Class MGraphicsDeviceMap

class MGraphicsDeviceMap;

Description

Interface class for mapping between twips and device-specific units (pixels).

TZoomFactor is derived from MGraphicsDeviceMap.

Members

Defined in 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.
• MGraphicsDeviceMap()Default constructor.
• 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.
• ~MGraphicsDeviceMap()Destructor.

See also:

• CGraphicsDeviceSpecifies the interface for concrete device classes.
• TZoomFactorThe interface for mapping between twips and device-specific units enriched with ...

IMPORT_C MGraphicsDeviceMap();

Description

Default constructor.

IMPORT_C virtual ~MGraphicsDeviceMap();

Description

Destructor.

IMPORT_C TPoint TwipsToPixels(const TPoint &aTwipPoint) const;

Description

Converts a point in twips to a point in pixels.

Parameters

Return value

IMPORT_C TRect TwipsToPixels(const TRect &aTwipRect) const;

Description

Converts a rectangle in twips to a rectangle in pixels.

Parameters

Return value

IMPORT_C TPoint PixelsToTwips(const TPoint &aPixelPoint) const;

Description

Converts a point in pixels to a point in twips.

Parameters

Return value

IMPORT_C TRect PixelsToTwips(const TRect &aPixelRect) const;

Description

Converts a rectangle in pixels to a rectangle in twips.

Parameters

Return value

virtual TInt HorizontalTwipsToPixels(TInt aTwips) const=0;

Description

Converts a horizontal dimension from twips to pixels.

An implementation is supplied by a derived class.

Parameters

Return value

virtual TInt VerticalTwipsToPixels(TInt aTwips) const=0;

Description

Converts a vertical dimension from twips to pixels.

An implementation is supplied by a derived class.

Parameters

Return value

virtual TInt HorizontalPixelsToTwips(TInt aPixels) const=0;

Description

Converts a horizontal dimension from pixels to twips.

An implementation is supplied by a derived class.

Parameters

Return value

virtual TInt VerticalPixelsToTwips(TInt aPixels) const=0;

Description

Converts a vertical dimension from pixels to twips.

An implementation is supplied by a derived class.

Parameters

Return value

virtual TInt GetNearestFontInTwips(CFont *&aFont, const TFontSpec &aFontSpec)=0;

Description

Gets the font which is the nearest to the given font specification.

When the font is no longer needed, call ReleaseFont() .

Note that this deprecated function is replaced by the new GetNearestFontToDesignHeightInTwips() yielding (virtually) the same result. However clients are strongly encouraged to use the new GetNearestFontToMaxHeightInTwips() function instead. This will guarantee that every character within any given text string will fit within the given amount of twips, whereas the design height is an aesthetic unit decided by the font designer without strict physical meaning, which may result in cropped characters.

Parameters

Return value

inline virtual TInt GetNearestFontToDesignHeightInTwips(CFont *&, const TFontSpec &);

Description

Gets the font which is the nearest to the given font specification.

When the font is no longer needed, call ReleaseFont() .

This new function replaces the deprecated GetNearestFontInTwips() yielding (virtually) the same result. However clients are strongly encouraged to use the new GetNearestFontToMaxHeightInTwips() function instead. This will guarantee that every character within any given text string will fit within the given amount of twips, whereas the design height is an aesthetic unit decided by the font designer without strict physical meaning, which may result in cropped characters.

Parameters

Return value

inline virtual TInt GetNearestFontToMaxHeightInTwips(CFont *&, const TFontSpec &, TInt);

Description

Gets the font which is the nearest to the given font specification.

When the font is no longer needed, call ReleaseFont() .

The font and bitmap server returns a pointer to the nearest matching font from those available. Matches to max height of font - this does its best to return a font that will fit within the maximum height specified (but note that variations due to hinting algorithms may rarely result in this height being exceeded by up to one pixel). Problems can also be encountered with bitmap fonts where the typeface exists but doesn't have a font small enough.

Parameters

Return value

virtual void ReleaseFont(CFont *aFont)=0;

Description

Releases the specified font.

It is used to indicate that the specified font is no longer needed for use by the device map. As fonts can be shared between applications, this function does not delete the copy of the font from RAM unless the font was only being used by this particular device map.

An implementation is supplied by a derived class.

Parameters