Touch UI observer interfaces

To support the touch functionality in the UI components, following observer interfaces are provided:

  • Navigation decorator observer (MAknNaviDecoratorObserver)- It is used in the navigation pane. The interface receives an event indicating that the decorator’s right or left arrow has been tapped (or the navi label). Based on the event received, the observer implementation performs an action (for example, raise the volume or change focus to the next tab). This observer is useful when custom controls needs to be implemented in the navigation control. The observer can be set using CAknNavigationDecorator::SetNaviDecoratorObserver().

  • Long tap detector (CAknLongTapDetector) - It is an AVKON component that an application or control can use to receive long tap events.

    The long tap handler must inherit from MAknLongTapDetectorCallBack and implement the HandleLongTapEventL() call back function for long tap events.

    When the stylus/finger is held down in the same position, an animation starts in about 0.15 s to show that the long tap functionality has started. Animation is provided by AVKON and cannot be changed by the application or control. However, animation can be turned off using the class CAknLongTapDetector in the Touch UI utilities API.

    For implementation information, see the Touch UI utilities API specification.

  • Title pane touch observer - The title pane touch observer enables you to provide functionality for title pane touch events. For implementation information, see the Title pane touch observer API specification.