button - Create and manipulate button widgets
button pathName ?options?
-activebackground -disabledcolor -justify
-activeforeground -font -relief
-anchor -foreground -takefocus
-background -highlightcolor -text
-bitmap -highlightthickness -underline
-borderwidth -image
- -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 displayed 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 determines 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.
The button command creates a new window (given by the
pathName 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 button command returns its pathName argument. At the time this
command is invoked, there must not exist a window named pathName.
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 command specified in the -command option is
invoked.
The button command creates a new Tk command whose name is
pathName. 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 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 widget. 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 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 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.
Tk automatically creates bindings for buttons that give them the
following default behaviour:
- [1]
- A button activates whenever the mouse passes over it 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. However, if the mouse is not over the
button when button 1 is released, then no invocation occurs.
- [4]
- If the Enter or Space key is pressed when the button has
keyboard focus, the button is invoked.
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.