checkbutton(n) Tk (4.4) checkbutton(n)
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NAME
checkbutton - Create and manipulate checkbutton widgets
SYNOPSIS
checkbutton pathName ?options?
STANDARD OPTIONS
-activebackground-cursor-highlightthickness-takefocus
-activeforeground-disabledforeground-image-text
-anchor-font-justify-textvariable
-background-foreground-padx-underline
-bitmap-highlightbackground-pady-wraplength
-borderwidth-highlightcolor-relief
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:-offvalue
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checkbutton(n) Tk (4.4) checkbutton(n)
Database Name: offValue
Database Class: Value
Specifies value to store in the button's associated
variable whenever this button is deselected. 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:-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 displaying 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 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
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checkbutton(n) Tk (4.4) checkbutton(n)
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 window'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
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
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checkbutton(n) Tk (4.4) checkbutton(n)
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). |
Under Unix, the indicator is drawn with a sunken relief and |
a special 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 create the checkbutton. The
variable name, and the ``on'' and ``off'' 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'' 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 information 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
corresponding 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
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checkbutton(n) Tk (4.4) checkbutton(n)
this case the command returns an empty string. Option
may have any of the values 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 variable to reflect the
new state.
BINDINGS
Tk automatically creates class bindings for checkbuttons
that give them the following default behavior: |
[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 button, 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
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checkbutton(n) Tk (4.4) checkbutton(n)
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 completely 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
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