checkbutton(n) Tk Built-In Commands checkbutton(n)
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NAME
checkbutton - Create and manipulate checkbutton widgets
SYNOPSIS
checkbutton pathName ?options?
STANDARD OPTIONS
-activebackground -font -pady
-activeforeground -foreground -relief
-anchor -highlightbackground -takefocus
-background -highlightcolor -text
-bitmap -highlightthickness -textvariable
-borderwidth -image -underline
-cursor -justify -wraplength
-disabledforeground -padx
See the options manual entry for details on the standard options.
WIDGET-SPECIFIC OPTIONS
Command-Line Name:-command
Database Name: command
Database Class: Command
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.
Command-Line Name:-height
Database Name: height
Database Class: Height
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 isn't specified, the button's desired height
is computed from the size of the image or bitmap or text being displayed in it.
Command-Line Name:-indicatoron
Database Name: indicatorOn
Database Class: IndicatorOn
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. |
Command-Line Name:-offrelief |
Database Name: offRelief |
Database Class: OffRelief |
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 -indica- |
toron 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.
Command-Line Name:-offvalue
Database Name: offValue
Database Class: Value
Specifies value to store in the button's associated variable whenever this button is dese-lected. deselected.
lected. Defaults to ``0''.
Command-Line Name:-onvalue
Database Name: onValue
Database Class: Value
Specifies value to store in the button's associated variable whenever this button is selected.
Defaults to ``1''. |
Command-Line Name:-overrelief |
Database Name: overRelief |
Database Class: OverRelief |
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.
Command-Line Name:-selectcolor
Database Name: selectColor
Database Class: Background
Specifies a background color to use when the button is selected. If indicatorOn is true then
the color applies to the indicator. Under Windows, this 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 dis-playing displaying
playing when the widget is selected.
Command-Line Name:-selectimage
Database Name: selectImage
Database Class: SelectImage
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.
Command-Line Name:-state
Database Name: state
Database Class: State
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 check-button checkbutton
button is displayed using the activeForeground and activeBackground options. Disabled state
means that the checkbutton should be insensitive: the default bindings will refuse to acti-vate activate
vate the widget and will ignore mouse button presses. In this state the disabledForeground
and background options determine how the checkbutton is displayed.
Command-Line Name:-variable
Database Name: variable
Database Class: Variable
Specifies name of 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 win-dow's window's
dow's path name).
Command-Line Name:-width
Database Name: width
Database Class: Width
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 isn't specified, the button's desired width is
computed from the size of the image or bitmap or text being displayed in it.
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DESCRIPTION
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 ini-tial initial
tial 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 check-button. checkbutton.
button.
In addition, checkbuttons can be selected. If a checkbutton is selected then the indicator is nor-mally normally
mally drawn with a selected appearance, and a Tcl variable associated with the checkbutton is set to |
a particular value (normally 1). Under Unix, the indicator is drawn with a sunken relief and a spe- |
cial color. Under Windows, 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). Under Unix, the indicator is drawn with a raised relief |
and no special color. Under Windows, the indicator is drawn without a check mark inside. By
default, the name of the variable associated with a checkbutton is the same as the name used to cre-ate create
ate the checkbutton. The variable name, and the ``on'' and ``off'' values stored in it, may be modi-fied modified
fied 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'' value.
WIDGET COMMAND
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:
pathName cget option
Returns the current value of the configuration option given by option. Option may have any of
the values accepted by the checkbutton command.
pathName configure ?option? ?value option value ...?
Query or modify the configuration options of the widget. If no option is specified, returns a
list describing all of the available options for pathName (see Tk_ConfigureInfo for informa-tion information
tion on the format of this list). If option is specified with no value, then the command
returns a list describing the one named option (this list will be identical to the correspond-ing corresponding
ing sublist of the value returned if no option is specified). If one or more option-value
pairs are specified, then the command modifies the given widget option(s) to have the given
value(s); in this case the command returns an empty string. Option may have any of the val-ues values
ues accepted by the checkbutton command.
pathName deselect
Deselects the checkbutton and sets the associated variable to its ``off'' value.
pathName flash
Flashes the checkbutton. This is accomplished by redisplaying the checkbutton several times,
alternating between active and normal colors. At the end of the flash the checkbutton is left
in the same normal/active state as when the command was invoked. This command is ignored if
the checkbutton's state is disabled.
pathName invoke
Does just what would have happened if the user invoked the checkbutton with the mouse: toggle
the selection state of the button and invoke the Tcl command associated with the checkbutton,
if there is one. The return value is the return value from the Tcl command, or an empty
string if there is no command associated with the checkbutton. This command is ignored if the
checkbutton's state is disabled.
pathName select
Selects the checkbutton and sets the associated variable to its ``on'' value.
pathName toggle
Toggles the selection state of the button, redisplaying it and modifying its associated vari-able variable
able to reflect the new state.
BINDINGS
Tk automatically creates class bindings for checkbuttons that give them the following default behav-ior: behavior:
ior: |
[1] ||
On Unix systems, a checkbutton activates whenever the mouse passes over it and deactivates |
whenever the mouse leaves the checkbutton. On Mac and Windows systems, when mouse button 1 is |
pressed over a checkbutton, the button activates whenever the mouse pointer is inside the but- |
ton, and deactivates whenever the mouse pointer leaves the button.
[2] When mouse button 1 is pressed over a checkbutton, it is invoked (its selection state toggles
and the command associated with the button is invoked, if there is one). |
[3] ||
When a checkbutton has the input focus, the space key causes the checkbutton to be invoked. |
Under Windows, there are additional key bindings; plus (+) and equal (=) select the button, |
and minus (-) deselects the button.
If the checkbutton's state is disabled then none of the above actions occur: the checkbutton is com-pletely completely
pletely non-responsive.
The behavior of checkbuttons can be changed by defining new bindings for individual widgets or by
redefining the class bindings.
KEYWORDS
checkbutton, widget
Tk 4.4 checkbutton(n)
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