ImageProcessor::TPreview Class Reference

#include <imageprocessor/imageprocessorpreview.h>

Link against: imageprocessor.lib

class ImageProcessor::TPreview

Public Member Enumerations
enum	TState { EUninitialized, EInitializing, EInitialized, ERendering, EStatesCount }

Public Member Functions
IMPORT_C void	Cancel()
IMPORT_C TRect	CanvasAreaL()
IMPORT_C void	CanvasToCurrentCoordL(const TPoint &, TPoint &)
IMPORT_C CImageFrame *	CreateOutputL(const TSize &, const TFrameFormatBase &, const TFrameLayoutBase &)
IMPORT_C void	GetPanLevelSettings(TReal32 &, TReal32 &)
IMPORT_C void	GetZoomLevelSettings(TReal32 &, TReal32 &)
IMPORT_C void	InitializeL()
IMPORT_C void	PanL(TReal32 &, TReal32 &)
IMPORT_C TInt	PreviewId()
IMPORT_C void	PreviewToCurrentCoordL(const TPoint &, TPoint &)
IMPORT_C void	RenderL()
IMPORT_C void	ResetL()
IMPORT_C void	SetOutputL(CFbsBitmap &)
IMPORT_C void	SetOutputL(CImageFrame &)
IMPORT_C void	SetPanL(TReal32, TReal32)
IMPORT_C void	SetPreviewId(TInt)
IMPORT_C void	SetZoomL(TReal32)
IMPORT_C TSize	SizeL()
IMPORT_C TPreview::TState	State()
IMPORT_C void	SupportedImageFrameFormatsL(RArray< TUid > &)
IMPORT_C void	SupportedOutputDisplayModesL(RArray< TDisplayMode > &)
IMPORT_C void	UninitializeL()
IMPORT_C TReal32	ZoomL()

Detailed Description

A preview representation of the rendered image after effects and geometric operations have been applied. Has the ability to zoom and pan the output image in the supplied pixel buffer. Typically this is a low resolution representation of the image which allows effects and operations to be applied quickly to the image without needing to process the whole image.

Member Enumeration Documentation

Enum TState

The state of the preview screen

Enumerator	Value	Description
EUninitialized		State means the preview has not been initialized, need to call InitializeL() to initialize
EInitializing		State means the preview is being initialized by async call of InitializeL()
EInitialized		State means the initialize process has finished and preview is available to be rendered
ERendering		State means the preview is being rendered by async call of RenderL()
EStatesCount		Count of valid preview states (boundary marker - not a true state).

Member Function Documentation

Cancel ( )

IMPORT_C void

Cancel

(

)

Cancels the preview rendering if the preview state is EInitializing or ERendering, unconditionally aborts the operation.

CanvasAreaL ( )

IMPORT_C TRect

CanvasAreaL

(

)

const

Gets the current canvas as TRect in the given screen

leave: KErrNotReady The current state is EUninitialized.

leave: Other A range of system wide error codes.

Returns: The current canvas of the preview screen.

CanvasToCurrentCoordL ( const TPoint &, TPoint & )

IMPORT_C void	CanvasToCurrentCoordL	(	const TPoint &	aCanvasPoint,
			TPoint &	aCurrentPoint
		)	const

Converts a coordinate from canvas to current coordinate system.

leave: KErrNotReady The current state is EUninitialized.

leave: Other A range of system wide error codes.

Parameter	Description
aCanvasPoint	A TPoint pointer specifying a screen in which the canvas from which to convert the coordinate is located.
aCurrentPoint	Pointer to a TPoint object with the coordinate to convert. The converted coordinate is stored back into the object.

CreateOutputL ( const TSize &, const TFrameFormatBase &, const TFrameLayoutBase & )

IMPORT_C CImageFrame *	CreateOutputL	(	const TSize &	aFrameSize,
			const TFrameFormatBase &	aFrameFormat,
			const TFrameLayoutBase &	aFrameLayout
		)

Creates an internal pixel buffer for output. Internal buffer size is calculated using aPixelBuffer properties (size, scanline length, display mode).

leave: KErrNotReady The current state is not EInitialized or the ImageProcessor is busy

leave: Other A range of system wide error codes.

Parameter	Description
aFrameSize	A reference to a TSize object that defines the frame size in pixels of the CImageFrame object.
aFrameFormat	A reference to a TFrameFormatBase object that defines the format of the CImageFrame object.
aFrameLayout	A reference to a TFrameLayoutBase object that defines the memory layout of the CImageFrame object.

Returns: CImageFrame instance containing newly created pixel buffer. The image frame is owned by the client and deleting it does not delete the pixel buffer which is owned by the image processor framework. The pixel buffer becomes invalid if TPreview::CreateOutputL(const TSize &aFrameSize, const TFrameFormatBase &aFrameFormat, const TFrameLayoutBase &aFrameLayout) or TPreview::SetOutputL(CFbsBitmap& aBitmap) or TPreview::SetOutputL(CImageFrame& aPixelBuffer) calls are made.

GetPanLevelSettings ( TReal32 &, TReal32 & )

IMPORT_C void	GetPanLevelSettings	(	TReal32 &	aMinimumLevel,
			TReal32 &	aMaximumLevel
		)

Retrieves the pan level range.

Parameter	Description
aMinimumLevel	The minimum value of the pan factor.
aMaximumLevel	The maximum value of the pan factor.

GetZoomLevelSettings ( TReal32 &, TReal32 & )

IMPORT_C void	GetZoomLevelSettings	(	TReal32 &	aMinimumLevel,
			TReal32 &	aMaximumLevel
		)

Retrieves the zoom level range.

Parameter	Description
aMinimumLevel	The minimum value of the zoom factor.
aMaximumLevel	The maximum value of the zoom factor.

InitializeL ( )

IMPORT_C void

InitializeL

(

)

Initializes the preview.

leave: KErrNorReady if preview is not in state TPreview::EUninitialized

leave: A range of system wide error code.

PanL ( TReal32 &, TReal32 & )

IMPORT_C void	PanL	(	TReal32 &	aPanX,
			TReal32 &	aPanY
		)	const

Gets the current pan factor of the preview screen.

leave: KErrNotReady The current state is EUninitialized or the ImageProcessor is busy.

leave: Other A range of system wide error codes.

PreviewId ( )

IMPORT_C TInt

PreviewId

(

)

const

Gets the id of the preview.

Returns: The id of the preview.

PreviewToCurrentCoordL ( const TPoint &, TPoint & )

IMPORT_C void	PreviewToCurrentCoordL	(	const TPoint &	aPreviewPoint,
			TPoint &	aCurrentPoint
		)	const

Converts a coordinate from preview screen to current coordinate system.

leave: KErrNotReady The current state is EUninitialized.

leave: Other A range of system wide error codes.

Parameter	Description
aPreviewPoint	A TPoint pointer specifying the preview screen from which to convert the coordinate.
aCurrentPoint	Pointer to a TPoint object with the coordinate to convert. The converted coordinate is stored back into the object.

RenderL ( )

IMPORT_C void

RenderL

(

)

Starts the rendering. The preview state is set to ERendering

leave: KErrNotReady The current state is not EInitialized or the ImageProcessor is busy or input is not set or output is not set.

leave: Other A range of system wide error codes.

ResetL ( )

IMPORT_C void

ResetL

(

)

Resets the preview parameters and state.

SetOutputL ( CFbsBitmap & )

IMPORT_C void

SetOutputL

(

CFbsBitmap &

aBitmap

)

Sets CFbsBitmap as the output bitmap of the preview.

leave: KErrNotReady The current state is not EInitialized or the ImageProcessor is busy

leave: A range of system wide error codes

Parameter	Description
aBitmap	The output bitmap

SetOutputL ( CImageFrame & )

IMPORT_C void

SetOutputL

(

CImageFrame &

aPixelBuffer

)

Sets an image frame as the output bitmap of the preview.

leave: KErrNotReady The current state is not EInitialized or the ImageProcessor is busy

leave: Other A range of system wide error codes.

Parameter	Description
aPixelBuffer	The CImageFrame buffer.

SetPanL ( TReal32, TReal32 )

IMPORT_C void	SetPanL	(	TReal32	aPanX,
			TReal32	aPanY
		)

Specifies the pan factor for the preview screen. The zoomed screen will be panned to the new coordinate after rendering.

leave: KErrNotReady The current state is not EInitialized or the ImageProcessor is busy

leave: KErrArgument The pan factor is out of range.

leave: Other A range of system wide error codes.

Parameter	Description
aPanX	The horizontal pan factor for the current preview, -1.0f to 1.0f.
aPanY	The vertical pan factor for the current preview, -1.0f to 1.0f.

SetPreviewId ( TInt )

IMPORT_C void

SetPreviewId

(

TInt

aPreviewId

)

Specifies the id of the preview.

Parameter	Description
aPreviewId	The id of the current preview

SetZoomL ( TReal32 )

IMPORT_C void

SetZoomL

(

TReal32

aZoom

)

Specifies the zoom factor for the preview screen. The screen will be zoomed after rendering.

leave: KErrNotReady The current state is not EInitialized or the ImageProcessor is busy.

leave: Other A range of system wide error codes.

Parameter	Description
aZoom	The zoom factor for the current preview, 1.0f to infinite.

SizeL ( )

IMPORT_C TSize

SizeL

(

)

const

Gets the current size of the preview screen.

leave: KErrNotReady The current state is EUninitialized.

leave: Other A range of system wide error codes.

Returns: The current size of the preview screen.

State ( )

IMPORT_C TPreview::TState

State

(

)

const

Gets the current state of the preview.

Returns: The current state of the preview.

SupportedImageFrameFormatsL ( RArray< TUid > & )

IMPORT_C void

SupportedImageFrameFormatsL

(

RArray< TUid > &

aFormats

)

const

Gets the supported output formats for the preview.

Returns: The supported output image formats.

SupportedOutputDisplayModesL ( RArray< TDisplayMode > & )

IMPORT_C void

SupportedOutputDisplayModesL

(

RArray< TDisplayMode > &

aDisplayModes

)

const

Gets the supported output display modes for the preview.

Returns: The supported output display modes.

UninitializeL ( )

IMPORT_C void

UninitializeL

(

)

Uninitializes the preview.

leave: KErrNotReady The current state is not EInitialized or the ImageProcessor is busy

leave: Other A range of system wide error codes.

ZoomL ( )

IMPORT_C TReal32

ZoomL

(

)

const

Gets the current zoom factor of the preview screen.

leave: KErrNotReady The current state is EUninitialized or the ImageProcessor is busy.

leave: Other A range of system wide error codes.

Returns: The current zoom factor of the preview screen.