Class TZoomFactor

class TZoomFactor : public MGraphicsDeviceMap;

Description

The interface for mapping between twips and device-specific units enriched with facilities to allow zooming.

The class is recursive, because a TZoomFactor object can have a MGraphicsDeviceMap (which could itself be a TZoomFactor) in its member data. This allows a zoom factor object to contain another zoom factor object, and is used to allow objects with different zoom factors to be embedded in each other to an arbitrary depth by the application architecture.

Derivation

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

• TZoomFactor - The interface for mapping between twips and device-specific units enriched with ...

Members

Defined in TZoomFactor:

• EZoomOneToOne
• GetNearestFontToDesignHeightInTwips(CFont *&,const TFontSpec &)Gets the font which is the nearest to the given font specification. Matching to ...
• GetNearestFontToMaxHeightInTwips(CFont *&,const TFontSpec &,TInt)Gets the font which is the nearest to the given font specification. Matching to ...
• GraphicsDeviceMap()constGets the graphics device map of this zoom factor object.
• HorizontalPixelsToTwips(TInt)constConverts a horizontal dimension from pixels to twips on the graphics device.
• HorizontalTwipsToPixels(TInt)constConverts a horizontal dimension from twips to pixels on the graphics device.
• ReleaseFont(CFont *)Releases the specified font.
• SetGraphicsDeviceMap(const MGraphicsDeviceMap *)Sets the graphics device map for this zoom factor object.
• SetTwipToPixelMapping(const TSize &,const TSize &)Sets the twips to pixels mapping for the graphics device with which the zoom fac...
• SetZoomFactor(TInt)Sets the zoom factor.
• TZoomFactor()Constructs a default zoom factor object.
• TZoomFactor(const MGraphicsDeviceMap *)Constructs a zoom factor object for a specific graphics device map.
• TZoomFactor(const TZoomFactor *)
• VerticalPixelsToTwips(TInt)constConverts a vertical dimension from pixels to twips on the graphics device.
• VerticalTwipsToPixels(TInt)constConverts a vertical dimension from twips to pixels on the graphics device.
• ZoomFactor()constGets the zoom factor.
• anonymousOne to one zoom factor.
• ~TZoomFactor()Destructor.

Inherited from MGraphicsDeviceMap:

• GetNearestFontInTwips(CFont *&,const TFontSpec &)Gets the font which is the nearest to the given font specification.
• 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.
• 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.

IMPORT_C TZoomFactor();

Description

Constructs a default zoom factor object.

Note that a TZoomFactor object cannot be used until a CGraphicsDevice to which it is associated is specified (by TZoomFactor::SetGraphicsDeviceMap(const MGraphicsDeviceMap *)). Therefore the other constructor is normally used for constructing TZoomFactors. The default constructor function is provided for use in TZoomFactor-derived classes.

IMPORT_C ~TZoomFactor();

Description

Destructor.

Frees resources owned by the object, prior to its destruction.

inline TZoomFactor(const MGraphicsDeviceMap *aDevice);

Description

Constructs a zoom factor object for a specific graphics device map.

The graphics map is either directly associated with a particular graphics device itself, or is associated with a hierarchy of device maps whose root map is associated with a particular graphics device.

Parameters

inline TZoomFactor(const TZoomFactor *aDevice);

Description

Parameters

IMPORT_C TInt ZoomFactor() const;

Description

Gets the zoom factor.

Return value

IMPORT_C void SetZoomFactor(TInt aZoomFactor);

Description

Sets the zoom factor.

Parameters

inline void SetGraphicsDeviceMap(const MGraphicsDeviceMap *aDevice);

Description

Sets the graphics device map for this zoom factor object.

Parameters

inline const MGraphicsDeviceMap* GraphicsDeviceMap() const;

Description

Gets the graphics device map of this zoom factor object.

Return value

IMPORT_C void SetTwipToPixelMapping(const TSize &aSizeInPixels, const TSize &aSizeInTwips);

Description

Sets the twips to pixels mapping for the graphics device with which the zoom factor is associated.

This setting is used by all the twips to pixels and pixels to twips conversion functions.

Parameters

IMPORT_C virtual TInt HorizontalTwipsToPixels(TInt aTwipWidth) const;

Description

Converts a horizontal dimension from twips to pixels on the graphics device.

This function implements the pure virtual function defined in MGraphicsDeviceMap::HorizontalTwipsToPixels(TInt)const

Parameters

Return value

IMPORT_C virtual TInt VerticalTwipsToPixels(TInt aTwipHeight) const;

Description

Converts a vertical dimension from twips to pixels on the graphics device.

This function implements the pure virtual function defined in MGraphicsDeviceMap::VerticalTwipsToPixels(TInt)const

Parameters

Return value

IMPORT_C virtual TInt HorizontalPixelsToTwips(TInt aPixelWidth) const;

Description

Converts a horizontal dimension from pixels to twips on the graphics device.

This function implements the pure virtual function defined in MGraphicsDeviceMap::HorizontalPixelsToTwips(TInt)const

Parameters

Return value

IMPORT_C virtual TInt VerticalPixelsToTwips(TInt aPixelHeight) const;

Description

Converts a vertical dimension from pixels to twips on the graphics device.

This function implements the pure virtual function defined in MGraphicsDeviceMap::VerticalPixelsToTwips(TInt)const

Parameters

Return value

IMPORT_C virtual TInt GetNearestFontToDesignHeightInTwips(CFont *&aFont, const TFontSpec &aFontSpec);

Description

Gets the font which is the nearest to the given font specification. Matching to design height gives no guarantees on the actual physical size of the font.

Parameters

Return value

IMPORT_C virtual TInt GetNearestFontToMaxHeightInTwips(CFont *&aFont, const TFontSpec &aFontSpec, TInt aMaxHeight);

Description

Gets the font which is the nearest to the given font specification. Matching to maximum height returns a font that will fit within the height specified.

Parameters

Return value

IMPORT_C virtual void ReleaseFont(CFont *aFont);

Description

Releases the specified font.

This function implements the pure virtual function defined in MGraphicsDeviceMap::ReleaseFont(CFont *)

Parameters

n/a

Description

One to one zoom factor.