checkbutton(n) Tk Built-In Commands checkbutton(n) ______________________________________________________________________________
NAME
checkbutton - Create and manipulate 'checkbutton' boolean selection
widgets
SYNOPSIS
checkbutton pathName ?options?
STANDARD OPTIONS
-activebackground -disabledforeground -padx
-activeforeground -font -pady
-anchor -foreground -relief
-background -highlightbackground -takefocus
-bitmap -highlightcolor -text
-borderwidth -highlightthickness -textvariable
-compound -image -underline
-cursor -justify -wraplength
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 com-
mand 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 bit-
map 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.
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 typi-
cally 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 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:-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 -over-
relief 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 is used as the background
for the indicator regardless of the select state. If indica-
torOn is false, this color is used as the background for the
entire widget, in place of background or activeBackground, when-
ever 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 dis-
played 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 -disabledfore-
ground and -background options determine how the checkbutton is
displayed.
Command-Line Name:-tristateimage
Database Name: tristateImage
Database Class: TristateImage
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.
Command-Line Name:-tristatevalue
Database Name: tristateValue
Database Class: Value
Specifies the value that causes the checkbutton to display the
multi-value selection, also known as the tri-state mode.
Defaults to "".
Command-Line Name:-variable
Database Name: variable
Database Class: 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 but-
ton 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 is not specified, the
button's desired width is computed from the size of the image or
bitmap or text being displayed in it.
______________________________________________________________________________
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 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
the checkbutton.
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"
values.
WIDGET COMMAND
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
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 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.
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 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.
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 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.
EXAMPLE
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
SEE ALSO
checkbutton(n)
KEYWORDS
checkbutton, widget
Tk 4.4 checkbutton(n)
tk 8.6.3 - Generated Sun Nov 16 10:27:27 CST 2014