The toggle Widget
Syntax:
TYPE ::= (toggle [KEYWORD ARGUMENT]...)
The widget has two possible states, `on' and `off', which correspond to
a t or nil value respectively.
The following extra properties are recognized.
:on- String representing the `on' state. By default the string ‘on’.
:off- String representing the `off' state. By default the string ‘off’.
:on-glyph- Name of a glyph to be used instead of the `:on' text string, on emacsen
that supports it.
:off-glyph- Name of a glyph to be used instead of the `:off' text string, on emacsen
that supports it.