flutter_flutter/engine/platform/exported/WebImageSkia.cpp

/*
 * Copyright (C) 2009 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * 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.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "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 THE COPYRIGHT
 * OWNER 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,
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "sky/engine/config.h"

#include "sky/engine/public/platform/WebImage.h"

#include <algorithm>
#include "platform/image-decoders/ImageDecoder.h"
#include "sky/engine/platform/SharedBuffer.h"
#include "sky/engine/platform/graphics/Image.h"
#include "sky/engine/platform/graphics/skia/NativeImageSkia.h"
#include "sky/engine/public/platform/WebData.h"
#include "sky/engine/public/platform/WebSize.h"
#include "sky/engine/wtf/OwnPtr.h"
#include "sky/engine/wtf/PassOwnPtr.h"
#include "sky/engine/wtf/PassRefPtr.h"
#include "sky/engine/wtf/Vector.h"

namespace blink {

WebImage WebImage::fromData(const WebData& data, const WebSize& desiredSize)
{
    RefPtr<SharedBuffer> buffer = PassRefPtr<SharedBuffer>(data);
    OwnPtr<ImageDecoder> decoder(ImageDecoder::create(*buffer.get(), ImageSource::AlphaPremultiplied, ImageSource::GammaAndColorProfileIgnored));
    if (!decoder)
        return WebImage();

    decoder->setData(buffer.get(), true);
    if (!decoder->isSizeAvailable())
        return WebImage();

    // Frames are arranged by decreasing size, then decreasing bit depth.
    // Pick the frame closest to |desiredSize|'s area without being smaller,
    // which has the highest bit depth.
    const size_t frameCount = decoder->frameCount();
    size_t index = 0; // Default to first frame if none are large enough.
    int frameAreaAtIndex = 0;
    for (size_t i = 0; i < frameCount; ++i) {
        const IntSize frameSize = decoder->frameSizeAtIndex(i);
        if (WebSize(frameSize) == desiredSize) {
            index = i;
            break; // Perfect match.
        }

        const int frameArea = frameSize.width() * frameSize.height();
        if (frameArea < (desiredSize.width * desiredSize.height))
            break; // No more frames that are large enough.

        if (!i || (frameArea < frameAreaAtIndex)) {
            index = i; // Closer to desired area than previous best match.
            frameAreaAtIndex = frameArea;
        }
    }

    ImageFrame* frame = decoder->frameBufferAtIndex(index);
    if (!frame)
        return WebImage();

    RefPtr<NativeImageSkia> image = frame->asNewNativeImage();
    if (!image)
        return WebImage();

    return WebImage(image->bitmap());
}

WebVector<WebImage> WebImage::framesFromData(const WebData& data)
{
    // This is to protect from malicious images. It should be big enough that it's never hit in pracice.
    const size_t maxFrameCount = 8;

    RefPtr<SharedBuffer> buffer = PassRefPtr<SharedBuffer>(data);
    OwnPtr<ImageDecoder> decoder(ImageDecoder::create(*buffer.get(), ImageSource::AlphaPremultiplied, ImageSource::GammaAndColorProfileIgnored));
    if (!decoder)
        return WebVector<WebImage>();

    decoder->setData(buffer.get(), true);
    if (!decoder->isSizeAvailable())
        return WebVector<WebImage>();

    // Frames are arranged by decreasing size, then decreasing bit depth.
    // Keep the first frame at every size, has the highest bit depth.
    const size_t frameCount = decoder->frameCount();
    IntSize lastSize;

    Vector<WebImage> frames;
    for (size_t i = 0; i < std::min(frameCount, maxFrameCount); ++i) {
        const IntSize frameSize = decoder->frameSizeAtIndex(i);
        if (frameSize == lastSize)
            continue;
        lastSize = frameSize;

        ImageFrame* frame = decoder->frameBufferAtIndex(i);
        if (!frame)
            continue;

        RefPtr<NativeImageSkia> image = frame->asNewNativeImage();
        if (image && image->isDataComplete())
            frames.append(WebImage(image->bitmap()));
    }

    return frames;
}

void WebImage::reset()
{
    m_bitmap.reset();
}

void WebImage::assign(const WebImage& image)
{
    m_bitmap = image.m_bitmap;
}

bool WebImage::isNull() const
{
    return m_bitmap.isNull();
}

WebSize WebImage::size() const
{
    return WebSize(m_bitmap.width(), m_bitmap.height());
}

WebImage::WebImage(const PassRefPtr<Image>& image)
{
    operator=(image);
}

WebImage& WebImage::operator=(const PassRefPtr<Image>& image)
{
    RefPtr<NativeImageSkia> p;
    if (image && (p = image->nativeImageForCurrentFrame()))
        assign(p->bitmap());
    else
        reset();
    return *this;
}

} // namespace blink