third_party/WebKit/Source/core/layout/LayoutVideo.cpp

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 * Copyright (C) 2007, 2008, 2009, 2010 Apple Inc.  All rights reserved.
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 * Redistribution and use in source and binary forms, with or without
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#include "core/layout/LayoutVideo.h"

#include "core/HTMLNames.h"
#include "core/dom/Document.h"
#include "core/html/HTMLVideoElement.h"
#include "core/layout/LayoutBlockFlow.h"
#include "core/layout/LayoutFullScreen.h"
#include "core/paint/VideoPainter.h"
#include "public/platform/WebLayer.h"

namespace blink {

using namespace HTMLNames;

LayoutVideo::LayoutVideo(HTMLVideoElement* video)
    : LayoutMedia(video)
{
    setIntrinsicSize(calculateIntrinsicSize());
}

LayoutVideo::~LayoutVideo()
{
}

LayoutSize LayoutVideo::defaultSize()
{
    return LayoutSize(defaultWidth, defaultHeight);
}

void LayoutVideo::intrinsicSizeChanged()
{
    if (videoElement()->shouldDisplayPosterImage())
        LayoutMedia::intrinsicSizeChanged();
    updateIntrinsicSize();
}

void LayoutVideo::updateIntrinsicSize()
{
    LayoutSize size = calculateIntrinsicSize();
    size.scale(style()->effectiveZoom());

    // Never set the element size to zero when in a media document.
    if (size.isEmpty() && node()->ownerDocument() && node()->ownerDocument()->isMediaDocument())
        return;

    if (size == intrinsicSize())
        return;

    setIntrinsicSize(size);
    setPreferredLogicalWidthsDirty();
    setNeedsLayoutAndFullPaintInvalidation(LayoutInvalidationReason::SizeChanged);
}

LayoutSize LayoutVideo::calculateIntrinsicSize()
{
    HTMLVideoElement* video = videoElement();

    // Spec text from 4.8.6
    //
    // The intrinsic width of a video element's playback area is the intrinsic width
    // of the video resource, if that is available; otherwise it is the intrinsic
    // width of the poster frame, if that is available; otherwise it is 300 CSS pixels.
    //
    // The intrinsic height of a video element's playback area is the intrinsic height
    // of the video resource, if that is available; otherwise it is the intrinsic
    // height of the poster frame, if that is available; otherwise it is 150 CSS pixels.
    WebMediaPlayer* webMediaPlayer = mediaElement()->webMediaPlayer();
    if (webMediaPlayer && video->getReadyState() >= HTMLVideoElement::HAVE_METADATA) {
        IntSize size = webMediaPlayer->naturalSize();
        if (!size.isEmpty())
            return LayoutSize(size);
    }

    if (video->shouldDisplayPosterImage() && !m_cachedImageSize.isEmpty() && !imageResource()->errorOccurred())
        return m_cachedImageSize;

    // <video> in standalone media documents should not use the default 300x150
    // size since they also have audio-only files. By setting the intrinsic
    // size to 300x1 the video will resize itself in these cases, and audio will
    // have the correct height (it needs to be > 0 for controls to layout properly).
    if (video->ownerDocument() && video->ownerDocument()->isMediaDocument())
        return LayoutSize(defaultSize().width(), LayoutUnit(1));

    return defaultSize();
}

void LayoutVideo::imageChanged(WrappedImagePtr newImage, const IntRect* rect)
{
    LayoutMedia::imageChanged(newImage, rect);

    // Cache the image intrinsic size so we can continue to use it to draw the image correctly
    // even if we know the video intrinsic size but aren't able to draw video frames yet
    // (we don't want to scale the poster to the video size without keeping aspect ratio).
    if (videoElement()->shouldDisplayPosterImage())
        m_cachedImageSize = intrinsicSize();

    // The intrinsic size is now that of the image, but in case we already had the
    // intrinsic size of the video we call this here to restore the video size.
    updateIntrinsicSize();
}

IntRect LayoutVideo::videoBox() const
{
    const LayoutSize* overriddenIntrinsicSize = nullptr;
    if (videoElement()->shouldDisplayPosterImage())
        overriddenIntrinsicSize = &m_cachedImageSize;

    return pixelSnappedIntRect(replacedContentRect(overriddenIntrinsicSize));
}

bool LayoutVideo::shouldDisplayVideo() const
{
    return !videoElement()->shouldDisplayPosterImage();
}

void LayoutVideo::paintReplaced(const PaintInfo& paintInfo, const LayoutPoint& paintOffset) const
{
    VideoPainter(*this).paintReplaced(paintInfo, paintOffset);
}

void LayoutVideo::layout()
{
    updatePlayer();
    LayoutMedia::layout();
}

HTMLVideoElement* LayoutVideo::videoElement() const
{
    return toHTMLVideoElement(node());
}

void LayoutVideo::updateFromElement()
{
    LayoutMedia::updateFromElement();
    updatePlayer();

    // If the DisplayMode of the video changed, then we need to paint.
    setShouldDoFullPaintInvalidation();
}

void LayoutVideo::updatePlayer()
{
    updateIntrinsicSize();

    WebMediaPlayer* mediaPlayer = mediaElement()->webMediaPlayer();
    if (!mediaPlayer)
        return;

    if (!videoElement()->inActiveDocument())
        return;

    videoElement()->setNeedsCompositingUpdate();
}

LayoutUnit LayoutVideo::computeReplacedLogicalWidth(ShouldComputePreferred shouldComputePreferred) const
{
    return LayoutReplaced::computeReplacedLogicalWidth(shouldComputePreferred);
}

LayoutUnit LayoutVideo::computeReplacedLogicalHeight(LayoutUnit estimatedUsedWidth) const
{
    return LayoutReplaced::computeReplacedLogicalHeight(estimatedUsedWidth);
}

LayoutUnit LayoutVideo::minimumReplacedHeight() const
{
    return LayoutReplaced::minimumReplacedHeight();
}

bool LayoutVideo::supportsAcceleratedRendering() const
{
    return !!mediaElement()->platformLayer();
}

static const LayoutBlock* layoutObjectPlaceholder(const LayoutObject* layoutObject)
{
    LayoutObject* parent = layoutObject->parent();
    if (!parent)
        return nullptr;

    LayoutFullScreen* fullScreen = parent->isLayoutFullScreen() ? toLayoutFullScreen(parent) : 0;
    if (!fullScreen)
        return nullptr;

    return fullScreen->placeholder();
}

LayoutUnit LayoutVideo::offsetLeft(const Element* parent) const
{
    if (const LayoutBlock* block = layoutObjectPlaceholder(this))
        return block->offsetLeft(parent);
    return LayoutMedia::offsetLeft(parent);
}

LayoutUnit LayoutVideo::offsetTop(const Element* parent) const
{
    if (const LayoutBlock* block = layoutObjectPlaceholder(this))
        return block->offsetTop(parent);
    return LayoutMedia::offsetTop(parent);
}

LayoutUnit LayoutVideo::offsetWidth() const
{
    if (const LayoutBlock* block = layoutObjectPlaceholder(this))
        return block->offsetWidth();
    return LayoutMedia::offsetWidth();
}

LayoutUnit LayoutVideo::offsetHeight() const
{
    if (const LayoutBlock* block = layoutObjectPlaceholder(this))
        return block->offsetHeight();
    return LayoutMedia::offsetHeight();
}

CompositingReasons LayoutVideo::additionalCompositingReasons() const
{
    HTMLMediaElement* element = toHTMLMediaElement(node());
    if (element->isFullscreen() && element->usesOverlayFullscreenVideo())
        return CompositingReasonVideo;

    if (shouldDisplayVideo() && supportsAcceleratedRendering())
        return CompositingReasonVideo;

    return CompositingReasonNone;
}

} // namespace blink