Documentation generated from fossil trunk
Create and manipulate checkbutton widgets
checkbutton pathName ?options?
|Name||Database name||Database class|
|Specifies a Tcl command to associate with the button. This command is typically invoked when mouse button 1 is released over the button window. The button's global variable (-variable option) will be updated before the command is invoked.|
|Specifies a desired height for the button. If an image or bitmap is being displayed in the button then the value is in screen units (i.e. any of the forms acceptable to Tk_GetPixels); for text it is in lines of text. If this option is not specified, the button's desired height is computed from the size of the image or bitmap or text being displayed in it.|
|Specifies whether or not the indicator should be drawn. Must be a proper boolean value. If false, the -relief option is ignored and the widget's relief is always sunken if the widget is selected and raised otherwise.|
|Specifies the relief for the checkbutton when the indicator is not drawn and the checkbutton is off. The default value is "raised". By setting this option to "flat" and setting -indicatoron to false and -overrelief to "raised", the effect is achieved of having a flat button that raises on mouse-over and which is depressed when activated. This is the behavior typically exhibited by the Bold, Italic, and Underline checkbuttons on the toolbar of a word-processor, for example.|
|Specifies value to store in the button's associated variable whenever this button is deselected. Defaults to "0".|
|Specifies value to store in the button's associated variable whenever this button is selected. Defaults to "1".|
|Specifies an alternative relief for the checkbutton, to be used when the mouse cursor is over the widget. This option can be used to make toolbar buttons, by configuring -relief flat -overrelief raised. If the value of this option is the empty string, then no alternative relief is used when the mouse cursor is over the checkbutton. The empty string is the default value.|
|Specifies a background color to use when the button is selected. If indicatorOn is true then the color is used as the background for the indicator regardless of the select state. If indicatorOn is false, this color is used as the background for the entire widget, in place of background or activeBackground, whenever the widget is selected. If specified as an empty string then no special color is used for displaying when the widget is selected.|
|Specifies an image to display (in place of the -image option) when the checkbutton is selected. This option is ignored unless the -image option has been specified.|
|Specifies one of three states for the checkbutton: normal, active, or disabled. In normal state the checkbutton is displayed using the -foreground and -background options. The active state is typically used when the pointer is over the checkbutton. In active state the checkbutton is displayed using the -activeforeground and -activebackground options. Disabled state means that the checkbutton should be insensitive: the default bindings will refuse to activate the widget and will ignore mouse button presses. In this state the -disabledforeground and -background options determine how the checkbutton is displayed.|
|Specifies an image to display (in place of the -image option) when the checkbutton is in tri-state mode. This option is ignored unless the -image option has been specified.|
|Specifies the value that causes the checkbutton to display the multi-value selection, also known as the tri-state mode. Defaults to "".|
|Specifies the name of a global variable to set to indicate whether or not this button is selected. Defaults to the name of the button within its parent (i.e. the last element of the button window's path name).|
|Specifies a desired width for the button. If an image or bitmap is being displayed in the button then the value is in screen units (i.e. any of the forms acceptable to Tk_GetPixels); for text it is in characters. If this option is not specified, the button's desired width is computed from the size of the image or bitmap or text being displayed in it.|
The checkbutton command creates a new window (given by the pathName argument) and makes it into a checkbutton widget. Additional options, described above, may be specified on the command line or in the option database to configure aspects of the checkbutton such as its colors, font, text, and initial relief. The checkbutton command returns its pathName argument. At the time this command is invoked, there must not exist a window named pathName, but pathName's parent must exist.
A checkbutton is a widget that displays a textual string, bitmap or image and a square called an indicator. If text is displayed, it must all be in a single font, but it can occupy multiple lines on the screen (if it contains newlines or if wrapping occurs because of the -wraplength option) and one of the characters may optionally be underlined using the -underline option. A checkbutton has all of the behavior of a simple button, including the following: it can display itself in either of three different ways, according to the -state option; it can be made to appear raised, sunken, or flat; it can be made to flash; and it invokes a Tcl command whenever mouse button 1 is clicked over the checkbutton.
In addition, checkbuttons can be selected. If a checkbutton is selected then the indicator is normally drawn with a selected appearance, and a Tcl variable associated with the checkbutton is set to a particular value (normally 1). The indicator is drawn with a check mark inside. If the checkbutton is not selected, then the indicator is drawn with a deselected appearance, and the associated variable is set to a different value (typically 0). The indicator is drawn without a check mark inside. In the special case where the variable (if specified) has a value that matches the tristatevalue, the indicator is drawn with a tri-state appearance and is in the tri-state mode indicating mixed or multiple values. (This is used when the check box represents the state of multiple items.) The indicator is drawn in a platform dependent manner. Under Unix and Windows, the background interior of the box is "grayed". Under Mac, the indicator is drawn with a dash mark inside. By default, the name of the variable associated with a checkbutton is the same as the name used to create the checkbutton. The variable name, and the "on", "off" and "tristate" values stored in it, may be modified with options on the command line or in the option database. Configuration options may also be used to modify the way the indicator is displayed (or whether it is displayed at all). By default a checkbutton is configured to select and deselect itself on alternate button clicks. In addition, each checkbutton monitors its associated variable and automatically selects and deselects itself when the variables value changes to and from the button's "on", "off" and "tristate" values.
The checkbutton command creates a new Tcl command whose name is pathName. This command may be used to invoke various operations on the widget. It has the following general form:
pathName option ?arg arg ...?
Option and the args determine the exact behavior of the command. The following commands are possible for checkbutton widgets:
Tk automatically creates class bindings for checkbuttons that give them the following default behavior:
If the checkbutton's state is disabled then none of the above actions occur: the checkbutton is completely non-responsive.
The behavior of checkbuttons can be changed by defining new bindings for individual widgets or by redefining the class bindings.
This example shows a group of uncoupled checkbuttons.
labelframe .lbl -text "Steps:" checkbutton .c1 -text Lights -variable lights checkbutton .c2 -text Cameras -variable cameras checkbutton .c3 -text Action! -variable action pack .c1 .c2 .c3 -in .lbl pack .lbl