// Copyright (c) 1994-2009 Nokia Corporation and/or its subsidiary(-ies).

 // All rights reserved.

 // This component and the accompanying materials are made available

 // under the terms of "Eclipse Public License v1.0"

 // which accompanies this distribution, and is available

 // at the URL "http://www.eclipse.org/legal/epl-v10.html".

 //

 // Initial Contributors:

 // Nokia Corporation - initial contribution.

 //

 // Contributors:

 //

 // Description:

 // Shells for window server graphics class

 // 

 //

 #include <e32std.h>

 #include <graphics/wsdrawresource.h>

 #include "../SERVER/w32cmd.h"

 #include "CLIENT.H"

 #include "w32comm.h"

 #include "graphicsresourcewrapper.h"

 #include <graphics/gdi/gdiconsts.h>

 #include <graphics/gdi/gdistructs.h>

 #include "graphics/windowserverconstants.h"

 #define KDefaultShadowColor KRgbGray

 enum {EPolygonMaxHeaderSize=sizeof(TWsCmdHeader)+sizeof(TWsGcCmdSegmentedDrawPolygonData)};

 //

 // class CWindowGc::CPimpl

 //

 NONSHARABLE_STRUCT(CWindowGc::CPimpl): public CBase, public MWsDrawResource

 /** @internalComponent @released */

 	{

 public:

 	enum TStateType

 	    {

 	    EStateBrushColor           = 1<<0,

 	    EStateBrushStyle           = 1<<1,

 	    EStatePenColor             = 1<<2,

 	    EStatePenStyle             = 1<<3,

 	    EStatePenSize              = 1<<4,           

 	    EStateDrawMode             = 1<<5,

 	    EStateClippingRect         = 1<<6,

         EStateUnderlineStyle       = 1<<7,

         EStateStrikethroughStyle   = 1<<8,

         EStateWordJustification    = 1<<9,

         EStateCharJustification    = 1<<10,

 	    };

 	CPimpl(CWindowGc& aGc);

 	void WriteAnyPendingStateChanges();

 	void ResetPendingState();

 	void StorePendingStateChange(TStateType aState, const TAny* aValue);

 	TUint32 GetState() const {return iPendingState;}

 	void CancelPendingClippingRect();

 	~CPimpl();

 public: //from MWsDrawResource

 	void DrawResource(const TPoint& aPos, const RWsDrawableSource& aSource, CWindowGc::TGraphicsRotation aRotation=CWindowGc::EGraphicsRotationNone)

 		{

 		iGc.DrawResource(aPos, aSource, aRotation);

 		}

 	void DrawResource(const TRect& aDestRect, const RWsDrawableSource& aSource, CWindowGc::TGraphicsRotation aRotation=CWindowGc::EGraphicsRotationNone)

 		{

 		iGc.DrawResource(aDestRect, aSource, aRotation);

 		}

 	void DrawResource(const TRect& aDestRect, const RWsDrawableSource& aSource, const TRect& aSrcRect, CWindowGc::TGraphicsRotation aRotation=CWindowGc::EGraphicsRotationNone)

 		{

 		iGc.DrawResource(aDestRect, aSource, aSrcRect, aRotation);

 		}

 	void DrawResource(const TRect& aDestRect, const RWsDrawableSource& aSource, const TDesC8& aParam)

 		{

 		iGc.DrawResource(aDestRect, aSource, aParam);

 		}

 public:

 	CWindowGc& iGc;

 	CFbsFont* iFont;

 	TRgb iShadowColor;

     TBool iForceWrite;

     TBool iClippingRectSet;

 private:

     TUint32 iPendingState;

     // Pending state - used to store requested state changes not yet written to wserv

     TRgb iPendingBrushColor;

 	TBrushStyle iPendingBrushStyle;

     TRgb iPendingPenColor;

     TPenStyle iPendingPenStyle;

     TSize iPendingPenSize;

     TDrawMode iPendingDrawMode;

     TRect iPendingClippingRect;

     TFontUnderline iPendingUnderlineStyle;

     TFontStrikethrough iPendingStrikethroughStyle;

     TWsGcCmdSetJustification iPendingWordJustification;

     TWsGcCmdSetJustification iPendingCharJustification;

     // Current state - values that have actually been written to wserv

     TRgb iCurrentBrushColor;

 	TBrushStyle iCurrentBrushStyle;

     TRgb iCurrentPenColor;

     TPenStyle iCurrentPenStyle;

     TSize iCurrentPenSize;

     TDrawMode iCurrentDrawMode;

     TFontUnderline iCurrentUnderlineStyle;

     TFontStrikethrough iCurrentStrikethroughStyle;

     TWsGcCmdSetJustification iCurrentWordJustification;

     TWsGcCmdSetJustification iCurrentCharJustification;

 	};

 CWindowGc::CPimpl::CPimpl(CWindowGc& aGc)

 	: iGc(aGc), iFont(NULL), iShadowColor(KDefaultShadowColor)

 	{

 	ResetPendingState();

 	}

 CWindowGc::CPimpl::~CPimpl()

 	{

 	iFont = NULL;

 	}

 void CWindowGc::CPimpl::CancelPendingClippingRect()

     {

     iPendingState &= ~EStateClippingRect;

     }

 void CWindowGc::CPimpl::WriteAnyPendingStateChanges()

     {

     if (iPendingState == 0)

         return;

     if (iPendingState & EStateDrawMode)

         {

         if (iPendingDrawMode != iCurrentDrawMode)

             {

             iGc.WriteInt(iPendingDrawMode,EWsGcOpSetDrawMode);

             iCurrentDrawMode = iPendingDrawMode;

             }

         }

     if (iPendingState & EStateBrushStyle)

         {

         if (iPendingBrushStyle != iCurrentBrushStyle)

             {

             iGc.WriteInt(iPendingBrushStyle,EWsGcOpSetBrushStyle);

             iCurrentBrushStyle = iPendingBrushStyle;

             }

         }

     if (iPendingState & EStateBrushColor)

         {

         // Brush colour optimisation more conservative (than for other state changes) because server-side code modifies it without client's knowledge

         if (iPendingBrushColor != iCurrentBrushColor || iForceWrite)

             {

             iGc.WriteInt(iPendingBrushColor.Internal(),EWsGcOpSetBrushColor);

             iCurrentBrushColor = iPendingBrushColor;

             iForceWrite = EFalse;

             }

         }

     if (iPendingState & EStatePenStyle)

         {

         if (iPendingPenStyle != iCurrentPenStyle)

             {

             iGc.WriteInt(iPendingPenStyle,EWsGcOpSetPenStyle);

             iCurrentPenStyle = iPendingPenStyle;   

             }

         }

     if (iPendingState & EStatePenColor)

         {

         if (iPendingPenColor != iCurrentPenColor)

             {

             iGc.WriteInt(iPendingPenColor.Internal(),EWsGcOpSetPenColor);

             iCurrentPenColor = iPendingPenColor;            

             }

         }

     if (iPendingState & EStateClippingRect)

         {

         iGc.WriteRect(iPendingClippingRect,EWsGcOpSetClippingRect);

         iClippingRectSet = ETrue;

         }

     if (iPendingState & EStateUnderlineStyle)

         {

         if (iPendingUnderlineStyle != iCurrentUnderlineStyle)

             {

             iGc.WriteInt(iPendingUnderlineStyle,EWsGcOpSetUnderlineStyle);

             iCurrentUnderlineStyle = iPendingUnderlineStyle;            

             }

         }

     if (iPendingState & EStateStrikethroughStyle)

         {

         if (iPendingStrikethroughStyle != iCurrentStrikethroughStyle)

             {

             iGc.WriteInt(iPendingStrikethroughStyle,EWsGcOpSetStrikethroughStyle);

             iCurrentStrikethroughStyle = iPendingStrikethroughStyle;

             }

         }

     if (iPendingState & EStatePenSize)

         {

         if (iPendingPenSize != iCurrentPenSize)

             {

             iGc.WriteSize(iPendingPenSize,EWsGcOpSetPenSize);

             iCurrentPenSize = iPendingPenSize;

             }

         }    

     if (iPendingState & EStateWordJustification)

         {

         if (iPendingWordJustification.excessWidth != iCurrentWordJustification.excessWidth

             || iPendingWordJustification.numGaps != iCurrentWordJustification.numGaps)

             {

             iGc.Write(&iPendingWordJustification,sizeof(iPendingWordJustification),EWsGcOpSetWordJustification);

             iCurrentWordJustification = iPendingWordJustification;

             }

         }    

     if (iPendingState & EStateCharJustification)

         {

         if (iPendingCharJustification.excessWidth != iCurrentCharJustification.excessWidth

             || iPendingCharJustification.numGaps != iCurrentCharJustification.numGaps)

             {

             iGc.Write(&iPendingCharJustification,sizeof(iPendingCharJustification),EWsGcOpSetCharJustification);

             iCurrentCharJustification = iPendingCharJustification;

             }

         }    

     iPendingState = 0;

     }

 void CWindowGc::CPimpl::ResetPendingState()

     {

     // This function should only be called from CWindowGc::Reset()

     iForceWrite = EFalse;

     iPendingState = 0;

     iClippingRectSet = EFalse;

     // The following default values are the same as those used by CFbsBitGc::Reset()

     iPendingBrushColor = KRgbWhite;

     iPendingBrushStyle = CGraphicsContext::ENullBrush;

     iPendingPenColor = KRgbBlack;

     iPendingPenStyle = CGraphicsContext::ESolidPen;

     iPendingPenSize = TSize(1,1);

     iPendingDrawMode = CGraphicsContext::EDrawModePEN;

     iPendingUnderlineStyle = EUnderlineOff;    

     iPendingStrikethroughStyle = EStrikethroughOff;

     iPendingWordJustification.excessWidth = 0;

     iPendingWordJustification.numGaps = 0;

     iPendingCharJustification.excessWidth = 0;

     iPendingCharJustification.numGaps = 0;

     iCurrentBrushColor = iPendingBrushColor;

     iCurrentBrushStyle = iPendingBrushStyle;

     iCurrentPenColor = iPendingPenColor;

     iCurrentPenStyle = iPendingPenStyle;

     iCurrentPenSize = iPendingPenSize;    

     iCurrentDrawMode = iPendingDrawMode;

     iCurrentUnderlineStyle = iPendingUnderlineStyle;

     iCurrentStrikethroughStyle = iPendingStrikethroughStyle;

     iCurrentWordJustification.excessWidth = iPendingWordJustification.excessWidth;

     iCurrentWordJustification.numGaps = iPendingWordJustification.numGaps;

     iCurrentCharJustification.excessWidth = iPendingCharJustification.excessWidth;

     iCurrentCharJustification.numGaps = iPendingCharJustification.numGaps;

     }

 void CWindowGc::CPimpl::StorePendingStateChange(TStateType aState, const TAny* aValue)

     {

     switch (aState)

         {

         case EStateBrushColor:

             iPendingState |= EStateBrushColor;

             iPendingBrushColor = *((TRgb*)(aValue));

             break;

         case EStateBrushStyle:

             iPendingState|=EStateBrushStyle;

             iPendingBrushStyle = *((TBrushStyle*)(aValue));

             break;

         case EStatePenColor:

             iPendingState|=EStatePenColor;

             iPendingPenColor = *((TRgb*)(aValue));

             break;

         case EStatePenStyle:

             iPendingState|=EStatePenStyle;

             iPendingPenStyle = *((TPenStyle*)(aValue));

             break;

         case EStateDrawMode:

             iPendingState|=EStateDrawMode;

             iPendingDrawMode = *((TDrawMode*)(aValue));

             break;

         case EStateClippingRect:

             iPendingState|=EStateClippingRect;

             iPendingClippingRect = *((TRect*)(aValue));

             break;

         case EStateUnderlineStyle:

             iPendingState|=EStateUnderlineStyle;

             iPendingUnderlineStyle = *((TFontUnderline*)(aValue));

             break;

         case EStateStrikethroughStyle:

             iPendingState|=EStateStrikethroughStyle;

             iPendingStrikethroughStyle= *((TFontStrikethrough*)(aValue));

             break;

         case EStatePenSize:

             iPendingState|=EStatePenSize;

             iPendingPenSize = *((TSize*)(aValue));

             break;

         case EStateWordJustification:

             iPendingState|=EStateWordJustification;

             iPendingWordJustification = *((TWsGcCmdSetJustification*)(aValue));

             break;

         case EStateCharJustification:

             iPendingState|=EStateCharJustification;

             iPendingCharJustification = *((TWsGcCmdSetJustification*)(aValue));

             break;

         default:

             break;

         }

     }

 //

 // class CWindowGc

 //

 EXPORT_C CWindowGc::CWindowGc(CWsScreenDevice *aDevice) : MWsClientClass(aDevice->iBuffer), iPimpl(NULL), iDevice(aDevice)

 /** Constructor which creates, but does not initialise a graphics context. 

 @param aDevice Any screen device owned by the same session. Its life time 

 should be at least as long as the gc itself. 

 @see CWsScreenDevice::CreateContext() */

 	{}

 EXPORT_C CWindowGc::~CWindowGc()

 /** Destructor. */

 	{

 	if (iBuffer && iWsHandle)

 		Write(EWsGcOpFree);

 	delete iPimpl;

 	}

 void CWindowGc::WriteTextCommand(TAny *cmd, TInt len,const TDesC &aBuf,TInt opcode,TInt opcodePtr) const

 	{

 	if ((aBuf.Size()+len)>(TInt)(iBuffer->BufferSize()-sizeof(TWsCmdHeader)))

 		{

 		WriteReplyByProvidingRemoteReadAccess(cmd,len,&aBuf,opcodePtr);

 		}

 	else

 		{

 		Write(cmd,len,aBuf.Ptr(),aBuf.Size(),opcode);

 		}

 	}

 void CWindowGc::WriteTextCommand(TAny *cmd, TInt len,const TDesC8 &aBuf,TInt opcode,TInt opcodePtr) const

 	{

 	if ((aBuf.Size()+len)>(TInt)(iBuffer->BufferSize()-sizeof(TWsCmdHeader)))

 		{

 		WriteReplyByProvidingRemoteReadAccess(cmd,len,&aBuf,opcodePtr);

 		}

 	else

 		{

 		Write(cmd,len,aBuf.Ptr(),aBuf.Size(),opcode);

 		}

 	}	

 EXPORT_C TInt CWindowGc::Construct()

 /** Completes construction. 

 @return KErrNone if successful, otherwise a leave error. 

 @panic TW32Panic 17 in debug builds if called on an already constructed object.

 This function always causes a flush of the window server buffer. */

 	{

 	__ASSERT_DEBUG(iWsHandle == KNullHandle, Panic(EW32PanicGraphicDoubleConstruction));

 	iPimpl = new CPimpl(*this);

 	if (!iPimpl)

 		return KErrNoMemory;

 	TInt ret;

 	if ((ret=iBuffer->WriteReplyWs(EWsClOpCreateGc))<0)

 		return(ret);

 	iWsHandle=ret;

 	return(KErrNone);

 	}

 EXPORT_C void CWindowGc::Activate(RDrawableWindow &aDevice)

 /** Activates the context for a given window and updates iDevice with the pointer to the screen device of the screen on which aDevice is found.  

 When drawing is complete, the code using the context should call Deactivate(). 

 Draw methods invoked after an Activate() will affect the window specified. 

 A graphics context can only be active for one window at a time. A panic occurs 

 if a draw function is called before calling this function, or if Activate() 

 is called twice without an intervening Deactivate().

 @param aWindow The window for which the graphics context is to be activated. */

 	{

 	TUint devicePointer = WriteReplyInt(aDevice.WsHandle(),EWsGcOpActivate);

 	iDevice = (CWsScreenDevice*)devicePointer;

 	iPimpl->iForceWrite = ETrue; // needed because brush colour set to window background colour in CWsGc::Activate

 	}

 EXPORT_C void CWindowGc::Deactivate()

 /** Frees the graphics context to be used with another window. 

 This method should be called when the application has completed drawing to 

 the window. */

 	{

 	iPimpl->ResetPendingState(); // needed because server-side state is reset on deactivation

 	Write(EWsGcOpDeactivate);

 	iPimpl->iFont=NULL;

 	iPimpl->iShadowColor = KDefaultShadowColor;

 	}

 //====================Functions from GDI.H===============================

 EXPORT_C CGraphicsDevice* CWindowGc::Device() const

 /** Returns a pointer to the device, more specifically a CWsScreenDevice, for the screen that the WindowGc was last activated on.

 If the WindowGc has not been activated at all, it then returns the device that was passed to its constructor.

 The user should be careful when calling this function since it can return the screen device of any screen in the system.

 Hence, the return value of this function will be useful only if the user is aware of how the WindowGc was used before this function is called.

 @return A pointer to the device for the screen that the WindowGc was last activated on or the device passed at construction*/

 	{

 	return(iDevice);

 	}

 EXPORT_C void CWindowGc::SetOrigin(const TPoint &aPoint)

 /** Sets the position of the co-ordinate origin. 

 All subsequent drawing operations are then done relative to this origin. The 

 default origin is (0,0), the top left corner of the window.

 @param aPoint A point for the origin, default (0,0). 

 @see CGraphicsContext::SetOrigin() */

 	{

 	if ( iPimpl->GetState() & CPimpl::EStateClippingRect )

 	    {

 	    iPimpl->WriteAnyPendingStateChanges();

 	    }

 	WritePoint(aPoint,EWsGcOpSetOrigin);

 	}

 EXPORT_C void CWindowGc::SetClippingRect(const TRect& aRect)

 /** Sets a clipping rectangle.

 Graphics drawn to the window are clipped, so that only items which fall within 

 the rectangle are displayed. 

 Note that clipping is additive. If a clipping region has been set using SetClippingRegion() 

 then clipping will be to the intersection of that region and this rectangle.

 @param aRect The clipping rectangle in window co-ordinates. Note that this rectangle is 

 tranformed by the current drawing co-ordinate origin before it is used. 

 The co-ordinate origin is set using SetOrigin().

 @see SetClippingRegion() */

 	{

     TRect rect(aRect);

     iPimpl->StorePendingStateChange(CPimpl::EStateClippingRect, &rect);

 	}

 EXPORT_C void CWindowGc::CancelClippingRect()

 /** Cancels the clipping rectangle. 

 @see SetClippingRect() */

 	{

 	if (iPimpl->GetState() & CPimpl::EStateClippingRect)

 	    {

 	    iPimpl->CancelPendingClippingRect();

 	    }

 	if (iPimpl->iClippingRectSet)

 	    {

         Write(EWsGcOpCancelClippingRect);

 	    }

 	iPimpl->iClippingRectSet = EFalse;

 	}

 EXPORT_C TInt CWindowGc::SetClippingRegion(const TRegion &aRegion)

 /** Sets the clipping region.

 Drawing is always clipped to the visible area of a window. The region specified 

 by this function is in addition to that area.

 This function always causes a flush of the window server buffer.

 @param aRegion The new clipping region in window co-ordinates 

 as used in SetClippingRect(). The clipping region is transformed by the current 

 drawing origin before use.

 @return KErrNone if successful, KErrNoMemory if there is insufficient memory 

 to create the region on the server side, otherwise another error code. 

 @see SetClippingRect() */

 	{

 	const TInt regionCount=aRegion.Count();

 	TPtrC8 ptrRect(reinterpret_cast<const TUint8*>(aRegion.RectangleList()),regionCount*sizeof(TRect));

 	return(WriteReplyByProvidingRemoteReadAccess(&regionCount,sizeof(regionCount),&ptrRect,EWsGcOpSetClippingRegion));

 	}

 EXPORT_C void CWindowGc::CancelClippingRegion()

 /** Cancels the current clipping region. */

 	{

 	Write(EWsGcOpCancelClippingRegion);

 	}

 EXPORT_C void CWindowGc::SetDrawMode(TDrawMode aDrawingMode)

 /** Sets the drawing mode. 

 This affects the colour that is actually drawn, because it defines the way 

 that the current screen colour logically combines with the current pen colour 

 and brush colour. 

 There are 13 drawing modes (see CGraphicsContext::TDrawMode enum), each giving 

 different logical combinations of pen, brush and screen colours. Each mode 

 is produced by ORing together different combinations of seven drawing mode 

 components (see CGraphicsContext::TDrawModeComponents enum).

 The three most important modes are TDrawMode::EDrawModePEN, TDrawMode::EDrawModeNOTSCREEN 

 and TDrawMode::EDrawModeXOR. The default drawing mode is TDrawMode::EDrawModePEN.

 The drawing mode is over-ridden for line and shape drawing functions when 

 a wide pen line has been selected. It is forced to TDrawMode::EDrawModePEN. 

 This is to prevent undesired effects at line joins (vertexes).

 Notes:

 TDrawMode::EDrawModeAND gives a "colour filter" effect. For example:

 ANDing with white gives the original colour 

 ANDing with black gives black 

 TDrawMode::EDrawModeOR gives a "colour boost" effect. For example:

 ORing with black gives the original colour 

 ORing with white gives white 

 TDrawMode::EDrawModeXOR gives an "Exclusive OR" effect. For example:

 white XOR black gives white 

 white XOR white gives black 

 black XOR black gives black

 @param aDrawingMode A drawing mode. 

 @see CGraphicsContext::SetDrawMode() */

 	{

     iPimpl->StorePendingStateChange(CPimpl::EStateDrawMode, &aDrawingMode);

 	}

 EXPORT_C void CWindowGc::UseFont(const CFont *aFont)

 /** Sets this context's font.

 The font is used for text drawing. If the font is already in the font and 

 bitmap server's memory the GDI will share that copy.

 Note that this function must be called prior to drawing text or the calling 

 thread will panic.

 @param aFont A device font. 

 @see CGraphicsContext::UseFont() */

 	{

 	if (iPimpl->iFont!=(CFbsFont *)aFont)

 		{

 		iPimpl->iFont=(CFbsFont *)aFont;

 		WriteInt(iPimpl->iFont->Handle(),EWsGcOpUseFont);

 		}

 	}

 EXPORT_C void CWindowGc::DiscardFont()

 /** Discards a font. 

 This frees up the memory used (if the font is not being shared with some other 

 process).

 Note that if no font is in use when this function is called, then there is no effect.

 @see CGraphicsContext::DiscardFont() */

 	{

 	Write(EWsGcOpDiscardFont);

 	iPimpl->iFont=NULL;

 	}

 EXPORT_C void CWindowGc::SetUnderlineStyle(TFontUnderline aUnderlineStyle)

 /** Sets the underline style for all subsequently drawn text.

 @param aUnderlineStyle The underline style: either on or off.

 @see CGraphicsContext::SetUnderlineStyle() */

 	{

     iPimpl->StorePendingStateChange(CPimpl::EStateUnderlineStyle, &aUnderlineStyle);	

 	}

 EXPORT_C void CWindowGc::SetStrikethroughStyle(TFontStrikethrough aStrikethroughStyle)

 /** Sets the strikethrough style for all subsequently drawn text.

 @param aStrikethroughStyle The strikethrough style: either on or off. 

 @see CGraphicsContext::SetStrikethroughStyle() */

 	{

 	iPimpl->StorePendingStateChange(CPimpl::EStateStrikethroughStyle, &aStrikethroughStyle);

 	}

 void CWindowGc::SetJustification(TInt aExcessWidth,TInt aNumGaps, TInt aOpcode)

 	{

 	TWsGcCmdSetJustification justification;

 	justification.excessWidth=aExcessWidth;

 	justification.numGaps=aNumGaps;

 	if (aOpcode == EWsGcOpSetWordJustification)

 	    {

         iPimpl->StorePendingStateChange(CPimpl::EStateWordJustification, &justification);

 	    }

 	else if (aOpcode == EWsGcOpSetCharJustification)

 	    {

         iPimpl->StorePendingStateChange(CPimpl::EStateCharJustification, &justification);

 	    }

 	}

 EXPORT_C void CWindowGc::SetWordJustification(TInt aExcessWidth,TInt aNumGaps)

 /** Sets word justification.

 This function is particularly useful for doing WYSIWYG underlining or strikethrough, 

 as it ensures that the lines extend correctly into the gaps between words. It is not 

 intended for regular use by developers.

 @param aExcessWidth The excess width (in pixels) to be distributed between 

 the specified number of gaps (starting immediately) 

 @param aNumGaps The number of gaps between words 

 @see CGraphicsContext::SetWordJustification() */

 	{

 	SetJustification(aExcessWidth, aNumGaps, EWsGcOpSetWordJustification);

 	}

 EXPORT_C void CWindowGc::SetCharJustification(TInt aExcessWidth,TInt aNumChars)

 /** Sets the character justification.

 This function is used primarily to get accurate WYSIWYG, and is not intended 

 for regular use by developers.

 The text line that is to be justified has a certain number of characters (this 

 includes the spaces between the words). It also has a distance (in pixels) 

 between the end of the last word and the actual end of the line (right hand 

 margin, usually). These excess width pixels are distributed amongst all the 

 characters, increasing the gaps between them, to achieve full justification 

 of the text line.

 This function is particularly useful for WYSIWYG underlining or strikethrough, 

 as it ensures that the lines extend into the gaps between characters.

 See CGraphicsContext::SetCharJustification() for more information.

 @param aExcessWidth The excess width (in pixels) to be distributed between 

 the specified number of characters. 

 @param aNumChars The number of characters involved 

 @see CGraphicsContext::SetCharJustification() */

 	{

 	SetJustification(aExcessWidth, aNumChars, EWsGcOpSetCharJustification);

 	}

 EXPORT_C void CWindowGc::SetPenColor(const TRgb &aColor)

 /** Sets the pen colour.

 The effective pen colour depends on the drawing mode (see SetDrawMode()).

 The default pen colour is black.

 @param aColor The RGB colour for the pen. 

 @see CGraphicsContext::SetPenColor() */

 	{

 	TRgb color = aColor;

     iPimpl->StorePendingStateChange(CPimpl::EStatePenColor, &color);

 	}

 EXPORT_C void CWindowGc::SetPenStyle(TPenStyle aPenStyle)

 /** Sets the line drawing style for the pen. 

 The pen is used when drawing lines and for the outline of filled shapes. There 

 are 6 pen styles (see CGraphicsContext::TPenStyle enum). If no pen style is 

 set, the default is TPenStyle::ESolidPen.

 To use a pen style, its full context must be given, e.g. for a null pen: CGraphicsContext::TPenStyle::ENullPen.

 @param aPenStyle A pen style. 

 @see CGraphicsContext::SetPenStyle() */

 	{

 	iPimpl->StorePendingStateChange(CPimpl::EStatePenStyle, &aPenStyle);

 	}

 EXPORT_C void CWindowGc::SetPenSize(const TSize& aSize)

 /** Sets the line drawing size for the pen.

 Lines of size greater than one pixel are drawn with rounded ends that extend 

 beyond the end points, (as if the line is drawn using a circular pen tip of 

 the specified size). Rounded ends of lines drawn with a wide pen are always 

 drawn in TDrawMode::EDrawModePEN mode, overriding whatever mode has been set 

 using SetDrawMode().

 @param aSize A line size, the default being 1 pixel. 

 @see CGraphicsContext::SetPenSize() */

 	{

 	TSize size(aSize);

 	iPimpl->StorePendingStateChange(CPimpl::EStatePenSize, &size);

 	}

 EXPORT_C void CWindowGc::SetBrushColor(const TRgb &aColor)

 /** Sets the brush colour. 

 The effective brush colour depends on the drawing mode (see SetDrawMode()). 

 If no brush colour has been set, it defaults to white. However the default 

 brush style is null, so when drawing to a window, the default appears to be 

 the window's background colour.

 @param aColor The RGB colour for the brush. 

 @see CGraphicsContext::SetBrushColor() */

 	{

 	TRgb color = aColor;

     iPimpl->StorePendingStateChange(CPimpl::EStateBrushColor, &color);

 	}

 EXPORT_C void CWindowGc::SetBrushStyle(TBrushStyle aBrushStyle)

 /** Sets the line drawing style for the brush.

 The GDI provides ten brush styles, including six built-in hatching patterns 

 (see CGraphicsContext::TBrushStyle).

 Use TBrushStyle::ENullBrush to draw the outline of a fillable shape on its 

 own, without filling.

 If the TBrushStyle::EPatternedBrush style is set, but no bitmap pattern has 

 been selected using UseBrushPattern(), then the brush defaults to TBrushStyle::ENullBrush.

 Hatching lines are done in the current brush colour, set using SetBrushColor(). 

 Hatching can be overlaid on other graphics. The hatching pattern starts at 

 the brush origin, set using SetBrushOrigin().

 @param aBrushStyle The brush style. 

 @see CGraphicsContext::SetBrushStyle() */

 	{

 	iPimpl->StorePendingStateChange(CPimpl::EStateBrushStyle, &aBrushStyle);

 	}

 EXPORT_C void CWindowGc::SetBrushOrigin(const TPoint &aOrigin)

 /** Sets the brush pattern origin. 

 This specifies the position of the pixel in the top left corner of a reference 

 pattern tile, (in absolute device co-ordinates). Other copies of the pattern 

 tile are then drawn around the reference one. Thus the brush origin can be 

 set as the top left corner of a shape.

 The brush pattern may be a built-in style (see SetBrushStyle()), or a bitmap. 

 To use a bitmap, the brush must have a pattern set (see UseBrushPattern()) 

 and the brush style must be set to TBrushStyle::EPatternedBrush.

 Notes:

 If SetBrushOrigin() is not used, then the origin defaults to (0,0).

 This brush origin remains in effect for all fillable shapes drawn subsequently, 

 until a new brush origin is set. Shapes can thus be considered as windows 

 onto a continuous pattern field (covering the whole clipping region of a screen 

 device, or the whole device area of a printer).

 @param aOrigin The origin point for the brush. 

 @see CGraphicsContext::SetBrushOrigin() */

 	{

 	WritePoint(aOrigin,EWsGcOpSetBrushOrigin);

 	}

 EXPORT_C void CWindowGc::UseBrushPattern(const CFbsBitmap *aDevice)

 /** Sets the brush pattern to the specified bitmap. 

 For the brush to actually use the bitmap, TBrushStyle::EPatternedBrush must 

 be used to set the brush style (see SetBrushStyle()). When the brush pattern 

 is no longer required, use DiscardBrushPattern() to free up the memory used, 

 (if the bitmap is not being shared). If UseBrushPattern() is used again without 

 using DiscardBrushPattern() then the previous pattern is discarded automatically.

 Notes:

 When loading a bitmap, the GDI checks to see if the bitmap is already in memory. 

 If the bitmap is already there, then that copy is shared.

 The brush does not need to have a pattern set at all. There are several built-in 

 hatching patterns, which can be selected using SetBrushStyle().

 @param aDevice A bitmap pattern for the brush 

 @see CGraphicsContext::UseBrushPattern() */

 	{

 	WriteInt(aDevice->Handle(),EWsGcOpUseBrushPattern);

 	AddToBitmapArray(aDevice->Handle());

 	}

 EXPORT_C void CWindowGc::DiscardBrushPattern()

 /** Discards a non-built-in brush pattern. 

 This frees up the memory used for the bitmap, if it is not being shared by 

 another process.

 If no brush pattern has been set when this function is called, it has no effect.

 @see CGraphicsContext::DiscardBrushPattern() */

 	{

 	Write(EWsGcOpDiscardBrushPattern);

 	}

 EXPORT_C void CWindowGc::Plot(const TPoint &aPoint)

 /** Draws a single point. 

 The point is drawn with the current pen settings using the current drawing 

 mode.

 Note: if the pen size is greater than one pixel, a filled circle of the current 

 pen colour is drawn, with the pen size as the diameter and the plotted point 

 as the centre. If the pen size is an even number of pixels, the extra pixels 

 are drawn below and to the right of the centre. See SetPenSize().

 @param aPoint The point to be drawn. 

 @see CGraphicsContext::Plot() */

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	WritePoint(aPoint,EWsGcOpPlot);

 	}

 EXPORT_C void CWindowGc::DrawLine(const TPoint &aPoint1,const TPoint &aPoint2)

 /** Draws a straight line between two points.

 @param aPoint1 The point at the start of the line. 

 @param aPoint2 The point at the end of the line. 

 @see CGraphicsContext::DrawLine() */

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	TWsGcCmdDrawLine drawLine(aPoint1,aPoint2);

 	Write(&drawLine,sizeof(drawLine),EWsGcOpDrawLine);

 	}

 EXPORT_C void CWindowGc::MoveTo(const TPoint &aPoint)

 /** Moves the internal drawing position relative to the co-ordinate origin, without 

 drawing a line.

 A subsequent call to DrawLineTo() or DrawLineBy() will then use the new internal 

 drawing position as the start point for the line drawn.

 Notes:

 The operations DrawLine(), DrawLineTo(), DrawLineBy() and DrawPolyline() also 

 change the internal drawing position to the last point of the drawn line(s).

 The internal drawing position is set to the co-ordinate origin if no drawing 

 or moving operations have yet taken place.

 @param aPoint The point to move the internal drawing position to. 

 @see CGraphicsContext::MoveTo()

 @see CGraphicsContext::MoveBy() */

 	{

 	WritePoint(aPoint,EWsGcOpMoveTo);

 	}

 EXPORT_C void CWindowGc::MoveBy(const TPoint &aPoint)

 /** Moves the internal drawing position by a vector, without drawing a line.

 The internal drawing position is moved relative to its current co-ordinates.

 @param aPoint The vector to move the internal drawing position by. 

 @see CGraphicsContext::MoveBy()

 @see CGraphicsContext::MoveTo() */

 	{

 	WritePoint(aPoint,EWsGcOpMoveBy);

 	}

 EXPORT_C void CWindowGc::DrawLineTo(const TPoint &aPoint)

 /** Draws a straight line from the current internal drawing position to a point.

 @param aPoint The point at the end of the line. 

 @see CGraphicsContext::DrawLineTo() */

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	WritePoint(aPoint,EWsGcOpDrawTo);

 	}

 EXPORT_C void CWindowGc::DrawLineBy(const TPoint &aPoint)

 /** Draws a straight line relative to the current internal drawing position, using 

 a vector.

 The start point of the line is the current internal drawing position. The 

 vector aVector is added to the internal drawing position to give the end point 

 of the line

 @param aPoint The vector to add to the current internal drawing position, 

 giving the end point of the line. 

 @see CGraphicsContext::DrawLineBy() */

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	WritePoint(aPoint,EWsGcOpDrawBy);

 	}

 void CWindowGc::doDrawPolyLine(const CArrayFix<TPoint> *aPointArray, const TPoint* aPointList,TInt aNumPoints)

 	{

 	TWsGcOpcodes opcode=EWsGcOpDrawPolyLine;

 	TWsGcCmdDrawPolyLine polyLine;

 	TInt maxBufLen=(iBuffer->BufferSize()-sizeof(TWsCmdHeader)-sizeof(polyLine))/sizeof(TPoint);

 	TInt sent=0;

 	while(sent<aNumPoints)

 		{

 		TInt availableLen;

 		const TPoint *ptr;

 		if (aPointArray)

 			{

 			ptr=&(*aPointArray)[sent];

 			availableLen=aPointArray->End(sent)-ptr;

 			}

 		else

 			{

 			ptr=aPointList+sent;

 			availableLen=aNumPoints-sent;

 			}

 		polyLine.numPoints=Min(availableLen,maxBufLen);

 		sent+=polyLine.numPoints;

 		polyLine.more=(sent!=aNumPoints);

 		Write(&polyLine,sizeof(polyLine),ptr,polyLine.numPoints*sizeof(TPoint),opcode);

 		polyLine.last=ptr[polyLine.numPoints-1];

 		opcode=EWsGcOpDrawPolyLineContinued;

 		} 

 	}

 EXPORT_C void CWindowGc::DrawPolyLine(const TPoint* aPointList,TInt aNumPoints)

 /** Draws a polyline using points in a list. 

 A polyline is a series of concatenated straight lines joining a set of points.

 @param aPointList Pointer to a list of points on the polyline. 

 @param aNumPoints The number of points in the point list. 

 @see CGraphicsContext::DrawPolyLine() */

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	doDrawPolyLine(NULL,aPointList,aNumPoints);

 	}

 EXPORT_C void CWindowGc::DrawPolyLine(const CArrayFix<TPoint> *aPointArray)

 /** Draws a polyline using points in an array. 

 A polyline is a series of concatenated straight lines joining a set of points.

 @param aPointArray An array containing the points on the polyline. 

 @see CGraphicsContext::DrawPolyLine() */

 	{

    	iPimpl->WriteAnyPendingStateChanges();

 	doDrawPolyLine(aPointArray,NULL,aPointArray->Count());

 	}

 TInt CWindowGc::doDrawPolygon(const CArrayFix<TPoint> *aPointArray,const TPoint* aPointList,TInt aNumPoints,TFillRule aFillRule)

 	{

 	if (aNumPoints<=0)

 		return(KErrNone);

 	TWsGcCmdSegmentedDrawPolygonData polyData;

 	polyData.index=0;

 	TInt maxBufLen=(iBuffer->BufferSize()-EPolygonMaxHeaderSize)/sizeof(TPoint);

 	FOREVER

 		{

 		const TPoint *ptr;

 		TInt availableLen;

 		if (aPointArray)

 			{

 			ptr=&(*aPointArray)[polyData.index];

 			availableLen=aPointArray->End(polyData.index)-ptr;

 			}

 		else

 			{

 			ptr=aPointList+polyData.index;

 			availableLen=aNumPoints-polyData.index;

 			}

 		polyData.numPoints=Min(availableLen,maxBufLen);

 		if (polyData.index==0)	// First time around

 			{

 			if (polyData.numPoints==aNumPoints)	// Can it be done in one go?

 				{

 				TWsGcCmdDrawPolygon drawPolygon;

 				drawPolygon.numPoints=aNumPoints;

 				drawPolygon.fillRule=aFillRule;

 				Write(&drawPolygon,sizeof(drawPolygon),ptr,aNumPoints*sizeof(TPoint),EWsGcOpDrawPolygon);

 				break;

 				}

 			TWsGcCmdStartSegmentedDrawPolygon start;

 			start.totalNumPoints=aNumPoints;

 			TInt err=WriteReply(&start,sizeof(start),EWsGcOpStartSegmentedDrawPolygon);

 			if (err!=KErrNone)

 				return(err);

 			}

 		Write(&polyData,sizeof(polyData),ptr,polyData.numPoints*sizeof(TPoint),EWsGcOpSegmentedDrawPolygonData);

 		polyData.index+=polyData.numPoints;

 		if (polyData.index==aNumPoints)

 			{

 			TWsGcCmdDrawSegmentedPolygon draw;

 			draw.fillRule=aFillRule;

 			Write(&draw,sizeof(draw),EWsGcOpDrawSegmentedPolygon);

 			break;

 			}

 		}

 	return(KErrNone);

 	}

 EXPORT_C TInt CWindowGc::DrawPolygon(const TPoint* aPointList,TInt aNumPoints,TFillRule aFillRule)

 /** Draws and fills a polygon using points defined in a list.

 The first TPoint in the list defines the start of the first side of the polygon. 

 The second TPoint defines the second vertex (the end point of the first side 

 and the start point of the second side) and so on. The final side of the polygon 

 is drawn using the last TPoint from the array or list, and the line drawn 

 to the start point of the first side.

 Self-crossing polygons can be filled according to one of two rules, TFillRule::EAlternate 

 (the default), or TFillRule::EWinding. To explain the difference between these 

 rules, the concept of a winding number needs to be introduced. The area outside 

 any of the loops of the polygon has a winding number of zero, and is never 

 filled. An inside a loop which is bounded by an area with winding number 0 

 has a winding number of 1. If an area is within a loop that is bounded by 

 an area with winding number 1, e.g. a loop within a loop, has a winding number 

 of 2, and so on.

 The filling of a polygon proceeds according to this algorithm:

 If aFillRule is TFillRule::EAlternate (default) and it has an odd winding 

 number, then fill the surrounding area.

 If aFillRule is TFillRule::EWinding and it has a winding number greater than 

 zero, then fill the surrounding area.

 This function always causes a flush of the window server buffer.

 @param aPointList Pointer to a list of points, specifying the vertices of 

 the polygon. 

 @param aNumPoints The number of points in the vertex list 

 @param aFillRule Either TFillRule::EAlternate (the default) or TFillRule::EWinding. 

 @return KErrNone if successful, otherwise another of the system-wide error 

 codes. 

 @see CGraphicsContext::DrawPolygon() */

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	return(doDrawPolygon(NULL,aPointList,aNumPoints,aFillRule));

 	}

 EXPORT_C TInt CWindowGc::DrawPolygon(const CArrayFix<TPoint> *aPointArray,TFillRule aFillRule)

 /** Draws and fills a polygon using points defined in an array.

 The first TPoint in the array defines the start of the first side of the polygon. 

 The second TPoint defines the second vertex (the end point of the first side 

 and the start point of the second side) and so on. The final side of the polygon 

 is drawn using the last TPoint from the array or list, and the line drawn 

 to the start point of the first side.

 Self-crossing polygons can be filled according to one of two rules, TFillRule::EAlternate 

 (the default), or TFillRule::EWinding. To explain the difference between these 

 rules, the concept of a winding number needs to be introduced. The area outside 

 any of the loops of the polygon has a winding number of zero, and is never 

 filled. An inside a loop which is bounded by an area with winding number 0 

 has a winding number of 1. If an area is within a loop that is bounded by 

 an area with winding number 1, e.g. a loop within a loop, has a winding number 

 of 2, and so on.

 The filling of a polygon proceeds according to this algorithm:

 If aFillRule is TFillRule::EAlternate (default) and it has an odd winding 

 number, then fill the surrounding area.

 If aFillRule is TFillRule::EWinding and it has a winding number greater than 

 zero, then fill the surrounding area.

 This function always causes a flush of the window server buffer.

 @param aPointArray An array of points, specifying the vertices of the polygon. 

 @param aFillRule Either TFillRule::EAlternate (the default) or TFillRule::EWinding. 

 @return KErrNone if successful, otherwise another of the system-wide error 

 codes. 

 @see CGraphicsContext::DrawPolygon() */

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	return(doDrawPolygon(aPointArray,NULL,aPointArray->Count(),aFillRule));

 	}

 void CWindowGc::DrawArcOrPie(const TRect &aRect,const TPoint &aStart,const TPoint &aEnd, TInt aOpcode)

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	TWsGcCmdDrawArcOrPie cmd(aRect,aStart,aEnd);

 	Write(&cmd,sizeof(cmd),aOpcode);

 	}

 EXPORT_C void CWindowGc::DrawArc(const TRect &aRect,const TPoint &aStart,const TPoint &aEnd)

 /** Draws an arc (a portion of an ellipse).

 The point aStart is used to define one end of a line from the geometric centre 

 of the ellipse. The point of intersection between this line and the ellipse 

 defines the start point of the arc. The point aEnd is used to define one end 

 of a second line from the geometric centre of the ellipse. The point of intersection 

 between this line and the ellipse defines the end point of the arc. The pixels 

 at both the start point and the end point are drawn.

 The arc itself is the segment of the ellipse in an anti-clockwise direction 

 from the start point to the end point.

 Notes

 A rectangle is used in the construction of the ellipse of which the arc is 

 a segment. This rectangle is passed as an argument of type TRect.

 A wide line arc is drawn with the pixels distributed either side of a true 

 ellipse, in such a way that the outer edge of the line would touch the edge 

 of the construction rectangle. In other words, the ellipse used to construct 

 it is slightly smaller than that for a single pixel line size.

 If aStart or aEnd are the ellipse centre then the line that defines the start/end 

 of the arc defaults to one extending vertically above the centre point.

 If aStart and aEnd are the same point, or points on the same line through 

 the ellipse centre then a complete unfilled ellipse is drawn.

 Line drawing is subject to pen colour, width and style and draw mode

 @param aRect The rectangle in which to draw the ellipse (of which the arc is 

 a segment).

 @param aStart A point to define the start of the arc.

 @param aEnd A point to define the end of the arc.

 @see CGraphicsContext::DrawArc() */

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	DrawArcOrPie(aRect,aStart,aEnd,EWsGcOpDrawArc);

 	}

 EXPORT_C void CWindowGc::DrawPie(const TRect &aRect,const TPoint &aStart,const TPoint &aEnd)

 /** Draws and fills a pie-shaped slice of an ellipse.

 Outlines are subject to the current pen colour, width, style and draw mode. 

 Set the pen to ENullPen for no outline. The fill is subject to brush style 

 (colour, hash or pattern), the origin and the current drawing mode. Set the 

 brush to ENullBrush for no fill.

 The point aStart is used to define one end of a line to the centre of the 

 ellipse. The point of intersection between this line and the ellipse defines 

 the start point of the arc bounding the pie slice. The point aEnd is used 

 to define one end of a second line to the centre of the ellipse. The point 

 of intersection between this line and the ellipse defines the end point of 

 the arc bounding the pie slice. The pixels at the end point are not drawn.

 The pie slice itself is the area bounded by: the arc of the ellipse in an 

 anticlockwise direction from the start point to the end point; the straight 

 line from the start point from the geometric centre of the ellipse; the 

 straight line from the end point from the geometric centre of the ellipse.

 The line drawn by the pen goes inside the rectangle given by the aRect argument.

 Notes:

 A rectangle is used in the construction of the pie slice. This rectangle is 

 passed as an argument of type TRect. The curved edge of the pie slice is an 

 arc of an ellipse constructed within the rectangle.

 A wide line edged pie slice has the arc drawn with the pixels distributed 

 either side of a true ellipse. This is done in such a way that the outer edge 

 of the line would touch the edge of the construction rectangle. In other words, 

 the ellipse used to construct it is slightly smaller than that for a single 

 pixel line size.

 If aStart or aEnd are the ellipse centre then the line that defines the start/end 

 of the arc defaults to one extending vertically above the centre point.

 If aStart and aEnd are the same point, or points on the same line through 

 the ellipse centre then a complete filled ellipse is drawn. A line is also 

 drawn from the edge to the ellipse centre.

 @param aRect A rectangle in which to draw the ellipse bounding the pie slice 

 @param aStart A point to define the start of the pie slice 

 @param aEnd A point to define the end of the pie slice 

 @see CGraphicsContext::DrawPie() */

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	DrawArcOrPie(aRect,aStart,aEnd,EWsGcOpDrawPie);

 	}

 EXPORT_C void CWindowGc::DrawEllipse(const TRect &aRect)

 /** Draws and fills an ellipse.

 The ellipse is drawn inside the rectangle defined by the aRect argument. Any 

 TRect that has odd pixel dimensions, has the bottom right corner trimmed to 

 give even pixel dimensions before the ellipse is constructed.

 The column and row of pixels containing the bottom right co-ordinate of the 

 aRect argument are not part of the rectangle.

 Note: a wide outline ellipse is drawn with the pixels distributed either side of 

 a true ellipse, in such a way that the outer edge of the line touches the 

 edge of the construction rectangle. In other words, the ellipse used to construct 

 it is smaller than that for a single pixel line size.

 @param aRect The rectangle in which to draw the ellipse 

 @see CGraphicsContext::DrawEllipse() */

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	WriteRect(aRect,EWsGcOpDrawEllipse);

 	}

 EXPORT_C void CWindowGc::DrawRect(const TRect &aRect)

 /** Draws and fills a rectangle. 

 The rectangle's border is drawn with the pen, and it is filled using the brush.

 @param aRect The rectangle to be drawn. 

 @see CGraphicsContext::DrawRect() */

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	WriteRect(aRect,EWsGcOpDrawRect);

 	}

 EXPORT_C void CWindowGc::DrawRoundRect(const TRect &aRect,const TSize &aEllipse)

 /** Draws and fills a rectangle with rounded corners.

 The rounded corners are each constructed as an arc of an ellipse. The dimensions 

 of each corner (corner size and corner height) are given by aEllipse. See 

 DrawArc() for a description of arc construction.

 The line drawn by the pen (if any) goes inside the rectangle given by the 

 TRect argument.

 Notes:

 Dotted and dashed pen styles cannot be used for the outline of a rounded rectangle.

 If either corner size dimension is greater than half the corresponding rectangle 

 length, the corner size dimension is reduced to half the rectangle size.

 @param aRect The rectangle to be drawn. 

 @param aEllipse The dimensions of each corner. 

 @see CGraphicsContext::DrawRoundRect() */

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	TWsGcCmdDrawRoundRect drawRoundRect(aRect,aEllipse);

 	Write(&drawRoundRect,sizeof(drawRoundRect),EWsGcOpDrawRoundRect);

 	}

 EXPORT_C void CWindowGc::DrawBitmap(const TPoint &aTopLeft, const CFbsBitmap *aDevice)

 /** Draws a bitmap at a specified point. 

 The function does a compress/stretch based on its internally stored size in 

 twips. Note that if the twips value of the bitmap is not set then nothing 

 is drawn (this is the default situation).

 Windows that store their redraw commands will only store drawing position and a handle to bitmaps 

 that are drawn in it. The bitmap handle is just a pointer to the bitmap in the FBSERV heap. 

 At some point later WSERV may need to draw that window again and it will just replay the 

 stored commands including the draw bitmap.  However, if the client has changed the content of the bitmap,

 WSERV will effectively draw a different bitmap when it replays the commands.

 Note: this member function uses the bitmap's size in twips and does a stretch/compress 

 blit using a linear DDA.

 @param aTopLeft The point where the top left pixel of the bitmap is to be 

 drawn 

 @param aDevice The source bitmap. 

 @see CGraphicsContext::DrawBitmap() */

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	TWsGcCmdDrawBitmap drawBitmap(aTopLeft,aDevice->Handle());

 	Write(&drawBitmap,sizeof(drawBitmap),EWsGcOpDrawBitmap);

 	AddToBitmapArray(aDevice->Handle());

 	}

 EXPORT_C void CWindowGc::DrawBitmap(const TRect &aDestRect, const CFbsBitmap *aDevice)

 /** Draws a bitmap in a rectangle.

 The bitmap is compressed/stretched to fit the specified rectangle. Note that 

 if the twips value of the bitmap is not set then nothing is drawn (this is 

 the default situation).

 Windows that store their redraw commands will only store drawing position and a handle to bitmaps 

 that are drawn in it. The bitmap handle is just a pointer to the bitmap in the FBSERV heap. 

 At some point later WSERV may need to draw that window again and it will just replay the 

 stored commands including the draw bitmap.  However, if the client has changed the content of the bitmap,

 WSERV will effectively draw a different bitmap when it replays the commands.

 Notes: this member function uses the bitmap's size in pixels and does a stretch/compress 

 blit using a linear DDA.

 @param aDestRect The rectangle within which the bitmap is to be drawn. 

 @param aDevice The source bitmap. 

 @see CGraphicsContext::DrawBitmap() */

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	TWsGcCmdDrawBitmap2 drawBitmap(aDestRect,aDevice->Handle());

 	Write(&drawBitmap,sizeof(drawBitmap),EWsGcOpDrawBitmap2);

 	AddToBitmapArray(aDevice->Handle());

 	}

 EXPORT_C void CWindowGc::DrawBitmap(const TRect &aDestRect, const CFbsBitmap *aDevice, const TRect &aSourceRect)

 /** Draws a specified rectangle from a bitmap into another rectangle.

 The function compresses/stretches the specified rectangle from the bitmap 

 to fit the destination rectangle. Note that if the twips value of the bitmap 

 is not set then nothing is drawn (this is the default situation).

 Windows that store their redraw commands will only store drawing position and a handle to bitmaps 

 that are drawn in it. The bitmap handle is just a pointer to the bitmap in the FBSERV heap. 

 At some point later WSERV may need to draw that window again and it will just replay the 

 stored commands including the draw bitmap. However, if the client has changed the content of the bitmap,

 WSERV will effectively draw a different bitmap when it replays the commands.

 Note: this member function uses rectangle sizes in pixels and does a stretch/compress 

 blit using a linear DDA.

 @param aDestRect The rectangle within which the bitmap is to be drawn. 

 @param aDevice A source bitmap. 

 @param aSourceRect The rectangle in the source bitmap that is copied to the 

 destination rectangle. 

 @see CGraphicsContext::DrawBitmap() */

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	TWsGcCmdDrawBitmap3 drawBitmap(aDestRect,aDevice->Handle(),aSourceRect);

 	Write(&drawBitmap,sizeof(drawBitmap),EWsGcOpDrawBitmap3);

 	AddToBitmapArray(aDevice->Handle());

 	}

 /** Draws a specified rectangle from a bitmap and its mask into another rectangle.

 The function compresses/stretches the specified rectangle from the bitmap 

 to fit the destination rectangle. 

 The mask bitmap can be used as either a positive or negative mask. Masked 

 pixels are not mapped to the destination rectangle.

 A black and white (binary) mask bitmap is used. With aInvertMask=EFalse, black 

 pixels in the mask bitmap stop corresponding pixels in the source bitmap from 

 being transferred to the destination rectangle. With aInvertMask=ETrue, white 

 pixels in the mask bitmap stop corresponding pixels in the source bitmap from 

 being transferred to the destination rectangle.

 If mask bitmap's display mode is EColor256, the function does AplhaBlending

 and ignores aInvertMask parameter.

 Windows that store their redraw commands will only store drawing position and a handle to bitmaps 

 that are drawn in it. The bitmap handle is just a pointer to the bitmap in the FBSERV heap. 

 At some point later WSERV may need to draw that window again and it will just replay the 

 stored commands including the draw bitmap.  However, if the client has changed the content of the bitmap,

 WSERV will effectively draw a different bitmap when it replays the commands.

 Note: this member function uses rectangle sizes in pixels and does a stretch/compress 

 blit using a linear DDA.

 @param aDestRect The rectangle within which the masked bitmap is to be drawn. 

 @param aBitmap A source bitmap. 

 @param aSourceRect The rectangle in the source bitmap that is copied to the 

 destination rectangle.

 @param aMaskBitmap A mask bitmap. 

 @param aInvertMask If false, a source pixel that is masked by a black pixel 

 is not transferred to the destination rectangle. If true, then a source pixel 

 that is masked by a white pixel is not transferred to the destination rectangle. */

 EXPORT_C void CWindowGc::DrawBitmapMasked(const TRect& aDestRect, const CFbsBitmap* aBitmap, const TRect& aSourceRect, const CFbsBitmap* aMaskBitmap, TBool aInvertMask)

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	TWsGcCmdDrawBitmapMasked drawBitmap(aDestRect,aBitmap->Handle(),aSourceRect,aMaskBitmap->Handle(),aInvertMask);

 	Write(&drawBitmap,sizeof(drawBitmap),EWsGcOpDrawBitmapMasked);

 	AddToBitmapArray(aBitmap->Handle());

 	AddToBitmapArray(aMaskBitmap->Handle());

 	}

 EXPORT_C void CWindowGc::DrawBitmapMasked(const TRect& aDestRect, const CWsBitmap* aBitmap, const TRect& aSourceRect, const CWsBitmap* aMaskBitmap, TBool aInvertMask)

 /** Draws a specified rectangle from a wserv bitmap and its mask into 

 another rectangle.

 The function compresses/stretches the specified rectangle from the bitmap 

 to fit the destination rectangle. 

 The mask bitmap can be used as either a positive or negative mask. Masked 

 pixels are not mapped to the destination rectangle.

 A black and white (binary) mask bitmap is used. With aInvertMask=EFalse, black 

 pixels in the mask bitmap stop corresponding pixels in the source bitmap from 

 being transferred to the destination rectangle. With aInvertMask=ETrue, white 

 pixels in the mask bitmap stop corresponding pixels in the source bitmap from 

 being transferred to the destination rectangle.

 If mask bitmap's display mode is EColor256, the function does AplhaBlending

 and ignores aInvertMask parameter.

 Windows that store their redraw commands will only store drawing position and a handle to bitmaps 

 that are drawn in it. The bitmap handle is just a pointer to the bitmap in the FBSERV heap. 

 At some point later WSERV may need to draw that window again and it will just replay the 

 stored commands including the draw bitmap.  However, if the client has changed the content of the bitmap,

 WSERV will effectively draw a different bitmap when it replays the commands.

 Note: this member function uses rectangle sizes in pixels and does a stretch/compress 

 blit using a linear DDA.

 @param aDestRect The rectangle within which the masked bitmap is to be drawn. 

 @param aBitmap A source wserv bitmap. 

 @param aSourceRect The rectangle in the source bitmap that is copied to the 

 destination rectangle.

 @param aMaskBitmap A mask wserv bitmap. 

 @param aInvertMask If false, a source pixel that is masked by a black pixel 

 is not transferred to the destination rectangle. If true, then a source pixel 

 that is masked by a white pixel is not transferred to the destination rectangle. */

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	TWsGcCmdDrawBitmapMasked drawBitmap(aDestRect,aBitmap->WsHandle(),aSourceRect,aMaskBitmap->WsHandle(),aInvertMask);

 	Write(&drawBitmap,sizeof(drawBitmap),EWsGcOpWsDrawBitmapMasked);

 	AddToBitmapArray(aBitmap->Handle());

 	AddToBitmapArray(aMaskBitmap->Handle());

 	}

 EXPORT_C void CWindowGc::DrawText(const TDesC &aBuf, const TPoint &aPos)

 /** Draws horizontal text with no surrounding box. 

 The appearance of the text is subject to the drawing mode, the font, pen colour, 

 word justification and character justification. 

 A panic occurs if this function is called when there is no font: see UseFont().

 @param aBuf The string to write. 

 @param aPos The point specifying the position of the baseline at the left 

 end of the text.

 @see CGraphicsContext::DrawText() */

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	TWsGcCmdDrawText printText(aPos,aBuf.Length());

     __ASSERT_ALWAYS(((aBuf.Size()+sizeof(printText))<=EClientBufferMaxSize),Panic(EW32PanicSizeNotExpected));    

 	WriteTextCommand(&printText,sizeof(printText),aBuf,EWsGcOpDrawText,EWsGcOpDrawTextPtr);

 	}

 EXPORT_C void CWindowGc::DrawText(const TDesC &aBuf,const TRect &aBox,TInt aBaselineOffset,TTextAlign aHoriz,TInt aLeftMrg)

 /** Draws horizontal text within a cleared box.

 The appearance of the text is subject to the drawing mode, the font, pen colour, 

 word justification and character justification. It is also subject to the 

 background brush (set brush to ENullBrush for no effect on background).

 A panic occurs if this function is called when there is no font: see UseFont().

 Note: the text is clipped to the box. You must ensure that the specified string 

 is not too large.

 @param aBuf The text to write.

 @param aBox The box to draw the text in. 

 @param aBaselineOffset An offset from the top of the box to the text baseline. 

 Note that the baseline is the line on which letters sit, for instance below r, s, t, and 

 above the tail of q, and y. 

 @param aHoriz The text alignment mode (default is left, rather than centre 

 or right). 

 @param aLeftMrg The left margin for left-aligned text, or the right margin 

 for right-aligned text (default is zero). 

 @see CGraphicsContext::DrawText() */

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	if (aBuf.Size()<(TInt)(iBuffer->BufferSize()-sizeof(TWsCmdHeader)-sizeof(TWsGcCmdBoxTextOptimised2))) 

 		{

 		if (aHoriz==ELeft && aLeftMrg==0)

 			{

 			TWsGcCmdBoxTextOptimised1 boxTextOpt1(aBox,aBaselineOffset,aBuf.Length());

 			__ASSERT_ALWAYS(((aBuf.Size()+sizeof(boxTextOpt1))<=EClientBufferMaxSize),Panic(EW32PanicSizeNotExpected)); 

 			Write(&boxTextOpt1,sizeof(boxTextOpt1),aBuf.Ptr(),aBuf.Size(),EWsGcOpDrawBoxTextOptimised1);

 			}

 		else

 			{

 			TWsGcCmdBoxTextOptimised2 boxTextOpt2(aBox,aBaselineOffset,aHoriz,aLeftMrg,aBuf.Length());

 			__ASSERT_ALWAYS(((aBuf.Size()+sizeof(boxTextOpt2))<=EClientBufferMaxSize),Panic(EW32PanicSizeNotExpected)); 

 			Write(&boxTextOpt2,sizeof(boxTextOpt2),aBuf.Ptr(),aBuf.Size(),EWsGcOpDrawBoxTextOptimised2);

 			}

 		}

 	else

 		{

 		TWsGcCmdBoxText boxText(aBox,aBaselineOffset,aHoriz,aLeftMrg,aBuf.Length(),iPimpl->iFont->TextWidthInPixels(aBuf));

 		__ASSERT_ALWAYS(((aBuf.Size()+sizeof(boxText))<=EClientBufferMaxSize),Panic(EW32PanicSizeNotExpected)); 

 		WriteTextCommand(&boxText,sizeof(boxText),aBuf,EWsGcOpDrawBoxText,EWsGcOpDrawBoxTextPtr);

 		}

 	}

 TInt CWindowGc::APIExDrawText(const TDesC& aBuf,const TTextParameters* aParam,const TPoint& aPos)

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	TWsGcCmdDrawTextInContext printTextInContext(aPos,aBuf.Length(),aParam->iStart,aParam->iEnd);

 	__ASSERT_ALWAYS(((aBuf.Size()+sizeof(printTextInContext))<=EClientBufferMaxSize),Panic(EW32PanicSizeNotExpected)); 

 	WriteTextCommand(&printTextInContext,sizeof(printTextInContext),aBuf,EWsGcOpDrawTextInContext,EWsGcOpDrawTextInContextPtr);

 	return KErrNone;

 	}

 TInt CWindowGc::APIExDrawText(const TDesC& aBuf,const TTextParameters* aParam,const TRect& aBox,TInt aBaselineOffset,TTextAlign aHoriz,TInt aLeftMrg)

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	if (aBuf.Size()<(TInt)(iBuffer->BufferSize()-sizeof(TWsCmdHeader)-sizeof(TWsGcCmdBoxTextInContextOptimised2))) 

 		{

 		if (aHoriz==ELeft && aLeftMrg==0)

 			{

 			TWsGcCmdBoxTextInContextOptimised1 boxTextOpt1(aBox,aBaselineOffset,aBuf.Length(),aParam->iStart,aParam->iEnd);

 			__ASSERT_ALWAYS(((aBuf.Size()+sizeof(boxTextOpt1))<=EClientBufferMaxSize),Panic(EW32PanicSizeNotExpected)); 

 			Write(&boxTextOpt1,sizeof(boxTextOpt1),aBuf.Ptr(),aBuf.Size(),EWsGcOpDrawBoxTextInContextOptimised1);

 			}

 		else

 			{

 			TWsGcCmdBoxTextInContextOptimised2 boxTextOpt2(aBox,aBaselineOffset,aHoriz,aLeftMrg,aBuf.Length(),aParam->iStart,aParam->iEnd);

 			__ASSERT_ALWAYS(((aBuf.Size()+sizeof(boxTextOpt2))<=EClientBufferMaxSize),Panic(EW32PanicSizeNotExpected)); 

 			Write(&boxTextOpt2,sizeof(boxTextOpt2),aBuf.Ptr(),aBuf.Size(),EWsGcOpDrawBoxTextInContextOptimised2);

 			}

 		}

 	else

 		{

 		TWsGcCmdBoxTextInContext boxText(aBox,aBaselineOffset,aHoriz,aLeftMrg,aBuf.Length(),iPimpl->iFont->TextWidthInPixels(aBuf),aParam->iStart,aParam->iEnd);

 		__ASSERT_ALWAYS(((aBuf.Size()+sizeof(boxText))<=EClientBufferMaxSize),Panic(EW32PanicSizeNotExpected)); 

 		WriteTextCommand(&boxText,sizeof(boxText),aBuf,EWsGcOpDrawBoxTextInContext,EWsGcOpDrawBoxTextInContextPtr);

 		}

 	return KErrNone;

 	}

 EXPORT_C void CWindowGc::DrawTextVertical(const TDesC& aText,const TPoint& aPos,TBool aUp)

 /** Draws vertical text in the specified direction.

 A panic occurs if this function is called when there is no font: see UseFont().

 @param aText The text to be drawn. 

 @param aPos Point of origin of the text baseline. 

 @param aUp Direction. ETrue for up, EFalse for down. */

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	TWsGcCmdDrawTextVertical printText(aPos,aText.Length(),aUp);

 	__ASSERT_ALWAYS(((aText.Size()+sizeof(printText))<=EClientBufferMaxSize),Panic(EW32PanicSizeNotExpected)); 

 	WriteTextCommand(&printText,sizeof(printText),aText,EWsGcOpDrawTextVertical,EWsGcOpDrawTextVerticalPtr);

 	}

 EXPORT_C void CWindowGc::DrawTextVertical(const TDesC& aText,const TRect& aBox,TInt aBaselineOffset,TBool aUp,TTextAlign aVert,TInt aMargin)

 /** Draws text vertically in the specified direction, within a box of the specified 

 size.

 A panic occurs if this function is called when there is no font: see UseFont().

 @param aText The text to be drawn. 

 @param aBox The bounding box within which the text should be drawn, and which 

 it is clipped to.

 @param aBaselineOffset The height of the top of the characters from their text 

 baseline. 

 @param aUp The direction. ETrue for up, EFalse for down.

 @param aVert The text alignment. 

 @param aMargin The margin. */

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	TWsGcCmdBoxTextVertical boxText(aBox);

 	boxText.baselineOffset=aBaselineOffset;

 	boxText.up=aUp;

 	boxText.vert=aVert;

 	boxText.margin=aMargin;

 	boxText.length=aText.Length();

 	boxText.width=iPimpl->iFont->TextWidthInPixels(aText);

 	__ASSERT_ALWAYS(((aText.Size()+sizeof(boxText))<=EClientBufferMaxSize),Panic(EW32PanicSizeNotExpected)); 

 	WriteTextCommand(&boxText,sizeof(boxText),aText,EWsGcOpDrawBoxTextVertical,EWsGcOpDrawBoxTextVerticalPtr);

 	}

 TInt CWindowGc::APIExDrawTextVertical(const TDesC& aText,const TTextParameters* aParam,const TPoint& aPos,TBool aUp)

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	TWsGcCmdDrawTextInContextVertical printText(aPos,aText.Length(),aUp,aParam->iStart,aParam->iEnd);

 	__ASSERT_ALWAYS(((aText.Size()+sizeof(printText))<=EClientBufferMaxSize),Panic(EW32PanicSizeNotExpected)); 

 	WriteTextCommand(&printText,sizeof(printText),aText,EWsGcOpDrawTextInContextVertical,EWsGcOpDrawTextInContextVerticalPtr);

 	return KErrNone;

 	}

 TInt CWindowGc::APIExDrawTextVertical(const TDesC& aText,const TTextParameters* aParam,const TRect& aBox,TInt aBaselineOffset,TBool aUp,TTextAlign aVert,TInt aMargin)

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	TWsGcCmdBoxTextInContextVertical boxText(aBox);

 	boxText.baselineOffset=aBaselineOffset;

 	boxText.up=aUp;

 	boxText.vert=aVert;

 	boxText.margin=aMargin;

 	boxText.length=aText.Length();

 	boxText.width=iPimpl->iFont->TextWidthInPixels(aText);

 	boxText.start = aParam->iStart;

 	boxText.end = aParam->iEnd;

 	__ASSERT_ALWAYS(((aText.Size()+sizeof(boxText))<=EClientBufferMaxSize),Panic(EW32PanicSizeNotExpected)); 

 	WriteTextCommand(&boxText,sizeof(boxText),aText,EWsGcOpDrawBoxTextInContextVertical,EWsGcOpDrawBoxTextInContextVerticalPtr);

 	return KErrNone;

 	}

 //========================Extra functions============================

 EXPORT_C void CWindowGc::CopyRect(const TPoint &anOffset,const TRect &aRect)

 /** Copies a rectangle from any part of the screen into the window that the gc 

 is active on.

 The copy part of the operation applies to the whole rectangle, irrespective 

 of whether or not it within the window, however the "paste" is clipped to 

 the drawing area.

 The rectangle is specified in window coordinates (if the top-left of the rectangle 

 is (0,0) then the area of the screen it specifies has its top-left at the 

 top left corner of the window, if it is (-10,-10) then it starts 10 pixels 

 above and to the left of the window). 

 Note: shadows in the source rectangle will be copied. None of the area drawn to 

 will gain shadowing (even if the window is already in shadow).

 This version of this function is only really suitable for testing.

 @param anOffset The offset from the original position to the point where the 

 rectangle is copied. 

 @param aRect The rectangular area to be copied. This is in window co-ordinates, 

 e.g. the top left corner of the window is position (0,0) with respect to the 

 rectangle.

 @see CBitmapContext::CopyRect() */

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	TWsGcCmdCopyRect copyRect(anOffset,aRect);

 	Write(&copyRect,sizeof(copyRect),EWsGcOpCopyRect);

 	}

 EXPORT_C void CWindowGc::BitBlt(const TPoint &aPoint, const CFbsBitmap *aBitmap)

 /** Performs a bitmap block transfer.

 Windows that store their redraw commands will only store drawing position and a handle to bitmaps 

 that are drawn in it. The bitmap handle is just a pointer to the bitmap in the FBSERV heap. 

 At some point later WSERV may need to draw that window again and it will just replay the 

 stored commands including the draw bitmap. However, if the client has changed the content of the bitmap,

 WSERV will effectively draw a different bitmap when it replays the commands.

 @param aPoint The position for the top left corner of the bitmap. 

 @param aBitmap A memory-resident bitmap. 

 @see CBitmapContext::BitBlt() */

 	{

 	if (aBitmap == NULL || !aBitmap->Handle())

 		return; 

 	iPimpl->WriteAnyPendingStateChanges();

 	TWsGcCmdGdiBlt2 gdiBlit(aPoint,aBitmap->Handle());

 	Write(&gdiBlit,sizeof(gdiBlit),EWsGcOpGdiBlt2);

 	AddToBitmapArray(aBitmap->Handle());

 	}

 EXPORT_C void CWindowGc::BitBlt(const TPoint &aDestination,const CFbsBitmap *aBitmap,const TRect &aSource)

 /** Performs a bitmap block transfer of a rectangular piece of a bitmap.

 Windows that store their redraw commands will only store drawing position and a handle to bitmaps 

 that are drawn in it. The bitmap handle is just a pointer to the bitmap in the FBSERV heap. 

 At some point later WSERV may need to draw that window again and it will just replay the 

 stored commands including the draw bitmap.  However, if the client has changed the content of the bitmap,

 WSERV will effectively draw a different bitmap when it replays the commands.

 Note: if the rectangle aSource is larger than the bitmap then the bitmap will be padded 

 with white.

 @param aDestination The position for the top left corner of the bitmap. 

 @param aBitmap A memory-resident bitmap 

 @param aSource A rectangle defining the piece of the bitmap to be drawn, with 

 co-ordinates relative to the top left corner of the bitmap 

 @see CBitmapContext::BitBlt() */

 	{

 	if (aBitmap == NULL || !aBitmap->Handle())

 		return; 

 	iPimpl->WriteAnyPendingStateChanges();

 	TWsGcCmdGdiBlt3 gdiBlit(aDestination,aBitmap->Handle(),aSource);

 	Write(&gdiBlit,sizeof(gdiBlit),EWsGcOpGdiBlt3);

 	AddToBitmapArray(aBitmap->Handle());

 	}

 EXPORT_C void CWindowGc::BitBltMasked(const TPoint& aPoint,const CFbsBitmap* aBitmap,const TRect& aSourceRect,const CFbsBitmap* aMaskBitmap,TBool aInvertMask)

 /** Performs a masked bitmap block transfer of a memory resident source bitmap.

 The mask bitmap can be used as either a positive or negative mask. Masked 

 pixels are not mapped to the destination rectangle.

 A black and white (binary) mask bitmap is used. With aInvertMask=EFalse, black 

 pixels in the mask bitmap stop corresponding pixels in the source bitmap from 

 being transferred to the destination rectangle. With aInvertMask=ETrue, white 

 pixels in the mask bitmap stop corresponding pixels in the source bitmap from 

 being transferred to the destination rectangle.

 Windows that store their redraw commands will only store drawing position and a handle to bitmaps 

 that are drawn in it. The bitmap handle is just a pointer to the bitmap in the FBSERV heap. 

 At some point later WSERV may need to draw that window again and it will just replay the 

 stored commands including the draw bitmap.  However, if the client has changed the content of the bitmap,

 WSERV will effectively draw a different bitmap when it replays the commands.

 @param aPoint A position for the top left corner of the bitmap. 

 @param aBitmap A memory-resident source bitmap. 

 @param aSourceRect A rectangle defining the piece of the bitmap to be drawn, 

 with co-ordinates relative to the top left corner of the bitmap 

 @param aMaskBitmap A mask bitmap. 

 @param aInvertMask If false, a source pixel that is masked by a black pixel 

 is not transferred to the destination rectangle. If true, then a source pixel 

 that is masked by a white pixel is not transferred to the destination rectangle. 

 @see CBitmapContext::BitBltMasked() */

 	{

 	if (aBitmap == NULL || !aBitmap->Handle() || aMaskBitmap == NULL || !aMaskBitmap->Handle())

 		return; 

 	iPimpl->WriteAnyPendingStateChanges();

 	TWsGcCmdBltMasked gdiBlitMasked(aPoint,aBitmap->Handle(),aSourceRect,aMaskBitmap->Handle(),aInvertMask);

 	Write(&gdiBlitMasked,sizeof(gdiBlitMasked),EWsGcOpGdiBltMasked);

 	AddToBitmapArray(aBitmap->Handle());

 	AddToBitmapArray(aMaskBitmap->Handle());

 	}

 EXPORT_C void CWindowGc::BitBlt(const TPoint &aPoint, const CWsBitmap *aBitmap)

 /** Performs a bitmap block transfer on a bitmap to which the window server already 

 has a handle.

 Windows that store their redraw commands will only store drawing position and a handle to bitmaps 

 that are drawn in it. The bitmap handle is just a pointer to the bitmap in the FBSERV heap. 

 At some point later WSERV may need to draw that window again and it will just replay the 

 stored commands including the draw bitmap.  However, if the client has changed the content of the bitmap,

 WSERV will effectively draw a different bitmap when it replays the commands.

 This function should be used in preference to the CFbsBitmap overload if the 

 bitmap is to be used more than once, as it is a lot quicker.

 @param aPoint The position for the top left corner of the bitmap. 

 @param aBitmap A window server bitmap. 

 @see CBitmapContext::BitBlt() */

 	{

 	if (aBitmap == NULL || !aBitmap->Handle())

 		return; 

 	iPimpl->WriteAnyPendingStateChanges();

 	TWsGcCmdGdiBlt2 gdiBlit(aPoint,aBitmap->WsHandle());

 	Write(&gdiBlit,sizeof(gdiBlit),EWsGcOpGdiWsBlt2);

 	AddToBitmapArray(aBitmap->Handle());

 	}

 EXPORT_C void CWindowGc::BitBlt(const TPoint &aDestination,const CWsBitmap  *aBitmap,const TRect &aSource)

 /** Performs a bitmap block transfer of a rectangular piece of a bitmap to which 

 the window server already has a handle.

 Windows that store their redraw commands will only store drawing position and a handle to bitmaps 

 that are drawn in it. The bitmap handle is just a pointer to the bitmap in the FBSERV heap. 

 At some point later WSERV may need to draw that window again and it will just replay the 

 stored commands including the draw bitmap.  However, if the client has changed the content of the bitmap,

 WSERV will effectively draw a different bitmap when it replays the commands.

 This function should be used in preference to the CFbsBitmap overload if the 

 bitmap is to be used more than once, as it is a lot quicker.

 Note: if the rectangle aSource is larger than the bitmap then the bitmap will be padded 

 with white.

 @param aDestination The position for the top left corner of the bitmap. 

 @param aBitmap A window server bitmap. 

 @param aSource A rectangle defining the piece of the bitmap to be drawn, with 

 co-ordinates relative to the top left corner of the bitmap 

 @see CBitmapContext::BitBlt() */

 	{

 	if (aBitmap == NULL || !aBitmap->Handle())

 		return; 

 	iPimpl->WriteAnyPendingStateChanges();

 	TWsGcCmdGdiBlt3 gdiBlit(aDestination,aBitmap->WsHandle(),aSource);

 	Write(&gdiBlit,sizeof(gdiBlit),EWsGcOpGdiWsBlt3);

 	AddToBitmapArray(aBitmap->Handle());

 	}

 EXPORT_C void CWindowGc::BitBltMasked(const TPoint& aPoint,const CWsBitmap * aBitmap,const TRect& aSourceRect,const CWsBitmap * aMaskBitmap,TBool aInvertMask)

 /** Performs a masked bitmap block transfer of a window server bitmap.

 The mask bitmap can be used as either a positive or negative mask. Masked 

 pixels are not mapped to the destination rectangle.

 A black and white (binary) mask bitmap is used. With aInvertMask=EFalse, black 

 pixels in the mask bitmap stop corresponding pixels in the source bitmap from 

 being transferred to the destination rectangle. With aInvertMask=ETrue, white 

 pixels in the mask bitmap stop corresponding pixels in the source bitmap from 

 being transferred to the destination rectangle.

 This function should be used in preference to the CFbsBitmap overload if the 

 bitmap is to be used more than once, as it is a lot quicker.

 Windows that store their redraw commands will only store drawing position and a handle to bitmaps 

 that are drawn in it. The bitmap handle is just a pointer to the bitmap in the FBSERV heap. 

 At some point later WSERV may need to draw that window again and it will just replay the 

 stored commands including the draw bitmap.  However, if the client has changed the content of the bitmap,

 WSERV will effectively draw a different bitmap when it replays the commands.

 @param aPoint A position for the top left corner of the bitmap. 

 @param aBitmap A window server bitmap. 

 @param aSourceRect A rectangle defining the piece of the bitmap to be drawn, 

 with co-ordinates relative to the top left corner of the bitmap. 

 @param aMaskBitmap A window server mask bitmap. 

 @param aInvertMask If false, a source pixel that is masked by a black pixel 

 is not transferred to the destination rectangle. If true, then a source pixel 

 that is masked by a white pixel is not transferred to the destination rectangle. 

 @see CBitmapContext::BitBltMasked() */

 	{

 	if (aBitmap == NULL || !aBitmap->Handle() || aMaskBitmap == NULL || !aMaskBitmap->Handle())

 		return;

 	iPimpl->WriteAnyPendingStateChanges();

 	TWsGcCmdBltMasked gdiBlitMasked(aPoint,aBitmap->WsHandle(),aSourceRect,aMaskBitmap->WsHandle(),aInvertMask);

 	Write(&gdiBlitMasked,sizeof(gdiBlitMasked),EWsGcOpGdiWsBltMasked);

 	AddToBitmapArray(aBitmap->Handle());

 	AddToBitmapArray(aMaskBitmap->Handle()); 

 	}

 /**

 This method has been deprecated. It is no longer possible to re-map pixel colours

 within a rectangle. Calling it has no effect.

 @param aRect Ignored.

 @param aColors Ignored.

 @param aNumPairs Ignored.

 @param aMapForwards Ignored.

 @deprecated

 */

 EXPORT_C void CWindowGc::MapColors(const TRect& /*aRect*/, const TRgb* /*aColors*/, TInt /*aNumPairs*/, TBool /*aMapForwards*/)

 	{

 	}

 EXPORT_C void CWindowGc::Clear(const TRect &aRect)

 /** Clears a rectangular area of a window.

 The cleared area is filled with the current brush colour.

 @param aRect The rectangle to clear. 

 @see CBitmapContext::Clear() */

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	WriteRect(aRect,EWsGcOpClearRect);

 	}

 EXPORT_C void CWindowGc::Clear()

 /** Clears the whole window.

 The cleared area is filled with the current brush colour.

 @see CBitmapContext::Clear() */

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	Write(EWsGcOpClear);

 	}

 EXPORT_C void CWindowGc::Reset()

 /** Resets the graphics context to its default settings.

 The drawing mode is set to TDrawMode::EDrawModePen (pen and brush colours used as 

 they are); there is no clipping rectangle; the pen settings are black, 

 solid, single pixel size; the brush style is null; no text font is selected.

 @see CGraphicsContext::Reset() */

 	{

 	Write(EWsGcOpReset);

 	iPimpl->iFont=NULL;

 	iPimpl->iShadowColor = KDefaultShadowColor;

     iPimpl->ResetPendingState();

     iPimpl->iForceWrite = ETrue; // needed because brush colour set to window background colour in CPlaybackGc::CommandL and CWsGc::SetGcAttribute

 	}

 /**

 This method has been deprecated. Dithering is no longer supported. Calling it

 has no effect.

 @param aPoint Ignored.

 @deprecated

 */

 EXPORT_C void CWindowGc::SetDitherOrigin(const TPoint& /*aPoint*/)

 	{

 	}

 EXPORT_C void CWindowGc::SetFaded(TBool aFaded)

 /** Sets whether the graphics context is faded.

 Fading is used to make a window appear less colourful so that other windows 

 stand out. For example, a window would be faded when a dialogue is displayed 

 in front of it.

 @param aFaded ETrue to fade the graphics context, EFalse to unfade it. */

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	WriteInt(aFaded,EWsGcOpSetFaded);

 	}

 EXPORT_C void CWindowGc::SetFadingParameters(TUint8 aBlackMap,TUint8 aWhiteMap)

 /** Sets the fading parameters.

 This function allows you to override the map used when drawing with a faded 

 graphics context. However if you draw to a faded window with a faded graphics 

 context, then fading on the graphics context is ignored and it will use the 

 fading of the window.

 Fading is used to make a window appear less colourful so that other windows stand 

 out. For example, a window would be faded when a dialogue is displayed 

 in front of it. 

 You can either make a faded window closer to white or closer to black. 

 The fading map allows you to over-ride the default fading parameters set in 

 RWsSession::SetDefaultFadingParameters(). 

 Fading re-maps colours to fall between the specified black and white map values. 

 If aBlackMap=0 and aWhiteMap=255 then the colours are mapped unchanged. As the 

 values converge, the colours are mapped to a smaller range, so the differences 

 between colours in the faded graphics context decrease. If the values are reversed 

 then the colours are inverted (i.e. where the gc would be black, it is now white). 

 @param aBlackMap Black map fading parameter. Unfaded this is 0. 

 @param aWhiteMap White map fading parameter. Unfaded this is 255. 

 @see RWsSession::SetDefaultFadingParameters()

 @see RWindowTreeNode::SetFaded() */

 	{

 	WriteInt(WservEncoding::Encode8BitValues(aBlackMap,aWhiteMap),EWsGcOpSetFadeParams);

 	}

 EXPORT_C TInt CWindowGc::AlphaBlendBitmaps(const TPoint& aDestPt, const CFbsBitmap* aSrcBmp, const TRect& aSrcRect,const CFbsBitmap* aAlphaBmp, const TPoint& aAlphaPt)

 /**

 Performs an alpha blending of the source data, aSrcBmp, with the window, using

 the data from aAlphaBmp as an alpha blending factor.

 The formula used is:

 (S * A + W * (255 - A)) / 255, where:

 - S - a pixel from aSrcBmp;

 - W - a pixel from the window;

 - A - a pixel from aAlphaBmp;

 The contents of source and alpha bitmap are preserved.

 The calculated alpha blended pixels are written to the destination - the window image.

 Windows that store their redraw commands will only store drawing position and a handle to bitmaps 

 that are drawn in it. The bitmap handle is just a pointer to the bitmap in the FBSERV heap. 

 At some point later WSERV may need to draw that window again and it will just replay the 

 stored commands including the draw bitmap.  However, if the client has changed the content of the bitmap,

 WSERV will effectively draw a different bitmap when it replays the commands.

 This method is supported from version 8.1

 @param aDestPt Position in the target the result should be drawn to.

 @param aSrcBmp A pointer to the source bitmap.

 @param aSrcRect The part of the source bitmap that should be used.

 @param aAlphaBmp A pointer to the bitmap used as an alpha blending factor.

 @param aAlphaPt Position of the first pixel in the alpha bitmap that should be used as a source 

                 for the alpha blending. The size of the area is the same as the 

                 source bitmap area - aSrcRect parameter.

 @see CFbsBitGc::AlphaBlendBitmaps()

 */

 	{

    	iPimpl->WriteAnyPendingStateChanges();

 	TWsGcCmdAlphaBlendBitmaps alphaBlend(aDestPt, aSrcBmp->Handle(), aSrcRect, aAlphaBmp->Handle(), aAlphaPt);

 	Write(&alphaBlend,sizeof(alphaBlend),EWsGcOpGdiAlphaBlendBitmaps);

 	AddToBitmapArray(aSrcBmp->Handle());

 	AddToBitmapArray(aAlphaBmp->Handle());

 	return KErrNone;

 	}

 EXPORT_C TInt CWindowGc::AlphaBlendBitmaps(const TPoint& aDestPt, const CWsBitmap* aSrcBmp, const TRect& aSrcRect,const CWsBitmap* aAlphaBmp, const TPoint& aAlphaPt)

 /**

 The method performs an alpha blending of the source data, aSrcBmp, with the window, using

 the data from aAlphaBmp as an alpha blending factor.

 For information on how this function works, see the other overload.

 Windows that store their redraw commands will only store drawing position and a handle to bitmaps 

 that are drawn in it. The bitmap handle is just a pointer to the bitmap in the FBSERV heap. 

 At some point later WSERV may need to draw that window again and it will just replay the 

 stored commands including the draw bitmap. However, if the client has changed the content of the bitmap,

 WSERV will effectively draw a different bitmap when it replays the commands.

 This method is supported from version 8.1

 @param aDestPt Position in the target the result should be drawn to.

 @param aSrcBmp A pointer to the source bitmap.

 @param aSrcRect The part of the source bitmap that should be used.

 @param aAlphaBmp A pointer to the bitmap used as an alpha blending factor.

 @param aAlphaPt Position of the first pixel in the alpha bitmap that should be used as a source 

                 for the alpha blending. The size of the area is the same as the 

                 source bitmap area - aSrcRect parameter.

 @see CFbsBitGc::AlphaBlendBitmaps()

 */

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	TWsGcCmdAlphaBlendBitmaps alphaBlend(aDestPt, aSrcBmp->WsHandle(), aSrcRect, aAlphaBmp->WsHandle(), aAlphaPt);

 	Write(&alphaBlend,sizeof(alphaBlend),EWsGcOpGdiWsAlphaBlendBitmaps);

 	AddToBitmapArray(aSrcBmp->Handle());

 	AddToBitmapArray(aAlphaBmp->Handle());

 	return KErrNone;

 	}

 /**

 This method has been deprecated. Calling it has no effect.

 @param aDrawOpaque Ignored.

 @deprecated

 */

 EXPORT_C void CWindowGc::SetOpaque(TBool aDrawOpaque)

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	WriteInt(aDrawOpaque, EWsGcOpSetOpaque);

 	}

 /** APIExtension can contain as many additional methods as is required by 

 CGraphicsContext after its original conception. It takes 3 parameters.

 Function is exported due to constrains of retaining BC with earlier versions.

 This is not used directly by external methods, instead it is called by a named 

 method in CGraphicsContext which passes the relivant arguements including an 

 unique identifier for the required action.

 @param aUid The unique identifier for the method that is required. Selected 

 internally by a series of "if" statements. 

 @see Valid Uid identifiers are listed in header gdi.h

 @see CGraphicsContext

 @param aOutput is a TAny pointer to a reference. Used to output data as the structure

 does not need to be instantiated before the function call this adds greater 

 flexibility.

 @param aInput is a TAny pointer used to input data.

 */	

 EXPORT_C TInt CWindowGc::APIExtension(TUid aUid, TAny*& aOutput, TAny* aInput)

 	{

 	if (aUid == KGetUnderlineMetrics)

 		{		

 		return APIExGetUnderlineMetrics(aOutput);

 		}

 	else if (aUid == KSetShadowColor)

 		{

 		return APIExSetShadowColor(aInput);

 		}

 	else if (aUid == KGetShadowColor)

 		{

 		return APIExGetShadowColor(aOutput);

 		}

 	else if (aUid == KDrawTextInContextUid)

 		{

 		TDrawTextInContextInternal* contextParam = (TDrawTextInContextInternal*)aInput;

 		return APIExDrawText(contextParam->iText, &contextParam->iParam, contextParam->iPosition);

 		}

 	else if (aUid == KDrawBoxTextInContextUid)

 		{

 		TDrawTextInContextInternal* contextParam = (TDrawTextInContextInternal*)aInput;

 		return APIExDrawText(contextParam->iText,&contextParam->iParam,contextParam->iBox,contextParam->iBaselineOffset,contextParam->iAlign,contextParam->iMargin);

 		}

 	else if (aUid == KDrawTextInContextVerticalUid)

 		{

 		TDrawTextInContextInternal* contextParam = (TDrawTextInContextInternal*)aInput;

 		return APIExDrawTextVertical(contextParam->iText, &contextParam->iParam, contextParam->iPosition,contextParam->iUp);

 		}

 	else if (aUid == KDrawBoxTextInContextVerticalUid)

 		{

 		TDrawTextInContextInternal* contextParam = (TDrawTextInContextInternal*)aInput;

 		return APIExDrawTextVertical(contextParam->iText,&contextParam->iParam,contextParam->iBox,contextParam->iBaselineOffset,contextParam->iUp,contextParam->iAlign,contextParam->iMargin);

 		}

 	else if (aUid == KApiExtensionInterfaceUid)

 		{

 		return APIExInterface(aOutput, *static_cast<TUid*>(aInput));

 		}

 	/* Future cases may be placed here later.*/

 	else

 		return CBitmapContext::APIExtension(aUid, aOutput, aInput);

 	}

 //The methods listed above in APIExtension follow here with the prefix APIEx.

 TInt CWindowGc::APIExGetUnderlineMetrics(TAny*& aOutput)

 	{

 	const TInt width = Max(iPimpl->iFont->HeightInPixels() / 10,1);

 	TTwoTInt* ptr = (TTwoTInt*)aOutput;

 	ptr->iTop = 1 + width / 2;

 	ptr->iBottom = (ptr->iTop) + width;

 	return KErrNone;

 	}

 TInt CWindowGc::APIExSetShadowColor(TAny* aShadowColor)

 	{

 	const TRgb shadowColor = *(reinterpret_cast<TRgb*> (aShadowColor));

 	WriteInt(shadowColor.Internal(), EWsGcOpSetShadowColor);

 	iPimpl->iShadowColor = shadowColor;

 	return KErrNone;

 	}

 TInt CWindowGc::APIExGetShadowColor(TAny*& aOutput)

 	{

 	TRgb* ptr = (TRgb*)aOutput;

 	ptr->SetInternal(iPimpl->iShadowColor.Internal());

 	return KErrNone;

 	}

 //Default implementation of reserved virtual

 EXPORT_C void CWindowGc::Reserved_CGraphicsContext_2()

 	{

 	CBitmapContext::Reserved_CGraphicsContext_2();

 	}

 //Default implementation of reserved virtual

 EXPORT_C void CWindowGc::Reserved_CBitmapContext_1()

 	{

 	CBitmapContext::Reserved_CBitmapContext_1();

 	}

 //Default implementation of reserved virtual

 EXPORT_C void CWindowGc::Reserved_CBitmapContext_2()

 	{

 	CBitmapContext::Reserved_CBitmapContext_2();

 	}

 //Default implementation of reserved virtual

 EXPORT_C void CWindowGc::Reserved_CBitmapContext_3()

 	{

 	CBitmapContext::Reserved_CBitmapContext_3();

 	}

 // was Reserved_CWindowGc_1

 EXPORT_C void CWindowGc::DrawWsGraphic(const TWsGraphicId& aId,const TRect& aDestRect)

 /** Draws an abstract artwork.

 It does nothing if aDestRect values fall outside the window area.

 @param aId the identifier for the artwork

 @param aDestRect the destination rect within the active window for this artwork

 @since 9.2

 @released

 */

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	TWsGcCmdDrawWsGraphic drawWsGraphic(aId,aDestRect);

 	Write(&drawWsGraphic,sizeof(drawWsGraphic),EWsGcOpDrawWsGraphic);

 	}

 // Reserved_CWindowGc_2

 EXPORT_C void CWindowGc::DrawWsGraphic(const TWsGraphicId& aId,const TRect& aDestRect,const TDesC8& aData)

 /** Draws an abstract artwork.

 It does nothing if aDestRect values fall outside the window area.

 @param aId the identifier for the artwork

 @param aDestRect the destination rect within the active window for this artwork

 @param aData opaque datagram to associate with this occasion of drawing.  The format is dependent upon the artwork

 @since 9.2

 @released

 */

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	TWsGcCmdDrawWsGraphic drawWsGraphic(aId,aDestRect);

 	drawWsGraphic.iDataLen = aData.Size();

 	WriteTextCommand(&drawWsGraphic, sizeof(drawWsGraphic),	aData, EWsGcOpDrawWsGraphic, EWsGcOpDrawWsGraphicPtr);	

 	}

 /**

 Gets an extension interface specified by the supplied UID, or NULL if it isn't supported.

 @param aInterfaceId The UID of the requested interface

 @return A pointer to the interface, or NULL if the interface isn't supported

 @publishedPartner

 @prototype

 */

 EXPORT_C TAny* CWindowGc::Interface(TUid aInterfaceId)

 	{

 	TAny* interface = NULL;

 	if(KErrNone == APIExtension(KApiExtensionInterfaceUid, interface, &aInterfaceId))

 		return interface;

 	return NULL;

 	}

 /**

 Gets an extension interface specified by the supplied UID, or NULL if it isn't supported.

 @param aInterfaceId The UID of the requested interface

 @return A pointer to the interface, or NULL if the interface isn't supported

 @publishedPartner

 @prototype

 */

 EXPORT_C const TAny* CWindowGc::Interface(TUid aInterfaceId) const

 	{

 	return const_cast<CWindowGc*>(this)->Interface(aInterfaceId);

 	}

 TInt CWindowGc::APIExInterface(TAny*& aInterface, TUid aInterfaceId)

 	{

 	if(aInterfaceId == KMWsDrawResourceInterfaceUid)

 		{

 		aInterface = static_cast<MWsDrawResource*>(iPimpl);

 		return KErrNone;

 		}

 	return KErrNotSupported;

 	}

 void CWindowGc::DrawResource(const TPoint& aPos, const RWsDrawableSource& aSource, TGraphicsRotation aRotation)

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	TWsGcCmdDrawResourceToPos drawWsResource(aSource.WsHandle(), aPos, aRotation);

 	Write(&drawWsResource, sizeof(drawWsResource), EWsGcOpDrawResourceToPos);

 	}

 void CWindowGc::DrawResource(const TRect& aDestRect, const RWsDrawableSource& aSource, TGraphicsRotation aRotation)

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	TWsGcCmdDrawResourceToRect drawWsResource(aSource.WsHandle(), aDestRect, aRotation);

 	Write(&drawWsResource, sizeof(drawWsResource), EWsGcOpDrawResourceToRect);

 	}

 void CWindowGc::DrawResource(const TRect& aDestRect, const RWsDrawableSource& aSource, const TRect& aSrcRect, TGraphicsRotation aRotation)

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	TWsGcCmdDrawResourceFromRectToRect drawWsResource(aSource.WsHandle(), aDestRect, aSrcRect, aRotation);

 	Write(&drawWsResource, sizeof(drawWsResource), EWsGcOpDrawResourceFromRectToRect);

 	}

 void CWindowGc::DrawResource(const TRect& aDestRect, const RWsDrawableSource& aSource, const TDesC8& aParam)

 	{

 	iPimpl->WriteAnyPendingStateChanges();

 	TWsGcCmdDrawResourceWithData drawWsResource(aSource.WsHandle(), aDestRect, &aParam);

 	Write(&drawWsResource, sizeof(drawWsResource),EWsGcOpDrawResourceWithData);

 	}

 //Default implementation of reserved virtual

 EXPORT_C void CWindowGc::Reserved_CWindowGc_3()

 	{

 	}

 //Default implementation of reserved virtual

 EXPORT_C void CWindowGc::Reserved_CWindowGc_4()

 	{

 	}

 //Default implementation of reserved virtual

 EXPORT_C void CWindowGc::Reserved_CWindowGc_5()

 	{

 	}

 /**

 Default constructor. 

 Only for embedding instances of RWsDrawableSource into other classes as data members. 

 Before a RWsDrawableSource can be used the other constructor must be called. 

  */

 EXPORT_C RWsDrawableSource::RWsDrawableSource()

 	: iDrawableId(KSgNullDrawableId), iScreenNumber(KSgScreenIdMain)

 	{

 	}

 /**

 Constructor.

 @param aWs Session to the window server

 @pre Connection to the window server is established

  */

 EXPORT_C RWsDrawableSource::RWsDrawableSource(RWsSession &aWs)

 	: MWsClientClass(aWs.iBuffer), iDrawableId(KSgNullDrawableId), iScreenNumber(KSgScreenIdMain)

 	{

 	}

 /**

 Create window server object for resource drawing operation via window server.

 This object will be identified by a unique handle and will be associated with drawable resource which is passed as a parameter.

 This object will be created for drawing onto the default screen only.

 @see CWindowGc

 @param  aDrawable Drawable resource.

 @post Drawable source is created and can be used by window server. The reference counter of the underlying

 		image resource is incremented. 

 @return KErrNone if successful, KErrArgument if the image resource is not valid,

 		KErrAlreadyExists if this handle is already associated with a 

 		specific resource,  otherwise one of the system-wide error codes.

  */

 EXPORT_C TInt RWsDrawableSource::Create(const RSgDrawable& aDrawable)

 	{

 	return Create(aDrawable, KSgScreenIdMain);

 	}

 /**

 Create window server object for resource drawing operation via window server.

 This object will be identified by  unique handle and will be associated with drawable resource which is passed as a parameter.

 This object will be created for drawing onto the specified screen only.

 @see CWindowGc

 @param  aDrawable Drawable resource.

 @param  aScreenNumber The screen onto which this drawable resource can be drawn.

 @post Drawable source is created and can be used by window server. The reference counter of the underlying

 		image resource is incremented. 

 @return KErrNone if successful, KErrArgument if the image resource is not valid

 		or if the specified screen is invalid, KErrAlreadyExists if this handle

 		is already associated with a specific resource, otherwise one of the

 		system-wide error codes.

  */

 EXPORT_C TInt RWsDrawableSource::Create(const RSgDrawable& aDrawable, TInt aScreenNumber)

 	{

 	if (iWsHandle)

 		{

 		return KErrAlreadyExists;

 		}

 	CGraphicsResourceWrapperFactory* grwFactory = new CGraphicsResourceWrapperFactory();

 	if (!grwFactory)

 		return KErrNoMemory;

 	// coverity[uninit_use_in_call]

 	CGraphicsResourceWrapper* graphicsResource = grwFactory->NewGraphicsResourceWrapper();

 	if(!graphicsResource)

 		{

 		delete grwFactory;

 		return KErrNotSupported;

 		}

 	if (graphicsResource->IsNull(aDrawable) || aScreenNumber < 0)

 		{

 		delete graphicsResource;

 		delete grwFactory;

 		return KErrArgument;

 		}

 	TWsClCmdCreateDrawableSource create(graphicsResource->Id(aDrawable), aScreenNumber);

 	TInt ret;

 	if ((ret = iBuffer->WriteReplyWs(&create, sizeof(TWsClCmdCreateDrawableSource), EWsClOpCreateDrawableSource)) < 0)

 		{

 		delete graphicsResource;

 		delete grwFactory;

 		return ret;

 		}

 	iWsHandle = ret;

 	iDrawableId = graphicsResource->Id(aDrawable);

 	iScreenNumber = aScreenNumber;

 	delete graphicsResource;

 	delete grwFactory;

 	return KErrNone;

 	}

 /**

 Destroy the window server drawable source. 

 Calling this method on a object that is not associated with any RSgDrawable 

 resource will have no effect. Once Close() is called, this drawable source object can be reused.

 @post	The window server drawable object is destroyed. The instance is no longer associated

 		with a RSgDrawable specific resource. The reference counter of the underlying

 		image resource is decremented. 

 */

 EXPORT_C void RWsDrawableSource::Close()

 	{

 	if (iWsHandle)

 		{

 		Write(EWsDrawableSourceOpFree);

 		iWsHandle = 0;

 		iDrawableId = KSgNullDrawableId;

 		iScreenNumber = KSgScreenIdMain;

 		}

 	}

 /**

  Get the unique ID of the associated drawable resource.

  */

 EXPORT_C const TSgDrawableId& RWsDrawableSource::DrawableId() const

 	{

 	return iDrawableId;

 	}

 /**

  Get the screen number of the drawable source.

  */

 EXPORT_C TInt RWsDrawableSource::ScreenNumber() const

 	{

 	return iScreenNumber;

 	}