QFeedbackEffect Class Reference

The QFeedbackEffect class is the abstract base class for feedback effects. More...

 #include <QFeedbackEffect>

Inherits: QObject.

Inherited by: QFeedbackFileEffect and QFeedbackHapticsEffect.

This class was introduced in Qt Mobility 1.1.

List of all members, including inherited members

Public Types

enum	Duration { Infinite }
enum	ErrorType { UnknownError, DeviceBusy }
enum	State { Stopped, Paused, Running, Loading }
enum	ThemeEffect { ThemeBasic, ThemeSensitive, ThemeBasicButton, ThemeSensitiveButton, ..., ThemeUser }

Properties

duration : const int
state : const State

1 property inherited from QObject

Public Functions

	QFeedbackEffect ( QObject * parent = 0 )
virtual int	duration () const = 0
virtual State	state () const = 0

29 public functions inherited from QObject

Public Slots

void	pause ()
void	start ()
void	stop ()

1 public slot inherited from QObject

Signals

void	error ( QFeedbackEffect::ErrorType error ) const
void	stateChanged ()

1 signal inherited from QObject

Static Public Members

bool	playThemeEffect ( ThemeEffect effect )
bool	supportsThemeEffect ()

4 static public members inherited from QObject

Protected Functions

virtual void setState ( State state ) = 0

7 protected functions inherited from QObject

Additional Inherited Members

1 public variable inherited from QObject
2 protected variables inherited from QObject

Detailed Description

The QFeedbackEffect class is the abstract base class for feedback effects.

It represents an effect to provide feedback to a person (i.e., an effect that affect human senses). The technology available today usually only provides haptic effects, which deal with the sense of touch, and audio effects. The QFeedbackHapticsEffect and QFeedbackFileEffect are implementations of haptic effects and can be used to control a mobile device's vibrator. In addition, the QFeedbackFileEffect can also be used to play audio feedback.

Feedback effects have a duration, which is measured in milliseconds. Subclasses reimplement duration() to inform how long the effect lasts. The duration is the total time the effect will last, and thus includes any envelope modifiers (attack and fade).

At any given time, a feedback effect is in one of four states: Loading, Stopped, Running, or Paused. See the State enum documentation for further details. Subclasses must reimplement state() to report which state an effect is in, and setState() to receive state change requests. The start(), pause(), and stop() slots calls setState() with the corresponding new State. Changes in state are reported through the stateChanged() signal and may happen asynchronously some time after the state change request.

A system often has a set of standard feedback effects for user interface interaction (e.g., button clicks). The ThemeEffect describes the standard effects that QFeedbackEffect supports. It is named so because the effects often depend on the theme of the user interface. You can play these effects using the playThemeEffect() function.

 QFeedbackEffect::playThemeEffect(QFeedbackEffect::ThemeBasicButton);

The playThemeEffect() function returns true if the effect was played successfully. An effect may not be played if the system does not support it or if an error occurred.

Member Type Documentation

enum QFeedbackEffect::Duration

This enum describes the possible effect predefined duration types. Generally a specific milliseconds value can be supplied instead of one of these values.

Constant	Value	Description
`QFeedbackEffect::Infinite`	`-1`	Infinite effect duration

enum QFeedbackEffect::ErrorType

This enum describes the possible errors happening on the effect.

Constant	Value	Description
`QFeedbackEffect::UnknownError`	`0`	An unknown error occurred.
`QFeedbackEffect::DeviceBusy`	`1`	The feedback could not start because the device is busy.

See also error().

enum QFeedbackEffect::State

This enum describes the state of the effect. An effect will be in one of these states.

Constant	Value	Description
`QFeedbackEffect::Stopped`	`0`	The effect is not running. This is the initial state. The state changes to either Loading when loading an effect or to Running when the effect is started by calling start(). When an effect has finished playing, it will enter the Stopped state again.
`QFeedbackEffect::Paused`	`1`	The effect is paused. Calling start() will resume it.
`QFeedbackEffect::Running`	`2`	The effect is running. You can control the current state by calling the stop() or pause() functions.
`QFeedbackEffect::Loading`	`3`	The effect is loading. That can happen when loading is done asynchronously. When the effect has loaded, the state will change to either Running (if start() has been called) or Stopped.

See also state().

enum QFeedbackEffect::ThemeEffect

This enum describes all possible theme effect types. In general, "sensitive" versions of effects are useful if it is less important that the effect is noticed, or when a lot of the effects are going to be played close together. Theme effects might be tactile, or audio or visual.

Not all platforms and devices have distinct effects for each type.

Constant	Value	Description
`QFeedbackEffect::ThemeBasic`	`0`	Generic feedback.
`QFeedbackEffect::ThemeSensitive`	`1`	Generic sensitive feedback.
`QFeedbackEffect::ThemeBasicButton`	`2`	Feedback for interacting with a button (e.g. pressing).
`QFeedbackEffect::ThemeSensitiveButton`	`3`	Sensitive feedback for interacting with a button (e.g. auto repeat).
`QFeedbackEffect::ThemeBasicKeypad`	`4`	Feedback for interacting with a keypad button.
`QFeedbackEffect::ThemeSensitiveKeypad`	`5`	Sensitive feedback for interacting with a keypad button.
`QFeedbackEffect::ThemeBasicSlider`	`6`	Feedback for moving a slider.
`QFeedbackEffect::ThemeSensitiveSlider`	`7`	Sensitive feedback for moving a slider.
`QFeedbackEffect::ThemeBasicItem`	`8`	Feedback when interacting with a list or grid item.
`QFeedbackEffect::ThemeSensitiveItem`	`9`	Sensitive feedback when interacting with a list or grid item.
`QFeedbackEffect::ThemeItemScroll`	`10`	Feedback when scrolling a list or grid item view.
`QFeedbackEffect::ThemeItemPick`	`11`	Feedback when selecting an item to move in a list or grid view.
`QFeedbackEffect::ThemeItemDrop`	`12`	Feedback when dropping an item in a list or grid view.
`QFeedbackEffect::ThemeItemMoveOver`	`13`	Feedback when moving an item in a list or grid view.
`QFeedbackEffect::ThemeBounceEffect`	`14`	Feedback for a bounce effect.
`QFeedbackEffect::ThemeCheckBox`	`15`	Feedback for selecting a checkbox.
`QFeedbackEffect::ThemeMultipleCheckBox`	`16`	Feedback for selecting checkboxes of multiple items.
`QFeedbackEffect::ThemeEditor`	`17`	Feedback for interacting with an editor.
`QFeedbackEffect::ThemeTextSelection`	`18`	Feedback for selecting text.
`QFeedbackEffect::ThemeBlankSelection`	`19`	Feedback for a blank selection.
`QFeedbackEffect::ThemeLineSelection`	`20`	Feedback for selecting a line.
`QFeedbackEffect::ThemeEmptyLineSelection`	`21`	Feedback for selecting an empty line.
`QFeedbackEffect::ThemePopUp`	`22`	Generic feedback for interacting with a popup.
`QFeedbackEffect::ThemePopupOpen`	`23`	Generic feedback when a popup opens.
`QFeedbackEffect::ThemePopupClose`	`24`	Generic feedback when a popup closes.
`QFeedbackEffect::ThemeFlick`	`25`	Generic feedback when starting a flick gesture.
`QFeedbackEffect::ThemeStopFlick`	`26`	Generic feedback when stopping a flick.
`QFeedbackEffect::ThemeMultiPointTouchActivate`	`27`	Generic feedback when a touch gesture with more than one point is started.
`QFeedbackEffect::ThemeRotateStep`	`28`	Feedback when rotating using a gesture.
`QFeedbackEffect::ThemeLongPress`	`29`	Feedback for a long press (or tap and hold) gesture.
`QFeedbackEffect::ThemePositiveTacticon`	`30`	Generic feedback for notification of a successful operation.
`QFeedbackEffect::ThemeNeutralTacticon`	`31`	Generic feedback for notification.
`QFeedbackEffect::ThemeNegativeTacticon`	`32`	Generic feedback for notification of a failed operation.
`QFeedbackEffect::NumberOfThemeEffects`	`33`	The number of built-in effects.
`QFeedbackEffect::ThemeUser`	`65535`	The starting point for any user defined effects, where supported.

Property Documentation

duration : const int

This property holds duration of the feedback effect, in milliseconds.

In some cases the duration will be unknown, which will be reported as 0. If the duration is infinite, QFeedbackEffect::Infinite will be returned. Some subclasses may have more than one type of duration (for example, QFeedbackHapticsEffect), and this property will return the total duration of the effect.

Access functions:

virtual int duration () const = 0

state : const State

This property holds state of the feedback effect.

This returns the state of the feedback effect. The State enumeration reports the possible states.

Access functions:

virtual State state () const = 0

Notifier signal:

void	stateChanged ()

Member Function Documentation

QFeedbackEffect::QFeedbackEffect ( QObject * parent = 0 )

Constructs the QFeedbackEffect base class, and passes parent to QObject's constructor. This is called by the classes that inherit from this class.

void QFeedbackEffect::error ( QFeedbackEffect::ErrorType error ) const `[signal]`

This signal is emitted by subclasses if an error occurred during playback of an effect. The ErrorType enum describes the errors that can be reported.