Sets the status of the toggle button.
Set to true if you want the `GtkToggleButton` to be “pressed in”, and false to raise it.
If the status of the button changes, this action causes the [signal@GtkToggleButton:GtkToggleButton:toggled] signal to be
emitted.
| this |
a `GtkToggleButton`. |
| is_active |
true or false. |