Indicates that the action was just activated.
parameter will always be of the expected type, i.e. the parameter type
specified when the action was created. If an incorrect type is given when
activating the action, this signal is not emitted.
Since GLib 2.40, if no handler is connected to this signal then the
default behaviour for boolean-stated actions with a
type is to toggle them via the
For stateful actions where the state type is equal to the parameter
type, the default is to forward them directly to
GSimpleAction::change-state. This should allow almost all users
GSimpleAction to connect only one handler or the other.
|Default handler:|| |
The default handler is called after the handlers added via
The parameter to the activation, or
NULLif it has no parameter.
The argument can be
The data is owned by the caller of the function.