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Internal/Contributor docs for the Qt SDK. <b>Note:</b> These are NOT official API docs; those are found <a href='https://doc.qt.io/'>here</a>.
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QPdfIOHandler Class Reference

#include <qpdfiohandler_p.h>

+ Inheritance diagram for QPdfIOHandler:
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Public Member Functions

 QPdfIOHandler ()
 
 ~QPdfIOHandler () override
 
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.
 
int currentImageNumber () const override
 For image formats that support animation, this function returns the sequence number of the current image in the animation.
 
QRect currentImageRect () const override
 Returns the rect of the current image.
 
int imageCount () const override
 For image formats that support animation, this function returns the number of images in the animation.
 
bool read (QImage *image) override
 Read an image from the device, and stores it in image.
 
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.
 
bool jumpToImage (int frame) override
 For image formats that support animation, this function jumps to the image whose sequence number is imageNumber.
 
bool jumpToNextImage () override
 For image formats that support animation, this function jumps to the next image.
 
- 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.
 
QIODevicedevice () 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 write (const QImage &image)
 Writes the image image to the assigned device.
 
virtual int loopCount () const
 For image formats that support animation, this function returns the number of times the animation should loop.
 
virtual int nextImageDelay () const
 For image formats that support animation, this function returns the number of milliseconds to wait until reading the next 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< QImageIOHandlerPrivated_ptr
 

Detailed Description

Definition at line 23 of file qpdfiohandler_p.h.

Constructor & Destructor Documentation

◆ QPdfIOHandler()

QT_BEGIN_NAMESPACE QPdfIOHandler::QPdfIOHandler ( )

Definition at line 13 of file qpdfiohandler.cpp.

◆ ~QPdfIOHandler()

QPdfIOHandler::~QPdfIOHandler ( )
override

Definition at line 17 of file qpdfiohandler.cpp.

Member Function Documentation

◆ canRead() [1/2]

bool QPdfIOHandler::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 23 of file qpdfiohandler.cpp.

References canRead(), QImageIOHandler::device(), and QImageIOHandler::setFormat().

Referenced by canRead(), and QPdfPlugin::capabilities().

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◆ canRead() [2/2]

bool QPdfIOHandler::canRead ( QIODevice * device)
static

Definition at line 36 of file qpdfiohandler.cpp.

References QImageIOHandler::device(), QIODevice::peek(), Q_UNLIKELY, and qstrncmp().

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◆ currentImageNumber()

int QPdfIOHandler::currentImageNumber ( ) const
overridevirtual

For image formats that support animation, this function returns the sequence number of the current image in the animation.

If this function is called before any image is read(), -1 is returned. The number of the first image in the sequence is 0.

If the image format does not support animation, 0 is returned.

See also
read()

Reimplemented from QImageIOHandler.

Definition at line 43 of file qpdfiohandler.cpp.

◆ currentImageRect()

QRect QPdfIOHandler::currentImageRect ( ) const
overridevirtual

Returns the rect of the current image.

If no rect is defined for the image, and empty QRect() is returned.

This function is useful for animations, where only parts of the frame may be updated at a time.

Reimplemented from QImageIOHandler.

Definition at line 48 of file qpdfiohandler.cpp.

References QPdfDocument::pagePointSize(), and QSizeF::toSize().

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◆ imageCount()

int QPdfIOHandler::imageCount ( ) const
overridevirtual

For image formats that support animation, this function returns the number of images in the animation.

If the image format does not support animation, or if it is unable to determine the number of images, 0 is returned.

The default implementation returns 1 if canRead() returns true; otherwise 0 is returned.

Reimplemented from QImageIOHandler.

Definition at line 53 of file qpdfiohandler.cpp.

References QImageIOHandler::device(), QPdfDocument::pageCount, qCDebug, and ret.

Referenced by jumpToImage().

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◆ jumpToImage()

bool QPdfIOHandler::jumpToImage ( int imageNumber)
overridevirtual

For image formats that support animation, this function jumps to the image whose sequence number is imageNumber.

The next call to read() will attempt to read this image.

The default implementation does nothing, and returns false.

Reimplemented from QImageIOHandler.

Definition at line 187 of file qpdfiohandler.cpp.

References frame, imageCount(), and qCDebug.

Referenced by jumpToNextImage().

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◆ jumpToNextImage()

bool QPdfIOHandler::jumpToNextImage ( )
overridevirtual

For image formats that support animation, this function jumps to the next image.

The default implementation does nothing, and returns false.

Reimplemented from QImageIOHandler.

Definition at line 196 of file qpdfiohandler.cpp.

References jumpToImage().

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◆ option()

QVariant QPdfIOHandler::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 125 of file qpdfiohandler.cpp.

References QImageIOHandler::BackgroundColor, QImageIOHandler::ClipRect, QImageIOHandler::device(), QImage::Format_ARGB32_Premultiplied, QImageIOHandler::ImageFormat, QPdfDocument::metaData(), QImageIOHandler::Name, QPdfDocument::pagePointSize(), qMax(), QImageIOHandler::ScaledClipRect, QImageIOHandler::ScaledSize, QImageIOHandler::Size, and QPdfDocument::Title.

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◆ read()

bool QPdfIOHandler::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.

See also
canRead()

Implements QImageIOHandler.

Definition at line 62 of file qpdfiohandler.cpp.

References QImageIOHandler::device(), QImage::Format_ARGB32_Premultiplied, QSize::height(), QSizeF::height(), QPointer< T >::isNull(), QRect::isValid(), QSize::isValid(), QPdfDocument::pageCount, QPdfDocument::pagePointSize(), qCDebug, qWarning, QPdfDocument::render(), QColor::rgba(), QTransform::scale(), QPdfDocumentRenderOptions::setScaledClipRect(), QPdfDocumentRenderOptions::setScaledSize(), QRect::size(), QRect::topLeft(), QSizeF::toSize(), QTransform::translate(), QSize::width(), QSizeF::width(), and xform.

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◆ setOption()

void QPdfIOHandler::setOption ( ImageOption option,
const QVariant & value )
overridevirtual

Sets the option option with the value value.

See also
option(), ImageOption

Reimplemented from QImageIOHandler.

Definition at line 149 of file qpdfiohandler.cpp.

References QImageIOHandler::BackgroundColor, QImageIOHandler::ClipRect, QImageIOHandler::ScaledClipRect, QImageIOHandler::ScaledSize, and QColor::value().

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◆ supportsOption()

bool QPdfIOHandler::supportsOption ( ImageOption option) const
overridevirtual

Returns true if the QImageIOHandler supports the option option; otherwise returns false.

For example, if the QImageIOHandler supports the \l Size option, supportsOption(Size) must return true.

See also
setOption(), option()

Reimplemented from QImageIOHandler.

Definition at line 169 of file qpdfiohandler.cpp.

References QImageIOHandler::BackgroundColor, QImageIOHandler::ClipRect, QImageIOHandler::ImageFormat, QImageIOHandler::Name, QImageIOHandler::ScaledClipRect, QImageIOHandler::ScaledSize, and QImageIOHandler::Size.


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