public bool activate ()
For widgets that can be “activated” (buttons, menu items, etc.
), this function activates them.
The activation will emit the signal set using [method@Gtk.WidgetClass.set_activate_signal] during class initialization.
Activation is what happens when you press <kbd>Enter</kbd> on a widget during key navigation.
If you wish to handle the activation keybinding yourself, it is recommended to use [method@Gtk.WidgetClass.add_shortcut] with an action created with [ctor@Gtk.SignalAction.new].
If this isn't activatable, the function returns false.
a `GtkWidget` that’s activatable
true if the widget was activatable