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dir: /man/9/checkbutton/

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.TH CHECKBUTTON 9
.SH NAME
checkbutton \- Create and manipulate checkbutton widgets
.SH SYNOPSIS
\f5checkbutton\fI pathname \fR?\fIoptions\fR?
.SH STANDARD OPTIONS
.EX
-activebackground -disabledcolor      -justify
-activeforeground -font               -relief
-anchor           -foreground         -takefocus
-background       -highlightcolor     -text
-bitmap           -highlightthickness -underline
-borderwidth      -image
.EE
.SH "WIDGET-SPECIFIC OPTIONS"
.TP
.B -command \fIcommand\fP
Specifies a Tk 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 (\f5-variable\fR option) will
be updated before the command is invoked.
.TP
.B -height \fIdist\fP
Specifies a desired height for the button.
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.
.TP
.B -indicatoron \fIboolean\fP
Specifies whether or not the indicator should be drawn.
If false, the \f5relief\fP option is ignored and the widget's
relief is always \f5sunken\fP if the widget is selected
and \f5raised\fP otherwise.
.TP
.B -offvalue \fIstring\fP
Specifies value to store in the button's associated variable whenever
this button is deselected.  Defaults to ``0''.
.TP
.B -onvalue \fIstring\fP
Specifies value to store in the button's associated variable whenever
this button is selected.  Defaults to ``1''.
.TP
.B -selectcolor \fIcolour\fP
Specifies a background colour to use when the button is selected.
If \f5indicatoron\fR is true then the colour applies to the indicator.
If \f5indicatoron\fR is false, this colour is used as the background
for the entire widget, in place of \f5background\fR or \f5activebackground\fR,
whenever the widget is selected.
If specified as an empty string then no special colour is used for
displaying when the widget is selected.
.ig
.TP
.B -selectimage \fIimage\fP
Specifies an image to display (in place of the \f5image\fR option)
when the checkbutton is selected.
This option is ignored unless the \f5image\fR option has been
specified.
..
.TP
.B -state \fIstate\fP
Specifies one of three states for the checkbutton:  \f5normal\fR, \f5active\fR,
or \f5disabled\fR.  In normal state the checkbutton is displayed using the
\f5foreground\fR and \f5background\fR options.  The active state is
typically used when the pointer is over the checkbutton.  In active state
the checkbutton is displayed using the \f5activeforeground\fR and
\f5activebackground\fR 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 \f5disabledcolor\fR and
\f5background\fR options determine how the checkbutton is displayed.
.TP
.B -variable \fIstring\fP
Specifies name of global variable to set whenever this button is
selected.  Changes in this variable also cause the button to select
or deselect itself.
.TP
.B -width \fIdist\fP
Specifies a desired width for the button.
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.
.SH DESCRIPTION
The \f5checkbutton\fR command creates a new window (given by the
\fIpathname\fR argument) and makes it into a checkbutton widget.
Additional
options, described above, may be specified on the command line
to configure aspects of the checkbutton such as its colours, font,
text, and initial relief.  The \f5checkbutton\fR command returns its
\fIpathname\fR argument.  At the time this command is invoked,
there must not exist a window named \fIpathname\fR.
.PP
A checkbutton is a widget
that displays a textual string, bitmap or image
and a square called an \fIindicator\fR.
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) and
one of the characters may optionally be underlined using the
\f5underline\fR option.
A checkbutton has
all of the behaviour of a simple button, including the
following: it can display itself in either of three different
ways, according to the \f5state\fR option;
it can be made to appear
raised, sunken, or flat; and it invokes
a Tk command whenever mouse button 1 is clicked over the
checkbutton.
.PP
In addition, checkbuttons can be \fIselected\fR.
If a checkbutton is selected then the indicator is normally
drawn with a sunken relief and a tick (check) mark, and
a Tk variable associated with the checkbutton is set to the
.B onvalue
(normally 1).
If the checkbutton is not selected, then the indicator is drawn as an empty box with
raised relief, and the associated variable is
set to the
.B offvalue
(normally 0).
The variable name
may be modified with options on the command line (\f5-variable\fR option).
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.
.SH "WIDGET COMMAND"
The \f5checkbutton\fR command creates a new Tk command whose
name is \fIpathname\fR.  This
command may be used to invoke various
operations on the widget.  It has the following general form:
.RS
.EX
\fIpathname option \fR?\fIarg arg ...\fR?
.EE
.RE
\fIOption\fR and the \fIarg\fRs
determine the exact behaviour of the command.  The following
commands are possible for checkbutton widgets:
.TP
\fIpathname \f5cget\fR \fIoption\fR
Returns the current value of the configuration option given
by \fIoption\fR.
\fIOption\fR may have any of the values accepted by the \f5checkbutton\fR
command.
.TP
\fIpathname \f5configure\fR ?\fIoption\fR? ?\fIvalue option value ...\fR?
Query or modify the configuration options of the widget.
If no \fIoption\fR is specified, returns a list of all of
the available options for \fIpathname\fR.  If
one or more \fIoption-value\fR 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.
\fIOption\fR may have any of the values accepted by the \f5checkbutton\fR
command.
.TP
\fIpathname \f5deselect\fR
Deselects the checkbutton and sets the associated variable to its ``off''
value.
.TP
\fIpathname \f5invoke\fR
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 Tk command associated with the checkbutton, if there is one.
The return value is the return value from the Tk command, or an
empty string if there is no command associated with the checkbutton.
This command is ignored if the checkbutton's state is \f5disabled\fR.
.TP
\fIpathname \f5select\fR
Selects the checkbutton and sets the associated variable to 1.
.TP
\fIpathname \f5toggle\fR
Toggles the selection state of the button, redisplaying it and
modifying its associated variable to reflect the new state.

.SH BINDINGS
Tk automatically creates bindings for checkbuttons that give them
the following default behaviour:
.IP [1]
A checkbutton activates whenever the mouse passes over it and deactivates
whenever the mouse leaves the checkbutton.
.IP [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).
.PP
If the checkbutton's state is \f5disabled\fR then none of the above
actions occur:  the checkbutton is completely non-responsive.
.PP
The behaviour of checkbuttons can be changed by defining new bindings for
individual widgets.
.SH SEE ALSO
.IR button (9),
.IR choicebutton (9),
.IR options (9),
.IR radiobutton (9),
.IR types (9)