\brief The HbWidgetFeedback class provides an interface for widgets

    to inform the feedback framework about user interactions in order

    to trigger feedback effects.

    The HbWidgetFeedback class is for use in widget implementations.

    It is not relevant when you are simply using existing widgets in

    an application.

    As a widget developer, you may want to give feedback when the user

    interacts with your widget. Audio signals or vibration are examples of

    possible feedback effects. To trigger the feedback effects supported by

    the feedback framework, you must inform the feedback framework about

    the detected user interaction and its specific type.

    Interactions are divided into two main types:

    <ul>

    <li><b>Instant interactions.</b> Short user actions, such as clicking

    a button or changing a selection on a list. A typical feedback effect

    for these interactions is a fire-and-forget type of event, where

    the physical response is played from beginning to end.</li>

    <li><b>Continuous interactions.</b> Longer user actions, such as scrolling

    or dragging. Playing the feedback for these interactions continues until

    explicitly stopped.</li>

    </ul>

    HbWidgetFeedback provides static methods for informing the feedback

    framework about user interactions:

    \link HbWidgetFeedback::triggered() triggered() \endlink for instant interactions,

    and \link HbWidgetFeedback::continuousTriggered() continuousTriggered() \endlink

    and \link HbWidgetFeedback::continuousStopped() continuousStopped() \endlink

    for continuous interactions. Information on the target widget of the interaction

    and the interaction type is passed in the method parameters. The feedback framework

    makes decisions about the actual effects, based on the widget type, situation,

    and specific interaction type.

    A widget should only call interaction methods when the user actually

    interacts with the widget, and not when the widget state changes for some

    other reason. For example, feedback effects are not desirable when

    an application resets widget states by calling the widget API, or when

    a progress bar is moved during a file transfer.

    How you use this class or whether you need to use it at all depends on 

    what kind of widget you are developing:

    <b>Standard widgets.</b> If you are developing a standard %Hb widget, 

    such as HbPushButton, HbComboBox, and so on, you should use this class,

    %HbWidgetFeedback, for triggering feedback effects upon user interaction.

    See the use case below for details.

    <b>Custom widgets that derive from a standard widget.</b> If you are 

    developing a custom widget that derives from one of the standard

    %Hb widgets (such as HbPushButton, HbComboBox, and so on),

    the base class widget most probably has predefined feedback effects,

    and you do not need to do anything. The base class takes care of triggering

    the default effects upon user interaction.

    <b>Custom widgets that derive directly from HbWidget.</b> If your custom

    widget derives directly from HbWidget, and not through any of the standard

    %Hb widgets, you should not use %HbWidgetFeedback. The recommended way

    to define feedback for your widget is to use classes HbInstantFeedback and

    HbContinuousFeedback.

    \section _usecases_hbwidgetfeedback Using HbWidgetFeedback

    \subsection _uc_standardhb_hbwidgetfeedback Supporting feedback effects in a standard widget

    Call the HbWidgetFeedback methods in a standard widget when the user

    interacts with the widget. Choose the correct method according to

    the interaction style: instant or continuous.

    To support instant feedback features in a standard %Hb widget, call 

    HbWidgetFeedback::triggered() with a suitable Hb::InstantInteraction

    parameter to specify the interaction type, whenever you detect any

    user interaction that is instant by nature. For example:

    \code

    // The widget has been pressed down and released

    HbWidgetFeedback::triggered(this, Hb::InstantClicked);

    \endcode

    See Hb::InstantInteraction for the list of all predefined instant

    interactions.

    Whenever you detect any of the specified continuous user interactions in

    your standard %Hb widget, or when the continuous interaction ends, call

    either HbWidgetFeedback::continuousTriggered() or HbWidgetFeedback::continuousStopped()

    with the suitable Hb::ContinuousInteraction parameter. For example:

    \code

    // User has started moving the slider handle.

    HbWidgetFeedback::continuousTriggered(this, Hb::ContinuousDragged);

    \endcode

    \code

    // User has stopped moving the slider handle.

    HbWidgetFeedback::continuousStopped(this, Hb::ContinuousDragged);

    \endcode

    See Hb::ContinuousInteraction for the list of all predefined

    continuous interactions.

    \sa HbInstantFeedback, HbContinuousFeedback

    Passes information about an instant interaction from the widget to the

    feedback manager, which forwards it to all active feedback plugins.

    \param widget Target widget of the interaction

    \param interaction The instant interaction type

    \param modifiers Optional Hb::InteractionModifier flags with more detailed

    information about the interaction

    Passes information about a started continuous interaction from the

    widget to the feedback manager, which forwards it to all active feedback

    plugins.

    \param widget Target widget of the interaction

    \param interaction The continuous interaction type

    \param delta The direction and distance of the interaction

    Passes information about the stopped continuous interaction from the

    widget to the feedback manager, which forwards it to all active feedback

    plugins. This method is needed for stopping the continuous feedback

    \param widget Target widget of the interaction

    \param interaction The continuous interaction type