QGestureRecognizer Class Reference
[QtGui module]

Supporting New Gestures

To add support for new gestures, you need to derive from QGestureRecognizer to create a custom recognizer class, construct an instance of this class, and register it with the application by calling QGestureRecognizer::registerRecognizer(). You can also subclass QGesture to create a custom gesture class, or rely on dynamic properties to express specific details of the gesture you want to handle.

Your custom QGestureRecognizer subclass needs to reimplement the recognize() function to handle and filter the incoming input events for QWidget and QGraphicsObject subclasses. Although the logic for gesture recognition is implemented in this function, you can store persistent information about the state of the recognition process in the QGesture object supplied. The recognize() function must return a value of QGestureRecognizer::Result that indicates the state of recognition for a given gesture and target object. This determines whether or not a gesture event will be delivered to a target object.

If you choose to represent a gesture by a custom QGesture subclass, you will need to reimplement the create() function to construct instances of your gesture class. Similarly, you may need to reimplement the reset() function if your custom gesture objects need to be specially handled when a gesture is canceled.

See also QGesture.

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