The Radiobutton Widget (Perl in a Nutshell, 2nd Edition)

21.6. The Radiobutton Widget

Create a radiobutton with the Radiobutton method. A radiobutton has an indicator to the left of the label indicating whether the button is selected. It differs from a checkbutton in that only one button may be selected at a time. Each button in a group of radiobuttons uses the same variable specified with the -variable option; when selected, the button assigns that variable the value specified by the -value option.

$parentwidget->Radiobutton (options)

The standard configuration options that apply to Radiobutton are: -activeback-ground, -activeforeground, -anchor, -background, -bg, -bitmap, -borderwidth, -bd, -cursor, -disabledforeground, -font, -foreground, -fg, -height, -highlight-background, -highlightcolor, -highlightthickness, -image, -justify, -padx, -pady, -relief, -state, -underline, -width, and -wraplength.

Other options are:

-command => callback: Pointer to a function that will be called when the radiobutton is pressed.
-indicatoron => boolean: Determines whether to display the indicator. Default is on (1).
-selectcolor => color: Color of the indicator when the radiobutton is on.
-selectimage => imgptr: Defines the image to be displayed instead of text when the radiobutton is on. Ignored if -image is not used.
-text => 'text': Defines the text string displayed in the radiobutton. See also -textvariable.
-textvariable => \$variable: Points to the variable containing text to be displayed in the radiobutton. Button text will change as $variable does.
-value => value: Sets $variable to the specified value when the radiobutton is selected. Default is 1.
-variable => \$variable: Associates the on/off value of the indicator with the specified variable.

21.6.1. Radiobutton Methods

In addition to configure and cget, the following methods are supported by Radiobutton:

deselect: Deselects the button and sets the variable to the empty string.
select: Sets the radio button.
flash: Causes the button to flash from the normal to active state colors.
invoke: Selects the button and invokes the callback command as if the radiobutton was clicked.