#include <qpnghandler_p.h>

Inheritance diagram for QPngHandler:

Collaboration diagram for QPngHandler:

Public Member Functions
	QPngHandler ()

	~QPngHandler ()

bool	canRead () const override
	Returns `true` if an image can be read from the device (i.e., the image format is supported, the device can be read from and the initial header information suggests that the image can be read); otherwise returns `false`.

bool	read (QImage *image) override
	Read an image from the device, and stores it in image.

bool	write (const QImage &image) override
	Writes the image image to the assigned device.

QVariant	option (ImageOption option) const override
	Returns the value assigned to option as a QVariant.

void	setOption (ImageOption option, const QVariant &value) override
	Sets the option option with the value value.

bool	supportsOption (ImageOption option) const override
	Returns `true` if the QImageIOHandler supports the option option; otherwise returns `false`.

Public Member Functions inherited from QImageIOHandler
	QImageIOHandler ()
	Constructs a QImageIOHandler object.

virtual	~QImageIOHandler ()
	Destructs the QImageIOHandler object.

void	setDevice (QIODevice *device)
	Sets the device of the QImageIOHandler to device.

QIODevice *	device () const
	Returns the device currently assigned to the QImageIOHandler.

void	setFormat (const QByteArray &format)
	Sets the format of the QImageIOHandler to format.

void	setFormat (const QByteArray &format) const
	Sets the format of the QImageIOHandler to format.

QByteArray	format () const
	Returns the format that is currently assigned to QImageIOHandler.

virtual bool	canRead () const =0
	Returns `true` if an image can be read from the device (i.e., the image format is supported, the device can be read from and the initial header information suggests that the image can be read); otherwise returns `false`.

virtual bool	read (QImage *image)=0
	Read an image from the device, and stores it in image.

virtual bool	write (const QImage &image)
	Writes the image image to the assigned device.

virtual QVariant	option (ImageOption option) const
	Returns the value assigned to option as a QVariant.

virtual void	setOption (ImageOption option, const QVariant &value)
	Sets the option option with the value value.

virtual bool	supportsOption (ImageOption option) const
	Returns `true` if the QImageIOHandler supports the option option; otherwise returns `false`.

virtual bool	jumpToNextImage ()
	For image formats that support animation, this function jumps to the next image.

virtual bool	jumpToImage (int imageNumber)
	For image formats that support animation, this function jumps to the image whose sequence number is imageNumber.

virtual int	loopCount () const
	For image formats that support animation, this function returns the number of times the animation should loop.

virtual int	imageCount () const
	For image formats that support animation, this function returns the number of images in the animation.

virtual int	nextImageDelay () const
	For image formats that support animation, this function returns the number of milliseconds to wait until reading the next image.

virtual int	currentImageNumber () const
	For image formats that support animation, this function returns the sequence number of the current image in the animation.

virtual QRect	currentImageRect () const
	Returns the rect of the current image.

Static Public Member Functions
static bool	canRead (QIODevice *device)

Static Public Member Functions inherited from QImageIOHandler
static bool	allocateImage (QSize size, QImage::Format format, QImage *image)

Additional Inherited Members
Public Types inherited from QImageIOHandler
enum	ImageOption { Size , ClipRect , Description , ScaledClipRect , ScaledSize , CompressionRatio , Gamma , Quality , Name , SubType , IncrementalReading , Endianness , Animation , BackgroundColor , ImageFormat , SupportedSubTypes , OptimizedWrite , ProgressiveScanWrite , ImageTransformation }
	This enum describes the different options supported by QImageIOHandler. More...

enum	Transformation { TransformationNone = 0 , TransformationMirror = 1 , TransformationFlip = 2 , TransformationRotate180 = TransformationMirror \| TransformationFlip , TransformationRotate90 = 4 , TransformationMirrorAndRotate90 = TransformationMirror \| TransformationRotate90 , TransformationFlipAndRotate90 = TransformationFlip \| TransformationRotate90 , TransformationRotate270 = TransformationRotate180 \| TransformationRotate90 }

Protected Member Functions inherited from QImageIOHandler
	QImageIOHandler (QImageIOHandlerPrivate &dd)

Protected Attributes inherited from QImageIOHandler
QScopedPointer< QImageIOHandlerPrivate >	d_ptr

Detailed Description

Definition at line 26 of file qpnghandler_p.h.

Constructor & Destructor Documentation

◆ QPngHandler()

QPngHandler::QPngHandler ( )

Definition at line 1148 of file qpnghandler.cpp.

◆ ~QPngHandler()

QPngHandler::~QPngHandler ( )

Definition at line 1153 of file qpnghandler.cpp.

References QPngHandlerPrivate::end_info, QPngHandlerPrivate::info_ptr, and QPngHandlerPrivate::png_ptr.

Member Function Documentation

◆ canRead() [1/2]

bool QPngHandler::canRead ( ) const

overridevirtual

Returns true if an image can be read from the device (i.e., the image format is supported, the device can be read from and the initial header information suggests that the image can be read); otherwise returns false.

When reimplementing canRead(), make sure that the I/O device (device()) is left in its original state (e.g., by using peek() rather than read()).

See also: read(), QIODevice::peek()

Implements QImageIOHandler.

Definition at line 1160 of file qpnghandler.cpp.

References canRead(), QImageIOHandler::device(), QPngHandlerPrivate::Error, QPngHandlerPrivate::Ready, QImageIOHandler::setFormat(), and QPngHandlerPrivate::state.

Referenced by canRead(), createReadHandlerHelper(), and read().

Here is the call graph for this function:

Here is the caller graph for this function:

◆ canRead() [2/2]

bool QPngHandler::canRead ( QIODevice * device )

static

Definition at line 1173 of file qpnghandler.cpp.

References QImageIOHandler::device(), QIODevice::peek(), and qCWarning.

Here is the call graph for this function:

◆ option()

QVariant QPngHandler::option ( ImageOption option ) const

overridevirtual

Returns the value assigned to option as a QVariant.

The type of the value depends on the option. For example, option(Size) returns a QSize variant.

See also: setOption(), supportsOption()

Reimplemented from QImageIOHandler.

Definition at line 1206 of file qpnghandler.cpp.

Here is the call graph for this function:

◆ read()

bool QPngHandler::read ( QImage * image )

overridevirtual

Read an image from the device, and stores it in image.

Returns true if the image is successfully read; otherwise returns false.

For image formats that support incremental loading, and for animation formats, the image handler can assume that image points to the previous frame.