Toggle buttons are derived from normal buttons and are very similar, except they will always be in one of two states, alternated by a click. They may be depressed (toggled), and when you click again, they will pop back up. Click again and they will pop back down.
Toggle buttons are the basis for check buttons and radio buttons, as such, many of the calls used for toggle buttons are inherited by radio and check buttons. I will point these out when we come to them.
Creating a new toggle button goes a little like this:
Gtk::ToggleButton.new Gtk::ToggleButton.new( label ) Gtk::ToggleButton.new( item )
As you can imagine, these work identically to the normal button widget calls. The first creates a blank toggle button, while the second creates one with a label widget already packed into it, with label being the string of the label. The third method is for putting a Gtk::Stock item into the button. We'll cover Stock items in detail later in the tutorial.
To retrieve the state of the toggle widget, including radio and check buttons, we use Gtk::ToggleButton#active?. It returns true if the button is toggled, and false if the button is not toggled. The callback could be something like this:
Gtk::ToggleButton.signal_connect( 'toggled' ) {
|widget|
if widget.active?
toggled_callback
elsif not widget.active?
not_toggled_callback
end
}
To force the state of the toggle button, and it's children, the radio and check buttons, use these methods:
Gtk::ToggleButton#set_active( active ) Gtk::ToggleButton#active=( active )
The above call can be used to set the state of the toggle button, and it's children the radio and check buttons. The first, and only argument is a boolean true or false to specify whether it should be down (depressed) or up (released). The default is up, or false.
Note that when you use the Gtk::ToggleButton#set_active method, and the state is actually changed, it causes the "clicked" and "toggled" signals to be emitted from the button.
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