", "FrontEnd", "Helper" etc.

If the socket server accept the connection request, it must send back a Transaction with following content:

- SCIM_TRANS_CMD_REPLY
- (scim::String) a comma separated server types which are supported by the server, eg. "SocketFrontEnd" etc.
- (uint32) a magic key used to validate the communication later.

Then if the client accept the result too, it must send the following content back to the socket server:

- SCIM_TRANS_CMD_REPLY
- SCIM_TRANS_CMD_OK

Otherwise, the client must return:

- SCIM_TRANS_CMD_REPLY
- SCIM_TRANS_CMD_FAIL

If the socket server do not accept the connection in the first stage, it should discard the request and send nothing back.

## SCIM_TRANS_CMD_CLOSE_CONNECTION

const int scim::SCIM_TRANS_CMD_CLOSE_CONNECTION = 6

It's used to request the socket server to close the connection forcedly.

It's currently not used at all.

## SCIM_TRANS_CMD_LOAD_FILE

const int scim::SCIM_TRANS_CMD_LOAD_FILE = 7

Request the socket server to load and send a file to the client.

The corresponding data is:

- (scim::String) the full file path to be loaded.

If the file is loaded successfully, then the server should send back:

- SCIM_TRANS_CMD_REPLY
- (raw buffer) the buffer which holds the file content.
- SCIM_TRANS_CMD_OK

Otherwise it should send back:

- SCIM_TRANS_CMD_REPLY
- SCIM_TRANS_CMD_FAIL

This command is only supported by SocketFrontEnd.

## SCIM_TRANS_CMD_SAVE_FILE

const int scim::SCIM_TRANS_CMD_SAVE_FILE = 8

Request the socket server to save a buffer into a file.

The corresponding data is:

- (scim::String) the full file path to be used to save the buffer.
- (raw buffer) the buffer to be saved.

If the file is saved successfully, then the server should return:

- SCIM_TRANS_CMD_REPLY
- SCIM_TRANS_CMD_OK

Otherwise it should return:

- SCIM_TRANS_CMD_REPLY
- SCIM_TRANS_CMD_FAIL

This command is currently not supported by any servers.

## SCIM_TRANS_CMD_EXIT

const int scim::SCIM_TRANS_CMD_EXIT = 99

This command should be sent from a socket server to its clients to let them exit.

No data is associated to this command.

This command is currently only used by Panel server.

## SCIM_TRANS_CMD_PROCESS_KEY_EVENT

const int scim::SCIM_TRANS_CMD_PROCESS_KEY_EVENT = 100

This command is used in SocketIMEngine to SocketFrontEnd and Panel to FrontEnd protocols to send a KeyEvent to an IMEngineInstance.

When used in SocketIMEngine to SocketFrontEnd protocol, the corresponding data is:

- (uint32) the id of the IMEngineInstance to process the KeyEvent.
- (KeyEvent) the KeyEvent object to be processed.

The Transaction returned from SocketFrontEnd should contain:

- SCIM_TRANS_CMD_REPLY
- (any valid commands and their corresponding data)
- SCIM_TRANS_CMD_OK or SCIM_TRANS_CMD_FAIL to indicate that if the KeyEvent was processed successfully.

When used in Panel to FrontEnds protocol, the corresponding data is:

- (KeyEvent) the KeyEvent object to be processed.

## SCIM_TRANS_CMD_MOVE_PREEDIT_CARET

const int scim::SCIM_TRANS_CMD_MOVE_PREEDIT_CARET = 101

## SCIM_TRANS_CMD_SELECT_CANDIDATE

const int scim::SCIM_TRANS_CMD_SELECT_CANDIDATE = 102

## SCIM_TRANS_CMD_UPDATE_LOOKUP_TABLE_PAGE_SIZE

const int scim::SCIM_TRANS_CMD_UPDATE_LOOKUP_TABLE_PAGE_SIZE = 103

## SCIM_TRANS_CMD_LOOKUP_TABLE_PAGE_UP

const int scim::SCIM_TRANS_CMD_LOOKUP_TABLE_PAGE_UP = 104

## SCIM_TRANS_CMD_LOOKUP_TABLE_PAGE_DOWN

const int scim::SCIM_TRANS_CMD_LOOKUP_TABLE_PAGE_DOWN = 105

## SCIM_TRANS_CMD_RESET

const int scim::SCIM_TRANS_CMD_RESET = 106

## SCIM_TRANS_CMD_FOCUS_IN

const int scim::SCIM_TRANS_CMD_FOCUS_IN = 107

## SCIM_TRANS_CMD_FOCUS_OUT

const int scim::SCIM_TRANS_CMD_FOCUS_OUT = 108

## SCIM_TRANS_CMD_TRIGGER_PROPERTY

const int scim::SCIM_TRANS_CMD_TRIGGER_PROPERTY = 109

## SCIM_TRANS_CMD_PROCESS_HELPER_EVENT

const int scim::SCIM_TRANS_CMD_PROCESS_HELPER_EVENT = 110

## SCIM_TRANS_CMD_UPDATE_CLIENT_CAPABILITIES

const int scim::SCIM_TRANS_CMD_UPDATE_CLIENT_CAPABILITIES = 111

## SCIM_TRANS_CMD_SHOW_PREEDIT_STRING

const int scim::SCIM_TRANS_CMD_SHOW_PREEDIT_STRING = 150

## SCIM_TRANS_CMD_SHOW_AUX_STRING

const int scim::SCIM_TRANS_CMD_SHOW_AUX_STRING = 151

## SCIM_TRANS_CMD_SHOW_LOOKUP_TABLE

const int scim::SCIM_TRANS_CMD_SHOW_LOOKUP_TABLE = 152

## SCIM_TRANS_CMD_HIDE_PREEDIT_STRING

const int scim::SCIM_TRANS_CMD_HIDE_PREEDIT_STRING = 153

## SCIM_TRANS_CMD_HIDE_AUX_STRING

const int scim::SCIM_TRANS_CMD_HIDE_AUX_STRING = 154

## SCIM_TRANS_CMD_HIDE_LOOKUP_TABLE

const int scim::SCIM_TRANS_CMD_HIDE_LOOKUP_TABLE = 155

## SCIM_TRANS_CMD_UPDATE_PREEDIT_CARET

const int scim::SCIM_TRANS_CMD_UPDATE_PREEDIT_CARET = 156

## SCIM_TRANS_CMD_UPDATE_PREEDIT_STRING

const int scim::SCIM_TRANS_CMD_UPDATE_PREEDIT_STRING = 157

## SCIM_TRANS_CMD_UPDATE_AUX_STRING

const int scim::SCIM_TRANS_CMD_UPDATE_AUX_STRING = 158

## SCIM_TRANS_CMD_UPDATE_LOOKUP_TABLE

const int scim::SCIM_TRANS_CMD_UPDATE_LOOKUP_TABLE = 159

## SCIM_TRANS_CMD_COMMIT_STRING

const int scim::SCIM_TRANS_CMD_COMMIT_STRING = 160

## SCIM_TRANS_CMD_FORWARD_KEY_EVENT

const int scim::SCIM_TRANS_CMD_FORWARD_KEY_EVENT = 161

## SCIM_TRANS_CMD_REGISTER_PROPERTIES

const int scim::SCIM_TRANS_CMD_REGISTER_PROPERTIES = 162

## SCIM_TRANS_CMD_UPDATE_PROPERTY

const int scim::SCIM_TRANS_CMD_UPDATE_PROPERTY = 163

## SCIM_TRANS_CMD_BEEP

const int scim::SCIM_TRANS_CMD_BEEP = 164

## SCIM_TRANS_CMD_START_HELPER

const int scim::SCIM_TRANS_CMD_START_HELPER = 165

## SCIM_TRANS_CMD_STOP_HELPER

const int scim::SCIM_TRANS_CMD_STOP_HELPER = 166

## SCIM_TRANS_CMD_SEND_HELPER_EVENT

const int scim::SCIM_TRANS_CMD_SEND_HELPER_EVENT = 167

## SCIM_TRANS_CMD_GET_SURROUNDING_TEXT

const int scim::SCIM_TRANS_CMD_GET_SURROUNDING_TEXT = 168

## SCIM_TRANS_CMD_DELETE_SURROUNDING_TEXT

const int scim::SCIM_TRANS_CMD_DELETE_SURROUNDING_TEXT = 169

## SCIM_TRANS_CMD_NEW_INSTANCE

const int scim::SCIM_TRANS_CMD_NEW_INSTANCE = 200

## SCIM_TRANS_CMD_DELETE_INSTANCE

const int scim::SCIM_TRANS_CMD_DELETE_INSTANCE = 201

## SCIM_TRANS_CMD_DELETE_ALL_INSTANCES

const int scim::SCIM_TRANS_CMD_DELETE_ALL_INSTANCES = 202

## SCIM_TRANS_CMD_GET_FACTORY_LIST

const int scim::SCIM_TRANS_CMD_GET_FACTORY_LIST = 203

## SCIM_TRANS_CMD_GET_FACTORY_NAME

const int scim::SCIM_TRANS_CMD_GET_FACTORY_NAME = 204

## SCIM_TRANS_CMD_GET_FACTORY_AUTHORS

const int scim::SCIM_TRANS_CMD_GET_FACTORY_AUTHORS = 205

## SCIM_TRANS_CMD_GET_FACTORY_CREDITS

const int scim::SCIM_TRANS_CMD_GET_FACTORY_CREDITS = 206

## SCIM_TRANS_CMD_GET_FACTORY_HELP

const int scim::SCIM_TRANS_CMD_GET_FACTORY_HELP = 207

## SCIM_TRANS_CMD_GET_FACTORY_LOCALES

const int scim::SCIM_TRANS_CMD_GET_FACTORY_LOCALES = 208

## SCIM_TRANS_CMD_GET_FACTORY_ICON_FILE

const int scim::SCIM_TRANS_CMD_GET_FACTORY_ICON_FILE = 209

## SCIM_TRANS_CMD_GET_FACTORY_LANGUAGE

const int scim::SCIM_TRANS_CMD_GET_FACTORY_LANGUAGE = 210

## SCIM_TRANS_CMD_FLUSH_CONFIG

const int scim::SCIM_TRANS_CMD_FLUSH_CONFIG = 300

## SCIM_TRANS_CMD_ERASE_CONFIG

const int scim::SCIM_TRANS_CMD_ERASE_CONFIG = 301

## SCIM_TRANS_CMD_GET_CONFIG_STRING

const int scim::SCIM_TRANS_CMD_GET_CONFIG_STRING = 302

## SCIM_TRANS_CMD_SET_CONFIG_STRING

const int scim::SCIM_TRANS_CMD_SET_CONFIG_STRING = 303

## SCIM_TRANS_CMD_GET_CONFIG_INT

const int scim::SCIM_TRANS_CMD_GET_CONFIG_INT = 304

## SCIM_TRANS_CMD_SET_CONFIG_INT

const int scim::SCIM_TRANS_CMD_SET_CONFIG_INT = 305

## SCIM_TRANS_CMD_GET_CONFIG_BOOL

const int scim::SCIM_TRANS_CMD_GET_CONFIG_BOOL = 306

## SCIM_TRANS_CMD_SET_CONFIG_BOOL

const int scim::SCIM_TRANS_CMD_SET_CONFIG_BOOL = 307

## SCIM_TRANS_CMD_GET_CONFIG_DOUBLE

const int scim::SCIM_TRANS_CMD_GET_CONFIG_DOUBLE = 308

## SCIM_TRANS_CMD_SET_CONFIG_DOUBLE

const int scim::SCIM_TRANS_CMD_SET_CONFIG_DOUBLE = 309

## SCIM_TRANS_CMD_GET_CONFIG_VECTOR_STRING

const int scim::SCIM_TRANS_CMD_GET_CONFIG_VECTOR_STRING = 310

## SCIM_TRANS_CMD_SET_CONFIG_VECTOR_STRING

const int scim::SCIM_TRANS_CMD_SET_CONFIG_VECTOR_STRING = 311

## SCIM_TRANS_CMD_GET_CONFIG_VECTOR_INT

const int scim::SCIM_TRANS_CMD_GET_CONFIG_VECTOR_INT = 312

## SCIM_TRANS_CMD_SET_CONFIG_VECTOR_INT

const int scim::SCIM_TRANS_CMD_SET_CONFIG_VECTOR_INT = 313

## SCIM_TRANS_CMD_RELOAD_CONFIG

const int scim::SCIM_TRANS_CMD_RELOAD_CONFIG = 314

## SCIM_TRANS_CMD_UPDATE_SCREEN

const int scim::SCIM_TRANS_CMD_UPDATE_SCREEN = 400

## SCIM_TRANS_CMD_UPDATE_SPOT_LOCATION

const int scim::SCIM_TRANS_CMD_UPDATE_SPOT_LOCATION = 401

## SCIM_TRANS_CMD_PANEL_EXIT

const int scim::SCIM_TRANS_CMD_PANEL_EXIT = 500

## SCIM_TRANS_CMD_PANEL_TURN_ON

const int scim::SCIM_TRANS_CMD_PANEL_TURN_ON = 501

## SCIM_TRANS_CMD_PANEL_TURN_OFF

const int scim::SCIM_TRANS_CMD_PANEL_TURN_OFF = 502

## SCIM_TRANS_CMD_PANEL_UPDATE_FACTORY_INFO

const int scim::SCIM_TRANS_CMD_PANEL_UPDATE_FACTORY_INFO = 503

## SCIM_TRANS_CMD_PANEL_SHOW_HELP

const int scim::SCIM_TRANS_CMD_PANEL_SHOW_HELP = 504

## SCIM_TRANS_CMD_PANEL_SHOW_FACTORY_MENU

const int scim::SCIM_TRANS_CMD_PANEL_SHOW_FACTORY_MENU = 505

## SCIM_TRANS_CMD_PANEL_REGISTER_INPUT_CONTEXT

const int scim::SCIM_TRANS_CMD_PANEL_REGISTER_INPUT_CONTEXT = 506

## SCIM_TRANS_CMD_PANEL_REMOVE_INPUT_CONTEXT

const int scim::SCIM_TRANS_CMD_PANEL_REMOVE_INPUT_CONTEXT = 507

## SCIM_TRANS_CMD_PANEL_REQUEST_HELP

const int scim::SCIM_TRANS_CMD_PANEL_REQUEST_HELP = 520

## SCIM_TRANS_CMD_PANEL_REQUEST_FACTORY_MENU

const int scim::SCIM_TRANS_CMD_PANEL_REQUEST_FACTORY_MENU = 521

## SCIM_TRANS_CMD_PANEL_CHANGE_FACTORY

const int scim::SCIM_TRANS_CMD_PANEL_CHANGE_FACTORY = 522

## SCIM_TRANS_CMD_PANEL_REGISTER_HELPER

const int scim::SCIM_TRANS_CMD_PANEL_REGISTER_HELPER = 540

## SCIM_TRANS_CMD_PANEL_SEND_IMENGINE_EVENT

const int scim::SCIM_TRANS_CMD_PANEL_SEND_IMENGINE_EVENT = 541

## SCIM_TRANS_CMD_PANEL_SEND_KEY_EVENT

const int scim::SCIM_TRANS_CMD_PANEL_SEND_KEY_EVENT = 542

## SCIM_TRANS_CMD_HELPER_PROCESS_IMENGINE_EVENT

const int scim::SCIM_TRANS_CMD_HELPER_PROCESS_IMENGINE_EVENT = 602

## SCIM_TRANS_CMD_HELPER_ATTACH_INPUT_CONTEXT

const int scim::SCIM_TRANS_CMD_HELPER_ATTACH_INPUT_CONTEXT = 603

## SCIM_TRANS_CMD_HELPER_DETACH_INPUT_CONTEXT

const int scim::SCIM_TRANS_CMD_HELPER_DETACH_INPUT_CONTEXT = 604

## SCIM_TRANS_CMD_HELPER_MANAGER_GET_HELPER_LIST

const int scim::SCIM_TRANS_CMD_HELPER_MANAGER_GET_HELPER_LIST = 700

## SCIM_TRANS_CMD_HELPER_MANAGER_RUN_HELPER

const int scim::SCIM_TRANS_CMD_HELPER_MANAGER_RUN_HELPER = 701

## SCIM_TRANS_CMD_CONTROLLER_REQUEST_FACTORY_MENU

const int scim::SCIM_TRANS_CMD_CONTROLLER_REQUEST_FACTORY_MENU = 800

## SCIM_TRANS_CMD_CONTROLLER_CHANGE_FACTORY

const int scim::SCIM_TRANS_CMD_CONTROLLER_CHANGE_FACTORY = 801

## SCIM_TRANS_CMD_CONTROLLER_GET_CURRENT_FACTORY

const int scim::SCIM_TRANS_CMD_CONTROLLER_GET_CURRENT_FACTORY = 802

## SCIM_TRANS_CMD_CONTROLLER_GET_CURRENT_CONTEXT

const int scim::SCIM_TRANS_CMD_CONTROLLER_GET_CURRENT_CONTEXT = 803

## SCIM_TRANS_CMD_PANEL_RETURN_CURRENT_FACTORY_INFO

const int scim::SCIM_TRANS_CMD_PANEL_RETURN_CURRENT_FACTORY_INFO = 820

## SCIM_TRANS_CMD_PANEL_RETURN_CURRENT_CONTEXT

const int scim::SCIM_TRANS_CMD_PANEL_RETURN_CURRENT_CONTEXT = 821

## SCIM_TRANS_CMD_USER_DEFINED

const int scim::SCIM_TRANS_CMD_USER_DEFINED = 10000