gtk:gesture-sequence-state (gesture sequence)

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

The gtk:gesture-sequence-state function returns the sequence state, as seen by gesture. The (setf gtk:gesture-sequence-state) function sets the state of sequence in gesture. Sequences start in :none state, and whenever they change state, they can never go back to that state. Likewise, sequences in :denied 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 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 sequence will be already be initialized to the group's global state when the second gesture processes the event.