The ToggleButton widget is a classic GUI ToggleButton with to states: pressed or not pressed.
The button is a classic GUI element, that supports two states: pressed and not pressed. The state is changed by a mouse (click) or keyboard (enter or space) event. There is an additional third state when the tri-state mode is enabled. The third state means that the widget was neither pressed nor unpressed, i.e. the state of the button is undetermined.
Here are some links that demonstrate the usage of the widget: