Class CImageDisplayPlugin

class CImageDisplayPlugin : public CBase;

Description

This is the plugin API for the Image Display framework Intended for use by plugin writers only.

Derivation

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

• CImageDisplayPlugin - This is the plugin API for the Image Display framework Intended for use by plugin writers only

Members

Defined in CImageDisplayPlugin:
AsyncCallbackImageReady(), CImageDisplayPlugin(), CallbackIsRunning(), CancelCallback(), DestinationSizeInPixels(), DisplayMode(), EImgSrcDescriptor, EImgSrcFileHandle, EImgSrcFileName, EImgSrcNotDefined, EStatusBusy, EStatusDisplayThisFrameIndefinetely, EStatusEraseOutputContents, EStatusFrameReady, EStatusNoMoreToDecode, EStatusPartialFrame, EStatusPaused, ExtensionInterface(), GetBitmap(), ImageStatus(), MaintainAspectRatio(), NumFrames(), OpenL(), Options(), Pause(), Play(), RecommendedImageSizes(), ReservedVirtual1(), ReservedVirtual2(), ReservedVirtual3(), ReservedVirtual4(), SourceData(), SourceDataId(), SourceDataIntent(), SourceFileHandle(), SourceFilename(), SourceImageSubType(), SourceImageType(), SourceMimeType(), SourceRect(), SourceType(), StopPlay(), TImageSourceType, TPluginStatus, ValidBitmap(), iImageSizes, ~CImageDisplayPlugin()

Inherited from CBase:
Delete(), Extension_(), operator new()

IMPORT_C ~CImageDisplayPlugin();

Description

Virtual destructor. Current implementation will call the REComSession::DestroyedImplementation() to finalize destruction of the ECom plugin

protected: IMPORT_C CImageDisplayPlugin();

Description

Exported default constructor

protected: virtual void OpenL()=0;

Description

Initialise the plugin and check the image display settings.

This is called by the ImageDisplay framework when the client app calls CImageDisplay::SetupL().

The plugin should check the validity of the source image and all other settings set by the client API. If any of these is unsupported then it should leave with KErrArgument

A plugin implementing CImageDisplayPluginExtension to allow extension of the client API should initialise it here.

This is a virtual function that each individual plugin must implement.

Leave codes

KErrArgument Some of the configuration parameters are invalid

protected: virtual void Play()=0;

Description

Initiate the image display operation

This is a virtual function that each individual plugin must implement.

protected: virtual void Pause()=0;

Description

Pause image decoding

This is a virtual function that each individual plugin must implement.

protected: virtual void StopPlay()=0;

Description

Cancel the image display operation May be called by the framework even when there is no outstanding request.

This is a virtual function that each individual plugin must implement.

protected: virtual const CImageDisplay::RImageSizeArray &RecommendedImageSizes() const=0;

Description

Should return an array of recommended image sizes i.e. sizes which would be processed faster This is a virtual function that each individual plugin must implement.

Return value

const CImageDisplay::RImageSizeArray & a reference to the array of recommended image sizes

protected: IMPORT_C TImageSourceType SourceType() const;

Description

returns an image datasource type

Return value

TImageSourceType TImageSourceType

protected: IMPORT_C const TDesC &SourceFilename() const;

Description

returns an image source file name

Return value

const TDesC & const TDesC& a reference to read-only descriptor

Panic codes

ImageDisplay 4 EImageWrongType if image data source is of type other than the file name

protected: IMPORT_C RFile &SourceFileHandle() const;

Description

returns an image source file handle

Return value

RFile & const RFile& a reference to a file handle

Panic codes

ImageDisplay 4 EImageWrongType if image data source is of type other than the file handle

protected: IMPORT_C const TDesC8 &SourceData() const;

Description

returns an image source descriptor

Return value

const TDesC8 & const TDesC8& a reference to a 8 bit descriptor

Panic codes

ImageDisplay 4 EImageWrongType if image data source is of type other than the descriptor

protected: IMPORT_C ContentAccess::TIntent SourceDataIntent() const;

Description

returns an intent that is requested by client for opening the image source

Return value

ContentAccess::TIntent ContentAccess::TIntent a desired intent value

protected: IMPORT_C const TDesC &SourceDataId() const;

Description

returns requested content data Id that should be used to open content

Return value

const TDesC & const TDesC& a desired data unique Id

protected: IMPORT_C const TDesC8 &SourceMimeType() const;

Description

returns an image source MIME type or KNullDesC8 if not defined

Return value

const TDesC8 & const TDesC8& a reference to a 8 bit descriptor

protected: IMPORT_C const TUid SourceImageType() const;

Description

returns a global image type

Return value

const TUid const TUid an image type Uid

protected: IMPORT_C const TUid SourceImageSubType() const;

Description

returns a global image subtype or KNullUid if not defined

Return value

const TUid const TUid an image subtype Uid

protected: IMPORT_C TBool SourceRect(TRect &aRect) const;

Description

returns a requested by an API client source clipping rect

Parameters

TRect &aRect a reference to source clipping rect which is valid only if return value is ETrue

Return value

TBool ETrue if clipping rect was defined by client

protected: IMPORT_C const TSize &DestinationSizeInPixels() const;

Description

returns a requested by an API client destination image size

Return value

const TSize & const TSize - requested image size in pixels

protected: IMPORT_C TUint Options() const;

Description

returns a requested by an API client image options e.g. combination of the TImageOptions

Return value

TUint TUint - requested image option set

protected: IMPORT_C TBool MaintainAspectRatio() const;

Description

returns ETrue if an API client requested to preserve source image aspect ratio

Return value

TBool TBool - requested aspect ratio flag

protected: IMPORT_C TDisplayMode DisplayMode() const;

Description

returns a requested by an API client display mode for an image being decoded

Return value

TDisplayMode TDisplayMode - requested display mode

protected: virtual IMPORT_C TInt ExtensionInterface(TUid aIFaceUid, TAny *&aIFacePtr);

Description

A plug-in that supports an extension interface has to override this function

Parameters

TUid aIFaceUid a request extension Uid TAny *&aIFacePtr a reference to the pointer that should be given extension interface pointer on success

Return value

TInt KErrNotSupported if requested extension is not supported otherwise KErrNone

protected: virtual IMPORT_C void GetBitmap(const CFbsBitmap *&aBitmap, const CFbsBitmap *&aMask) const;

Description

A plug-in that supports image mask getting has to override this function

Parameters

const CFbsBitmap *&aBitmap a reference to bitmap pointer const CFbsBitmap *&aMask a reference to bitmap pointer, a plug-in may return NULL if no mask is available

protected: virtual IMPORT_C TBool ValidBitmap() const;

Description

A plug-in that supports target bitmap status checkig has to override this function

Return value

TBool TBool - ETrue if subsequent call to the GetBitmap() able to return valid bitmaps

protected: virtual IMPORT_C TUint ImageStatus() const;

Description

A plug-in that supports source image status checking has to override this function

Return value

TUint TUint - set of the TImageStatus flags

protected: virtual IMPORT_C TInt NumFrames(TInt &aNumFrames) const;

Description

A plug-in that supports getting of source image number of frames has to override this function

Parameters

TInt &aNumFrames Number of frames in the source image

Return value

TInt TInt - KErrNone if aNumFrames contains a valid number of frames

protected: IMPORT_C TBool CallbackIsRunning() const;

Description

A plug-in may use this function to determine if a previuos callback function to an API client has been completed

Return value

TBool ETrue if callback has not been completed yet

protected: IMPORT_C void AsyncCallbackImageReady(const CFbsBitmap *aBitmap, TUint aStatus, const TRect &aUpdatedArea, TInt aError);

Description

A plug-in should use this function to pass information asinchronously to an API client. This function is asinchronous.

Parameters

const CFbsBitmap *aBitmap a pointer to the bitmap that contains decoding result TUint aStatus the plugin status that should be combination of the TPluginStatus set const TRect &aUpdatedArea a rectangle within the aBitmap that was updated during the latest operation TInt aError error code of latest operation

protected: IMPORT_C void CancelCallback();

Description

A plug-in should use this function to cancel callback to a client if it is stil pending

private: virtual IMPORT_C void ReservedVirtual1();

Description

Reserved. Not for public use

private: virtual IMPORT_C void ReservedVirtual2();

Description

Reserved. Not for public use

private: virtual IMPORT_C void ReservedVirtual3();

Description

Reserved. Not for public use

private: virtual IMPORT_C void ReservedVirtual4();

Description

Reserved. Not for public use

TImageSourceType

Description

Data source type definitions for plug-ins

EImgSrcNotDefined Undefined. Plug-in won't be given this value EImgSrcFileName The datasource is a file name EImgSrcFileHandle The datasource is a file handle EImgSrcDescriptor The datasource is a descriptor

TPluginStatus

Description

Defines an ImageDisplay plug-in status flag values

EStatusNoMoreToDecode A plug-in has nothing more to decode; also must be set also on fatal error contidition EStatusBusy The next frame is not ready yet, bitmap may contain distorted image EStatusPaused Image decoding is paused i.e. call Play() to continue (if EStatusNoMoreToDecode is not set) EStatusFrameReady The next frame has been already decoded EStatusDisplayThisFrameIndefinetely May be set after image decode completion i.e. when EStatusNoMoreToDecode is set EStatusPartialFrame May be set if the image format supports progressive decoding; indicates that a bitmap contains roughtly decoded image EStatusEraseOutputContents May be set in case when a plug-in asks to invalidate previous frame contents

protected: CImageDisplay::RImageSizeArray iImageSizes;

Description

An array containing the sizes of the images.