imagesourceqt.cpp

linux下开源浏览器WebKit的源码,市面上的很多商用浏览器都是移植自WebKit

/*
 * Copyright (C) 2006 Apple Computer, Inc.  All rights reserved. 
 * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
 *
 * 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 "ImageSource.h"
#include "ImageDecoderQt.h"
#include "NotImplemented.h"
#include "SharedBuffer.h"

#include <QBuffer>
#include <QImage>
#include <QImageReader>

namespace WebCore {

ImageSource::ImageSource()
    : m_decoder(0)
{
}

ImageSource::~ImageSource()
{
    clear(true);
}

bool ImageSource::initialized() const
{
    return m_decoder;
}

void ImageSource::setData(SharedBuffer* data, bool allDataReceived)
{
    // Make the decoder by sniffing the bytes.
    // This method will examine the data and instantiate an instance of the appropriate decoder plugin.
    // If insufficient bytes are available to determine the image type, no decoder plugin will be
    // made.
    if (!m_decoder)
        m_decoder = ImageDecoderQt::create(*data);

    if (!m_decoder)
        return;

    m_decoder->setData(data->buffer(), allDataReceived);
}

String ImageSource::filenameExtension() const
{
    if (!m_decoder)
        return String();

    return m_decoder->filenameExtension();
}

bool ImageSource::isSizeAvailable()
{
    if (!m_decoder)
        return false;

    return m_decoder->isSizeAvailable();
}

IntSize ImageSource::size() const
{
    if (!m_decoder)
        return IntSize();

    return m_decoder->size();
}

IntSize ImageSource::frameSizeAtIndex(size_t) const
{
    return size();
}

int ImageSource::repetitionCount()
{
    if (!m_decoder)
        return cAnimationNone;

    return m_decoder->repetitionCount();
}

size_t ImageSource::frameCount() const
{
    if (!m_decoder)
        return 0;

    return m_decoder->frameCount();
}

NativeImagePtr ImageSource::createFrameAtIndex(size_t index)
{
    if (!m_decoder)
        return 0;

    return m_decoder->imageAtIndex(index);
}

float ImageSource::frameDurationAtIndex(size_t index)
{
    if (!m_decoder)
        return 0;
    
    // Many annoying ads specify a 0 duration to make an image flash as quickly
    // as possible.  We follow WinIE's behavior and use a duration of 100 ms
    // for any frames that specify a duration of <= 50 ms.  See
    // <http://bugs.webkit.org/show_bug.cgi?id=14413> or Radar 4051389 for
    // more.
    const float duration = m_decoder->duration(index) / 1000.0f;
    return (duration < 0.051f) ? 0.100f : duration;
}

bool ImageSource::frameHasAlphaAtIndex(size_t index)
{
    if (!m_decoder || !m_decoder->supportsAlpha())
        return false;
    
    const QPixmap* source = m_decoder->imageAtIndex( index);
    if (!source)
        return false;
    
    return source->hasAlphaChannel();
}

bool ImageSource::frameIsCompleteAtIndex(size_t index)
{
    return (m_decoder && m_decoder->imageAtIndex(index) != 0);
}

void ImageSource::clear(bool destroyAll, size_t clearBeforeFrame, SharedBuffer* data, bool allDataReceived)
{
    if (!destroyAll) {
        if (m_decoder)
            m_decoder->clearFrameBufferCache(clearBeforeFrame);
        return;
    }

    delete m_decoder;
    m_decoder = 0;
    if (data)
        setData(data, allDataReceived);
}

}

// vim: ts=4 sw=4 et