button(3Tk) button(3Tk)
button - Create and manipulate button widgets
button pathName ?options?
activeBackground cursor highlightThicknesstakeFocus|
activeForeground disabledForegroundimagetext |
anchor font justify textVariable |
background foreground padX underline |
bitmap highlightColor padY wrapLength |
borderWidth highlightBackground relief
See the ``options'' manual entry for details on the standard options.
WIDGET-SPECIFIC OPTIONS
Name: command
Class: Command
Command-Line Switch:-command
Specifies a Tcl command to associate with the button. This command
is typically invoked when mouse button 1 is released over the button
window.
Name: height
Class: Height
Command-Line Switch:-height
Specifies a desired height 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 lines of text. 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.
Name: state
Class: State
Command-Line Switch:-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
disabledForeground and background options determine how the button
is displayed.
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button(3Tk) button(3Tk)
Name: width
Class: Width
Command-Line Switch:-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 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 or in the option database to
configure aspects of the button such as its colors, 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, 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 or if wrapping |
occurs because of the wrapLength option) 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; and it can be made to
flash. When a user invokes the button (by pressing mouse button 1 with
the cursor over the button), then the Tcl command specified in the
-command option is invoked.
The button command creates a new Tcl 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 behavior 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 describing all of the available
options for pathName (see Tk_ConfigureInfo for information on the
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button(3Tk) button(3Tk)
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 button command.
pathName flash
Flash the button. This is accomplished by redisplaying the button
several times, alternating between active and normal colors. At the
end of the flash the button is left in the same normal/active state
as when the command was invoked. This command is ignored if the
button's state is disabled.
pathName invoke
Invoke the Tcl command associated with the button, if there is one.
The return value is the return value from the Tcl 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 class bindings for buttons that give them the
following default behavior:
[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] When a button has the input focus, the space key causes the button |
to be invoked.
If the button's state is disabled then none of the above actions occur:
the button is completely non-responsive.
The behavior of buttons can be changed by defining new bindings for
individual widgets or by redefining the class bindings.
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button(3Tk) button(3Tk)
KEYWORDS
button, widget
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