gtk:gesture-set-state (gesture state)

gesture -- a gtk:gesture object
state -- a gtk:event-sequence-state value

True if the state of at least one event sequence was changed successfully.

Sets the state of all event sequences that the gesture is currently interacting with. Event sequences start in :none state, and whenever they change state, they can never go back to that state. Likewise, event sequences in :denied state cannot turn back to a not denied state. With these rules, the lifetime of an event sequence is constrained to the next four:

• None
• None → Denied
• None → Claimed
• None → Claimed → Denied

Note: Due to event handling ordering, it may be unsafe to set the state on another gesture within a "begin" signal handler, as the callback might be executed before the other gesture knows about the event sequence. A safe way to perform this could be:

static void
first_gesture_begin_cb (GtkGesture       *first_gesture,
                        GdkEventSequence *sequence,
                        gpointer          user_data)
{
  gtk_gesture_set_sequence_state (first_gesture,
                                  sequence, GTK_EVENT_SEQUENCE_CLAIMED);
  gtk_gesture_set_sequence_state (second_gesture,
                                  sequence, GTK_EVENT_SEQUENCE_DENIED);
}


static void
second_gesture_begin_cb (GtkGesture       *second_gesture,
                         GdkEventSequence *sequence,
                         gpointer          user_data)
{
  if (gtk_gesture_get_sequence_state (first_gesture, sequence)
       == GTK_EVENT_SEQUENCE_CLAIMED)
    gtk_gesture_set_sequence_state (second_gesture,
                                    sequence, GTK_EVENT_SEQUENCE_DENIED);
}  

If both gestures are in the same group, just set the state on the gesture emitting the event, the event sequence will be already be initialized to the global state of the group when the second gesture processes the event.