Provides user-definable palette support to the GDI. More...

#include <gdi.h>

Inheritance diagram for CPalette:

Public Member Functions
IMPORT_C	~CPalette ()
	Destructor.

IMPORT_C void	Clear ()
	Clears all the entries in the palette to TRgb(0).

TInt	Entries () const
	Gets the number of entries in the palette.

IMPORT_C TRgb	GetEntry (TInt aPaletteIndex) const
	Gets the RGB value of the palette entry at aPaletteIndex.

IMPORT_C TRgb	NearestEntry (const TRgb &aColor) const
	Gets the colour in the palette which is closest to the specified colour.

IMPORT_C TInt	NearestIndex (const TRgb &aColor) const
	Gets the index of the colour in the palette which is closest to the specified colour.

IMPORT_C void	SetEntry (TInt aPaletteIndex, const TRgb &aPaletteEntry)
	Sets the palette entry at aPaletteIndex to the RGB value aPaletteEntry.

IMPORT_C void	GetDataPtr (TInt aFirstColor, TInt aNumColors, TPtr8 &aPtr)
	Returns a descriptor over the palette entries for the specifed colors.

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.

Static Public Member Functions
static IMPORT_C CPalette *	NewL (TInt aNumberOfEntries)
	Creates a new palette with the specified number of entries.

static IMPORT_C CPalette *	NewDefaultL (TDisplayMode aDispMode)
	Creates a new default palette for the specified display mode.

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

Protected Member Functions
IMPORT_C	CPalette ()

void	ConstructL (TInt aNumberOfEntries)

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

Protected Attributes
TRgb *	iArray

TInt	iNumEntries

Detailed Description

Provides user-definable palette support to the GDI.

A palette is a user-defined set of colours, which is a subset of the full range of 24-bit colours. This allows users the advantages of having a low bpp colour mode whilst being able to specify the colours available in that mode. To give an example, the EColor16 mode provides a palette of 16 colours as it provides a mapping between an integer index and a TRgb colour (see the table EGA Low-colour constants). Only a palette of 16 colour enables you to change the palette. Palettes are also used to allow 24-bit bitmaps to be stored in a more compressed form by finding the actual number of different colours used in the bitmap, creating a palette to allow the mapping of these colours to a smaller index space, and encoding the bitmaps pixels using indexes to this new index space.

A palette has a size which is set at its creation and cannot be altered the number of entries in the palette. Each entry in a palette is a mapping between that entrys index and a TRgb value. Palette entries can be got and set at any time between the palettes creation and destruction. The GDIs palette support also provides functions to find the nearest palette colour to a requested TRgb colour.

API status: Published to all clients. Released API.

Definition at line 364 of file gdi.h.

Constructor & Destructor Documentation

◆ ~CPalette()

IMPORT_C CPalette::~CPalette ( )

Destructor.

(generated from Symbian Developer Library)

◆ CPalette()

IMPORT_C CPalette::CPalette ( )

protected

Member Function Documentation

◆ Clear()

IMPORT_C void CPalette::Clear ( )

Clears all the entries in the palette to TRgb(0).

(generated from Symbian Developer Library)

◆ ConstructL()

void CPalette::ConstructL ( TInt aNumberOfEntries )

protected

◆ Entries()

TInt CPalette::Entries ( ) const

inline

Gets the number of entries in the palette.

(generated from Symbian Developer Library)

◆ GetDataPtr()

IMPORT_C void CPalette::GetDataPtr	(	TInt	aFirstColor,
		TInt	aNumColors,
		TPtr8 &	aPtr
	)

Returns a descriptor over the palette entries for the specifed colors.

It is designed so that the descriptor can be passed to another thread and that thread copy the relevant entries.

Parameters

aFirstColor	The first colour.
aNumColors	Number of colours.
aPtr	Descriptor.

(generated from Symbian Developer Library)

◆ GetEntry()

IMPORT_C TRgb CPalette::GetEntry ( TInt aPaletteIndex ) const

Gets the RGB value of the palette entry at aPaletteIndex.

Parameters

aPaletteIndex The index of the palette entry to get.

(generated from Symbian Developer Library)

◆ NearestEntry()

IMPORT_C TRgb CPalette::NearestEntry ( const TRgb & aColor ) const

Gets the colour in the palette which is closest to the specified colour.

Parameters

aColor The colour to find.

(generated from Symbian Developer Library)

◆ NearestIndex()

IMPORT_C TInt CPalette::NearestIndex ( const TRgb & aColor ) const

Gets the index of the colour in the palette which is closest to the specified colour.

Parameters

aColor The colour to find.

(generated from Symbian Developer Library)

◆ NewDefaultL()

static IMPORT_C CPalette * CPalette::NewDefaultL ( TDisplayMode aDispMode )

static

Creates a new default palette for the specified display mode.

The default palette for a particular display mode has one entry for each possible colour in that display mode (2 entries for EGray2, 16 entries for EColor16 etc.); the colour of each index p in the default palette is set to its default value according to its display mode (e.g. if the mode is EColor16 then palette[p]==TRgbColor16(p); if the mode is EGray4 then palette[p]==TRgb_Gray4(p)).

Parameters

aDispMode The display mode for which the palette is to be created.

(generated from Symbian Developer Library)

◆ NewL()

static IMPORT_C CPalette * CPalette::NewL ( TInt aNumberOfEntries )

static

Creates a new palette with the specified number of entries.

Parameters

aNumberOfEntries The number of entries in the palette being created.

(generated from Symbian Developer Library)

◆ SetEntry()

IMPORT_C void CPalette::SetEntry	(	TInt	aPaletteIndex,
		const TRgb &	aPaletteEntry
	)

Sets the palette entry at aPaletteIndex to the RGB value aPaletteEntry.

Parameters

aPaletteIndex	The index of the palette entry to be set.
aPaletteEntry	The RGB value to set that entry to.

(generated from Symbian Developer Library)

Member Data Documentation

◆ iArray

TRgb* CPalette::iArray

protected

Definition at line 381 of file gdi.h.

◆ iNumEntries

TInt CPalette::iNumEntries

protected

Definition at line 382 of file gdi.h.

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

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ ~CPalette()

◆ CPalette()

Member Function Documentation

◆ Clear()

◆ ConstructL()

◆ Entries()

◆ GetDataPtr()

◆ GetEntry()

◆ NearestEntry()

◆ NearestIndex()

◆ NewDefaultL()

◆ NewL()

◆ SetEntry()

Member Data Documentation

◆ iArray

◆ iNumEntries