RADIOBUTTON(9)RADIOBUTTON(9)NAMEradiobutton - Create and manipulate radiobutton widgets
SYNOPSISradiobutton pathName ?options?
STANDARD OPTIONS-activebackground -disabledcolor -justify
-activeforeground -font -relief
-anchor-foreground-takefocus
-background-highlightcolor-text
-bitmap-highlightthickness -underline
-borderwidth-image
WIDGET-SPECIFIC OPTIONS
-command command
Specifies a Tk command to associate with the button. This com‐
mand is typically invoked when mouse button 1 is released over
the button window. The button's global variable (-variable
option) will be updated before the command is invoked.
-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.
-indicatoron boolean
Specifies whether or not the indicator should be drawn. If
false, the relief option is ignored and the widget's relief is
always sunken if the widget is selected and raised otherwise.
-selectcolor colour
Specifies a background colour to use when the button is
selected. If indicatoron is true, the colour applies to the
indicator. If indicatoron is false, this colour is used as the
background for the entire widget, in place of background or
activebackground, whenever the widget is selected. If specified
as an empty string, no special colour is used for displaying
when the widget is selected.
-state state
Specifies one of three states for the radiobutton: normal,
active, or disabled. In normal state the radiobutton is dis‐
played using the foreground and background options. The active
state is typically used when the pointer is over the radiobut‐
ton. In active state the radiobutton is displayed using the
activeforeground and activebackground options. Disabled state
means that the radiobutton should be insensitive: the default
bindings will refuse to activate the widget and will ignore
mouse button presses. In this state the disabledcolor and back‐
ground options determine how the radiobutton is displayed.
-value string
Specifies value to store in the button's associated variable
whenever this button is selected.
-variable string
Specifies name of global variable to set whenever this button is
selected. Changes in this variable also cause the button to
select or deselect itself. Defaults to the value selectedBut‐
ton.
-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 radiobutton command creates a new window (given by the pathName
argument) and makes it into a radiobutton widget. Additional options,
described above, may be specified on the command line to configure
aspects of the radiobutton such as its colours, font, text, and initial
relief. The radiobutton command returns its pathName argument. At the
time this command is invoked, there must not exist a window named path‐
Name.
A radiobutton is a widget that displays a textual string, bitmap or
image and a circle called an indicator. 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. A radiobutton has all of the
behaviour of a simple button: 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 invokes a Tk command whenever mouse
button 1 is clicked over the check button.
In addition, radiobuttons can be selected. If a radiobutton is
selected, the indicator is normally drawn as a circle containing a disc
(possibly in a special colour), and a Tk variable associated with the
radiobutton is set to a particular value. If the radiobutton is not
selected, the indicator is drawn as an empty circle. Typically, sev‐
eral radiobuttons share a single variable and the value of the variable
indicates which radiobutton is to be selected. When a radiobutton is
selected it sets the value of the variable to indicate that fact; each
radiobutton also monitors the value of the variable and automatically
selects and deselects itself when the variable's value changes. By
default the variable selectedButton is used; its contents give the
name of the button that is selected, or the empty string if no button
associated with that variable is selected. The name of the variable
for a radiobutton, plus the variable to be stored into it, may be modi‐
fied with options on the command line. Configuration options may also
be used to modify the way the indicator is displayed (or whether it is
displayed at all). By default a radiobutton is configured to select
itself on button clicks.
WIDGET COMMAND
The radiobutton command creates a new Tk command whose name is path‐
Name. 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 radiobutton 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
radiobutton 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, 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
radiobutton command.
pathName deselect
Deselects the radiobutton and sets the associated variable to an
empty string. If this radiobutton was not currently selected,
the command has no effect.
pathName invoke
Does just what would have happened if the user invoked the
radiobutton with the mouse: selects the button and invokes its
associated Tk command, 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 radiobutton. This command is
ignored if the radiobutton's state is disabled.
pathName select
Selects the radiobutton and sets the associated variable to the
value corresponding to this widget.
BINDINGS
Tk automatically creates bindings for radiobuttons that give them the
following default behaviour:
[1] The radiobutton activates whenever the mouse passes over it and
deactivates whenever the mouse leaves the radiobutton.
[2] When mouse button 1 is pressed over a radiobutton it is invoked
(it becomes selected and the command associated with the button
is invoked, if there is one).
If the radiobutton's state is disabled then none of the above actions
occur: the radiobutton is completely non-responsive.
The behaviour of radiobuttons can be changed by defining new bindings
for individual widgets.
SEE ALSObutton(9), checkbutton(9), choicebutton(9), options(9), types(9)RADIOBUTTON(9)
