button(n) Tk Built-In Commands button(n)
button - Create and manipulate button widgets
button pathName ?options?
-activebackground -cursor -highlightthickness-takefocus
-activeforeground -disabledforeground -image-text
-anchor -font -justify-textvariable
-background -foreground -padx-underline
-bitmap -highlightbackground -pady-wraplength
-borderwidth -highlightcolor -relief
See the options manual entry for details on the standard options.
[-command 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.
[-default default] Specifies one of three states for the default ring: normal, active, or |
disabled. In active state, the button is drawn with the platform specific appearance for |
a default button. In normal state, the button is drawn with the platform specific appear- |
ance for a non-default button, leaving enough space to draw the default button appearance. |
The normal and active states will result in buttons of the same size. In disabled state, |
the button is drawn with the non-default button appearance without leaving space for the |
default appearance. The disabled state may result in a smaller button than the active |
state. ring. [-height 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. [-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 active-
Background 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. [-width width] Specifies a desired width for the button. If an image or bit-
map 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 dis-
played, 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 but-
ton (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 speci-
fied, returns a list describing all of the available options for pathName (see
Tk_ConfigureInfo for information on the format of this list). If option is speci-
fied 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.
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 com-
mand is ignored if the button's state is disabled.
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
Tk automatically creates class bindings for buttons that give them default behavior:
 A button activates whenever the mouse passes over it and deactivates whenever the
mouse leaves the button. Under Windows, this binding is only active when mouse |
button 1 has been pressed over the button.
 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
 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.
 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
The behavior of buttons can be changed by defining new bindings for individual widgets or
by redefining the class bindings.
Tk 4.4 button(n)