checkbutton(n) Tk Built-In Commands checkbutton(n)
checkbutton - Create and manipulate checkbutton widgets
checkbutton pathName ?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.
[-command 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.
[-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 isn't speci-
fied, the button'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.
[-offvalue offValue] Specifies value to store in the button'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''. [-selectcolor selectColor] 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.
[-selectimage 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. [-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 insensi-
tive: the default bindings will refuse to activate the widget and will ignore mouse but-
ton presses. In this state the disabledForeground and background options determine how
the checkbutton is displayed. [-variable variable] Specifies name of global variable to
set to indicate whether or not this button is selected. Defaults to the name of the but-
ton 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 accept-
able 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 dis-
played 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 path-
Name, 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 indica-
tor 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 check-
button. The variable name, and the ``on'' and ``off'' values stored in it, may be modi-
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 alter-
nate 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.
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
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 speci-
fied, 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 speci-
fied 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 sev-
eral 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 associ-
ated 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.
Selects the checkbutton and sets the associated variable to its ``on'' value.
Toggles the selection state of the button, redisplaying it and modifying its asso-
ciated 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
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 check-
button is completely non-responsive.
The behavior of checkbuttons can be changed by defining new bindings for individual wid-
gets or by redefining the class bindings.
Tk 4.4 checkbutton(n)