CFont Class Reference

class CFont : public CBase

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.

CFbsFont

CGraphicsContext::UseFont()

Inherits from

Nested Classes and Structures

Public Member Functions
IMPORT_C TIntAscentInPixels()
IMPORT_C TIntBaselineOffsetInPixels()
IMPORT_C TIntCharWidthInPixels(TChar)
IMPORT_C TBoolCharactersJoin(TInt, TInt)
IMPORT_C TIntDescentInPixels()
IMPORT_C TIntExtendedFunction(TUid, TAny *)
TInt FontCapitalAscent()
TInt FontLineGap()
TInt FontMaxAscent()
TInt FontMaxDescent()
TInt FontMaxHeight()
IMPORT_C TFontSpecFontSpecInTwips()
TInt FontStandardDescent()
IMPORT_C TCharacterDataAvailabilityGetCharacterData(TUint, TOpenFontCharMetrics &, const TUint8 *&, TSize &)
IMPORT_C TBoolGetCharacterPosition(TPositionParam &)
IMPORT_C TBoolGetCharacterPosition2(TPositionParam &, RShapeInfo &)
IMPORT_C TIntHeightInPixels()
IMPORT_C TIntMaxCharWidthInPixels()
IMPORT_C TIntMaxNormalCharWidthInPixels()
IMPORT_C TIntMeasureText(const TDesC &, const TMeasureTextInput *, TMeasureTextOutput *)
IMPORT_C TIntTextCount(const TDesC &, TInt)
IMPORT_C TIntTextCount(const TDesC &, TInt, TInt &)
IMPORT_C TIntTextWidthInPixels(const TDesC &)
IMPORT_C TIntTextWidthInPixels(const TDesC &, const TMeasureTextInput *)
IMPORT_C TUidTypeUid()
IMPORT_C TIntWidthZeroInPixels()
Protected Member Functions
~CFont()
IMPORT_C TIntDoExtendedFunction(TUid, TAny *)
IMPORT_C TCharacterDataAvailabilityDoGetCharacterData(TUint, TOpenFontCharMetrics &, const TUint8 *&, TSize &)
IMPORT_C TBoolDoGetCharacterPosition(TPositionParam &)
Private Member Functions
TInt DoAscentInPixels()
TInt DoBaselineOffsetInPixels()
TInt DoCharWidthInPixels(TChar)
IMPORT_C TIntDoDescentInPixels()
TFontSpec DoFontSpecInTwips()
TInt DoHeightInPixels()
TInt DoMaxCharWidthInPixels()
TInt DoMaxNormalCharWidthInPixels()
TInt DoTextCount(const TDesC &, TInt)
TInt DoTextCount(const TDesC &, TInt, TInt &)
TInt DoTextWidthInPixels(const TDesC &)
TUid DoTypeUid()
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()
Public Member Enumerations
enumTCharacterDataAvailability { ENoCharacterData, ECharacterWidthOnly, EAllCharacterData }
enumTTextDirection { EHorizontal, EVertical }

Constructor & Destructor Documentation

~CFont()

IMPORT_C~CFont()[protected, virtual]

Member Functions Documentation

AscentInPixels()

IMPORT_C TIntAscentInPixels()const

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

The font ascent in pixels.

FontCapitalAscent()

FontMaxAscent()

BaselineOffsetInPixels()

IMPORT_C TIntBaselineOffsetInPixels()const

Gets the baseline offset in pixels.

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

Offset from normal baseline, in pixels.

CharWidthInPixels(TChar)

IMPORT_C TIntCharWidthInPixels(TCharaChar)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.

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

Parameters

TChar aCharThe character whose width should be determined.

CharactersJoin(TInt, TInt)

IMPORT_C TBoolCharactersJoin(TIntaLeftCharacter,
TIntaRightCharacter
)[static]

Parameters

TInt aLeftCharacter
TInt aRightCharacter

DescentInPixels()

IMPORT_C TIntDescentInPixels()const

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

The font descent in pixels.

FontStandardDescent()

FontMaxDescent()

DoAscentInPixels()

TInt DoAscentInPixels()const [private, pure virtual]

WARNING: Function for internal use ONLY. Compatibility is not guaranteed in future releases. Please see derived class for implementation.

DoBaselineOffsetInPixels()

TInt DoBaselineOffsetInPixels()const [private, pure virtual]

WARNING: Function for internal use ONLY. Compatibility is not guaranteed in future releases. Please see derived class for implementation.

DoCharWidthInPixels(TChar)

TInt DoCharWidthInPixels(TCharaChar)const [private, pure virtual]

WARNING: Function for internal use ONLY. Compatibility is not guaranteed in future releases. Please see derived class for implementation.

Parameters

TChar aChar

DoDescentInPixels()

IMPORT_C TIntDoDescentInPixels()const [private, virtual]

DoExtendedFunction(TUid, TAny *)

IMPORT_C TIntDoExtendedFunction(TUidaFunctionId,
TAny *aParam = NULL
)const [protected, virtual]

Parameters

TUid aFunctionId
TAny * aParam = NULL

DoFontSpecInTwips()

TFontSpec DoFontSpecInTwips()const [private, pure virtual]

WARNING: Function for internal use ONLY. Compatibility is not guaranteed in future releases. Please see derived class for implementation.

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

IMPORT_C TCharacterDataAvailabilityDoGetCharacterData(TUintaCode,
TOpenFontCharMetrics &aMetrics,
const TUint8 *&aBitmap,
TSize &aBitmapSize
)const [protected, virtual]

Parameters

TUint aCode
TOpenFontCharMetrics & aMetrics
const TUint8 *& aBitmap
TSize & aBitmapSize

DoGetCharacterPosition(TPositionParam &)

IMPORT_C TBoolDoGetCharacterPosition(TPositionParam &aParam)const [protected, virtual]

Parameters

TPositionParam & aParam

DoHeightInPixels()

TInt DoHeightInPixels()const [private, pure virtual]

WARNING: Function for internal use ONLY. Compatibility is not guaranteed in future releases. Please see derived class for implementation.

DoMaxCharWidthInPixels()

TInt DoMaxCharWidthInPixels()const [private, pure virtual]

WARNING: Function for internal use ONLY. Compatibility is not guaranteed in future releases. Please see derived class for implementation.

DoMaxNormalCharWidthInPixels()

TInt DoMaxNormalCharWidthInPixels()const [private, pure virtual]

WARNING: Function for internal use ONLY. Compatibility is not guaranteed in future releases. Please see derived class for implementation.

DoTextCount(const TDesC &, TInt)

TInt DoTextCount(const TDesC &aText,
TIntaWidthInPixels
)const [private, pure virtual]

WARNING: Function for internal use ONLY. Compatibility is not guaranteed in future releases. Please see derived class for implementation.

Parameters

const TDesC & aText
TInt aWidthInPixels

DoTextCount(const TDesC &, TInt, TInt &)

TInt DoTextCount(const TDesC &aText,
TIntaWidthInPixels,
TInt &aExcessWidthInPixels
)const [private, pure virtual]

WARNING: Function for internal use ONLY. Compatibility is not guaranteed in future releases. Please see derived class for implementation.

Parameters

const TDesC & aText
TInt aWidthInPixels
TInt & aExcessWidthInPixels

DoTextWidthInPixels(const TDesC &)

TInt DoTextWidthInPixels(const TDesC &aText)const [private, pure virtual]

WARNING: Function for internal use ONLY. Compatibility is not guaranteed in future releases. Please see derived class for implementation.

Parameters

const TDesC & aText

DoTypeUid()

TUid DoTypeUid()const [private, pure virtual]

WARNING: Function for internal use ONLY. Compatibility is not guaranteed in future releases. Please see derived class for implementation.

ExtendedFunction(TUid, TAny *)

IMPORT_C TIntExtendedFunction(TUidaFunctionId,
TAny *aParam = NULL
)const

Parameters

TUid aFunctionId
TAny * aParam = NULL

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. 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. 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. 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. 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.

The maximum height of the font.

FontSpecInTwips()

IMPORT_C TFontSpecFontSpecInTwips()const

Gets the font specification of this font in twips.

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. The positive distance from the font baseline to the bottom of the lowest ANSI descender

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

IMPORT_C TCharacterDataAvailabilityGetCharacterData(TUintaCode,
TOpenFontCharMetrics &aMetrics,
const TUint8 *&aBitmap,
TSize &aBitmapSize
)const

Parameters

TUint aCode
TOpenFontCharMetrics & aMetrics
const TUint8 *& aBitmap
TSize & aBitmapSize

GetCharacterPosition(TPositionParam &)

IMPORT_C TBoolGetCharacterPosition(TPositionParam &aParam)const

Parameters

TPositionParam & aParam

GetCharacterPosition2(TPositionParam &, RShapeInfo &)

IMPORT_C TBoolGetCharacterPosition2(TPositionParam &aParam,
RShapeInfo &aShapeInfo
)const

Parameters

TPositionParam & aParam
RShapeInfo & aShapeInfo

HeightInPixels()

IMPORT_C TIntHeightInPixels()const

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

The font height in pixels.

FontMaxHeight()

MaxCharWidthInPixels()

IMPORT_C TIntMaxCharWidthInPixels()const

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

The width of the maximum width character, in pixels.

MaxNormalCharWidthInPixels()

IMPORT_C TIntMaxNormalCharWidthInPixels()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).

The width of the maximum width normal character, in pixels.

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

IMPORT_C TIntMeasureText(const TDesC &aText,
const TMeasureTextInput *aInput = NULL,
TMeasureTextOutput *aOutput = NULL
)const

Parameters

const TDesC & aText
const TMeasureTextInput * aInput = NULL
TMeasureTextOutput * aOutput = NULL

TextCount(const TDesC &, TInt)

IMPORT_C TIntTextCount(const TDesC &aText,
TIntaWidthInPixels
)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.

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.

Parameters

const TDesC & aTextThe descriptor.
TInt aWidthInPixelsThe available width for character display.

TextCount(const TDesC &, TInt, TInt &)

IMPORT_C TIntTextCount(const TDesC &aText,
TIntaWidthInPixels,
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.

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.

Parameters

const TDesC & aTextThe descriptor.
TInt aWidthInPixelsThe available width for character display.
TInt & aExcessWidthInPixelsThe excess width after displaying the portion of the descriptor, in pixels.

TextWidthInPixels(const TDesC &)

IMPORT_C TIntTextWidthInPixels(const TDesC &aText)const

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

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

Parameters

const TDesC & aTextThe descriptor whose width should be determined.

TextWidthInPixels(const TDesC &, const TMeasureTextInput *)

IMPORT_C TIntTextWidthInPixels(const TDesC &aText,
const TMeasureTextInput *aParam
)const

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

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

Parameters

const TDesC & aTextThe descriptor whose width should be determined.
const TMeasureTextInput * aParamParameter block that controls how much of aText is measured

TypeUid()

IMPORT_C TUidTypeUid()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.

The font-type identifier.

WidthZeroInPixels()

IMPORT_C TIntWidthZeroInPixels()const

Member Enumerations 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.

GetCharacterData()

Enumerators

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.

TMeasureTextInput

Enumerators

EHorizontal

Text is drawn horizontally. Text is drawn horizontally.

EVertical

Text is drawn vertically.

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