Class CGraphicsDevice

class CGraphicsDevice : public CBase, public MGraphicsDeviceMap;

Description

Specifies the interface for concrete device classes.

It holds information on the capabilities and attributes of a graphics device. The CBitmapDevice and CPrinterDevice classes are derived from CGraphicsDevice.

Derivation

• MGraphicsDeviceMap - Interface class for mapping between twips and device-specific units (pixels).
• CBase - Base class for all classes to be instantiated on the heap.

• CGraphicsDevice - Specifies the interface for concrete device classes.

Members

Defined in CGraphicsDevice:

• CreateContext(CGraphicsContext *&)Creates a graphics context for the device.
• DisplayMode()constGets the display mode of the device.
• FontHeightInTwips(TInt,TInt)constGet the height of a font in twips.
• GetPalette(CPalette *&)constGets the device's current palette.
• NumTypefaces()constGets the number of typefaces supported by the graphics device.
• PaletteAttributes(TBool &,TInt &)constGets the palette attributes of the device.
• SetPalette(CPalette *)Sets the device's palette.
• SizeInPixels()constGets the size of the device area in pixels.
• SizeInTwips()constGets the size of the device area in twips.
• TypefaceSupport(TTypefaceSupport &,TInt)constGets typeface information for a specified typeface.

Inherited from CBase:

• Delete(CBase *)Deletes the specified object.
• Extension_(TUint,TAny *&,TAny *)Extension function
• operator new(TUint)Allocates the object from the heap and then initialises its contents to binary z...
• operator new(TUint,TAny *)Initialises the object to binary zeroes.
• operator new(TUint,TLeave)Allocates the object from the heap and then initialises its contents to binary z...
• operator new(TUint,TLeave,TUint)Allocates the object from the heap and then initialises its contents to binary z...
• operator new(TUint,TUint)Allocates the object from the heap and then initialises its contents to binary z...

Inherited from MGraphicsDeviceMap:

• GetNearestFontInTwips(CFont *&,const TFontSpec &)Gets the font which is the nearest to the given font specification.
• GetNearestFontToDesignHeightInTwips(CFont *&,const TFontSpec &)Gets the font which is the nearest to the given font specification.
• GetNearestFontToMaxHeightInTwips(CFont *&,const TFontSpec &,TInt)Gets the font which is the nearest to the given font specification.
• HorizontalPixelsToTwips(TInt)constConverts a horizontal dimension from pixels to twips.
• HorizontalTwipsToPixels(TInt)constConverts a horizontal dimension from twips to pixels.
• PixelsToTwips(const TPoint &)constConverts a point in pixels to a point in twips.
• PixelsToTwips(const TRect &)constConverts a rectangle in pixels to a rectangle in twips.
• ReleaseFont(CFont *)Releases the specified font.
• TwipsToPixels(const TPoint &)constConverts a point in twips to a point in pixels.
• TwipsToPixels(const TRect &)constConverts a rectangle in twips to a rectangle in pixels.
• VerticalPixelsToTwips(TInt)constConverts a vertical dimension from pixels to twips.
• VerticalTwipsToPixels(TInt)constConverts a vertical dimension from twips to pixels.

See also:

• CPrinterDevicePrinter graphics device interface.

virtual TDisplayMode DisplayMode() const=0;

Description

Gets the display mode of the device.

Return value

TDisplayMode The display mode of the device.

virtual TSize SizeInPixels() const=0;

Description

Gets the size of the device area in pixels.

Return value

TSize The width and height of the device area, in pixels

virtual TSize SizeInTwips() const=0;

Description

Gets the size of the device area in twips.

Return value

TSize The width and height of the device area, in twips

virtual TInt CreateContext(CGraphicsContext *&aGC)=0;

Description

Creates a graphics context for the device.

Parameters

CGraphicsContext *&aGC On return, contains a pointer to the created graphics context.

Return value

TInt KErrNone, if successful; otherwise, another of the system-wide error codes.

virtual TInt NumTypefaces() const=0;

Description

Gets the number of typefaces supported by the graphics device.

Return value

TInt The number of typefaces supported.

virtual void TypefaceSupport(TTypefaceSupport &aTypefaceSupport, TInt aTypefaceIndex) const=0;

Description

Gets typeface information for a specified typeface.

This information is returned in aTypefaceSupport, and includes:

the typeface name and typeface attributes

the number of font heights

the maximum and minimum font heights

whether it is a scalable typeface

Parameters

TTypefaceSupport &aTypefaceSupport On return, contains the typeface information. TInt aTypefaceIndex A typeface index number, in the range: zero to (CGraphicsDevice::NumTypefaces()const - 1).

See also:

• CGraphicsDevice::NumTypefaces()constGets the number of typefaces supported by the graphics device.

virtual TInt FontHeightInTwips(TInt aTypefaceIndex, TInt aHeightIndex) const=0;

Description

Get the height of a font in twips.

The font is identified by typeface and height.

The value returned is rounded up or down to the nearest font height in twips.

Parameters

TInt aTypefaceIndex An index identifying the typeface, in the range: 0 to (CGraphicsDevice::NumTypefaces()const - 1). TInt aHeightIndex An index identifying the font height, in the range: 0 to (iNumHeights - 1). Note that iNumHeights is in the TTypefaceSupport object returned by CGraphicsDevice::TypefaceSupport(TTypefaceSupport &,TInt)const.

Return value

TInt The height of the font, in twips.

virtual void PaletteAttributes(TBool &aModifiable, TInt &aNumEntries) const=0;

Description

Gets the palette attributes of the device.

Parameters

TBool &aModifiable On return, holds information on whether or not the device's palette is modifiable (ETrue) or fixed (EFalse). TInt &aNumEntries On return, holds the number of entries in the device's palette.

virtual void SetPalette(CPalette *aPalette)=0;

Description

Sets the device's palette.

Parameters

CPalette *aPalette The new palette for the device.

virtual TInt GetPalette(CPalette *&aPalette) const=0;

Description

Gets the device's current palette.

Parameters

CPalette *&aPalette On return, holds the device's current palette.

Return value

TInt KErrNone, if successful; otherwise, another of the system-wide error codes.