CFont Class Reference

#include <textbase.h>

class CFont : public CBase

Inherits from

CFont
- CBase

Nested Classes and Structures

Public Member Enumerations
enum	TCharacterDataAvailability { ENoCharacterData, ECharacterWidthOnly, EAllCharacterData }
enum	TTextDirection { EHorizontal, EVertical }

Public Member Functions
IMPORT_C TInt	AscentInPixels()
IMPORT_C TInt	BaselineOffsetInPixels()
IMPORT_C TInt	CharWidthInPixels(TChar)
IMPORT_C TBool	CharactersJoin(TInt, TInt)
IMPORT_C TInt	DescentInPixels()
IMPORT_C TInt	ExtendedFunction(TUid, TAny *)
TInt	FontCapitalAscent()
TInt	FontLineGap()
TInt	FontMaxAscent()
TInt	FontMaxDescent()
TInt	FontMaxHeight()
IMPORT_C TFontSpec	FontSpecInTwips()
TInt	FontStandardDescent()
IMPORT_C TCharacterDataAvailability	GetCharacterData(TUint, TOpenFontCharMetrics &, const TUint8 *&, TSize &)
IMPORT_C TBool	GetCharacterPosition(TPositionParam &)
IMPORT_C TBool	GetCharacterPosition2(TPositionParam &, RShapeInfo &)
IMPORT_C TInt	HeightInPixels()
IMPORT_C TInt	MaxCharWidthInPixels()
IMPORT_C TInt	MaxNormalCharWidthInPixels()
IMPORT_C TInt	MeasureText(const TDesC &, const TMeasureTextInput , TMeasureTextOutput )
IMPORT_C TInt	TextCount(const TDesC &, TInt)
IMPORT_C TInt	TextCount(const TDesC &, TInt, TInt &)
IMPORT_C TInt	TextWidthInPixels(const TDesC &)
IMPORT_C TInt	TextWidthInPixels(const TDesC &, const TMeasureTextInput *)
IMPORT_C TUid	TypeUid()
IMPORT_C TInt	WidthZeroInPixels()

Protected Member Functions
virtual	~CFont()
virtual IMPORT_C TInt	DoExtendedFunction(TUid, TAny *)
virtual IMPORT_C TCharacterDataAvailability	DoGetCharacterData(TUint, TOpenFontCharMetrics &, const TUint8 *&, TSize &)
virtual IMPORT_C TBool	DoGetCharacterPosition(TPositionParam &)

Inherited Functions
	CBase::CBase()
	CBase::Delete(CBase *)
	CBase::Extension_(TUint,TAny &,TAny )
	CBase::operator new(TUint)
	CBase::operator new(TUint,TAny *)
	CBase::operator new(TUint,TLeave)
	CBase::operator new(TUint,TLeave,TUint)
	CBase::operator new(TUint,TUint)
	CBase::~CBase()

Detailed Description

Abstract font interface.

The CFont class provides a device-independent interface to a device-dependent font usually obtained from a call to GetNearestFont...() on a graphics device. It is used as a handle in CGraphicsContext::UseFont() and to obtain device-dependent information about the font - notably the pixel width of a text string.

Member Enumeration Documentation

Enum TCharacterDataAvailability

Data availability flags.

Some fonts like printer fonts may only have width information and can return ECharacterWidthOnly to show this: the text drawing routines in CFont synthesize the rest of the data if necessary.

Enumerator	Value	Description
ENoCharacterData		No font information available.
ECharacterWidthOnly		Width information only is available.
EAllCharacterData		All character data is available.

Enum TTextDirection

Text direction flags.

This enum is used in TMeasureTextInput and determines whether the text is drawn horizontally or vertically. Note: text is drawn vertically in some styles of Japanese, etc.

Enumerator	Value	Description
EHorizontal		Text is drawn horizontally. Text is drawn horizontally.
EVertical		Text is drawn vertically.

Constructor & Destructor Documentation

~CFont ( )

IMPORT_C

~CFont

(

)

[protected, virtual]

Member Function Documentation

AscentInPixels ( )

IMPORT_C TInt

AscentInPixels

(

)

const

Deprecated

Gets the font ascent in pixels. Note that this deprecated function is replaced by the new FontMaxAscent() or in some cases FontCapitalAscent().

Return Value: The font ascent in pixels.

BaselineOffsetInPixels ( )

IMPORT_C TInt

BaselineOffsetInPixels

(

)

const

Gets the baseline offset in pixels.

The baseline offset is how far a font is raised or lowered from its normal baseline.

Return Value: Offset from normal baseline, in pixels.

CharWidthInPixels ( TChar )

IMPORT_C TInt

CharWidthInPixels

(

TChar

aChar

)

const

Gets the width in pixels in this font of the specified character.

Note: For OpenType fonts this function returns the horizontal advance of the character, which may be different from the actual width.

Parameters
aChar	The character whose width should be determined.

Return Value: The width in pixels of the specified character in this font.

CharactersJoin ( TInt, TInt )

IMPORT_C TBool	CharactersJoin	(	TInt	aLeftCharacter,
			TInt	aRightCharacter
		)	[static]

DescentInPixels ( )

IMPORT_C TInt

DescentInPixels

(

)

const

Deprecated

Gets the font descent in pixels. Note that this deprecated function is replaced by the new FontMaxDescent() or in some cases FontStandardDescent().

Return Value: The font descent in pixels.

DoExtendedFunction ( TUid, TAny * )

IMPORT_C TInt	DoExtendedFunction	(	TUid	aFunctionId,
			TAny *	aParam = 0
		)	const [protected, virtual]

DoGetCharacterData ( TUint, TOpenFontCharMetrics &, const TUint8 *&, TSize & )

IMPORT_C TCharacterDataAvailability	DoGetCharacterData	(	TUint	aCode,
			TOpenFontCharMetrics &	aMetrics,
			const TUint8 *&	aBitmap,
			TSize &	aBitmapSize
		)	const [protected, virtual]

DoGetCharacterPosition ( TPositionParam & )

IMPORT_C TBool

DoGetCharacterPosition

(

TPositionParam &

aParam

)

const [protected, virtual]

ExtendedFunction ( TUid, TAny * )

IMPORT_C TInt	ExtendedFunction	(	TUid	aFunctionId,
			TAny *	aParam = 0
		)	const

FontCapitalAscent ( )

TInt

FontCapitalAscent

(

)

const [inline]

Gets the ascent of an ANSI capital letter in the font whether or not there are any ANSI capitals in the font.

Return Value: The positive distance from the font baseline to the top of a standard ANSI capital letter

FontLineGap ( )

TInt

FontLineGap

(

)

const [inline]

Gets the suggested line gap for the font. This is the recommended baseline to baseline distance between successive lines of text in the font.

Return Value: The positive recommended gap between successive lines

FontMaxAscent ( )

TInt

FontMaxAscent

(

)

const [inline]

Gets the max ascent of any pre-composed glyph in the font. This will include accents or diacritics that form part of pre-composed glyphs. It is not guaranteed to cover the max ascent of composite glyphs that have to be created by a layout engine. This is also the recommended distance between the top of a text box and the baseline of the first line of text.

Return Value: The positive distance from the font baseline to the top of the highest pre-composed glyph (including accents) above the baseline

FontMaxDescent ( )

TInt

FontMaxDescent

(

)

const [inline]

Gets the max descent of any pre-composed glyph in the font. This will include accents or diacritics that form part of pre-composed glyphs. It is not guaranteed to cover the max descent of composite glyphs that have to be created by a layout engine.

Return Value: The positive distance from the font baseline to the bottom of the lowest pre-composed glyph (including accents) below the baseline

FontMaxHeight ( )

TInt

FontMaxHeight

(

)

const [inline]

Gets the (positive) maximum height in pixels of the font. This may differ from the design height.

Return Value: The maximum height of the font.

FontSpecInTwips ( )

IMPORT_C TFontSpec

FontSpecInTwips

(

)

const

Gets the font specification of this font in twips.

Return Value: The font specification of this font (in twips).

FontStandardDescent ( )

TInt

FontStandardDescent

(

)

const [inline]

Gets the descent of an ANSI descending character in the font. Whether or not there are any ANSI descenders in the font.

Return Value: The positive distance from the font baseline to the bottom of the lowest ANSI descender

GetCharacterData ( TUint, TOpenFontCharMetrics &, const TUint8 *&, TSize & )

IMPORT_C TCharacterDataAvailability	GetCharacterData	(	TUint	aCode,
			TOpenFontCharMetrics &	aMetrics,
			const TUint8 *&	aBitmap,
			TSize &	aBitmapSize
		)	const

GetCharacterPosition ( TPositionParam & )

IMPORT_C TBool

GetCharacterPosition

(

TPositionParam &

aParam

)

const

GetCharacterPosition2 ( TPositionParam &, RShapeInfo & )

IMPORT_C TBool	GetCharacterPosition2	(	TPositionParam &	aParam,
			RShapeInfo &	aShapeInfo
		)	const

HeightInPixels ( )

IMPORT_C TInt

HeightInPixels

(

)

const

Deprecated

Gets the font height in pixels. Note that this deprecated function is replaced by the new FontMaxHeight().

MaxCharWidthInPixels ( )

IMPORT_C TInt

MaxCharWidthInPixels

(

)

const

Gets the width in pixels of the widest character in this font.

Return Value: The width of the maximum width character, in pixels.

MaxNormalCharWidthInPixels ( )

IMPORT_C TInt

MaxNormalCharWidthInPixels

(

)

const

Gets the width in pixels of the widest normal character in this font.

Normal characters include all character in a character set except non-alphabetic characters (e.g. the copyright symbol, or a block graphics symbol, for example).

Return Value: The width of the maximum width normal character, in pixels.

MeasureText ( const TDesC &, const TMeasureTextInput , TMeasureTextOutput )

IMPORT_C TInt	MeasureText	(	const TDesC &	aText,
			const TMeasureTextInput *	aInput = 0,
			TMeasureTextOutput *	aOutput = 0
		)	const

TextCount ( const TDesC &, TInt )

IMPORT_C TInt	TextCount	(	const TDesC &	aText,
			TInt	aWidthInPixels
		)	const

Gets how much of the specified descriptor can be displayed in this font without exceeding the specified width.

Note:

This function does not display any of the descriptor itself - it is used before display, to test whether the whole descriptor can be displayed.

Parameters
aText	The descriptor.
aWidthInPixels	The available width for character display.

Return Value: The number of characters which will be able to be displayed without exceeding the specified width. The count starts from the beginning of the descriptor.

TextCount ( const TDesC &, TInt, TInt & )

IMPORT_C TInt	TextCount	(	const TDesC &	aText,
			TInt	aWidthInPixels,
			TInt &	aExcessWidthInPixels
		)	const

Gets how much of the specified descriptor can be displayed in this font without exceeding the specified width.

It also returns the excess width - defined as the specified available width minus the width of the portion of the descriptor which can be displayed without exceeding the available width.

Parameters
aText	The descriptor.
aWidthInPixels	The available width for character display.
aExcessWidthInPixels	The excess width after displaying the portion of the descriptor, in pixels.

Return Value: The number of characters which will be able to be displayed without exceeding the specified width. The count starts from the beginning of the descriptor.

TextWidthInPixels ( const TDesC & )

IMPORT_C TInt

TextWidthInPixels

(

const TDesC &

aText

)

const

Gets the width in pixels of the specified descriptor when displayed in this font.

Parameters
aText	The descriptor whose width should be determined.

Return Value: The width of the specified descriptor when displayed in this font, in pixels.

TextWidthInPixels ( const TDesC &, const TMeasureTextInput * )

IMPORT_C TInt	TextWidthInPixels	(	const TDesC &	aText,
			const TMeasureTextInput *	aParam
		)	const

Gets the width in pixels of the specified descriptor when displayed in this font.

Parameters
aText	The descriptor whose width should be determined.
aParam	Parameter block that controls how much of aText is measured

Return Value: The width of the specified descriptor when displayed in this font, in pixels.

TypeUid ( )

IMPORT_C TUid

TypeUid

(

)

const

Gets run-time identity of the actual font type. This enables safe casting to a derived type.

For example, if the derived type is a CFbsFont, the return value is KCFbsFontUid. You would need to cast to a CFbsFont to get a character bounding box. Similarly, a CBitmapFont returns KCBitmapFontUidVal.

Return Value: The font-type identifier.

WidthZeroInPixels ( )

IMPORT_C TInt

WidthZeroInPixels

(

)

const

CFont Class Reference

Inherits from

Nested Classes and Structures

Detailed Description

Member Enumeration Documentation

Enum TCharacterDataAvailability

Enum TTextDirection

Constructor & Destructor Documentation

~CFont ( )

Member Function Documentation

AscentInPixels ( )

BaselineOffsetInPixels ( )

CharWidthInPixels ( TChar )

CharactersJoin ( TInt, TInt )

DescentInPixels ( )

DoExtendedFunction ( TUid, TAny * )

DoGetCharacterData ( TUint, TOpenFontCharMetrics &, const TUint8 *&, TSize & )

DoGetCharacterPosition ( TPositionParam & )

ExtendedFunction ( TUid, TAny * )

FontCapitalAscent ( )

FontLineGap ( )

FontMaxAscent ( )

FontMaxDescent ( )

FontMaxHeight ( )

FontSpecInTwips ( )

FontStandardDescent ( )

GetCharacterData ( TUint, TOpenFontCharMetrics &, const TUint8 *&, TSize & )

GetCharacterPosition ( TPositionParam & )

GetCharacterPosition2 ( TPositionParam &, RShapeInfo & )

HeightInPixels ( )

MaxCharWidthInPixels ( )

MaxNormalCharWidthInPixels ( )

MeasureText ( const TDesC &, const TMeasureTextInput *, TMeasureTextOutput * )

TextCount ( const TDesC &, TInt )

TextCount ( const TDesC &, TInt, TInt & )

TextWidthInPixels ( const TDesC & )

TextWidthInPixels ( const TDesC &, const TMeasureTextInput * )

TypeUid ( )

WidthZeroInPixels ( )

MeasureText ( const TDesC &, const TMeasureTextInput , TMeasureTextOutput )