135 	};

   136 

   137 class MWsAnimationScheduler: public MWsObjectProvider

   138 /** A system mechanism for customising the animation timer to a particular hardware variant or to a

   139 	particular external compositor e.g. an out-of-scene transition engine.

   140 	The default animation scheduler in WSERV does not understand device-dependant parameters e.g.

   141 	screen refresh rates

   142 	@publishedPartner

   143 	@released

   144 	to be adapted when WSERV migrates to surfaces

   145 */	{

   146 public:

   147 	/** Called to schedule an animation event for a screen to occur not before some point

   148 	A screen may be scheduled to animate several times without actually receiving an animation event from the scheduler

   149 	If the scheduler cannot honour the request e.g. device constraints, it ignores the request.

   150 	@param aScreen the screen to recieve the event

   151 	@param aWhen the point in time the event need not occur before

   152 	*/

   153 	virtual void ScheduleAnimation(MWsScreen& aScreen,const TTime& aWhen) = 0;

   154 	/** Called if a screen determines that it no longer needs to schedule any animation

   155 	@param aScreen the screen not needing to receive any animation events

   156 	*/

   157 	virtual void UnscheduleAnimation(MWsScreen& aScreen) = 0;

   158 	/** Called to schedule the redrawing of all screens containing this graphic.

   159 	The redrawing of affected screens can be deferred by the scheduler.

   160 	@param aId the ID of the graphic to be redrawn.  The graphic itself need not exist

   161 		(e.g. it has just been deleted, hence the need to redraw all potentially affected screens). */

   162 	virtual void Invalidate(const TGraphicDrawerId& aId) = 0;

   163 	/** Called when the Window Server receives a TRawEvent::EInactive  event, to signal power-saving */

   164 	virtual void OnInactive() = 0;

   165 	/** Called when the Window Server receives a TRawEvent::EActive event, to signal screen back on */

   166 	virtual void OnActive() = 0;

   167 

   168 	/** Called to schedule a redraw for a screen which is out of date

   169 	A screen may be scheduled to redraw several times without actually receiving aredraw event from the scheduler

   170 	If this request is ignored then the screen will be draw incorrectly untill a such a request is not ignored.

   171 	@param aScreen the screen to recieve the event

   172 	@param aWhen the point in time the event need not occur before

   173 	*/

   174 	virtual void ScheduleRedraw(MWsScreen& aScreen,const TTime& aWhen) = 0;

   175 	/** Called to force a previously scheduled redraw for a screen to happen synchronously

   176 	Used when we are about to loose our ability to perform the redraw correctly.

   177 	@param aScreen the screen to recieve the event

   178 	*/

   179 	virtual void DoRedrawNow(MWsScreen& aScreen) = 0;

   180 

   181 protected:

   182 	IMPORT_C void Animate(MWsScreen& aScreen);

   183 	IMPORT_C void Animate(MWsScreen& aScreen, TRequestStatus* aFinished);

   184 	IMPORT_C void Redraw(MWsScreen& aScreen);

   185 	IMPORT_C TBool RedrawInvalid(MWsScreen& aScreen,const TArray<TGraphicDrawerId>& aInvalid);