CImageDisplay in Multimedia Imaging

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. This class provide...

Members

Defined in CImageDisplay:

EImageAnimatedImage is animated
EImageHasThumbnailImage has got a thumbnail
EImageIsFullyScalableImage is fully scalable i.e. arbitrary scaling can be perofmed quite quickly
EImageMaskedImage has got a mask/alpha channel
EImageMultiFrameImage is multiframe
EImageSingleFrameImage is single frame
EImageTypeUnknownImageStatus is unknown
EOptionAutoRotateRotate the image automatically (if necessary)
EOptionMainImageUse the main image as source
EOptionMirrorHorizontalMirror an image about the horizontal axis
EOptionMirrorVerticalMirror an image about the vertical axis
EOptionRotateCw180Rotate the image by 180 degrees clockwise
EOptionRotateCw270Rotate the image by 270 degrees clockwise
EOptionRotateCw90Rotate the image by 90 degrees clockwise
EOptionThumbnailUse the thumbnail image as source
EOptionsUndefinedNo options defined
ExtensionInterface(TUid,TAny *&)Gets a pointer to a plugin extension
GetBitmap(const CFbsBitmap *&,const CFbsBitmap *&)constGets a reference to the current bitmap and mask
ImageStatus()constreturns an integer, corresponding to the current image status (if known), the va...
NewL(MIclImageDisplayObserver &,RFs &)Constructs a CImageDisplay object.
NumFrames(TInt &)constreturns the number of frames (if known) or an error code if unknown.
Pause()Instructs a plug-in to pause its operation. An operation can be resumed by calli...
Play()Initiates an image display operation. The framework will panic if no plugin has ...
RImageSizeArrayAn array containing the sizes of images.
RecommendedImageSizes()constReturns an array of recommended image sizes i.e. sizes which would be processed ...
Reset()Resets all SetXXX() calls so that the state is the same as that immediately afte...
ResetSourceRect()Clears settings for the clipping region, but not the image region
SetDisplayMode(TDisplayMode)Specifies the requested image display mode.
SetImageSource(const TMMSource &)Specifies the source of the image to display
SetOptions(TUint)Defines how the image is to be displayed.
SetPluginUid(TUid)Specifies the UID of the image display plugin to load
SetSizeInPixels(const TSize &,TBool)Specifies the requested image size.
SetSourceImageType(TUid,TUid)Specifies the source image's type and (optionally) its subtype
SetSourceMimeType(const TDesC8 &)Specifies the MIME type of the source image.
SetSourceRect(const TRect &)Defines a clipping region. Only the specified region will be processed.
SetupL()Requests that a suitable plugin be selected and instantiated. Leaves with KErrNo...
StopPlay()Cancels any image display operation currently in progress.
TImageOptionsFlags to control how the image is handled These can be combined using an OR oper...
TImageStatusReturn flags from CImageDisplay::ImageStatus()const
ValidBitmap()constCheck to see if the current frame can be displayed now
~CImageDisplay()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 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 CImageDisplay::Play() The framework will panic if no plugin has been instantiated already and CImageDisplay::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 CImageDisplay::NewL(MIclImageDisplayObserver &,RFs &). 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 CImageDisplay::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 RArray &

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. This is NULL if no mask is available or if aBitmap has a display mode of EColor16MA (see `CImageDisplay::SetDisplayMode(TDisplayMode)`).

Panic codes

ImageDisplay

1 EIllegalCallSequence No plugin loaded or decoding was not started

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 CImageDisplay::ImageStatus()const

`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.

Class CImageDisplay

Description

Derivation

Members

Construction and destruction

NewL(MIclImageDisplayObserver &,RFs &)

Description

Parameters

Return value

~CImageDisplay()

Description

Member functions

SetPluginUid(TUid)

Description

Parameters

Panic codes

SetImageSource(const TMMSource &)

Description

Parameters

Return value

Panic codes

SetSourceMimeType(const TDesC8 &)

Description

Parameters

Panic codes

SetSourceImageType(TUid,TUid)

Description

Parameters

Panic codes

SetSourceRect(const TRect &)

Description

Parameters

Panic codes

ResetSourceRect()

Description

Panic codes

SetSizeInPixels(const TSize &,TBool)

Description

Parameters

Panic codes

SetDisplayMode(TDisplayMode)

Description

Parameters

Panic codes

SetOptions(TUint)

Description

Parameters

Return value

Panic codes

SetupL()

Description

Leave codes

Panic codes

Play()

Description

Panic codes

Pause()

Description

Panic codes

StopPlay()

Description

Panic codes

Reset()

Description

ExtensionInterface(TUid,TAny *&)

Description

Parameters

Return value

Panic codes

ValidBitmap()const

Description

Return value

Panic codes

RecommendedImageSizes()const

Description

Return value

Panic codes

GetBitmap(const CFbsBitmap *&,const CFbsBitmap *&)const

Description

Parameters

Class `CImageDisplay`

`NewL(MIclImageDisplayObserver &,RFs &)`

`~CImageDisplay()`

`SetPluginUid(TUid)`

`SetImageSource(const TMMSource &)`

`SetSourceMimeType(const TDesC8 &)`

`SetSourceImageType(TUid,TUid)`

`SetSourceRect(const TRect &)`

`ResetSourceRect()`

`SetSizeInPixels(const TSize &,TBool)`

`SetDisplayMode(TDisplayMode)`

`SetOptions(TUint)`

`SetupL()`

`Play()`

`Pause()`

`StopPlay()`

`Reset()`

`ExtensionInterface(TUid,TAny *&)`

`ValidBitmap()const`

`RecommendedImageSizes()const`

`GetBitmap(const CFbsBitmap &,const CFbsBitmap &)const`

`ImageStatus()const`

`NumFrames(TInt &)const`

Enum `TImageOptions`

Enum `TImageStatus`

Typedef `RImageSizeArray`