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MCameraHistogram Class Reference

class MCameraHistogram

This is a mixin class to be implemented by providers of the extension API for the camera histogram.

Histograms can be sent to the client or directly displayed on the viewfinder.

Note:

This class is intended for sub classing by licensees only.

CCamera::CCameraHistogramuse MCameraV2Histogram

Public Member Functions
void	DestroyHistogramL(TUint)
void	GetActiveHistogramsL(RArray< TUint > &)
void	GetDSAHistogramPropertiesL(TUint, TPoint &, TSize &, TRgb &)
MHistogramBuffer &	HistogramDataL()
MHistogramBuffer &	HistogramDataL(TUint)
TUint	PrepareDSAHistogramL(CCamera::CCameraHistogram::THistogramType, const TPoint &, const TSize &, const TRgb &)
TUint	PrepareHistogramL(CCamera::CCameraHistogram::THistogramType)
void	Release()
void	StartHistogramL(TUint)
void	StopHistogramL(TUint)
TUint32	SupportedHistograms()
void	UpdateDSAHistogramPropertiesL(TUint, const TPoint &, const TSize &, const TRgb &)

Member Functions Documentation

DestroyHistogramL(TUint)

void

DestroyHistogramL

(

TUint

aHistHandle

)

[pure virtual]

only one histogram is available per buffer with the usage of MHistogramV2Buffer and MCameraV2Histogram.

Destroys a histogram on the ECam implementation and releases its handle.

leave: KErrArgument if aHistHandle is out of range; also any system wide error.

Parameters

TUint aHistHandle

The handle identifying the histogram on the ECam implementation.

GetActiveHistogramsL(RArray< TUint > &)

void

GetActiveHistogramsL

(

RArray< TUint > &

aActiveHistograms

)

[pure virtual]

use void MCameraV2Histogram::GetHistogramStateL(TBool& aIsHistogramActive)

Gets a list of all histograms that are active on the ECam implementation. A histogram is in an active state if StartHistogramL() has been called on it.

leave: KErrNoMemory if the ECam implementation cannot add more histogram handles due to low memory; also any system wide error.

Parameters

RArray< TUint > & aActiveHistograms

Returned list of histogram handles for which StartHistogramL() has been called.

GetDSAHistogramPropertiesL(TUint, TPoint &, TSize &, TRgb &)

void	GetDSAHistogramPropertiesL	(	TUint	aHistHandle,
			TPoint &	aPosition,
			TSize &	aSize,
			TRgb &	aColor
		)	[pure virtual]

use void MCameraV2Histogram::GetDirectHistogramPropertiesL

Gets the properties of a direct histogram.

leave: KErrArgument if aHistHandle is out of range; also any system wide error.

Parameters

TUint aHistHandle	The handle on the ECam implementation of the direct histogram whose properties are to be retrieved.
TPoint & aPosition	A reference to a TPoint object that will receive the position (in pixels) of the histogram on the screen.
TSize & aSize	A reference to a TSize object that will receive the size of the histogram in pixels.
TRgb & aColor	A reference to a TRgb object that will receive the colour and alpha blending of the histogram.

HistogramDataL()

MHistogramBuffer &

HistogramDataL

(

)

[pure virtual]

use MCaptureImageObserver, MCaptureVideoObserver, MDirectViewFinderObserver, and MClientViewFinderObserver which have callback functions which notify the client about availability of histogram data. These are sent when CCameraV2Histogram::StartHistogram() is called after CCameraV2Histogram::PrepareClientHistogramL(). If CCameraV2Histogram::PrepareClientHistogramL() is not called first then the callback returns KErrBadHandle.

Returns to the client the histogram data for all the histograms generated by the ECam implementation.

leave: KErrNoMemory if the ECam implementation has not been able to create the histogram buffer; also any system wide error.

HistogramDataL(TUint)

MHistogramBuffer &

HistogramDataL

(

TUint

aHistHandle

)

[pure virtual]

Returns the data for a single histogram from the ECam implementation to the client.

leave: KErrNoMemory if the ECam implementation has not been able to create the histogram buffer; also any system wide error.

Parameters

TUint aHistHandle

The handle on the ECam implementation of the histogram whose data is to be retrieved.

PrepareDSAHistogramL(CCamera::CCameraHistogram::THistogramType, const TPoint &, const TSize &, const TRgb &)

TUint	PrepareDSAHistogramL	(	CCamera::CCameraHistogram::THistogramType	aType,
			const TPoint &	aPosition,
			const TSize &	aSize,
			const TRgb &	aColor
		)	[pure virtual]

use void MCameraV2Histogram::PrepareDirectHistogramL

Request to prepare a direct histogram.

Note:

A direct histogram is directly embedded into the viewfinder.

leave: KErrNotSupported if the histogram type supplied in aType is not supported.

PrepareHistogramL

Parameters

CCamera::CCameraHistogram::THistogramType aType	The type of histogram to be prepared. This must be one of the supported histogram types returned by SupportedHistograms().
const TPoint & aPosition	The position on the screen (in pixels) where the histogram is to be displayed.
const TSize & aSize	The size of histogram in pixels.
const TRgb & aColor	The colour and alpha blending with which the histogram will be displayed.

PrepareHistogramL(CCamera::CCameraHistogram::THistogramType)

TUint

PrepareHistogramL

(

CCamera::CCameraHistogram::THistogramType

aType

)

[pure virtual]

use void MCameraV2Histogram::PrepareClientHistogramL

Request to prepare a non direct histogram.

Note:

A direct histogram is directly embedded into the viewfinder. If a non direct histogram is requested the histogram data will be passed to the camera client.

leave: KErrNotSupported if the histogram type supplied in aType is not supported.

PrepareDSAHistogramL

Parameters

CCamera::CCameraHistogram::THistogramType aType

The type of histogram to be prepared. This must be one of the supported histogram types returned by SupportedHistograms().

Release()

void

Release

(

)

[pure virtual]

use void MCameraV2Histogram::Release(CCamera::CCameraV2Histogram *aHistogramHandle)

Releases all the histogram handles created by this object and destroys them on the ECam implementation. This function is called from the destructor of CCamera::CCameraHistogram.

StartHistogramL(TUint)

void

StartHistogramL

(

TUint

aHistHandle

)

[pure virtual]

use void MCameraV2Histogram::StartHistogram()

Request to start getting histogram notifications.

leave: KErrArgument if aHistHandle is out of range; also any system wide error.

Parameters

TUint aHistHandle

The handle identifying the histogram on the ECam implementation.

StopHistogramL(TUint)

void

StopHistogramL

(

TUint

aHistHandle

)

[pure virtual]

use void MCameraV2Histogram::StopHistogram()

Request to stop getting histogram notifications.

leave: KErrArgument if aHistHandle is out of range; also any system wide error.

Parameters

TUint aHistHandle

The handle identifying the histogram on the ECam implementation.

SupportedHistograms()

TUint32

SupportedHistograms

(

)

[pure virtual]

use void MCameraV2Histogram::GetSupportedHistogramsL(TUint& aSupportedHistogramType)

Gets a list of the types of histograms the ECam implementation supports.

CCamera::CCameraHistogram::THistogramType

UpdateDSAHistogramPropertiesL(TUint, const TPoint &, const TSize &, const TRgb &)

void	UpdateDSAHistogramPropertiesL	(	TUint	aHistHandle,
			const TPoint &	aPosition,
			const TSize &	aSize,
			const TRgb &	aColor
		)	[pure virtual]

use void MCameraV2Histogram::UpdateDirectHistogramPropertiesL

Updates the properties of a direct histogram.

leave: KErrArgument if aHistHandle is out of range; also any system wide error.

Parameters

TUint aHistHandle	The handle identifying the histogram on the ECam implementation.
const TPoint & aPosition	The new position on the screen (in pixels) where the histogram is to be displayed.
const TSize & aSize	The new size of histogram in pixels.
const TRgb & aColor	The new colour and alpha blending with which the histogram will be displayed.