Class CImageTransform

class CImageTransform : public CBase;

Description

The public API for clients to call the Image Transform (scaling) library. This class provides functions to scale images held in files or descriptors.

Derivation

• CBase - Base class for all classes to be instantiated on the heap.

• CImageTransform - The public API for clients to call the Image Transform (scaling) library. This c...

Members

Defined in CImageTransform:

• CancelTransform()Cancels any asynchronous image transform operation currently in progress.
• ClearSourceRect()Clears the clipping region.
• EEnumBoundaryTOptions should not be set greater than or equal to this value.
• EIgnoreExifMetadataProcessingIf set, then the Exif data is not parsed and ExifMetaData() will always return N...
• EOptionNoneNo flag set. This is the default option
• EThumbnailIf set, the destination image will always have a thumbnail. If the source alread...
• Extension()constGets a pointer to a plugin extension
• NewL(RFs &)Constructs a CImageTransform object.
• Reset()Resets all SetXXX() calls so that the state is the same as that immediately afte...
• SetDestDataL(HBufC8 *&)Defines the destination descriptor. This is a reference to a pointer that is own...
• SetDestFilenameL(const TDesC &)Specifies the name of the destination file where the transformed image is to be ...
• SetDestSizeInPixelsL(const TSize &,TBool)Specifies the requested destination image size.
• SetOptionsL(TUint)Defines how the image is to be transformed. The specified option must be one of ...
• SetPluginUidL(TUid)Specifies the UID of the image transform plugin to load
• SetPreserveImageData(TBool)Specifies that either the original image data is to preserved, as far as possibl...
• SetSourceDataL(const TDesC8 &)Specifies the source descriptor containing the image to transform. Note that thi...
• SetSourceFilenameL(const TDesC &)Specifies the name of the source file containing the image to transform
• SetSourceImageTypeL(TUid,TUid)Specifies the source image's type and (optionally) its subtype
• SetSourceMimeTypeL(const TDesC8 &)Specifies the MIME type of the source image.
• SetSourceRect(const TRect &)Defines a clipping region. Only the specified region will be converted. It is no...
• SetupL()Requests that a suitable plugin be selected and instantiated. Leaves with KErrNo...
• TOptionsFlags to control how the image is transformed. The EThumbnail and EIgnoreExifMet...
• Transform(TRequestStatus &)Initiates an asynchronous image transform operation. The framework will panic if...
• ~CImageTransform()This is the destructor for this class and is responsible for deallocating all re...

Inherited from CBase:

• Delete(CBase *)Deletes the specified object.
• Extension_(TUint,TAny *&,TAny *)Extension function
• operator new(TUint)Allocates the object from the heap and then initialises its contents to binary z...
• operator new(TUint,TAny *)Initialises the object to binary zeroes.
• operator new(TUint,TLeave)Allocates the object from the heap and then initialises its contents to binary z...
• operator new(TUint,TLeave,TUint)Allocates the object from the heap and then initialises its contents to binary z...
• operator new(TUint,TUint)Allocates the object from the heap and then initialises its contents to binary z...

IMPORT_C static CImageTransform* NewL(RFs &aFs);

Description

Constructs a CImageTransform object.

Parameters

Return value

IMPORT_C ~CImageTransform();

Description

This is the destructor for this class and is responsible for deallocating all resources

IMPORT_C void SetPluginUidL(TUid aPluginUid);

Description

Specifies the UID of the image transform plugin to load

Parameters

Leave codes

IMPORT_C void SetSourceFilenameL(const TDesC &aFilename);

Description

Specifies the name of the source file containing the image to transform

Parameters

Leave codes

IMPORT_C void SetSourceDataL(const TDesC8 &aData);

Description

Specifies the source descriptor containing the image to transform. Note that this descriptor must persist while the the image is transformed. i.e. the data is not copied. Special care must be taken when passing a TPtrC8 or TPtr8 to this function: The TPtrC8/TPtr8 itself (as well as the data it points to) must be persistent.

Parameters

Leave codes

IMPORT_C void SetSourceMimeTypeL(const TDesC8 &aMIMEType);

Description

Specifies the MIME type of the source image.

Parameters

Leave codes

IMPORT_C void SetSourceImageTypeL(TUid aImageType, TUid aImageSubType=TUid::Null());

Description

Specifies the source image's type and (optionally) its subtype

Parameters

Leave codes

IMPORT_C void SetSourceRect(const TRect &aRect);

Description

Defines a clipping region. Only the specified region will be converted. It is not supported by the Symbian Jpeg ImageTransform Plugin.

Parameters

IMPORT_C void ClearSourceRect();

Description

Clears the clipping region.

IMPORT_C void SetDestFilenameL(const TDesC &aFilename);

Description

Specifies the name of the destination file where the transformed image is to be written to.

Parameters

Leave codes

IMPORT_C void SetDestDataL(HBufC8 *&aData);

Description

Defines the destination descriptor. This is a reference to a pointer that is owned by the client app. The pointer should be NULL: the plugin will take responsibility for allocating (and potentially growing) the descriptor.

Parameters

Leave codes

IMPORT_C void SetDestSizeInPixelsL(const TSize &aDestinationSize, TBool aMaintainAspectRatio=ETrue);

Description

Specifies the requested destination image size.

Parameters

Leave codes

IMPORT_C void SetOptionsL(TUint aOptions);

Description

Defines how the image is to be transformed. The specified option must be one of the options supported or a combination of them, see CImageTransform::TOptions.

Parameters

Leave codes

IMPORT_C void SetPreserveImageData(TBool aPreserveImageData);

Description

Specifies that either the original image data is to preserved, as far as possible, or that the image data should be re-encoded to produce a more size-efficient image.

Parameters

IMPORT_C void SetupL();

Description

Requests that a suitable plugin be selected and instantiated. Leaves with KErrNotFound if no suitable plugin found or if the framework or plugin finds any error in any of the preceeding SetXXX() calls

Leave codes

IMPORT_C void Transform(TRequestStatus &aStatus);

Description

Initiates an asynchronous image transform operation. The framework will panic if no plugin has been instantiated already.

Parameters

Panic codes

IMPORT_C void CancelTransform();

Description

Cancels any asynchronous image transform operation currently in progress.

IMPORT_C void Reset();

Description

Resets all SetXXX() calls so that the state is the same as that immediately after a call to CImageTransform::NewL(RFs &). Deletes the plugin if one is loaded.

IMPORT_C CImageTransformPluginExtension* Extension() const;

Description

Gets a pointer to a plugin extension

Return value

Panic codes

TOptions

Description

Flags to control how the image is transformed. The EThumbnail and EIgnoreExifMetadataProcessing are mutually exclusive, and SHOULD NOT be used together. If they are, then EThumbnail is used.