TZoomFactor Class Reference

#include <gdi.h>

Link against: gdi.lib

class TZoomFactor : public MGraphicsDeviceMap

Inherits from

Detailed 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.

Member Enumeration Documentation

Enum anonymous

One to one zoom factor.

EnumeratorValueDescription
EZoomOneToOne1000

Constructor & Destructor Documentation

TZoomFactor ( )

IMPORT_CTZoomFactor()

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 * )

TZoomFactor(const MGraphicsDeviceMap *aDevice)[inline]

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
aDeviceThe graphics device map with which the zoom factor is associated.

TZoomFactor ( const TZoomFactor * )

TZoomFactor(const TZoomFactor *aDevice)[inline]

~TZoomFactor ( )

IMPORT_C~TZoomFactor()

Destructor.

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

Member Function Documentation

GetNearestFontInTwips ( CFont *&, const TFontSpec & )

IMPORT_C TIntGetNearestFontInTwips(CFont *&aFont,
const TFontSpec &aFontSpec
)[virtual]

GetNearestFontToDesignHeightInTwips ( CFont *&, const TFontSpec & )

IMPORT_C TIntGetNearestFontToDesignHeightInTwips(CFont *&aFont,
const TFontSpec &aFontSpec
)[virtual]

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
aFontOn return, contains a pointer to the nearest font.
aFontSpecThe specification of the font to be matched.
Return Value
KErrNone if successful; a system-wide error code otherwise.

GetNearestFontToMaxHeightInTwips ( CFont *&, const TFontSpec &, TInt )

IMPORT_C TIntGetNearestFontToMaxHeightInTwips(CFont *&aFont,
const TFontSpec &aFontSpec,
TIntaMaxHeight
)[virtual]

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
aFontOn return, contains a pointer to the nearest font.
aFontSpecThe specification of the font to be matched.
aMaxHeightThe maximum height within which the font must fit. This overrides the height specified in aFontSpec. If maximum height is greater than 1024 pixels, the function returns KErrTooBig. And returns KErrArgument if equals to 1 pixel.
Return Value
KErrNone if successful; a system-wide error code otherwise.

GraphicsDeviceMap ( )

const MGraphicsDeviceMap *GraphicsDeviceMap()const [inline]

Gets the graphics device map of this zoom factor object.

Return Value
The graphics device map of the TZoomFactor.

HorizontalPixelsToTwips ( TInt )

IMPORT_C TIntHorizontalPixelsToTwips(TIntaPixelWidth)const [virtual]

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

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

HorizontalTwipsToPixels ( TInt )

IMPORT_C TIntHorizontalTwipsToPixels(TIntaTwipWidth)const [virtual]

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

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

ReleaseFont ( CFont * )

IMPORT_C voidReleaseFont(CFont *aFont)[virtual]

Releases the specified font.

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

Parameters
aFontA pointer to the font to be released.

SetGraphicsDeviceMap ( const MGraphicsDeviceMap * )

voidSetGraphicsDeviceMap(const MGraphicsDeviceMap *aDevice)[inline]

Sets the graphics device map for this zoom factor object.

Parameters
aDeviceThe graphics device map for this TZoomFactor.

SetTwipToPixelMapping ( const TSize &, const TSize & )

IMPORT_C voidSetTwipToPixelMapping(const TSize &aSizeInPixels,
const TSize &aSizeInTwips
)

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
aSizeInPixelsThe size of the graphics device area in pixels.
aSizeInTwipsThe size of the graphics device area in twips.

SetZoomFactor ( TInt )

IMPORT_C voidSetZoomFactor(TIntaZoomFactor)

Sets the zoom factor.

Parameters
aZoomFactorThe desired zoom factor.

VerticalPixelsToTwips ( TInt )

IMPORT_C TIntVerticalPixelsToTwips(TIntaPixelHeight)const [virtual]

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

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

VerticalTwipsToPixels ( TInt )

IMPORT_C TIntVerticalTwipsToPixels(TIntaTwipHeight)const [virtual]

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

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

ZoomFactor ( )

IMPORT_C TIntZoomFactor()const

Gets the zoom factor.

Return Value
The zoom factor