Symbian Developer Library

SYMBIAN OS V6.1 EDITION FOR C++

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Location: MdaImageConverter.h
Link against: MediaClientImage.lib

Class CMdaImageFileToBitmapUtility

CMdaImageFileToBitmapUtility

Support

Supported from 5.0

Description

Implements format conversion of a file based image to a bitmap.

The class provides functions to create an instance of this conversion utility and to open an existing image file.

Conversion is performed using the image conversion utility interface.

Derivation

CActiveThe core class of the active object abstraction
CBaseBase class for all classes to be instantiated on the heap
CMdaImageDataReadUtilityBase class used in the derivation of CMdaImageDescToBitmapUtility and CMdaImageFileToBitmapUtility
CMdaImageFileToBitmapUtilityImplements format conversion of a file based image to a bitmap
CMdaImageUtilityThe abstract base class for the image conversion utilities
CMdaResourceBase class used in the derivation of CMdaImageUtility
MMdaObjectStateChangeObserverAn interface class for handling the change of state of an audio data sample object

Defined in CMdaImageFileToBitmapUtility:
NewL(), OpenL()

Inherited from CActive:
Cancel(), Deque(), DoCancel(), EPriorityHigh, EPriorityIdle, EPriorityLow, EPriorityStandard, EPriorityUserInput, IsActive(), IsAdded(), Priority(), RunError(), RunL(), SetActive(), SetPriority(), TPriority, iStatus

Inherited from CBase:
operator new()

Inherited from CMdaImageUtility:
CancelConvertL(), Close(), ConvertL(), FrameCount(), FrameInfo()

Inherited from MMdaObjectStateChangeObserver:
MoscoStateChangeEvent()


Construction


NewL()

static CMdaImageFileToBitmapUtility* NewL(MMdaImageUtilObserver& aObserver,CMdaServer* aServer = NULL);

Description

Constructs a new instance of the file based image to bitmap conversion utility object.

The function leaves if this object cannot be created.

Parameters

MMdaImageUtilObserver& aObserver

The image utility observer interface

CMdaServer* aServer = NULL

A pointer to a server object. The default is NULL which means that one is automatically constructed and owned by this conversion utility object. If not NULL, the client must construct, and be responsible for, the server object. This option may be more efficient if a number of conversion utility objects are to be created.

Return value

CMdaImageFileToBitmapUtility*

Pointer to the new instance of the file based image to bitmap conversion utility.

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Opening


OpenL()

void OpenL(const TDesC& aFileName,TMdaClipFormat* aFormat = NULL,TMdaPackage* aCodec = NULL,TMdaPackage* aExtra = NULL);

Description

Opens the existing file based image.

The function is asynchronous. When the operation is complete, successfully or otherwise, the callback function MMdaImageUtilObserver::MiuoOpenComplete() is called.

Open must complete successfully before starting any conversion operation. The function can complete with KErrUnderflow, if there is insufficient information in the file. Typically, this occurs when using the file as a cache. In this situation, open should be performed repeatedly until the file has accumulated enough information for the operation to complete with KErrNone.

Notes

The optional parameters can be used to force the Media Server to interpret the file as being of a specific type. This is necessary for formats such as WAP wireless bitmap where the supplied file does not contain a uniquely recognisable signature.

Parameters

const TDesC& aFileName

The full path name of the file.

TMdaClipFormat* aFormat = NULL

The data format. This is optional.

TMdaPackage* aCodec = NULL

The codec to use. This is optional.

TMdaPackage* aExtra = NULL

Additional information which the Media Server may need to recognise the data format. This is optional.