The Tor Browser: layout/generic/nsVideoFrame.cpp@b8a032363ba2 (annotated)

layout/generic/nsVideoFrame.cpp@b8a032363ba2 (annotated)

layout/generic/nsVideoFrame.cpp

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* vim:set ts=2 sw=2 sts=2 et cindent: */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 /* rendering object for the HTML <video> element */
 #include "nsVideoFrame.h"
 #include "nsCOMPtr.h"
 #include "nsGkAtoms.h"
 #include "mozilla/dom/HTMLVideoElement.h"
 #include "nsIDOMHTMLVideoElement.h"
 #include "nsIDOMHTMLImageElement.h"
 #include "nsDisplayList.h"
 #include "nsGenericHTMLElement.h"
 #include "nsPresContext.h"
 #include "nsContentCreatorFunctions.h"
 #include "nsBoxLayoutState.h"
 #include "nsBoxFrame.h"
 #include "nsImageFrame.h"
 #include "nsIImageLoadingContent.h"
 #include "nsContentUtils.h"
 #include "ImageContainer.h"
 #include "ImageLayers.h"
 #include "nsContentList.h"
 #include <algorithm>
 using namespace mozilla;
 using namespace mozilla::layers;
 using namespace mozilla::dom;
 using namespace mozilla::gfx;
 nsIFrame*
 NS_NewHTMLVideoFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
 {
   return new (aPresShell) nsVideoFrame(aContext);
 }
 NS_IMPL_FRAMEARENA_HELPERS(nsVideoFrame)
 nsVideoFrame::nsVideoFrame(nsStyleContext* aContext) :
   nsContainerFrame(aContext)
 {
 }
 nsVideoFrame::~nsVideoFrame()
 {
 }
 NS_QUERYFRAME_HEAD(nsVideoFrame)
   NS_QUERYFRAME_ENTRY(nsVideoFrame)
   NS_QUERYFRAME_ENTRY(nsIAnonymousContentCreator)
 NS_QUERYFRAME_TAIL_INHERITING(nsContainerFrame)
 nsresult
 nsVideoFrame::CreateAnonymousContent(nsTArray<ContentInfo>& aElements)
 {
   nsNodeInfoManager *nodeInfoManager = GetContent()->GetCurrentDoc()->NodeInfoManager();
   nsCOMPtr<nsINodeInfo> nodeInfo;
   Element *element;
   if (HasVideoElement()) {
     // Create an anonymous image element as a child to hold the poster
     // image. We may not have a poster image now, but one could be added
     // before we load, or on a subsequent load.
     nodeInfo = nodeInfoManager->GetNodeInfo(nsGkAtoms::img,
                                             nullptr,
                                             kNameSpaceID_XHTML,
                                             nsIDOMNode::ELEMENT_NODE);
     NS_ENSURE_TRUE(nodeInfo, NS_ERROR_OUT_OF_MEMORY);
     element = NS_NewHTMLImageElement(nodeInfo.forget());
     mPosterImage = element;
     NS_ENSURE_TRUE(mPosterImage, NS_ERROR_OUT_OF_MEMORY);
     // Set the nsImageLoadingContent::ImageState() to 0. This means that the
     // image will always report its state as 0, so it will never be reframed
     // to show frames for loading or the broken image icon. This is important,
     // as the image is native anonymous, and so can't be reframed (currently).
     nsCOMPtr<nsIImageLoadingContent> imgContent = do_QueryInterface(mPosterImage);
     NS_ENSURE_TRUE(imgContent, NS_ERROR_FAILURE);
     imgContent->ForceImageState(true, 0);
     // And now have it update its internal state
     element->UpdateState(false);
     UpdatePosterSource(false);
     if (!aElements.AppendElement(mPosterImage))
       return NS_ERROR_OUT_OF_MEMORY;
     // Set up the caption overlay div for showing any TextTrack data
     nodeInfo = nodeInfoManager->GetNodeInfo(nsGkAtoms::div,
                                             nullptr,
                                             kNameSpaceID_XHTML,
                                             nsIDOMNode::ELEMENT_NODE);
     NS_ENSURE_TRUE(nodeInfo, NS_ERROR_OUT_OF_MEMORY);
     mCaptionDiv = NS_NewHTMLDivElement(nodeInfo.forget());
     NS_ENSURE_TRUE(mCaptionDiv, NS_ERROR_OUT_OF_MEMORY);
     nsGenericHTMLElement* div = static_cast<nsGenericHTMLElement*>(mCaptionDiv.get());
     div->SetClassName(NS_LITERAL_STRING("caption-box"));
     if (!aElements.AppendElement(mCaptionDiv))
       return NS_ERROR_OUT_OF_MEMORY;
   }
   // Set up "videocontrols" XUL element which will be XBL-bound to the
   // actual controls.
   nodeInfo = nodeInfoManager->GetNodeInfo(nsGkAtoms::videocontrols,
                                           nullptr,
                                           kNameSpaceID_XUL,
                                           nsIDOMNode::ELEMENT_NODE);
   NS_ENSURE_TRUE(nodeInfo, NS_ERROR_OUT_OF_MEMORY);
   NS_TrustedNewXULElement(getter_AddRefs(mVideoControls), nodeInfo.forget());
   if (!aElements.AppendElement(mVideoControls))
     return NS_ERROR_OUT_OF_MEMORY;
   return NS_OK;
 }
 void
 nsVideoFrame::AppendAnonymousContentTo(nsBaseContentList& aElements,
                                        uint32_t aFliter)
 {
   aElements.MaybeAppendElement(mPosterImage);
   aElements.MaybeAppendElement(mVideoControls);
   aElements.MaybeAppendElement(mCaptionDiv);
 }
 void
 nsVideoFrame::DestroyFrom(nsIFrame* aDestructRoot)
 {
   nsContentUtils::DestroyAnonymousContent(&mCaptionDiv);
   nsContentUtils::DestroyAnonymousContent(&mVideoControls);
   nsContentUtils::DestroyAnonymousContent(&mPosterImage);
   nsContainerFrame::DestroyFrom(aDestructRoot);
 }
 bool
 nsVideoFrame::IsLeaf() const
 {
   return true;
 }
 // Return the largest rectangle that fits in aRect and has the
 // same aspect ratio as aRatio, centered at the center of aRect
 static gfxRect
 CorrectForAspectRatio(const gfxRect& aRect, const nsIntSize& aRatio)
 {
   NS_ASSERTION(aRatio.width > 0 && aRatio.height > 0 && !aRect.IsEmpty(),
                "Nothing to draw");
   // Choose scale factor that scales aRatio to just fit into aRect
   gfxFloat scale =
     std::min(aRect.Width()/aRatio.width, aRect.Height()/aRatio.height);
   gfxSize scaledRatio(scale*aRatio.width, scale*aRatio.height);
   gfxPoint topLeft((aRect.Width() - scaledRatio.width)/2,
                    (aRect.Height() - scaledRatio.height)/2);
   return gfxRect(aRect.TopLeft() + topLeft, scaledRatio);
 }
 already_AddRefed<Layer>
 nsVideoFrame::BuildLayer(nsDisplayListBuilder* aBuilder,
                          LayerManager* aManager,
                          nsDisplayItem* aItem,
                          const ContainerLayerParameters& aContainerParameters)
 {
   nsRect area = GetContentRect() - GetPosition() + aItem->ToReferenceFrame();
   HTMLVideoElement* element = static_cast<HTMLVideoElement*>(GetContent());
   nsIntSize videoSize;
   if (NS_FAILED(element->GetVideoSize(&videoSize)) || area.IsEmpty()) {
     return nullptr;
   }
   nsRefPtr<ImageContainer> container = element->GetImageContainer();
   if (!container)
     return nullptr;
   // Retrieve the size of the decoded video frame, before being scaled
   // by pixel aspect ratio.
   mozilla::gfx::IntSize frameSize = container->GetCurrentSize();
   if (frameSize.width == 0 || frameSize.height == 0) {
     // No image, or zero-sized image. No point creating a layer.
     return nullptr;
   }
   // Compute the rectangle in which to paint the video. We need to use
   // the largest rectangle that fills our content-box and has the
   // correct aspect ratio.
   nsPresContext* presContext = PresContext();
   gfxRect r = gfxRect(presContext->AppUnitsToGfxUnits(area.x),
                       presContext->AppUnitsToGfxUnits(area.y),
                       presContext->AppUnitsToGfxUnits(area.width),
                       presContext->AppUnitsToGfxUnits(area.height));
   r = CorrectForAspectRatio(r, videoSize);
   r.Round();
   if (r.IsEmpty()) {
     return nullptr;
   }
   IntSize scaleHint(static_cast<int32_t>(r.Width()),
                     static_cast<int32_t>(r.Height()));
   container->SetScaleHint(scaleHint);
   nsRefPtr<ImageLayer> layer = static_cast<ImageLayer*>
     (aManager->GetLayerBuilder()->GetLeafLayerFor(aBuilder, aItem));
   if (!layer) {
     layer = aManager->CreateImageLayer();
     if (!layer)
       return nullptr;
   }
   layer->SetContainer(container);
   layer->SetFilter(nsLayoutUtils::GetGraphicsFilterForFrame(this));
   layer->SetContentFlags(Layer::CONTENT_OPAQUE);
   // Set a transform on the layer to draw the video in the right place
   gfx::Matrix transform;
   gfxPoint p = r.TopLeft() + aContainerParameters.mOffset;
   transform.Translate(p.x, p.y);
   transform.Scale(r.Width()/frameSize.width, r.Height()/frameSize.height);
   layer->SetBaseTransform(gfx::Matrix4x4::From2D(transform));
   layer->SetVisibleRegion(nsIntRect(0, 0, frameSize.width, frameSize.height));
   nsRefPtr<Layer> result = layer.forget();
   return result.forget();
 }
 class DispatchResizeToControls : public nsRunnable
 {
 public:
   DispatchResizeToControls(nsIContent* aContent)
     : mContent(aContent) {}
   NS_IMETHOD Run() MOZ_OVERRIDE {
     nsContentUtils::DispatchTrustedEvent(mContent->OwnerDoc(), mContent,
                                          NS_LITERAL_STRING("resizevideocontrols"),
                                          false, false);
     return NS_OK;
   }
   nsCOMPtr<nsIContent> mContent;
 };
 nsresult
 nsVideoFrame::Reflow(nsPresContext*           aPresContext,
                      nsHTMLReflowMetrics&     aMetrics,
                      const nsHTMLReflowState& aReflowState,
                      nsReflowStatus&          aStatus)
 {
   DO_GLOBAL_REFLOW_COUNT("nsVideoFrame");
   DISPLAY_REFLOW(aPresContext, this, aReflowState, aMetrics, aStatus);
   NS_FRAME_TRACE(NS_FRAME_TRACE_CALLS,
                   ("enter nsVideoFrame::Reflow: availSize=%d,%d",
                   aReflowState.AvailableWidth(), aReflowState.AvailableHeight()));
   NS_PRECONDITION(mState & NS_FRAME_IN_REFLOW, "frame is not in reflow");
   aStatus = NS_FRAME_COMPLETE;
   aMetrics.Width() = aReflowState.ComputedWidth();
   aMetrics.Height() = aReflowState.ComputedHeight();
   // stash this away so we can compute our inner area later
   mBorderPadding   = aReflowState.ComputedPhysicalBorderPadding();
   aMetrics.Width() += mBorderPadding.left + mBorderPadding.right;
   aMetrics.Height() += mBorderPadding.top + mBorderPadding.bottom;
   // Reflow the child frames. We may have up to two, an image frame
   // which is the poster, and a box frame, which is the video controls.
   for (nsIFrame *child = mFrames.FirstChild();
        child;
        child = child->GetNextSibling()) {
     if (child->GetContent() == mPosterImage) {
       // Reflow the poster frame.
       nsImageFrame* imageFrame = static_cast<nsImageFrame*>(child);
       nsHTMLReflowMetrics kidDesiredSize(aReflowState);
       nsSize availableSize = nsSize(aReflowState.AvailableWidth(),
                                     aReflowState.AvailableHeight());
       nsHTMLReflowState kidReflowState(aPresContext,
                                        aReflowState,
                                        imageFrame,
                                        availableSize,
                                        aMetrics.Width(),
                                        aMetrics.Height());
       uint32_t posterHeight, posterWidth;
       nsSize scaledPosterSize(0, 0);
       nsSize computedArea(aReflowState.ComputedWidth(), aReflowState.ComputedHeight());
       nsPoint posterTopLeft(0, 0);
       nsCOMPtr<nsIDOMHTMLImageElement> posterImage = do_QueryInterface(mPosterImage);
       NS_ENSURE_TRUE(posterImage, NS_ERROR_FAILURE);
       posterImage->GetNaturalHeight(&posterHeight);
       posterImage->GetNaturalWidth(&posterWidth);
       if (ShouldDisplayPoster() && posterHeight && posterWidth) {
         gfxFloat scale =
           std::min(static_cast<float>(computedArea.width)/nsPresContext::CSSPixelsToAppUnits(static_cast<float>(posterWidth)),
                  static_cast<float>(computedArea.height)/nsPresContext::CSSPixelsToAppUnits(static_cast<float>(posterHeight)));
         gfxSize scaledRatio = gfxSize(scale*posterWidth, scale*posterHeight);
         scaledPosterSize.width = nsPresContext::CSSPixelsToAppUnits(static_cast<float>(scaledRatio.width));
         scaledPosterSize.height = nsPresContext::CSSPixelsToAppUnits(static_cast<int32_t>(scaledRatio.height));
       }
       kidReflowState.SetComputedWidth(scaledPosterSize.width);
       kidReflowState.SetComputedHeight(scaledPosterSize.height);
       posterTopLeft.x = ((computedArea.width - scaledPosterSize.width) / 2) + mBorderPadding.left;
       posterTopLeft.y = ((computedArea.height - scaledPosterSize.height) / 2) + mBorderPadding.top;
       ReflowChild(imageFrame, aPresContext, kidDesiredSize, kidReflowState,
                         posterTopLeft.x, posterTopLeft.y, 0, aStatus);
       FinishReflowChild(imageFrame, aPresContext, kidDesiredSize, &kidReflowState,
                         posterTopLeft.x, posterTopLeft.y, 0);
     } else if (child->GetContent() == mVideoControls) {
       // Reflow the video controls frame.
       nsBoxLayoutState boxState(PresContext(), aReflowState.rendContext);
       nsSize size = child->GetSize();
       nsBoxFrame::LayoutChildAt(boxState,
                                 child,
                                 nsRect(mBorderPadding.left,
                                        mBorderPadding.top,
                                        aReflowState.ComputedWidth(),
                                        aReflowState.ComputedHeight()));
       if (child->GetSize() != size) {
         nsRefPtr<nsRunnable> event = new DispatchResizeToControls(child->GetContent());
         nsContentUtils::AddScriptRunner(event);
       }
     } else if (child->GetContent() == mCaptionDiv) {
       // Reflow to caption div
       nsHTMLReflowMetrics kidDesiredSize(aReflowState);
       nsSize availableSize = nsSize(aReflowState.AvailableWidth(),
                                     aReflowState.AvailableHeight());
       nsHTMLReflowState kidReflowState(aPresContext,
                                        aReflowState,
                                        child,
                                        availableSize,
                                        aMetrics.Width(),
                                        aMetrics.Height());
       nsSize size(aReflowState.ComputedWidth(), aReflowState.ComputedHeight());
       size.width -= kidReflowState.ComputedPhysicalBorderPadding().LeftRight();
       size.height -= kidReflowState.ComputedPhysicalBorderPadding().TopBottom();
       kidReflowState.SetComputedWidth(std::max(size.width, 0));
       kidReflowState.SetComputedHeight(std::max(size.height, 0));
       ReflowChild(child, aPresContext, kidDesiredSize, kidReflowState,
                   mBorderPadding.left, mBorderPadding.top, 0, aStatus);
       FinishReflowChild(child, aPresContext,
                         kidDesiredSize, &kidReflowState,
                         mBorderPadding.left, mBorderPadding.top, 0);
     }
   }
   aMetrics.SetOverflowAreasToDesiredBounds();
   FinishAndStoreOverflow(&aMetrics);
   NS_FRAME_TRACE(NS_FRAME_TRACE_CALLS,
                   ("exit nsVideoFrame::Reflow: size=%d,%d",
                   aMetrics.Width(), aMetrics.Height()));
   NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aMetrics);
   return NS_OK;
 }
 class nsDisplayVideo : public nsDisplayItem {
 public:
   nsDisplayVideo(nsDisplayListBuilder* aBuilder, nsVideoFrame* aFrame)
     : nsDisplayItem(aBuilder, aFrame)
   {
     MOZ_COUNT_CTOR(nsDisplayVideo);
   }
 #ifdef NS_BUILD_REFCNT_LOGGING
   virtual ~nsDisplayVideo() {
     MOZ_COUNT_DTOR(nsDisplayVideo);
   }
 #endif
   NS_DISPLAY_DECL_NAME("Video", TYPE_VIDEO)
   // It would be great if we could override GetOpaqueRegion to return nonempty here,
   // but it's probably not safe to do so in general. Video frames are
   // updated asynchronously from decoder threads, and it's possible that
   // we might have an opaque video frame when GetOpaqueRegion is called, but
   // when we come to paint, the video frame is transparent or has gone
   // away completely (e.g. because of a decoder error). The problem would
   // be especially acute if we have off-main-thread rendering.
   virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) MOZ_OVERRIDE
   {
     *aSnap = true;
     nsIFrame* f = Frame();
     return f->GetContentRect() - f->GetPosition() + ToReferenceFrame();
   }
   virtual already_AddRefed<Layer> BuildLayer(nsDisplayListBuilder* aBuilder,
                                              LayerManager* aManager,
                                              const ContainerLayerParameters& aContainerParameters) MOZ_OVERRIDE
   {
     return static_cast<nsVideoFrame*>(mFrame)->BuildLayer(aBuilder, aManager, this, aContainerParameters);
   }
   virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder,
                                    LayerManager* aManager,
                                    const ContainerLayerParameters& aParameters) MOZ_OVERRIDE
   {
     if (aManager->IsCompositingCheap()) {
       // Since ImageLayers don't require additional memory of the
       // video frames we have to have anyway, we can't save much by
       // making layers inactive. Also, for many accelerated layer
       // managers calling imageContainer->GetCurrentAsSurface can be
       // very expensive. So just always be active when compositing is
       // cheap (i.e. hardware accelerated).
       return LAYER_ACTIVE;
     }
     HTMLMediaElement* elem =
       static_cast<HTMLMediaElement*>(mFrame->GetContent());
     return elem->IsPotentiallyPlaying() ? LAYER_ACTIVE_FORCE : LAYER_INACTIVE;
   }
 };
 void
 nsVideoFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
                                const nsRect&           aDirtyRect,
                                const nsDisplayListSet& aLists)
 {
   if (!IsVisibleForPainting(aBuilder))
     return;
   DO_GLOBAL_REFLOW_COUNT_DSP("nsVideoFrame");
   DisplayBorderBackgroundOutline(aBuilder, aLists);
   DisplayListClipState::AutoClipContainingBlockDescendantsToContentBox
     clip(aBuilder, this, DisplayListClipState::ASSUME_DRAWING_RESTRICTED_TO_CONTENT_RECT);
   if (HasVideoElement() && !ShouldDisplayPoster()) {
     aLists.Content()->AppendNewToTop(
       new (aBuilder) nsDisplayVideo(aBuilder, this));
   }
   // Add child frames to display list. We expect various children,
   // but only want to draw mPosterImage conditionally. Others we
   // always add to the display list.
   for (nsIFrame *child = mFrames.FirstChild();
        child;
        child = child->GetNextSibling()) {
     if (child->GetContent() != mPosterImage || ShouldDisplayPoster()) {
       child->BuildDisplayListForStackingContext(aBuilder,
                                                 aDirtyRect - child->GetOffsetTo(this),
                                                 aLists.Content());
     } else if (child->GetType() == nsGkAtoms::boxFrame) {
       child->BuildDisplayListForStackingContext(aBuilder,
                                                 aDirtyRect - child->GetOffsetTo(this),
                                                 aLists.Content());
     }
   }
 }
 nsIAtom*
 nsVideoFrame::GetType() const
 {
   return nsGkAtoms::HTMLVideoFrame;
 }
 #ifdef ACCESSIBILITY
 a11y::AccType
 nsVideoFrame::AccessibleType()
 {
   return a11y::eHTMLMediaType;
 }
 #endif
 #ifdef DEBUG_FRAME_DUMP
 nsresult
 nsVideoFrame::GetFrameName(nsAString& aResult) const
 {
   return MakeFrameName(NS_LITERAL_STRING("HTMLVideo"), aResult);
 }
 #endif
 nsSize nsVideoFrame::ComputeSize(nsRenderingContext *aRenderingContext,
                                      nsSize aCBSize,
                                      nscoord aAvailableWidth,
                                      nsSize aMargin,
                                      nsSize aBorder,
                                      nsSize aPadding,
                                      uint32_t aFlags)
 {
   nsSize size = GetVideoIntrinsicSize(aRenderingContext);
   IntrinsicSize intrinsicSize;
   intrinsicSize.width.SetCoordValue(size.width);
   intrinsicSize.height.SetCoordValue(size.height);
   // Only video elements have an intrinsic ratio.
   nsSize intrinsicRatio = HasVideoElement() ? size : nsSize(0, 0);
   return nsLayoutUtils::ComputeSizeWithIntrinsicDimensions(aRenderingContext,
                                                            this,
                                                            intrinsicSize,
                                                            intrinsicRatio,
                                                            aCBSize,
                                                            aMargin,
                                                            aBorder,
                                                            aPadding);
 }
 nscoord nsVideoFrame::GetMinWidth(nsRenderingContext *aRenderingContext)
 {
   nscoord result = GetVideoIntrinsicSize(aRenderingContext).width;
   DISPLAY_MIN_WIDTH(this, result);
   return result;
 }
 nscoord nsVideoFrame::GetPrefWidth(nsRenderingContext *aRenderingContext)
 {
   nscoord result = GetVideoIntrinsicSize(aRenderingContext).width;
   DISPLAY_PREF_WIDTH(this, result);
   return result;
 }
 nsSize nsVideoFrame::GetIntrinsicRatio()
 {
   if (!HasVideoElement()) {
     // Audio elements have no intrinsic ratio.
     return nsSize(0, 0);
   }
   return GetVideoIntrinsicSize(nullptr);
 }
 bool nsVideoFrame::ShouldDisplayPoster()
 {
   if (!HasVideoElement())
     return false;
   HTMLVideoElement* element = static_cast<HTMLVideoElement*>(GetContent());
   if (element->GetPlayedOrSeeked() && HasVideoData())
     return false;
   nsCOMPtr<nsIImageLoadingContent> imgContent = do_QueryInterface(mPosterImage);
   NS_ENSURE_TRUE(imgContent, false);
   nsCOMPtr<imgIRequest> request;
   nsresult res = imgContent->GetRequest(nsIImageLoadingContent::CURRENT_REQUEST,
                                         getter_AddRefs(request));
   if (NS_FAILED(res) || !request) {
     return false;
   }
   uint32_t status = 0;
   res = request->GetImageStatus(&status);
   if (NS_FAILED(res) || (status & imgIRequest::STATUS_ERROR))
     return false;
   return true;
 }
 nsSize
 nsVideoFrame::GetVideoIntrinsicSize(nsRenderingContext *aRenderingContext)
 {
   // Defaulting size to 300x150 if no size given.
   nsIntSize size(300, 150);
   if (!HasVideoElement()) {
     if (!mFrames.FirstChild()) {
       return nsSize(0, 0);
     }
     // Ask the controls frame what its preferred height is
     nsBoxLayoutState boxState(PresContext(), aRenderingContext, 0);
     nscoord prefHeight = mFrames.LastChild()->GetPrefSize(boxState).height;
     return nsSize(nsPresContext::CSSPixelsToAppUnits(size.width), prefHeight);
   }
   HTMLVideoElement* element = static_cast<HTMLVideoElement*>(GetContent());
   if (NS_FAILED(element->GetVideoSize(&size)) && ShouldDisplayPoster()) {
     // Use the poster image frame's size.
     nsIFrame *child = mPosterImage->GetPrimaryFrame();
     nsImageFrame* imageFrame = do_QueryFrame(child);
     nsSize imgsize;
     if (NS_SUCCEEDED(imageFrame->GetIntrinsicImageSize(imgsize))) {
       return imgsize;
     }
   }
   return nsSize(nsPresContext::CSSPixelsToAppUnits(size.width),
                 nsPresContext::CSSPixelsToAppUnits(size.height));
 }
 void
 nsVideoFrame::UpdatePosterSource(bool aNotify)
 {
   NS_ASSERTION(HasVideoElement(), "Only call this on <video> elements.");
   HTMLVideoElement* element = static_cast<HTMLVideoElement*>(GetContent());
   if (element->HasAttr(kNameSpaceID_None, nsGkAtoms::poster)) {
     nsAutoString posterStr;
     element->GetPoster(posterStr);
     mPosterImage->SetAttr(kNameSpaceID_None,
                           nsGkAtoms::src,
                           posterStr,
                           aNotify);
   } else {
     mPosterImage->UnsetAttr(kNameSpaceID_None, nsGkAtoms::poster, aNotify);
   }
 }
 nsresult
 nsVideoFrame::AttributeChanged(int32_t aNameSpaceID,
                                nsIAtom* aAttribute,
                                int32_t aModType)
 {
   if (aAttribute == nsGkAtoms::poster && HasVideoElement()) {
     UpdatePosterSource(true);
   }
   return nsContainerFrame::AttributeChanged(aNameSpaceID,
                                             aAttribute,
                                             aModType);
 }
 bool nsVideoFrame::HasVideoElement() {
   nsCOMPtr<nsIDOMHTMLVideoElement> videoDomElement = do_QueryInterface(mContent);
   return videoDomElement != nullptr;
 }
 bool nsVideoFrame::HasVideoData()
 {
   if (!HasVideoElement())
     return false;
   HTMLVideoElement* element = static_cast<HTMLVideoElement*>(GetContent());
   nsIntSize size(0, 0);
   element->GetVideoSize(&size);
   return size != nsIntSize(0,0);
 }

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layout/generic/nsVideoFrame.cpp@b8a032363ba2 (annotated)

layout/generic/nsVideoFrame.cpp