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CGifScaler Class Reference

class CGifScaler : public CBase

The public API for clients to call the GifScaler scaling and color quantization library.

Inherits from

CGifScaler
- CBase

Public Member Functions
	~CGifScaler()
IMPORT_C void	Cancel()
IMPORT_C CGifScaler *	NewL(CFbsBitmap &, TOptions)
IMPORT_C CGifScaler *	NewL(CFbsBitmap &, CFbsBitmap &, TOptions)
IMPORT_C void	Scale(TRequestStatus *, CFbsBitmap &, CPalette &, TBool)
IMPORT_C void	ThresholdScale(TRequestStatus *, CFbsBitmap &, CPalette &, TUint8, TBool)

Private Member Functions
	CGifScaler()
void	ConstructL(CFbsBitmap &, CFbsBitmap *, TOptions)

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
enum	TOptions { ELowQualityQuantization, EMediumQualityQuantization, EHighQualityQuantization, EMaximumQualityQuantization }

Private Attributes
CBody *	iBody

Constructor & Destructor Documentation

CGifScaler()

CGifScaler

(

)

[private]

~CGifScaler()

IMPORT_C

~CGifScaler

(

)

This is the destructor for the CGifScaler and is responsible for deallocating all resources allocated by the CGifScaler.

Member Functions Documentation

Cancel()

IMPORT_C void

Cancel

(

)

Cancel any outstanding activity.

ConstructL(CFbsBitmap &, CFbsBitmap *, TOptions)

void	ConstructL	(	CFbsBitmap &	aSource,
			CFbsBitmap *	aSourceMask,
			TOptions	aOptions
		)	[private]

ConstructL Performs second phase of contruction

Parameters

CFbsBitmap & aSource
CFbsBitmap * aSourceMask
TOptions aOptions

NewL(CFbsBitmap &, TOptions)

IMPORT_C CGifScaler *	NewL	(	CFbsBitmap &	aSource,
			TOptions	aOptions = EHighQualityQuantization
		)	[static]

The function NewL constructs a CGifScaler. This version constructs a scaler for scaling and color quantizing only. No mask data is required in this case)

leave: KErrArgument if the source bitmap or the options are invalid.

panic: ENoSourceBitmap if the source bitmap has not been created.

Parameters

CFbsBitmap & aSource	The bitmap to be re-scaled.
TOptions aOptions = EHighQualityQuantization	Scaling and color quantization options.

NewL(CFbsBitmap &, CFbsBitmap &, TOptions)

IMPORT_C CGifScaler *	NewL	(	CFbsBitmap &	aSource,
			CFbsBitmap &	aSourceMask,
			TOptions	aOptions = EHighQualityQuantization
		)	[static]

The function NewL constructs a CGifScaler. This version constructs a scaler for scaling and color quantizing an image with transparency.

leave: KErrArgument if the source bitmap, source mask bitmap, or the options are invalid.

panic: ENoSourceBitmap if the source bitmap has not been created.

panic: ENoSourceMaskBitmap if the source mask bitmap has not been created.

Parameters

CFbsBitmap & aSource	The bitmap to be re-scaled.
CFbsBitmap & aSourceMask	The mask bitmap that provides the transparency data.
TOptions aOptions = EHighQualityQuantization	Scaling and color quantization options.

Scale(TRequestStatus *, CFbsBitmap &, CPalette &, TBool)

IMPORT_C void	Scale	(	TRequestStatus *	aStatus,
			CFbsBitmap &	aDestination,
			CPalette &	aPalette,
			TBool	aMaintainAspectRatio = ETrue
		)

Scale the source bitmap and mask to produce a single 8bpp bitmap and an output palette. If a mask was supplied during construction the last index in the palette will be used for transparency.

The scaling factor is based on the relative sizes of the source and target bitmaps. The operation is asynchronous. When it is complete, successfully or otherwise, the TRequestStatus aStatus is set, passing the state of the operation.

Parameters

TRequestStatus * aStatus	Request status to signal when scaling is complete.
CFbsBitmap & aDestination	The destination bitmap. (EColor256)
CPalette & aPalette	The output palette.
TBool aMaintainAspectRatio = ETrue	ETrue - the aspect ratio is retained; this is the default. The same scaling factor is applied in both the horizontal and vertical directions. This is the smaller of the horizontal scaling factor and the vertical scaling factor. EFalse - the aspect ratio need not be retained.

ThresholdScale(TRequestStatus *, CFbsBitmap &, CPalette &, TUint8, TBool)

IMPORT_C void	ThresholdScale	(	TRequestStatus *	aStatus,
			CFbsBitmap &	aDestination,
			CPalette &	aPalette,
			TUint8	aTransparencyThreshold,
			TBool	aMaintainAspectRatio = ETrue
		)

Scale the source bitmap and mask to produce a single 8bpp bitmap and an output palette, specifying a transparency level to be used when determining whether destination pixels are transparent. If a mask was supplied during construction the last index in the palette will be used for transparency.

Parameters

TRequestStatus * aStatus	Request status to signal when scaling is complete.
CFbsBitmap & aDestination	The destination bitmap. (EColor256)
CPalette & aPalette	The output palette.
TUint8 aTransparencyThreshold	The transparency level used to determine if destination pixels are transparent.
TBool aMaintainAspectRatio = ETrue	ETrue - the aspect ratio is retained; this is the default. The same scaling factor is applied in both the horizontal and vertical directions. This is the smaller of the horizontal scaling factor and the vertical scaling factor. EFalse - the aspect ratio need not be retained.

Member Enumerations Documentation

Enum TOptions

TOptions is an enumeration within the namespace CGifScaler The enumeration provides a set of supported quantization levels: (EHighQualityQuantization is the default setting as it provides the best balance between quality and speed)

Enumerators

ELowQualityQuantization	Provides the lowest quality, but also the fastest.
EMediumQualityQuantization	Provides medium quality quantization
EHighQualityQuantization	Provides high quality quantization
EMaximumQualityQuantization	Provides the highest quality quantization, but is also the slowest.

Member Data Documentation

CBody * iBody

CBody *

iBody

[private]