Abstract base class for: drawing a picture to a graphics context, storing and restoring the picture. More...

#include <gdi.h>

Inheritance diagram for CPicture:

Public Types
enum	TDetach { EDetachFull , EDetachDraw }
	Options for detaching pictures from stores. More...

Public Member Functions
virtual IMPORT_C	~CPicture ()
	Frees all resources owned by the object prior to its destruction.

virtual void	Draw (CGraphicsContext &aGc, const TPoint &aTopLeft, const TRect &aClipRect, MGraphicsDeviceMap *aMap) const =0
	Draws a picture.

virtual IMPORT_C TStreamId	StoreL (CStreamStore &aStore) const
	Stores the picture to the specified store.

virtual void	DetachFromStoreL (TDetach=EDetachFull)

virtual void	ExternalizeL (RWriteStream &aStream) const =0
	Externalises the picture to a stream.

virtual void	GetOriginalSizeInTwips (TSize &aSize) const =0
	Gets the pictur's original size, in twips.

virtual IMPORT_C void	SetScaleFactor (TInt aScaleFactorWidth, TInt aScaleFactorHeight)
	Sets the picture's scale factors.

virtual IMPORT_C void	SetCropInTwips (const TMargins &aMargins)
	Sets the cropping margins of a picture in twips.

virtual IMPORT_C TPictureCapability	Capability () const
	Gets the picture's capabilities.

virtual IMPORT_C void	GetCropInTwips (TMargins &aMargins) const
	Gets the cropping margins of a picture in twips.

virtual IMPORT_C TInt	ScaleFactorWidth () const
	Gets the picture's width scale factor.

virtual IMPORT_C TInt	ScaleFactorHeight () const
	Gets the pictures height scale factor.

virtual IMPORT_C TBool	LineBreakPossible (TUint aClass, TBool aBeforePicture, TBool aHaveSpaces) const
	States whether a line break is possible, either before or after a picture.

virtual IMPORT_C TBool	NativePixelSize (TSize &aPixelSize)
	Derived classes might be implemented as bitmaps, in that case it might be interesting to now the native pixel size of the bitmap.

IMPORT_C void	GetSizeInPixels (MGraphicsDeviceMap *aMap, TSize &aSize) const
	Gets the picture's size in pixels.

IMPORT_C void	SetSizeInPixels (MGraphicsDeviceMap *aMap, const TSize &aSize)
	Sets the picture's size in pixels.

IMPORT_C void	AddCropInPixels (MGraphicsDeviceMap *aMap, const TMargins &aMargins)
	Adds pixel cropping margins to the picture.

IMPORT_C void	GetSizeInTwips (TSize &aSize) const
	Gets the picture's size, in twips.

IMPORT_C void	SetSizeInTwips (const TSize &aSize)
	Sets the picture's size, in twips.

IMPORT_C void	ResetToOriginal ()
	Resets the picture's scaling and cropping attributes to their original values.

Public Member Functions inherited from CBase
	CBase ()
	Default constructor.

virtual IMPORT_C	~CBase ()
	Virtual destructor.

TAny *	operator new (TUint aSize, TAny *aBase) __NO_THROW
	Initialises the object to binary zeroes.

TAny *	operator new (TUint aSize) __NO_THROW
	Allocates the object from the heap and then initialises its contents to binary zeroes.

TAny *	operator new (TUint aSize, TLeave)
	Allocates the object from the heap and then initialises its contents to binary zeroes.

TAny *	operator new (TUint aSize, TUint aExtraSize) __NO_THROW
	Allocates the object from the heap and then initialises its contents to binary zeroes.

TAny *	operator new (TUint aSize, TLeave, TUint aExtraSize)
	Allocates the object from the heap and then initialises its contents to binary zeroes.

Protected Member Functions
IMPORT_C	CPicture ()

Protected Member Functions inherited from CBase
virtual IMPORT_C TInt	Extension_ (TUint aExtensionId, TAny &a0, TAny a1)
	Extension function.

Additional Inherited Members
Static Public Member Functions inherited from CBase
static IMPORT_C void	Delete (CBase *aPtr)
	Deletes the specified object.

Detailed Description

Abstract base class for: drawing a picture to a graphics context, storing and restoring the picture.

The class defines the protocol for a number of concrete picture classes. Its main role is to support glass doors used in object embedding.

The class provides a protocol for the provision of scaling and cropping functions by derived classes, together with default implementations.

Its main function is Draw(), which draws the picture onto the graphics context at a particular point. It also has two important pure virtual functions: ExternalizeL() and GetOriginalSizeInTwips().

A picture has both an original representation and an on-screen representation. The original representation has a size in twips, and can somehow be drawn. The on-screen representation is assumed to be drawn under the control of an application which may wish to re-size or scale the original in some way, to crop it at the edges, and/or to ensure it fits within a particular defined area on the screen.

The class provides several functions that allow an application to set scaling and cropping before invoking the Draw() function to draw the picture on-screen. It is up to the internal workings of the function to determine the order of application cropping and scaling.

API status: Published to all clients. Released API.

Definition at line 3590 of file gdi.h.

Member Enumeration Documentation

◆ TDetach

enum CPicture::TDetach

Options for detaching pictures from stores.

Used by DetachFromStoreL().

Enumerator
EDetachFull	Internalise all data that is required to fully store the picture later; null any references to containing stores.
EDetachDraw	Internalise enough information to draw the picture (and no more); null any references to containing stores.

Definition at line 3594 of file gdi.h.

Constructor & Destructor Documentation

◆ ~CPicture()

IMPORT_C CPicture::~CPicture ( )

virtual

Frees all resources owned by the object prior to its destruction.

(generated from Symbian Developer Library)

◆ CPicture()

IMPORT_C CPicture::CPicture ( )

protected

Member Function Documentation

◆ AddCropInPixels()

IMPORT_C void CPicture::AddCropInPixels	(	MGraphicsDeviceMap *	aMap,
		const TMargins &	aMargins
	)

Adds pixel cropping margins to the picture.

Parameters

aMap	The pixels to twips mapping interface of the graphics device
aMargins	The additional pixel cropping margins for the picture, in pixels.

(generated from Symbian Developer Library)

◆ Capability()

IMPORT_C TPictureCapability CPicture::Capability ( ) const

virtual

Gets the picture's capabilities.

These include whether it is scalable and croppable.

(generated from Symbian Developer Library)

◆ DetachFromStoreL()

virtual void CPicture::DetachFromStoreL ( TDetach = EDetachFull )

inlinevirtual

Definition at line 3619 of file gdi.h.

◆ Draw()

virtual void CPicture::Draw	(	CGraphicsContext &	aGc,
		const TPoint &	aTopLeft,
		const TRect &	aClipRect,
		MGraphicsDeviceMap *	aMap
	)		const

pure virtual

Draws a picture.

Parameters

aGc	The graphics context.
aTopLeft	The co-ordinates where the top left corner pixel of the picture should be placed. Note that whether this is actually drawn depends on the clipping area defined.
aClipRect	A clipping rectangle that defines the area to which the function should draw. An implementation should never draw outside this rectangle. Note that the graphics context may also have a clipping rectangle set on it.
aMap	The device map for the graphics device. The implementation should use this to find the scaling to apply to the picture.

◆ ExternalizeL()

virtual void CPicture::ExternalizeL ( RWriteStream & aStream ) const

pure virtual

Externalises the picture to a stream.

The presence of this function means that the standard templated stream operator<<() is available to externalise objects of this class.

A derived class must supply an implementation of this function.

Parameters

aStream The write stream.

◆ GetCropInTwips()

IMPORT_C void CPicture::GetCropInTwips ( TMargins & aMargins ) const

virtual

Gets the cropping margins of a picture in twips.

These margins are relative to the original unscaled size of the picture.

Parameters

aMargins The cropping margins of the picture, in twips

(generated from Symbian Developer Library)

◆ GetOriginalSizeInTwips()

virtual void CPicture::GetOriginalSizeInTwips ( TSize & aSize ) const

pure virtual

Gets the pictur's original size, in twips.

Parameters

aSize The size of the picture, in twips

◆ GetSizeInPixels()

IMPORT_C void CPicture::GetSizeInPixels	(	MGraphicsDeviceMap *	aMap,
		TSize &	aSize
	)		const

Gets the picture's size in pixels.

This is calculated from the original size of the picture, taking cropping and scaling into account.

Parameters

aMap	The pixels to twips mapping interface of the graphics device
aSize	The size of the picture, in pixels.

(generated from Symbian Developer Library)

◆ GetSizeInTwips()

IMPORT_C void CPicture::GetSizeInTwips ( TSize & aSize ) const

Gets the picture's size, in twips.

This size is calculated from the original size of the picture, taking cropping and scaling into account.

Parameters

aSize The size of the picture, in twips.

(generated from Symbian Developer Library)

◆ LineBreakPossible()

IMPORT_C TBool CPicture::LineBreakPossible	(	TUint	aClass,
		TBool	aBeforePicture,
		TBool	aHaveSpaces
	)		const

virtual

States whether a line break is possible, either before or after a picture.

The default implementation returns ETrue, implying that there is a break opportunity both before and after the picture, whether or not a space is present.

This may be overridden for special types of pictures.

Parameters

aClass	The line breaking class of the adjacent character. Line breaking classes are defined in the header file, tagma.h
aBeforePicture	ETrue, if the adjacent character is before the picture; EFalse, if the adjacent character is afterwards.
aHaveSpaces	ETrue, if spaces occur between the adjacent character and the picture; EFalse, otherwise.

(generated from Symbian Developer Library)

◆ NativePixelSize()

IMPORT_C TBool CPicture::NativePixelSize ( TSize & aPixelSize )

virtual

Derived classes might be implemented as bitmaps, in that case it might be interesting to now the native pixel size of the bitmap.

(generated from Symbian Developer Library)

◆ ResetToOriginal()

IMPORT_C void CPicture::ResetToOriginal ( )

Resets the picture's scaling and cropping attributes to their original values.

(generated from Symbian Developer Library)

◆ ScaleFactorHeight()

IMPORT_C TInt CPicture::ScaleFactorHeight ( ) const

virtual

Gets the pictures height scale factor.

(generated from Symbian Developer Library)

◆ ScaleFactorWidth()

IMPORT_C TInt CPicture::ScaleFactorWidth ( ) const

virtual

Gets the picture's width scale factor.

(generated from Symbian Developer Library)

◆ SetCropInTwips()

IMPORT_C void CPicture::SetCropInTwips ( const TMargins & aMargins )

virtual

Sets the cropping margins of a picture in twips.

These are relative to the original unscaled size of the picture.

Parameters

aMargins The cropping margins of the picture, in twips.

(generated from Symbian Developer Library)

◆ SetScaleFactor()

IMPORT_C void CPicture::SetScaleFactor	(	TInt	aScaleFactorWidth,
		TInt	aScaleFactorHeight
	)

virtual

Sets the picture's scale factors.

Parameters

aScaleFactorWidth	The width scale factor, in percent.
aScaleFactorHeight	The height scale factor, in percent.

(generated from Symbian Developer Library)

◆ SetSizeInPixels()

IMPORT_C void CPicture::SetSizeInPixels	(	MGraphicsDeviceMap *	aMap,
		const TSize &	aSize
	)

Sets the picture's size in pixels.

Parameters

aMap	The pixels to twips mapping interface of the graphics device.
aSize	The size of the picture, in pixels.

(generated from Symbian Developer Library)

◆ SetSizeInTwips()

IMPORT_C void CPicture::SetSizeInTwips ( const TSize & aSize )

Sets the picture's size, in twips.

Parameters

aSize The size of the picture, in twips.

(generated from Symbian Developer Library)

◆ StoreL()

IMPORT_C TStreamId CPicture::StoreL ( CStreamStore & aStore ) const

virtual

Stores the picture to the specified store.

The default implementation assumes that the content of the picture is externalized to a single stream. The implementation may need to be changed for those derived classes that have components.

Parameters

aStore The store.

(generated from Symbian Developer Library)

The documentation for this class was generated from the following files:

Public Types

Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ TDetach

Constructor & Destructor Documentation

◆ ~CPicture()

◆ CPicture()

Member Function Documentation

◆ AddCropInPixels()

◆ Capability()

◆ DetachFromStoreL()

◆ Draw()

◆ ExternalizeL()

◆ GetCropInTwips()

◆ GetOriginalSizeInTwips()

◆ GetSizeInPixels()

◆ GetSizeInTwips()

◆ LineBreakPossible()

◆ NativePixelSize()

◆ ResetToOriginal()

◆ ScaleFactorHeight()

◆ ScaleFactorWidth()

◆ SetCropInTwips()

◆ SetScaleFactor()

◆ SetSizeInPixels()

◆ SetSizeInTwips()

◆ StoreL()