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ref: c116550e6a41572796e4db65e4f6acbcb3d9d6f8
dir: /man/9/button/

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.TH BUTTON 9
.SH NAME
button \- Create and manipulate button widgets
.SH SYNOPSIS
\f5button\fI \fIpathName \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 \fItkcmd\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.
.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 -state \fIstate\fP
Specifies one of three states for the button:  \f5normal\fR, \f5active\fR,
or \f5disabled\fR.  In normal state the button is displayed using the
\f5foreground\fR and \f5background\fR options.  The active state is
typically used when the pointer is over the button.  In active state
the button is displayed using the \f5activeForeground\fR and
\f5activeBackground\fR options.  Disabled state means that the button
should be insensitive:  the default bindings will refuse to activate
the widget and will ignore mouse button presses.
In this state the \f5background\fR option determines how the button is
displayed.
.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 \f5button\fR command creates a new window (given by the
\fIpathName\fR argument) and makes it into a button widget.
Additional
options, described above, may be specified on the command line.
to configure aspects of the button such as its colours, font,
text, and initial relief.  The \f5button\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 button is a widget that displays a textual string, bitmap or image.
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.
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.  When a user invokes the
button (by pressing mouse button 1 with the cursor over the
button), then the Tk command specified in the \f5-command\fR
option is invoked.
.SH "WIDGET COMMAND"
The \f5button\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 button 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 \f5button\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 \f5button\fR
command.
.TP
\fIpathName \f5invoke\fR
Invoke the Tk command associated with the button, 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 button.
This command is ignored if the button's state is \f5disabled\fR.

.SH "DEFAULT BINDINGS"
Tk automatically creates bindings for buttons that give them
the following default behaviour:
.IP [1]
A button activates whenever the mouse passes over it and deactivates
whenever the mouse leaves the button.
.IP [2]
A button's relief is changed to sunken whenever mouse button 1 is
pressed over the button, and the relief is restored to its original
value when button 1 is later released.
.IP [3]
If mouse button 1 is pressed over a button and later released over
the button, the button is invoked.  However, if the mouse is not
over the button when button 1 is released, then no invocation occurs.
.IP [4]
If the
.B Enter
or
.B Space
key is pressed when the button has keyboard focus,
the button is invoked.
.PP
If the button's state is \f5disabled\fR then none of the above
actions occur:  the button is completely non-responsive.
.PP
The behaviour of buttons can be changed by defining new bindings for
individual widgets.
.SH SEE ALSO
.IR checkbutton (9),
.IR choicebutton (9),
.IR options (9),
.IR radiobutton (9),
.IR types (9)