BUTTON(9) BUTTON(9)
NAME
button - Create and manipulate button widgets
SYNOPSIS
button pathName ?options?
STANDARD OPTIONS
-activebackground -borderwidth -relief
-activeforeground -font -text
-anchor -foreground -underline
-background -image
-bitmap -justify
WIDGET-SPECIFIC OPTIONS
-command tkcmd
Specifies a Tk command to associate with the button.
This command is typically invoked when mouse button 1
is released over the button window.
-height dist
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.
-state state
Specifies one of three states for the button: normal,
active, or disabled. In normal state the button is
displayed using the foreground and background options.
The active state is typically used when the pointer is
over the button. In active state the button is dis-
played using the activeForeground and activeBackground
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 background option deter-
mines how the button is displayed.
-width dist
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.
DESCRIPTION
The button command creates a new window (given by the path-
Name argument) and makes it into a button widget. Addi-
tional 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 button
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BUTTON(9) BUTTON(9)
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 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 underline option. 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. When a user invokes the button (by pressing mouse
button 1 with the cursor over the button), then the Tk com-
mand specified in the -command option is invoked.
WIDGET COMMAND
The button command creates a new Tk command whose name is
pathName. This command may be used to invoke various opera-
tions on the widget. It has the following general form:
pathName option ?arg arg ...?
Option and the args determine the exact behaviour of the
command. The following commands are possible for button
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 button command.
pathName configure ?option? ?value option value ...?
Query or modify the configuration options of the wid-
get. If no option is specified, returns a list of all
of the available options for pathName. If one or more
option-value pairs are specified, then the command mod-
ifies 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 button command.
pathName invoke
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 disabled.
DEFAULT BINDINGS
Tk automatically creates bindings for buttons that give them
the following default behaviour:
[1] A button activates whenever the mouse passes over it
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BUTTON(9) BUTTON(9)
and deactivates whenever the mouse leaves the button.
[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.
[3] If mouse button 1 is pressed over a button and later
released over the button, the button is invoked. How-
ever, if the mouse is not over the button when button 1
is released, then no invocation occurs.
If the button's state is disabled then none of the above
actions occur: the button is completely non-responsive.
The behaviour of buttons can be changed by defining new
bindings for individual widgets.
SEE ALSO
options(9), types(9)
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