Class CImageDisplay

class CImageDisplay : public CBase;

Description

The public API for clients to call the Image Display library. This class provides functions to convert images stored in descriptors or files to bitmaps ready for display.

Derivation

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

• CImageDisplay - The public API for clients to call the Image Display library

Members

Defined in CImageDisplay:
EImageAnimated, EImageHasThumbnail, EImageIsFullyScalable, EImageMasked, EImageMultiFrame, EImageSingleFrame, EImageTypeUnknown, EOptionAutoRotate, EOptionMainImage, EOptionMirrorHorizontal, EOptionMirrorVertical, EOptionRotateCw180, EOptionRotateCw270, EOptionRotateCw90, EOptionThumbnail, EOptionsUndefined, ExtensionInterface(), GetBitmap(), ImageStatus(), NewL(), NumFrames(), Pause(), Play(), RImageSizeArray, RecommendedImageSizes(), Reset(), ResetSourceRect(), SetDisplayMode(), SetImageSource(), SetOptions(), SetPluginUid(), SetSizeInPixels(), SetSourceImageType(), SetSourceMimeType(), SetSourceRect(), SetupL(), StopPlay(), TImageOptions, TImageStatus, ValidBitmap(), ~CImageDisplay()

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

static IMPORT_C CImageDisplay *NewL(MIclImageDisplayObserver &aCallback, RFs &aFs);

Description

Constructs a CImageDisplay object.

Parameters

MIclImageDisplayObserver &aCallback A reference to a Image Display observer object which would recieve status notifications RFs &aFs A reference to a file server session for the display API to use.

Return value

CImageDisplay * A pointer to a fully constructed CImageDisplay.

IMPORT_C ~CImageDisplay();

Description

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

IMPORT_C void SetPluginUid(TUid aPluginUid);

Description

Specifies the UID of the image display plugin to load

Parameters

TUid aPluginUid The plugin's implementation UID

Panic codes

ImageDisplay 1 EIllegalCallSequence Raised when a plugin is already loaded

IMPORT_C TInt SetImageSource(const TMMSource &aSource);

Description

Specifies the source of the image to display

Parameters

const TMMSource &aSource The data source container. Note that the framework doesn't take a copy of actual data/filename etc. and they must persist during decoding

Return value

TInt KErrNone if the given source type is supported, otherwise KErrNotSupported

Panic codes

ImageDisplay 1 EIllegalCallSequence Raised if the function was called during decoding stage

IMPORT_C void SetSourceMimeType(const TDesC8 &aMIMEType);

Description

Specifies the MIME type of the source image.

Parameters

const TDesC8 &aMIMEType The MIME type of the source image

Panic codes

ImageDisplay 1 EIllegalCallSequence Raised if the function was called during decoding stage

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

Description

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

Parameters

TUid aImageType The UID of the source image's type TUid aImageSubType The UID of the source image's subtype

Panic codes

ImageDisplay 1 EIllegalCallSequence Raised if the function was called during decoding stage or a plugin is not loaded yet

IMPORT_C void SetSourceRect(const TRect &aRect);

Description

Defines a clipping region. Only the specified region will be processed.

Parameters

const TRect &aRect The coordinates of the clipping region

Panic codes

ImageDisplay 1 EIllegalCallSequence Raised if the function was called during decoding stage or a plugin is not loaded yet

IMPORT_C void ResetSourceRect();

Description

Clears settings for the clipping region, but not the image region

Panic codes

ImageDisplay 1 EIllegalCallSequence Raised if the function was called during decoding stage or a plugin is not loaded yet

IMPORT_C void SetSizeInPixels(const TSize &aSize, TBool aMaintainAspectRatio=ETrue);

Description

Specifies the requested image size.

Parameters

const TSize &aSize The requested size of the image in pixels TBool aMaintainAspectRatio Requests that the aspect ratio be maintained as far as possible Defaults to true

Panic codes

ImageDisplay 1 EIllegalCallSequence Raised if the function was called during decoding stage or a plugin is not loaded yet

IMPORT_C void SetDisplayMode(TDisplayMode aDisplayMode);

Description

Specifies the requested image display mode.

Parameters

TDisplayMode aDisplayMode The requested display mode

Panic codes

ImageDisplay 1 EIllegalCallSequence Raised if the function was called during decoding stage or a plugin is not loaded yet

IMPORT_C TInt SetOptions(TUint aOptions);

Description

Defines how the image is to be displayed.

Note that all plugins support EOptionMainImage, whereas the availability of the other options depends on the image display plugin loaded.

Parameters

TUint aOptions - image type selected using the TImageOptions flag set

Return value

TInt KErrArgument on wrong combination of options, especially if the rotate and mirror options aren't set together with EOptionThumbnail or EOptionMainImage.

Panic codes

ImageDisplay 1 EIllegalCallSequence Raised if the function was called during decoding stage or a plugin is not loaded yet

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

KErrNotFound No suitable plugin was found KErrArgument One of the previously supplied parameters (image size, mime type etc.) is invalid

Panic codes

ImageDisplay 2 EUndefinedSourceType Raised when image source is not defined yet

IMPORT_C void Play();

Description

Initiates an image display operation. The framework will panic if no plugin has been instantiated already. Note: That a plugin may perform some asynchronous operations within the current thread, so yielding to the Active Scheduler after calling this function is almost mandatory

Panic codes

ImageDisplay 1 EIllegalCallSequence No plugin loaded. ImageDisplay 3 EUndefinedDestSize Raised when destination image size is not defined yet

IMPORT_C void Pause();

Description

Instructs a plug-in to pause its operation. An operation can be resumed by calling the Play() The framework will panic if no plugin has been instantiated already and Play() has not been called yet.

Panic codes

ImageDisplay 1 EIllegalCallSequence No plugin loaded.

IMPORT_C void StopPlay();

Description

Cancels any image display operation currently in progress.

Panic codes

ImageDisplay 1 EIllegalCallSequence Raised when no plugin loaded yet.

IMPORT_C void Reset();

Description

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

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

Description

Gets a pointer to a plugin extension

Parameters

TUid aIFaceUid Requested extension interface Uid TAny *&aIFacePtr Reference to pointer which would have interface pointer on sucessful completion, otherwise NULL

Return value

TInt KErrNotSupported if given extension interface is not supported or other system-wide error code

Panic codes

ImageDisplay 1 EIllegalCallSequence No plugin loaded.

IMPORT_C TBool ValidBitmap() const;

Description

Check to see if the current frame can be displayed now

Return value

TBool ETrue The current bitmap contains a valid image. It will return ETrue only when it is called in between the ImageReady() callback and a subsequent call to Play().

Panic codes

ImageDisplay 1 EIllegalCallSequence No plugin loaded or decoding was not started

IMPORT_C const RImageSizeArray &RecommendedImageSizes() const;

Description

Returns an array of recommended image sizes i.e. sizes which would be processed faster

Return value

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

Panic codes

ImageDisplay 1 EIllegalCallSequence No plugin loaded.

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

Description

Gets a reference to the current bitmap and mask

Parameters

const CFbsBitmap *&aBitmap Reference to pointer which would have current frame bitmap address const CFbsBitmap *&aMask Reference to pointer which would have current frame mask address or NULL if no mask available

Panic codes

ImageDisplay 1 EIllegalCallSequence No plugin loaded or decoding was not started

IMPORT_C TUint ImageStatus() const;

Description

returns an integer, corresponding to the current image status (if known), the value will be comprised of elements of the TImageStatus bit field

Return value

TUint a combination TImageStatus flags

Panic codes

ImageDisplay 1 EIllegalCallSequence No plugin loaded.

IMPORT_C TInt NumFrames(TInt &aNumFrames) const;

Description

returns the number of frames (if known) or an error code if unknown.

Parameters

TInt &aNumFrames a reference to frame number parameter which has meaning only if retrun value is KErrNone

Return value

TInt KErrNotSupported if a plug-in can't determine number of frames

Panic codes

ImageDisplay 1 EIllegalCallSequence No plugin loaded.

TImageOptions

Description

Flags to control how the image is handled These can be combined using an OR operation. Note that the rotate and mirror options have to be set together with EOptionThumbnail or EOptionMainImage.

EOptionsUndefined No options defined EOptionThumbnail Use the thumbnail image as source EOptionMainImage Use the main image as source EOptionRotateCw90 Rotate the image by 90 degrees clockwise EOptionRotateCw180 Rotate the image by 180 degrees clockwise EOptionRotateCw270 Rotate the image by 270 degrees clockwise EOptionMirrorHorizontal Mirror an image about the horizontal axis EOptionMirrorVertical Mirror an image about the vertical axis EOptionAutoRotate Rotate the image automatically (if necessary)

TImageStatus

Description

Return flags from ImageStatus()

EImageTypeUnknown ImageStatus is unknown EImageSingleFrame Image is single frame EImageMultiFrame Image is multiframe EImageAnimated Image is animated EImageMasked Image has got a mask/alpha channel EImageHasThumbnail Image has got a thumbnail EImageIsFullyScalable Image is fully scalable i.e. arbitrary scaling can be perofmed quite quickly

typedef RArray<TSize> CImageDisplay::RImageSizeArray;

Description

An array containing the sizes of images.