Class TZoomFactor

TZoomFactor

Support

Supported from 5.0

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 facilities to allow zooming

Defined in TZoomFactor:
Anonymous, EZoomOneToOne, GetNearestFontInTwips(), GraphicsDeviceMap(), HorizontalPixelsToTwips(), HorizontalTwipsToPixels(), ReleaseFont(), SetGraphicsDeviceMap(), SetTwipToPixelMapping(), SetZoomFactor(), TZoomFactor(), VerticalPixelsToTwips(), VerticalTwipsToPixels(), ZoomFactor(), ~TZoomFactor()

Inherited from MGraphicsDeviceMap:
PixelsToTwips(), TwipsToPixels()

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 SetGraphicsDeviceMap()). Therefore the other constructor is normally used for constructing TZoomFactors. The default constructor function is provided for use in TZoomFactor-derived classes.

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

const MGraphicsDeviceMap* aDevice The graphics device map with which the zoom factor is associated.

~TZoomFactor();

Description

Destructor.

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

void SetZoomFactor(TInt aZoomFactor);

Description

Sets the zoom factor.

Parameters

TInt aZoomFactor The desired zoom factor.

TInt ZoomFactor() const;

Description

Gets the zoom factor.

Return value

TInt The zoom factor

void SetGraphicsDeviceMap(const MGraphicsDeviceMap* aDevice);

Description

Sets the graphics device map for this zoom factor object.

Parameters

const MGraphicsDeviceMap* aDevice The graphics device map for this TZoomFactor.

const MGraphicsDeviceMap* GraphicsDeviceMap() const;

Description

Gets the graphics device map of this zoom factor object.

Return value

MGraphicsDeviceMap* The graphics device map of the TZoomFactor.

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

const TSize& aSizeInPixels The size of the graphics device area in pixels. const TSize& aSizeInTwips The size of the graphics device area in twips.

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()

See also:

• MGraphicsDeviceMap::HorizontalTwipsToPixels()

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()

See also:

• MGraphicsDeviceMap::VerticalTwipsToPixels()

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()

See also:

• MGraphicsDeviceMap::HorizontalPixelsToTwips()

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()

See also:

• MGraphicsDeviceMap::VerticalPixelsToTwips()

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

Description

Gets the nearest font to that in the given font specification.

This function implements the pure virtual function defined in MGraphicsDeviceMap::GetNearestFontInTwips()

See also:

• MGraphicsDeviceMap::GetNearestFontInTwips()

void ReleaseFont(CFont* aFont);

Description

Releases the specified font.

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

See also:

• MGraphicsDeviceMap::ReleaseFont()

Anonymous

Description

One to one zoom factor.

EZoomOneToOne One to one zoom factor.