Tactile +feedback

There are two types of cases where vibration or audio of the +device is used as an output method when the user is interacting with the device +touch screen:

When the user has touched an active area of the screen, and an action +will be triggered on touch release
Interaction with given components has been successful

As with sounds, tactile feedback must be used carefully so as not to desensitize +the user to the vibration: the attention grabbing quality remains and functions +so long as the feedback is not too frequent.

Tactile feedback is included in those common UI components, where seen +as beneficial. When new components are designed, tactile feedback is to be +included in those if seen beneficial usability-wise. For example, in any button +type of UI component the tactile feedback is natural. Application can disable +tactile feedback from the common UI components it uses, if seen necessary. +This is acceptable only in cases, where tactile feedback would cause interference, +like during a phone call or when giving audio commands to the system.

The user can choose whether tactile feedback is on or off.

Characteristics +of haptics related APIs

You can use the following APIs to create +haptic effects:

Tactile +Feedback Client API
- available from S60 5.0 onwards
- can be used on all S60 5.0 or later mobile devices but the feedback +is played only on touch enabled layouts
- provides simple functions for triggering various predefined tactile +feedback (vibration or audio) effects
- enables a consistent user experience in all applications of the mobile +device (an application gives a logical feedback type as an input and the actual +physical effect depends on the mobile device configuration and end user settings)
- when the area feedback is used, latency is the smallest for the feedback +triggering (tactile feedback can be triggered at the window server level before +the corresponding pointer event is delivered to the visible application)
- direct feedback is easy to integrate into HandlePointerEventL code
- an application can select the logical tactile feedback from certain +types and the produced effect may be different on various mobile devices
Vibra +API
- available from S60 3.0 onwards
- can be used for running device vibrator with given intensity for given +period of time
- a privileged client application can use this for playing pulse effects +which have a really short duration (as the ones used for tactile feedback)

When to use +Tactile Feedback Client API and Vibra API

You should use

Tactile Feedback Client API for providing tactile feedback in custom +controls (grids, lists, etc.) which comply with the style of the Core UI components +to ensure a uniform user experience among applications
Vibra API to produce haptic effects such as ringing tone vibration

Using +tactile feedback in C++ applications

The API to use for tactile +feedback is the Tactile +feedback client API.

The Symbian platform includes a tactile +feedback interface to add, modify and remove feedback areas in the registry. +There is also an option to trigger direct feedback and bypass the registry. + MTouchFeedback::Instance() is used for acquiring a pointer +to a touch feedback instance. When touch feedback is activated, the mobile +device users get a slight vibration when the control with the feedback interface +is touched.

Tactile feedback can be set be disabled in a client +application or a mobile device in some situations, for example, during phone +calls.

Client applications cannot determine the actual physical +feedback that is generated. It depends on device configuration and current +settings. In current devices, the user changeable settings include vibration +and audio feedback intensity level.

In your application, you can use +the following feedback types, defined in TTouchLogicalFeedback:

+ + + +

ETouchFeedbackNone

Use for disabling feedback for some areas of the application window +when using the area registry.

+ + +

ETouchFeedbackBasic

Use as default feedback for stylus down events, for example, when +the mobile device user taps a button or tab.

+ + +

ETouchFeedbackSensitive

Sensitive feedback for situations where the triggering action is +not very important (e.g. change of focus in a list), or when there can be +a large number of feedback instances within a short time (e.g. text selection +which gives feedback on every new selected character). Also used for scrolling +and dragging.

+ + + +

To use vibration or audio feedback in your application:

Include touchfeedback.lib in +your .mmp file.
Include touchfeedback.h.
To enable +tactile feedback for your application, add the following code.
MTouchFeedback* feedback = MTouchFeedback::Instance(); +feedback->SetFeedbackEnabledForThisApp(ETrue); // enabling feedback is optional
Do +not delete the pointer in the controller destructor.
To use tactile +feedback when a mobile device user points at a control, add the following +code.
void CMyContainerControl::HandlePointerEventL(const TPointerEvent& aPointerEvent) + { + // Feedback is always played at pointer down event + if(aPointerEvent.iType == TPointerEvent::EButton1Down) + { + MTouchFeedback* feedback = MTouchFeedback::Instance(); + if (feedback) + { + feedback->InstantFeedback(ETouchFeedbackBasic); + } + } + + // Your other pointer event handling code here +
To enable +automatic feedback triggering in a specific area of a UI component, add
feedback->SetFeedbackArea(this, + 1, // area Id + TRect(0,0,20,20), + ETouchFeedbackBasic, + ETouchEventStylusDown); +

Using tactile feedback does not require additional platform +security capabilities for your application.