checkbutton(n) Tk Built-In Commands checkbutton(n)______________________________________________________________________________NAMEcheckbutton - Create and manipulate checkbutton widgets
SYNOPSIScheckbutton pathName ?options?
See the options manual entry for details on the standard options.
[-command command] Specifies a Tcl command to associate with the but‐
ton. 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.
[-height 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 is not specified, the but‐
ton's desired height is computed from the size of the image or bitmap
or text being displayed in it. [-indicatoron 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.
[-offrelief 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 -indi‐
catoron 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. [-offvalue offValue] Specifies value to store in the but‐
ton's associated variable whenever this button is deselected. Defaults
to “0”. [-onvalue onValue] Specifies value to store in the button's
associated variable whenever this button is selected. Defaults to “1”.
[-overrelief overRelief] Specifies an alternative relief for the check‐
button, 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. [-select‐
color selectColor] 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 indi‐
catorOn 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. [-selectimage selec‐
tImage] 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. [-state 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
presses. In this state the disabledForeground and background options
determine how the checkbutton is displayed. [-tristateimage tris‐
tateImage] 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. [-tristatevalue tristate‐
Value] Specifies the value that causes the checkbutton to display the │
multi-value selection, also known as the tri-state mode. Defaults to │
“”. [-variable variable] 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). [-width 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 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 under‐
lined using the underline option. A checkbutton has all of the behav‐
ior 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
In addition, checkbuttons can be selected. If a checkbutton is
selected then the indicator is normally drawn with a selected appear‐
ance, 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 speci‐ │
fied) has a value that matches the tristatevalue, the indicator is │
drawn with a tri-state appearance and is in the tri-state mode indicat‐ │
ing mixed or multiple values. (This is used when the check box repre‐ │
sents the state of multiple items.) The indicator is drawn in a plat‐ │
form 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 vari‐ │
ables value changes to and from the button's “on”, “off” and “tristate” │
The checkbutton command creates a new Tcl command whose name is path‐
Name. 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
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 avail‐
able 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 this
case the command returns an empty string. Option may have any
of the values accepted by the checkbutton command.
Deselects the checkbutton and sets the associated variable to
its “off” value.
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.
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 checkbut‐
ton, if there is one. The return value is the return value from
the Tcl command, or an empty string if there is no command asso‐
ciated with the checkbutton. This command is ignored if the
checkbutton's state is disabled.
Selects the checkbutton and sets the associated variable to its
Toggles the selection state of the button, redisplaying it and
modifying its associated variable to reflect the new state.
Tk automatically creates class bindings for checkbuttons that give them
the following default behavior:
 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.
 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).
 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.
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
SEE ALSObutton(n), options(n), radiobutton(n), ttk::checkbutton(n)KEYWORDS
Tk 4.4 checkbutton(n)