| class CDirectScreenAccess : public CActive |
An active object used to start direct screen access.
Direct screen access is a way of drawing to the screen without using the window server. As this avoids client-server communication, it is much faster, and may be useful for games and video. Note that some interaction with the window server is needed in order to prevent the application from drawing over other application's data.
The object's (private) RunL() function is called by the window server in order to abort direct screen access. This might occur when another window needs to be displayed in front or when the window with direct screen access is moved. The active object's priority is RDirectScreenAccess::EPriorityVeryHigh so that direct screen access will be aborted as quickly as possible.
| Public Member Functions | |
|---|---|
| ~CDirectScreenAccess() | |
| RRegion * | DrawingRegion() |
| CFbsBitGc * | Gc() |
| IMPORT_C CDirectScreenAccess * | NewL(RWsSession &, CWsScreenDevice &, RWindowBase &, MDirectScreenAccess &) |
| IMPORT_C CDirectScreenAccess * | NewL(RWsSession &, CWsScreenDevice &, RWindowBase &, MDirectScreenAccess &, TBool) |
| CFbsScreenDevice *& | ScreenDevice() |
| IMPORT_C void | StartL() |
| Private Member Functions | |
|---|---|
| CDirectScreenAccess(RWsSession &, CWsScreenDevice *, RWindowBase &, MDirectScreenAccess &) | |
| void | ConstructL(RWsSession &, TBool) |
| void | CreateScreenObjectsL(TDisplayMode) |
| void | DoCancel() |
| TInt | Restart(TAny *) |
| void | Restart() |
| void | RunL() |
| void | UpdateSizeAndRotation(CFbsBitGc *) |
| Private Member Enumerations | |
|---|---|
| enum | TFlags { EDirectCheckModeChange = 0x01, EDirectCheckSizeModeChange = 0x02, EDirectRegionTrackingOnly = 0x04 } |
| Inherited Enumerations | |
|---|---|
| CActive:TPriority | |
| Inherited Attributes | |
|---|---|
| CActive::iStatus | |
| CDirectScreenAccess | ( | RWsSession & | aWs, |
| CWsScreenDevice * | aScreenDevice, | ||
| RWindowBase & | aWindow, | ||
| MDirectScreenAccess & | aAbort | ||
| ) | [private, inline] | ||
| RWsSession & aWs | |
| CWsScreenDevice * aScreenDevice | |
| RWindowBase & aWindow | |
| MDirectScreenAccess & aAbort |
| void | ConstructL | ( | RWsSession & | aWs, |
| TBool | aRegionTrackingOnly | |||
| ) | [private] | |||
| RWsSession & aWs | |
| TBool aRegionTrackingOnly |
| void | CreateScreenObjectsL | ( | TDisplayMode | aCurrentMode | ) | [private] |
| TDisplayMode aCurrentMode |
| void | DoCancel | ( | ) | [private, virtual] |
Implements cancellation of an outstanding request.
This function is called as part of the active object's Cancel().
It must call the appropriate cancel function offered by the active object's asynchronous service provider. The asynchronous service provider's cancel is expected to act immediately.
DoCancel() must not wait for event completion; this is handled by Cancel().
| RRegion * | DrawingRegion | ( | ) | [inline] |
Gets the clipping region to draw to.
You must not draw outside of this region.
The clipping region is calculated when StartL() is called, and is only updated if StartL() is called again.
The region is specified in screen coordinates. This can be useful if you need to reapply the clipping region to the graphics context (CFbsBitGc::SetClippingRegion()).
The clipping region to draw to.
| CFbsBitGc * | Gc | ( | ) | [inline] |
Gets the graphics context for drawing to the screen.
This is set up by calling StartL(). Its origin is set so that you should use window coordinates to specify which part of the screen to draw to and its clipping region is set to the visible part of the window.
Code built to run on the Emulator must call CFbsScreenDevice::Update() in order to see the results of drawing to this graphics context, but this may not be required on all target hardware.
The graphics context for drawing to the screen.
| IMPORT_C CDirectScreenAccess * | NewL | ( | RWsSession & | aWs, |
| CWsScreenDevice & | aScreenDevice, | |||
| RWindowBase & | aWin, | |||
| MDirectScreenAccess & | aAbort | |||
| ) | [static] | |||
| RWsSession & aWs | |
| CWsScreenDevice & aScreenDevice | |
| RWindowBase & aWin | |
| MDirectScreenAccess & aAbort |
| IMPORT_C CDirectScreenAccess * | NewL | ( | RWsSession & | aWs, |
| CWsScreenDevice & | aScreenDevice, | |||
| RWindowBase & | aWin, | |||
| MDirectScreenAccess & | aAbort, | |||
| TBool | aRegionTrackingOnly | |||
| ) | [static] | |||
| RWsSession & aWs | |
| CWsScreenDevice & aScreenDevice | |
| RWindowBase & aWin | |
| MDirectScreenAccess & aAbort | |
| TBool aRegionTrackingOnly |
| void | RunL | ( | ) | [private, virtual] |
Handles an active object's request completion event.
A derived class must provide an implementation to handle the completed request. If appropriate, it may issue another request.
The function is called by the active scheduler when a request completion event occurs, i.e. after the active scheduler's WaitForAnyRequest() function completes.
Before calling this active object's RunL() function, the active scheduler has:
1. decided that this is the highest priority active object with a completed request
2. marked this active object's request as complete (i.e. the request is no longer outstanding)
RunL() runs under a trap harness in the active scheduler. If it leaves, then the active scheduler calls RunError() to handle the leave.
Note that once the active scheduler's Start() function has been called, all user code is run under one of the program's active object's RunL() or RunError() functions.
CActiveScheduler::WaitForAnyRequest
TRAPD
| CFbsScreenDevice *& | ScreenDevice | ( | ) | [inline] |
Gets the screen device to draw to.
You should not use this screen device to create fonts because the object is deleted and recreated when direct screen access is aborted and restarted. Instead, create and use your own CFbsScreenDevice object to create fonts.
The target screen device.
| void | UpdateSizeAndRotation | ( | CFbsBitGc * | aGc | ) | [private] |
| CFbsBitGc * aGc |
| EDirectCheckModeChange = 0x01 | |
| EDirectCheckSizeModeChange = 0x02 | |
| EDirectRegionTrackingOnly = 0x04 |
| RDirectScreenAccess::TTerminationReasons | iReason | [private] |