Emitted when the user activates a child widget in a
This can happen either by clicking or double-clicking, or via a keybinding.
This is a keybinding signal, but it can be used by applications for their own purposes.
The default bindings are Space and Enter.
|Default handler: |
The default handler is called before the handlers added via
|Signal can be directly emitted on objects from user code|
|Available since: 4.0|