WebCore/platform/graphics/qt/ImageDecoderQt.cpp - WebKit - Git at Google

 /*
  * Copyright (C) 2006 Friedemann Kleint <fkleint@trolltech.com>
  * Copyright (C) 2006 Trolltech ASA
  *
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 #include "config.h"
 #include "ImageDecoderQt.h"

 #include <QtCore/QByteArray>
 #include <QtCore/QBuffer>

 #include <QtGui/QImageReader>
 #include <qdebug.h>

 namespace {
     const  QImage::Format DesiredFormat = QImage::Format_ARGB32;
     const  bool debugImageDecoderQt = false;
 }

 namespace WebCore {
 ImageDecoderQt::ImageData::ImageData(const QPixmap& image, QImage::Format format,
                                      ImageState imageState, int duration)
     : m_image(image), m_format(format),
       m_imageState(imageState), m_duration(duration)
 {
 }

 // Context, maintains IODevice on a data buffer.
 class ImageDecoderQt::ReadContext {
 public:

     enum LoadMode {
         // Load images incrementally. This is still experimental and
         // will cause the image plugins to report errors.
         // Also note that as of Qt 4.2.2, the JPEG loader does not return error codes
         // on "preliminary end of data".
         LoadIncrementally,
             // Load images only if  all data have been received
             LoadComplete };

     ReadContext(const IncomingData & data, LoadMode loadMode, ImageList &target);

     enum ReadResult { ReadEOF, ReadFailed, ReadPartial, ReadComplete };

     // Append data and read out all images. Returns the result
     // of the last read operation, so, even if  ReadPartial is returned,
     // a few images might have been read.
     ReadResult read(bool allDataReceived);

 private:
     enum IncrementalReadResult { IncrementalReadFailed, IncrementalReadPartial, IncrementalReadComplete };
     // Incrementally read an image
     IncrementalReadResult readImageLines(ImageData &);

     const LoadMode m_loadMode;

     QByteArray m_data;
     QBuffer m_buffer;
     QImageReader m_reader;

     ImageList &m_target;

     // Detected data format of the stream
     enum QImage::Format m_dataFormat;
     QSize m_size;

 };

 ImageDecoderQt::ReadContext::ReadContext(const IncomingData & data, LoadMode loadMode, ImageList &target) :
     m_loadMode(loadMode),
     m_data(data.data(), data.size()),
     m_buffer(&m_data),
     m_reader(&m_buffer),
     m_target(target),
     m_dataFormat(QImage::Format_Invalid)
 {
     m_buffer.open(QIODevice::ReadOnly);
 }


 ImageDecoderQt::ReadContext::ReadResult
         ImageDecoderQt::ReadContext::read(bool allDataReceived)
 {
     // Complete mode: Read only all all data received
     if (m_loadMode == LoadComplete && !allDataReceived)
         return ReadPartial;

     // Attempt to read out all images
     while (true) {
         if (m_target.empty() || m_target.back().m_imageState == ImageComplete) {
             // Start a new image.
             if (!m_reader.canRead())
                 return ReadEOF;

             // Attempt to construct an empty image of the matching size and format
             // for efficient reading
             QImage newImage = m_dataFormat != QImage::Format_Invalid  ?
                           QImage(m_size,m_dataFormat) : QImage();
             m_target.push_back(ImageData(QPixmap::fromImage(newImage), m_dataFormat));
         }

         // read chunks
         switch (readImageLines(m_target.back())) {
         case IncrementalReadFailed:
             m_target.pop_back();
             return ReadFailed;
         case IncrementalReadPartial:
             return ReadPartial;
         case IncrementalReadComplete:
             m_target.back().m_imageState = ImageComplete;
             //store for next
             m_dataFormat = m_target.back().m_format;
             m_size = m_target.back().m_image.size();
             const bool supportsAnimation = m_reader.supportsAnimation();

             if (debugImageDecoderQt)
                 qDebug() << "readImage(): #" << m_target.size() << " complete, " << m_size << " format " << m_dataFormat
                 <<  " supportsAnimation=" <<  supportsAnimation ;
             // No point in readinfg further
             if (!supportsAnimation)
                 return ReadComplete;

             break;
         }
     }
     return ReadComplete;
 }


 ImageDecoderQt::ReadContext::IncrementalReadResult
         ImageDecoderQt::ReadContext::readImageLines(ImageData &imageData)
 {
     // TODO: Implement incremental reading here,
     // set state to reflect complete header, etc.
     // For now, we read the whole image.

     const qint64 startPos = m_buffer.pos ();
     // Oops, failed. Rewind.
     QImage image = imageData.m_image.toImage();
     if (!m_reader.read(&image)) {
         m_buffer.seek(startPos);
         const bool gotHeader = imageData.m_image.size().width();

         if (debugImageDecoderQt)
             qDebug() << "readImageLines(): read() failed: " << m_reader.errorString()
                 << " got header=" << gotHeader;
         // [Experimental] Did we manage to read the header?
         if (gotHeader) {
             imageData.m_imageState = ImageHeaderValid;
             return IncrementalReadPartial;
         }
         return IncrementalReadFailed;
     }
     imageData.m_image = QPixmap::fromImage(image);
     imageData.m_duration = m_reader.nextImageDelay();
     return IncrementalReadComplete;
 }


 // ImageDecoderQt
 ImageDecoderQt::ImageDecoderQt( )
 {
 }

 ImageDecoderQt::~ImageDecoderQt()
 {
 }

 bool ImageDecoderQt::hasFirstImageHeader() const
 {
     return  !m_imageList.empty() && m_imageList[0].m_imageState >= ImageHeaderValid;
 }

 void ImageDecoderQt::reset()
 {
     m_failed = false;
     m_imageList.clear();
     m_sizeAvailable = false;
     m_size = IntSize(-1, -1);
 }

 void ImageDecoderQt::setData(const IncomingData &data, bool allDataReceived)
 {
     reset();
     ReadContext readContext(data, ReadContext::LoadComplete, m_imageList);

     if (debugImageDecoderQt)
         qDebug() << " setData " << data.size() << " image bytes, complete=" << allDataReceived;

     const  ReadContext::ReadResult readResult =  readContext.read(allDataReceived);

     if (debugImageDecoderQt)
         qDebug()  << " read returns " << readResult;

     switch ( readResult)    {
     case ReadContext::ReadFailed:
         m_failed = true;
         break;
     case ReadContext::ReadEOF:
     case ReadContext::ReadPartial:
     case ReadContext::ReadComplete:
         // Did we read anything - try to set the size.
         if (hasFirstImageHeader()) {
             m_sizeAvailable = true;
             m_size = m_imageList[0].m_image.size();
         }
         break;
     }
 }


 bool ImageDecoderQt::isSizeAvailable() const
 {
     if (debugImageDecoderQt)
         qDebug() << " ImageDecoderQt::isSizeAvailable() returns" << m_sizeAvailable;
     return m_sizeAvailable;
 }

 int ImageDecoderQt::frameCount() const
 {
     return m_imageList.size();
 }


 int ImageDecoderQt::repetitionCount() const
 {
     // TODO: Am I Moses?!
     return cAnimationNone;
 }


 bool ImageDecoderQt::ImageDecoderQt::supportsAlpha() const
 {
     return hasFirstImageHeader() && m_imageList[0].m_image.hasAlphaChannel();
 }

 int ImageDecoderQt::duration(size_t index) const
 {
     if (index >= m_imageList.size())
         return 0;
     return  m_imageList[index].m_duration;
 }

 RGBA32Buffer* ImageDecoderQt::frameBufferAtIndex(size_t index)
 {
     Q_ASSERT("use imageAtIndex instead");
     return 0;
 }

 const QPixmap* ImageDecoderQt::imageAtIndex(size_t index) const
 {
     if (debugImageDecoderQt)
         qDebug() << "ImageDecoderQt::imageAtIndex(" << index << ')';

     if (index >= m_imageList.size())
         return 0;
     return &m_imageList[index].m_image;
 }

 }

 // vim: ts=4 sw=4 et
	/*
	* Copyright (C) 2006 Friedemann Kleint <fkleint@trolltech.com>
	* Copyright (C) 2006 Trolltech ASA
	*
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
	* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR
	* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
	* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
	* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
	* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#include "config.h"
	#include "ImageDecoderQt.h"

	#include <QtCore/QByteArray>
	#include <QtCore/QBuffer>

	#include <QtGui/QImageReader>
	#include <qdebug.h>

	namespace {
	const QImage::Format DesiredFormat = QImage::Format_ARGB32;
	const bool debugImageDecoderQt = false;
	}

	namespace WebCore {
	ImageDecoderQt::ImageData::ImageData(const QPixmap& image, QImage::Format format,
	ImageState imageState, int duration)
	: m_image(image), m_format(format),
	m_imageState(imageState), m_duration(duration)
	{
	}

	// Context, maintains IODevice on a data buffer.
	class ImageDecoderQt::ReadContext {
	public:

	enum LoadMode {
	// Load images incrementally. This is still experimental and
	// will cause the image plugins to report errors.
	// Also note that as of Qt 4.2.2, the JPEG loader does not return error codes
	// on "preliminary end of data".
	LoadIncrementally,
	// Load images only if all data have been received
	LoadComplete };

	ReadContext(const IncomingData & data, LoadMode loadMode, ImageList &target);

	enum ReadResult { ReadEOF, ReadFailed, ReadPartial, ReadComplete };

	// Append data and read out all images. Returns the result
	// of the last read operation, so, even if ReadPartial is returned,
	// a few images might have been read.
	ReadResult read(bool allDataReceived);

	private:
	enum IncrementalReadResult { IncrementalReadFailed, IncrementalReadPartial, IncrementalReadComplete };
	// Incrementally read an image
	IncrementalReadResult readImageLines(ImageData &);

	const LoadMode m_loadMode;

	QByteArray m_data;
	QBuffer m_buffer;
	QImageReader m_reader;

	ImageList &m_target;

	// Detected data format of the stream
	enum QImage::Format m_dataFormat;
	QSize m_size;

	};

	ImageDecoderQt::ReadContext::ReadContext(const IncomingData & data, LoadMode loadMode, ImageList &target) :
	m_loadMode(loadMode),
	m_data(data.data(), data.size()),
	m_buffer(&m_data),
	m_reader(&m_buffer),
	m_target(target),
	m_dataFormat(QImage::Format_Invalid)
	{
	m_buffer.open(QIODevice::ReadOnly);
	}


	ImageDecoderQt::ReadContext::ReadResult
	ImageDecoderQt::ReadContext::read(bool allDataReceived)
	{
	// Complete mode: Read only all all data received
	if (m_loadMode == LoadComplete && !allDataReceived)
	return ReadPartial;

	// Attempt to read out all images
	while (true) {
	if (m_target.empty() \|\| m_target.back().m_imageState == ImageComplete) {
	// Start a new image.
	if (!m_reader.canRead())
	return ReadEOF;

	// Attempt to construct an empty image of the matching size and format
	// for efficient reading
	QImage newImage = m_dataFormat != QImage::Format_Invalid ?
	QImage(m_size,m_dataFormat) : QImage();
	m_target.push_back(ImageData(QPixmap::fromImage(newImage), m_dataFormat));
	}

	// read chunks
	switch (readImageLines(m_target.back())) {
	case IncrementalReadFailed:
	m_target.pop_back();
	return ReadFailed;
	case IncrementalReadPartial:
	return ReadPartial;
	case IncrementalReadComplete:
	m_target.back().m_imageState = ImageComplete;
	//store for next
	m_dataFormat = m_target.back().m_format;
	m_size = m_target.back().m_image.size();
	const bool supportsAnimation = m_reader.supportsAnimation();

	if (debugImageDecoderQt)
	qDebug() << "readImage(): #" << m_target.size() << " complete, " << m_size << " format " << m_dataFormat
	<< " supportsAnimation=" << supportsAnimation ;
	// No point in readinfg further
	if (!supportsAnimation)
	return ReadComplete;

	break;
	}
	}
	return ReadComplete;
	}



	ImageDecoderQt::ReadContext::IncrementalReadResult
	ImageDecoderQt::ReadContext::readImageLines(ImageData &imageData)
	{
	// TODO: Implement incremental reading here,
	// set state to reflect complete header, etc.
	// For now, we read the whole image.

	const qint64 startPos = m_buffer.pos ();
	// Oops, failed. Rewind.
	QImage image = imageData.m_image.toImage();
	if (!m_reader.read(&image)) {
	m_buffer.seek(startPos);
	const bool gotHeader = imageData.m_image.size().width();

	if (debugImageDecoderQt)
	qDebug() << "readImageLines(): read() failed: " << m_reader.errorString()
	<< " got header=" << gotHeader;
	// [Experimental] Did we manage to read the header?
	if (gotHeader) {
	imageData.m_imageState = ImageHeaderValid;
	return IncrementalReadPartial;
	}
	return IncrementalReadFailed;
	}
	imageData.m_image = QPixmap::fromImage(image);
	imageData.m_duration = m_reader.nextImageDelay();
	return IncrementalReadComplete;
	}


	// ImageDecoderQt
	ImageDecoderQt::ImageDecoderQt( )
	{
	}

	ImageDecoderQt::~ImageDecoderQt()
	{
	}

	bool ImageDecoderQt::hasFirstImageHeader() const
	{
	return !m_imageList.empty() && m_imageList[0].m_imageState >= ImageHeaderValid;
	}

	void ImageDecoderQt::reset()
	{
	m_failed = false;
	m_imageList.clear();
	m_sizeAvailable = false;
	m_size = IntSize(-1, -1);
	}

	void ImageDecoderQt::setData(const IncomingData &data, bool allDataReceived)
	{
	reset();
	ReadContext readContext(data, ReadContext::LoadComplete, m_imageList);

	if (debugImageDecoderQt)
	qDebug() << " setData " << data.size() << " image bytes, complete=" << allDataReceived;

	const ReadContext::ReadResult readResult = readContext.read(allDataReceived);

	if (debugImageDecoderQt)
	qDebug() << " read returns " << readResult;

	switch ( readResult) {
	case ReadContext::ReadFailed:
	m_failed = true;
	break;
	case ReadContext::ReadEOF:
	case ReadContext::ReadPartial:
	case ReadContext::ReadComplete:
	// Did we read anything - try to set the size.
	if (hasFirstImageHeader()) {
	m_sizeAvailable = true;
	m_size = m_imageList[0].m_image.size();
	}
	break;
	}
	}


	bool ImageDecoderQt::isSizeAvailable() const
	{
	if (debugImageDecoderQt)
	qDebug() << " ImageDecoderQt::isSizeAvailable() returns" << m_sizeAvailable;
	return m_sizeAvailable;
	}

	int ImageDecoderQt::frameCount() const
	{
	return m_imageList.size();
	}


	int ImageDecoderQt::repetitionCount() const
	{
	// TODO: Am I Moses?!
	return cAnimationNone;
	}


	bool ImageDecoderQt::ImageDecoderQt::supportsAlpha() const
	{
	return hasFirstImageHeader() && m_imageList[0].m_image.hasAlphaChannel();
	}

	int ImageDecoderQt::duration(size_t index) const
	{
	if (index >= m_imageList.size())
	return 0;
	return m_imageList[index].m_duration;
	}

	RGBA32Buffer* ImageDecoderQt::frameBufferAtIndex(size_t index)
	{
	Q_ASSERT("use imageAtIndex instead");
	return 0;
	}

	const QPixmap* ImageDecoderQt::imageAtIndex(size_t index) const
	{
	if (debugImageDecoderQt)
	qDebug() << "ImageDecoderQt::imageAtIndex(" << index << ')';

	if (index >= m_imageList.size())
	return 0;
	return &m_imageList[index].m_image;
	}

	}

	// vim: ts=4 sw=4 et