controlwidget(3tk)

NAME
controlwidget - Collection of widgets for displaying and controlling numerical values

SYNOPSIS
package require Tcl ?8.5?

package require Tk ?8.5?

package require snit ?2.0?

package require controlwidget ?0.1?

::controlwidget::meter w args

::controlwidget::slider w args

::controlwidget::equalizerBar w args

::controlwidget::thermometer w args

::controlwidget::voltmeter w args

::controlwidget::tachometer w args

::controlwidget::rdial w args

$widget get

$widget set value

::controlwidget::led w args

::controlwidget::radioMatrix w args

$led on

$led off

$led setstate state

$matrix get

$matrix set index

DESCRIPTION

The controlwidget package focuses on the display and interactive control of numerical values. It mimicks several of the meters and controls found in laboratory settings but also daily life: volt meters, equalizers and tachometers to name a few. They can be seen as alternatives for the scale widget.

Note: The package has not sofar been tested extensively, and that may result in an unexpected appearance if you use sizes that are different than the defaults. Also not all options for the coloring of the various parts and fonts and so on have been tested, so that may be another source of bugs.

A last note: some parts have not been included in any option, most notably the colors of parts that require lighter and darker shades to cooperate.

TYPES OF WIDGETS
The package distinguishes several typed of widgets:

•   Vertical meters: the value of the variable is translated into a vertical position, like with the coloured bars you find on your stereo installation.

•   Angle displays: the value of the variable is related to the angle of a needle, like with tachometers.

•   Interactive widgets: most widgets allow you to change the value of the variable by pressing the mouse button on the needle and shifting it up and down or left and right.

•   Non-interactive widgets: some widgets, like the thermometer widget, do not allow such interaction.

•   Logical or choice widgets: some widgets display the values as either on/off (or true/false) or as one of a set of discrete choices.

All widgets have in common, however, that you can connect them to a variable and that changing the variable changes the display. Forthermore, all widgets have the set and get methods to interact with the value that the widget displays (whether that is stored in a global variable or not).

They also have in common that their appearance and behaviour is determined by one or more options that you can set at creation time and often later on as well. The widgets are all based on the snit package, so that the methods configure and cget are available to set and get these options.

COMMANDS
Currently the package contains these widgets of the vertical meter type:

::controlwidget::meter w args
    Create a vertical meter consisting of an axis and a moveable arrow.

    widget w (in)
        Name of the widget to be created.

    arguments args (in)
        List of key-value pairs, controlling the appearance and behaviour of the widget:

        variable name
            Name of the variable to be associated with the meter

        background color
            Background color for the widget

        height pixels
            Height of the widget

        width pixels
            Width of the widget

        arrowthickness pixels
            Thickness of the displayed arrow in pixels

        arrowcolor color
            Color of the displayed arrow

        readonly boolean
            Whether the arrow can be moved interactively or not

::controlwidget::slider w args
    Create a widget containing one or more vertical sliders and an axis. You can shift the slider handles interactively via the mouse.

    widget w (in)
        Name of the widget to be created.

    arguments args (in)
        List of key-value pairs, controlling the appearance and behaviour of the widget:

        variable name
            Name of the (list) variable to be associated with the widget

        number integer
            Number of sliders in the widget

        background color
            Background color for the widget

        height pixels
            Height of the widget

        width pixels
            Width of the widget

        sliderthickness pixels
            Thickness of the slider handles

        sliderwidth color
            Width of the slider handles

        troughwidth color
            Width of the troughs holding the sliders

::controlwidget::equalizerBar w args
    Create a widget containing one or more vertical bars resembling those found on hifi graphical equalizers. Note that it is a read-only widget.

    widget w (in)
        Name of the widget to be created.

    arguments args (in)
        List of key-value pairs, controlling the appearance and behaviour of the widget:

        variable name
            Name of the (list) variable to be associated with the widget

        number integer
            Number of bars in the widget

        background color
            Background color for the widget

        height pixels
            Height of the widget

        width pixels
            Width of the widget

        barwidth pixels
            Width of the bars

        segments integer
            Number of segments the bars are divided in

        safecolor color
            Color for values lower than the warning level

        warningcolor color
            Color for values greater than the warning level

        warninglevel double
            Threshold value, determines at what level the color changes

::controlwidget::thermometer w args
    Create a thermometer widget (read-only)

    widget w (in)
        Name of the widget to be created.

    arguments args (in)
        List of key-value pairs, controlling the appearance and behaviour of the widget:

        variable name
            Name of the (list) variable to be associated with the widget

        background color
            Background color for the widget

        height pixels
            Height of the widget

        width pixels
            Width of the widget

        linethickness pixels
            Thickness of the line representing the "temperature"

        linecolor color
            Color of the line

These widgets all use a vertical axis and have the following options in common for configuring the axis:

axisformat string
    Format string for formatting the numbers along the axis

axisfont string
    Name of the font to be used for the numbers

axiscolor color
    Color of the axis (including the numbers)

from color
    Lower value for the axis

to color
    Upper value for the axis

majorticks integer
    Number of major tickmarks to draw (each is labelled)

minorticks integer
    Number of minor tickmarks to draw between two major tickmarks

log boolean
    Use a logarithmic axis (true) or a linear axis (false)

The package contains the following widget based on angle displays:

::controlwidget::voltmeter w args
    Create a voltmeter-like widget.

    widget w (in)
        Name of the widget to be created.

    arguments args (in)
        List of key-value pairs, controlling the appearance and behaviour of the widget:

        variable name
            Name of the variable to be associated with the meter

        value value
            Value for the meter (if not associated with a variable)

        min value
            The minimum value for data in the display

        max value
            The maximum value for data in the display

        labels list
            The labels to be shown along the scale. (These are simply considered texts, so no relation with the minimum and maximum perse)

        title string
            String to be shown below the dial

        width pixels
            The width of the widget

        height pixels
            The height of the widget

        borderwidth pixels
            The width of the border surrounding the entire widget

        relief string
            The relief of the border surrounding the entire widget

        highlightthickness pixels
            The width of the border to indicate the widget has keyboard focus

        labelfont fontname
            Font of the labels to the scale

        titlefont fontname
            Font of the title below the dial

        dialcolor color
            Color of the dial holding the needle

        needlecolor color
            Color of the needle

        scalecolor color
            Color of the scale (arc and tickmarks)

        labelcolor color
            Color of the labels to the scale

        titlecolor color
            Color of the title below the dial

::controlwidget::tachometer w args
    Create a tachometer-like widget.

    widget w (in)
        Name of the widget to be created.

    arguments args (in)
        List of key-value pairs, controlling the appearance and behaviour of the widget. In addition to the ones given for the voltmeter widget:

        variable name
            Name of the variable to be associated with the meter

        value value
            Value for the meter (if not associated with a variable)

        dangerlevel value
            Level above which values are indicated with a different color

        dangercolor color
            Color for the values above the "danger level"

        dangerwidth pixels
            Width for the colored band indicating the "danger level"

        pincolor color
            Color for the needle and the pin

::controlwidget::rdial w args
    Create a rotating dial. You can drag the dial to change the value. With the shift button depressed the value changes slowly, with the control button depressed it changes fast. Similarly, you can control the dial via the mouse wheel, with the shift and control button working in the same way as with the mouse pointer. Note: The shift and control buttons currently have no effect on Windows.

    widget w (in)
        Name of the widget to be created.

    arguments args (in)
        List of key-value pairs, controlling the appearance and behaviour of the widget:

        variable name
            Name of the variable to be associated with the dial

        value value
            Value for the dial (if not associated with a variable)

        orient string
            Whether a horizontal disk/dial is required ("horizontal") or a vertical one ("vertical")

        step value
            Initial step for incrementing or decrementing the value

        bindwheel value
            Step size for controlling the dial's value via the mouse wheel

        slow value
            Factor on the step size for incrementing or decrementing the value slowly

        fast value
            Factor on the step size for incrementing or decrementing the value fast

        scale value
            Scale value to be applied to the actual value

        callback command
            Command to be called when the value changes

        width pixels
            The width of the widget

        height pixels
            The height of the widget

        background color
            The background color of the widget (coloring of the disk/dial)

        foreground color
            The foreground color of the widget (the marker lines)

All these widgets have the following methods:

$widget get
    Return the current value or values shown in the widget

$widget set value
    Reset the value or values shown in the widget. If the widget is associated with a variable, that variable is set as well.

    value double/list
        New value or values for the widget

Two further widgets are available, meant to display logical values:

::controlwidget::led w args
    Create a LED-like widget.

    widget w (in)
        Name of the widget to be created.

    arguments args (in)
        List of key-value pairs, controlling the appearance and behaviour of the widget. In addition to the ones given for the voltmeter widget:

        variable name
            Name of the variable to be associated with the LED

        size pixels
            Diameter of the LED widget

        on color
            Color to use for the "on" state

        off color
            Color to use for the "off" state

::controlwidget::radioMatrix w args
    Create a matrix of radio buttons that behaves as a single widget.

    widget w (in)
        Name of the widget to be created.

    arguments args (in)
        List of key-value pairs, controlling the appearance and behaviour of the widget. In addition to the ones given for the voltmeter widget:

        variable name
            Name of the variable to be associated with the matrix

        orient string
            The way the radio buttons are to be arranged (horizontal or vertical first)

        rows integer
            Number of rows in the matrix

        columns integer
            Number of columns in the matrix

        command list
            Command associated with the radio buttons. Invoked when the active radio button changes.

The LED widget has the following public methods:

$led on
    Set the state to "on"

$led off
    Set the state to "off"

$led setstate state
    Set the state according to the value of "state"

    state boolean (in)
        New state for the LED widget

The radioMatrix widget has two public methods:

$matrix get
    Return the index of the currently selected radio button

$matrix set index
    Select the radio button with index "index"

    index integer
        Index of the radio button to be set

ACKNOWLEDGMENTS
The code for most of these widgets first appeared on the Wiki. In many cases, Arjen Markus merely refactored the code a bit and "snitified" some of them. The original code was developed by the following people:

•   Vertical meter, LED display, radio matrix: Ron Fox

•   Rotating dials: Gerhard Reithofer

•   Voltmeter and tachometer: Marco Maggi

•   Code for moving the needle: ?

BUGS, IDEAS, FEEDBACK
This document, and the package it describes, will undoubtedly contain bugs and other problems. Please report such in the category controlwidget of the Tklib Trackers [http://core.tcl.tk/tklib/reportlist]. Please also report any ideas for enhancements you may have for either package and/or documentation.

KEYWORDS
controlling, displaying, numerical values, scale widget

COPYRIGHT
Copyright (c) 2010 Ron Fox <rfox@...>
Copyright (c) 2010 Gerhard Reithofer <...@...>
Copyright (c) 2010 Marco Maggi <...@...>
Copyright (c) 2010 Arjen Markus <arjenmarkus@users.sourceforge.net>