gtk.gesture

Module for [Gesture] class

class Gesture GestureGidBuilder GestureGidBuilderImpl

Types 3

classGesture : gtk.event_controller.EventController

[gtk.gesture.Gesture] is the base class for gesture recognition.

Although [gtk.gesture.Gesture] is quite generalized to serve as a base for multi-touch gestures, it is suitable to implement single-touch and pointer-based gestures (using the special null [gdk.event_sequence.EventSequence] value for these).

The number of touches that a [gtk.gesture.Gesture] need to be recognized is controlled by the property@Gtk.Gesture:n-points property, if a gesture is keeping track of less or more than that number of sequences, it won't check whether the gesture is recognized.

As soon as the gesture has the expected number of touches, it will check regularly if it is recognized, the criteria to consider a gesture as "recognized" is left to [gtk.gesture.Gesture] subclasses.

A recognized gesture will then emit the following signals:

[gtk.gesture.Gesture.begin] when the gesture is recognized.
[gtk.gesture.Gesture.update], whenever an input event is processed.
[gtk.gesture.Gesture.end] when the gesture is no longer recognized.

Event propagation

In order to receive events, a gesture needs to set a propagation phase through [gtk.event_controller.EventController.setPropagationPhase].

In the capture phase, events are propagated from the toplevel down to the target widget, and gestures that are attached to containers above the widget get a chance to interact with the event before it reaches the target.

In the bubble phase, events are propagated up from the target widget to the toplevel, and gestures that are attached to containers above the widget get a chance to interact with events that have not been handled yet.

States of a sequence

Whenever input interaction happens, a single event may trigger a cascade of [gtk.gesture.Gesture]s, both across the parents of the widget receiving the event and in parallel within an individual widget. It is a responsibility of the widgets using those gestures to set the state of touch sequences accordingly in order to enable cooperation of gestures around the [gdk.event_sequence.EventSequence]s triggering those.

Within a widget, gestures can be grouped through [gtk.gesture.Gesture.group]. Grouped gestures synchronize the state of sequences, so calling [gtk.gesture.Gesture.setState] on one will effectively propagate the state throughout the group.

By default, all sequences start out in the [gtk.types.EventSequenceState.None] state, sequences in this state trigger the gesture event handler, but event propagation will continue unstopped by gestures.

If a sequence enters into the [gtk.types.EventSequenceState.Denied] state, the gesture group will effectively ignore the sequence, letting events go unstopped through the gesture, but the "slot" will still remain occupied while the touch is active.

If a sequence enters in the [gtk.types.EventSequenceState.Claimed] state, the gesture group will grab all interaction on the sequence, by:

Setting the same sequence to [gtk.types.EventSequenceState.Denied] on every other

gesture group within the widget, and every gesture on parent widgets in the propagation chain.

Emitting [gtk.gesture.Gesture.cancel] on every gesture in widgets

underneath in the propagation chain.

Stopping event propagation after the gesture group handles the event.

Note

if a sequence is set early to [gtk.types.EventSequenceState.Claimed] on

[gdk.types.EventType.TouchBegin]/[gdk.types.EventType.ButtonPress] (so those events are captured before reaching the event widget, this implies [gtk.types.PropagationPhase.Capture]), one similar event will be emulated if the sequence changes to [gtk.types.EventSequenceState.Denied]. This way event coherence is preserved before event propagation is unstopped again.

Sequence states can't be changed freely. See [gtk.gesture.Gesture.setState] to know about the possible lifetimes of a [gdk.event_sequence.EventSequence].

Touchpad gestures

On the platforms that support it, [gtk.gesture.Gesture] will handle transparently touchpad gesture events. The only precautions users of [gtk.gesture.Gesture] should do to enable this support are:

If the gesture has [gtk.types.PropagationPhase.None], ensuring events of type

[gdk.types.EventType.TouchpadSwipe] and [gdk.types.EventType.TouchpadPinch] are handled by the [gtk.gesture.Gesture]

Methods

GType _getGType()

GType _gType() @property

Gesture self()Returns `this`, for use in `with` statements.

GestureGidBuilder builder()Get builder for [gtk.gesture.Gesture] Returns: New builder object

uint nPoints() @propertyGet `nPoints` property. Returns: The number of touch points that trigger recognition on this gesture.

bool getBoundingBox(out gdk.rectangle.Rectangle rect)If there are touch sequences being currently handled by gesture, returns true and fills in rect with the bounding box containing all active touches.

bool getBoundingBoxCenter(out double x, out double y)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.

gdk.device.Device getDevice()Returns the logical [gdk.device.Device] that is currently operating on gesture.

gtk.gesture.Gesture[] getGroup()Returns all gestures in the group of gesture Returns: The list of [gtk.gesture.Gesture]s, free with [glib.list.List.free]

gdk.event.Event getLastEvent(gdk.event_sequence.EventSequence sequence = null)Returns the last event that was processed for sequence.

gdk.event_sequence.EventSequence getLastUpdatedSequence()Returns the [gdk.event_sequence.EventSequence] that was last updated on gesture. Returns: The last updated sequence

bool getPoint(gdk.event_sequence.EventSequence sequence, out double x, out double y)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.

gtk.types.EventSequenceState getSequenceState(gdk.event_sequence.EventSequence sequence)Returns the sequence state, as seen by gesture.

gdk.event_sequence.EventSequence[] getSequences()Returns the list of `GdkEventSequences` currently being interpreted by gesture. Returns: A list of [gdk.event_sequence.EventSequence], the list elements are owned by GTK and must not be freed or mo...

void group(gtk.gesture.Gesture gesture)Adds gesture to the same group than group_gesture.

bool handlesSequence(gdk.event_sequence.EventSequence sequence = null)Returns true if gesture is currently handling events corresponding to sequence.

bool isActive()Returns true if the gesture is currently active.

bool isGroupedWith(gtk.gesture.Gesture other)Returns true if both gestures pertain to the same group.

bool isRecognized()Returns true if the gesture is currently recognized.

bool setSequenceState(gdk.event_sequence.EventSequence sequence, gtk.types.EventSequenceState state)Sets the state of sequence in gesture.

bool setState(gtk.types.EventSequenceState state)Sets the state of all sequences that gesture is currently interacting with.

void ungroup()Separates gesture into an isolated group.

gulong connectBegin(T)(T callback,  Flag!"After" after =  No.After) if (isCallable!T
    &&  is(ReturnType!T ==  void)
   && (Parameters!T.length <  1 || (ParameterStorageClassTuple!T[0]  ==  ParameterStorageClass.none &&  is(Parameters!T[0]  ==  gdk.event_sequence.EventSequence)))
   && (Parameters!T.length <  2 || (ParameterStorageClassTuple!T[1]  ==  ParameterStorageClass.none &&  is(Parameters!T[1] :  gtk.gesture.Gesture)))
   &&  Parameters!T.length <  3)

Connect to `Begin` signal.

gulong connectCancel(T)(T callback,  Flag!"After" after =  No.After) if (isCallable!T
    &&  is(ReturnType!T ==  void)
   && (Parameters!T.length <  1 || (ParameterStorageClassTuple!T[0]  ==  ParameterStorageClass.none &&  is(Parameters!T[0]  ==  gdk.event_sequence.EventSequence)))
   && (Parameters!T.length <  2 || (ParameterStorageClassTuple!T[1]  ==  ParameterStorageClass.none &&  is(Parameters!T[1] :  gtk.gesture.Gesture)))
   &&  Parameters!T.length <  3)

Connect to `Cancel` signal.

gulong connectEnd(T)(T callback,  Flag!"After" after =  No.After) if (isCallable!T
    &&  is(ReturnType!T ==  void)
   && (Parameters!T.length <  1 || (ParameterStorageClassTuple!T[0]  ==  ParameterStorageClass.none &&  is(Parameters!T[0]  ==  gdk.event_sequence.EventSequence)))
   && (Parameters!T.length <  2 || (ParameterStorageClassTuple!T[1]  ==  ParameterStorageClass.none &&  is(Parameters!T[1] :  gtk.gesture.Gesture)))
   &&  Parameters!T.length <  3)

Connect to `End` signal.

gulong connectSequenceStateChanged(T)(T callback,  Flag!"After" after =  No.After) if (isCallable!T
    &&  is(ReturnType!T ==  void)
   && (Parameters!T.length <  1 || (ParameterStorageClassTuple!T[0]  ==  ParameterStorageClass.none &&  is(Parameters!T[0]  ==  gdk.event_sequence.EventSequence)))
   && (Parameters!T.length <  2 || (ParameterStorageClassTuple!T[1]  ==  ParameterStorageClass.none &&  is(Parameters!T[1]  ==  gtk.types.EventSequenceState)))
   && (Parameters!T.length <  3 || (ParameterStorageClassTuple!T[2]  ==  ParameterStorageClass.none &&  is(Parameters!T[2] :  gtk.gesture.Gesture)))
   &&  Parameters!T.length <  4)

Connect to `SequenceStateChanged` signal.

gulong connectUpdate(T)(T callback,  Flag!"After" after =  No.After) if (isCallable!T
    &&  is(ReturnType!T ==  void)
   && (Parameters!T.length <  1 || (ParameterStorageClassTuple!T[0]  ==  ParameterStorageClass.none &&  is(Parameters!T[0]  ==  gdk.event_sequence.EventSequence)))
   && (Parameters!T.length <  2 || (ParameterStorageClassTuple!T[1]  ==  ParameterStorageClass.none &&  is(Parameters!T[1] :  gtk.gesture.Gesture)))
   &&  Parameters!T.length <  3)

Connect to `Update` signal.

Constructors

this(void * ptr, Flag!"Take" take)

classGestureGidBuilderImpl(T) : gtk.event_controller.EventControllerGidBuilderImpl!T

Methods

T nPoints(uint propval)Set `nPoints` property. Params: propval = The number of touch points that trigger recognition on this gesture. Returns: Builder instance for fluent chaining

classGestureGidBuilder : GestureGidBuilderImpl!GestureGidBuilder

Fluent builder for [gtk.gesture.Gesture]

Methods

Gesture build()