Gets whether a Button is in a toggle state or not.
If true, clicking the button toggles it between a selected and an unselected state. You can get or set this state programmatically by using the selected property. If false, the button does not stay pressed after the user releases it. In this case, its selected property is always false.
Buttons like this are used for performing actions. When toggle is set to false, selected is forced to false because only toggle buttons can be selected.
The default value is false.