---
name: "controlwidget"
section: "3tk"
platform: "linux"
package: "tklib"
version: "0.9-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/controlwidget"
---

# controlwidget(3tk)

Collection of widgets for displaying and controlling numerical values

```

```

## 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>
```