Memory-managed wrapper type.

Type class for types which can be safely cast to Gesture, for instance with toGesture.

Cast to Gesture, for types for which this is known to be safe. For general casts, use castTo.

If there are touch sequences being currently handled by gesture, returns True and fills in rect with the bounding box containing all active touches.

Otherwise, False will be returned.

Note: This function will yield unexpected results on touchpad gestures. Since there is no correlation between physical and pixel distances, these will look as if constrained in an infinitely small area, rect width and height will thus be 0 regardless of the number of touchpoints.

If there are touch sequences being currently handled by gesture, returns True and fills in x and y with the center of the bounding box containing all active touches.

Otherwise, False will be returned.

Returns the logical GdkDevice that is currently operating on gesture.

This returns Nothing if the gesture is not being interacted.

Returns all gestures in the group of gesture

Returns the last event that was processed for sequence.

Note that the returned pointer is only valid as long as the sequence is still interpreted by the gesture. If in doubt, you should make a copy of the event.

Returns the GdkEventSequence that was last updated on gesture.

If sequence is currently being interpreted by gesture, returns True and fills in x and y with the last coordinates stored for that event sequence.

The coordinates are always relative to the widget allocation.

Returns the sequence state, as seen by gesture.

Returns the list of GdkEventSequences currently being interpreted by gesture.

Adds gesture to the same group than groupGesture.

Gestures are by default isolated in their own groups.

Both gestures must have been added to the same widget before they can be grouped.

When gestures are grouped, the state of GdkEventSequences is kept in sync for all of those, so calling gestureSetSequenceState, on one will transfer the same value to the others.

Groups also perform an "implicit grabbing" of sequences, if a GdkEventSequence state is set to EventSequenceStateClaimed on one group, every other gesture group attached to the same GtkWidget will switch the state for that sequence to EventSequenceStateDenied.

Returns True if gesture is currently handling events corresponding to sequence.

Returns True if the gesture is currently active.

A gesture is active while there are touch sequences interacting with it.

Returns True if both gestures pertain to the same group.

Returns True if the gesture is currently recognized.

A gesture is recognized if there are as many interacting touch sequences as required by gesture.

Sets the state of sequence in gesture.

Sequences start in state EventSequenceStateNone, and whenever they change state, they can never go back to that state. Likewise, sequences in state EventSequenceStateDenied 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 Gesture::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:

c code

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.

Sets the state of all sequences that gesture is currently interacting with.

Sequences start in state EventSequenceStateNone, and whenever they change state, they can never go back to that state. Likewise, sequences in state EventSequenceStateDenied 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 Gesture::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:

c code

static void
first_gesture_begin_cb (GtkGesture       *first_gesture,
                        GdkEventSequence *sequence,
                        gpointer          user_data)
{
  gtk_gesture_set_state (first_gesture, GTK_EVENT_SEQUENCE_CLAIMED);
  gtk_gesture_set_state (second_gesture, 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_state (second_gesture, 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.

Separates gesture into an isolated group.

Construct a GValueConstruct with valid value for the “n-points” property. This is rarely needed directly, but it is used by new.

Get the value of the “n-points” property. When overloading is enabled, this is equivalent to

get gesture #nPoints

Emitted when the gesture is recognized.

This means the number of touch sequences matches Gesture:nPoints.

Note: These conditions may also happen when an extra touch (eg. a third touch on a 2-touches gesture) is lifted, in that situation sequence won't pertain to the current set of active touches, so don't rely on this being true.

Connect a signal handler for the begin signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after gesture #begin callback

By default the object invoking the signal is not passed to the callback. If you need to access it, you can use the implit ?self parameter. Note that this requires activating the ImplicitParams GHC extension.

Connect a signal handler for the begin signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on gesture #begin callback

Emitted whenever a sequence is cancelled.

This usually happens on active touches when eventControllerReset is called on gesture (manually, due to grabs...), or the individual sequence was claimed by parent widgets' controllers (see gestureSetSequenceState).

gesture must forget everything about sequence as in response to this signal.

Connect a signal handler for the cancel signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after gesture #cancel callback

By default the object invoking the signal is not passed to the callback. If you need to access it, you can use the implit ?self parameter. Note that this requires activating the ImplicitParams GHC extension.

Connect a signal handler for the cancel signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on gesture #cancel callback

Emitted when gesture either stopped recognizing the event sequences as something to be handled, or the number of touch sequences became higher or lower than Gesture:nPoints.

Note: sequence might not pertain to the group of sequences that were previously triggering recognition on gesture (ie. a just pressed touch sequence that exceeds Gesture:nPoints). This situation may be detected by checking through gestureHandlesSequence.

Connect a signal handler for the end signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after gesture #end callback

By default the object invoking the signal is not passed to the callback. If you need to access it, you can use the implit ?self parameter. Note that this requires activating the ImplicitParams GHC extension.

Connect a signal handler for the end signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on gesture #end callback

Emitted whenever a sequence state changes.

See gestureSetSequenceState to know more about the expectable sequence lifetimes.

Connect a signal handler for the sequenceStateChanged signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after gesture #sequenceStateChanged callback

By default the object invoking the signal is not passed to the callback. If you need to access it, you can use the implit ?self parameter. Note that this requires activating the ImplicitParams GHC extension.

Connect a signal handler for the sequenceStateChanged signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on gesture #sequenceStateChanged callback

Emitted whenever an event is handled while the gesture is recognized.

sequence is guaranteed to pertain to the set of active touches.

Connect a signal handler for the update signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after gesture #update callback

By default the object invoking the signal is not passed to the callback. If you need to access it, you can use the implit ?self parameter. Note that this requires activating the ImplicitParams GHC extension.

Connect a signal handler for the update signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on gesture #update callback