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

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

layout/generic/nsHTMLCanvasFrame.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 -*- */
 /* 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 <canvas> element */
 #include "nsHTMLCanvasFrame.h"
 #include "nsGkAtoms.h"
 #include "mozilla/dom/HTMLCanvasElement.h"
 #include "nsDisplayList.h"
 #include "nsLayoutUtils.h"
 #include "Layers.h"
 #include "ActiveLayerTracker.h"
 #include <algorithm>
 using namespace mozilla;
 using namespace mozilla::dom;
 using namespace mozilla::layers;
 class nsDisplayCanvas : public nsDisplayItem {
 public:
   nsDisplayCanvas(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame)
     : nsDisplayItem(aBuilder, aFrame)
   {
     MOZ_COUNT_CTOR(nsDisplayCanvas);
   }
 #ifdef NS_BUILD_REFCNT_LOGGING
   virtual ~nsDisplayCanvas() {
     MOZ_COUNT_DTOR(nsDisplayCanvas);
   }
 #endif
   NS_DISPLAY_DECL_NAME("nsDisplayCanvas", TYPE_CANVAS)
   virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
                                    bool* aSnap) MOZ_OVERRIDE {
     *aSnap = false;
     nsIFrame* f = Frame();
     HTMLCanvasElement *canvas =
       HTMLCanvasElement::FromContent(f->GetContent());
     nsRegion result;
     if (canvas->GetIsOpaque()) {
       result = GetBounds(aBuilder, aSnap);
     }
     return result;
   }
   virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder,
                            bool* aSnap) MOZ_OVERRIDE {
     *aSnap = true;
     nsHTMLCanvasFrame* f = static_cast<nsHTMLCanvasFrame*>(Frame());
     return f->GetInnerArea() + ToReferenceFrame();
   }
   virtual already_AddRefed<Layer> BuildLayer(nsDisplayListBuilder* aBuilder,
                                              LayerManager* aManager,
                                              const ContainerLayerParameters& aContainerParameters) MOZ_OVERRIDE
   {
     return static_cast<nsHTMLCanvasFrame*>(mFrame)->
       BuildLayer(aBuilder, aManager, this, aContainerParameters);
   }
   virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder,
                                    LayerManager* aManager,
                                    const ContainerLayerParameters& aParameters) MOZ_OVERRIDE
   {
     if (HTMLCanvasElement::FromContent(mFrame->GetContent())->ShouldForceInactiveLayer(aManager))
       return LAYER_INACTIVE;
     // If compositing is cheap, just do that
     if (aManager->IsCompositingCheap() ||
         ActiveLayerTracker::IsContentActive(mFrame))
       return mozilla::LAYER_ACTIVE;
     return LAYER_INACTIVE;
   }
 };
 nsIFrame*
 NS_NewHTMLCanvasFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
 {
   return new (aPresShell) nsHTMLCanvasFrame(aContext);
 }
 NS_QUERYFRAME_HEAD(nsHTMLCanvasFrame)
   NS_QUERYFRAME_ENTRY(nsHTMLCanvasFrame)
 NS_QUERYFRAME_TAIL_INHERITING(nsContainerFrame)
 NS_IMPL_FRAMEARENA_HELPERS(nsHTMLCanvasFrame)
 void
 nsHTMLCanvasFrame::Init(nsIContent* aContent,
                         nsIFrame*   aParent,
                         nsIFrame*   aPrevInFlow)
 {
   nsContainerFrame::Init(aContent, aParent, aPrevInFlow);
   // We can fill in the canvas before the canvas frame is created, in
   // which case we never get around to marking the content as active. Therefore,
   // we mark it active here when we create the frame.
   ActiveLayerTracker::NotifyContentChange(this);
 }
 nsHTMLCanvasFrame::~nsHTMLCanvasFrame()
 {
 }
 nsIntSize
 nsHTMLCanvasFrame::GetCanvasSize()
 {
   nsIntSize size(0,0);
   HTMLCanvasElement *canvas =
     HTMLCanvasElement::FromContentOrNull(GetContent());
   if (canvas) {
     size = canvas->GetSize();
   } else {
     NS_NOTREACHED("couldn't get canvas size");
   }
   return size;
 }
 /* virtual */ nscoord
 nsHTMLCanvasFrame::GetMinWidth(nsRenderingContext *aRenderingContext)
 {
   // XXX The caller doesn't account for constraints of the height,
   // min-height, and max-height properties.
   nscoord result = nsPresContext::CSSPixelsToAppUnits(GetCanvasSize().width);
   DISPLAY_MIN_WIDTH(this, result);
   return result;
 }
 /* virtual */ nscoord
 nsHTMLCanvasFrame::GetPrefWidth(nsRenderingContext *aRenderingContext)
 {
   // XXX The caller doesn't account for constraints of the height,
   // min-height, and max-height properties.
   nscoord result = nsPresContext::CSSPixelsToAppUnits(GetCanvasSize().width);
   DISPLAY_PREF_WIDTH(this, result);
   return result;
 }
 /* virtual */ nsSize
 nsHTMLCanvasFrame::GetIntrinsicRatio()
 {
   nsIntSize size(GetCanvasSize());
   return nsSize(nsPresContext::CSSPixelsToAppUnits(size.width),
                 nsPresContext::CSSPixelsToAppUnits(size.height));
 }
 /* virtual */ nsSize
 nsHTMLCanvasFrame::ComputeSize(nsRenderingContext *aRenderingContext,
                                nsSize aCBSize, nscoord aAvailableWidth,
                                nsSize aMargin, nsSize aBorder, nsSize aPadding,
                                uint32_t aFlags)
 {
   nsIntSize size = GetCanvasSize();
   IntrinsicSize intrinsicSize;
   intrinsicSize.width.SetCoordValue(nsPresContext::CSSPixelsToAppUnits(size.width));
   intrinsicSize.height.SetCoordValue(nsPresContext::CSSPixelsToAppUnits(size.height));
   nsSize intrinsicRatio = GetIntrinsicRatio(); // won't actually be used
   return nsLayoutUtils::ComputeSizeWithIntrinsicDimensions(
                             aRenderingContext, this,
                             intrinsicSize, intrinsicRatio, aCBSize,
                             aMargin, aBorder, aPadding);
 }
 nsresult
 nsHTMLCanvasFrame::Reflow(nsPresContext*           aPresContext,
                           nsHTMLReflowMetrics&     aMetrics,
                           const nsHTMLReflowState& aReflowState,
                           nsReflowStatus&          aStatus)
 {
   DO_GLOBAL_REFLOW_COUNT("nsHTMLCanvasFrame");
   DISPLAY_REFLOW(aPresContext, this, aReflowState, aMetrics, aStatus);
   NS_FRAME_TRACE(NS_FRAME_TRACE_CALLS,
                   ("enter nsHTMLCanvasFrame::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;
   if (GetPrevInFlow()) {
     nscoord y = GetContinuationOffset(&aMetrics.Width());
     aMetrics.Height() -= y + mBorderPadding.top;
     aMetrics.Height() = std::max(0, aMetrics.Height());
   }
   aMetrics.SetOverflowAreasToDesiredBounds();
   FinishAndStoreOverflow(&aMetrics);
   // Reflow the single anon block child.
   nsReflowStatus childStatus;
   nsSize availSize(aReflowState.ComputedWidth(), NS_UNCONSTRAINEDSIZE);
   nsIFrame* childFrame = mFrames.FirstChild();
   NS_ASSERTION(!childFrame->GetNextSibling(), "HTML canvas should have 1 kid");
   nsHTMLReflowMetrics childDesiredSize(aReflowState.GetWritingMode(), aMetrics.mFlags);
   nsHTMLReflowState childReflowState(aPresContext, aReflowState, childFrame,
                                      availSize);
   ReflowChild(childFrame, aPresContext, childDesiredSize, childReflowState,
 , 0, 0, childStatus, nullptr);
   FinishReflowChild(childFrame, aPresContext, childDesiredSize,
                     &childReflowState, 0, 0, 0);
   NS_FRAME_TRACE(NS_FRAME_TRACE_CALLS,
                   ("exit nsHTMLCanvasFrame::Reflow: size=%d,%d",
                   aMetrics.Width(), aMetrics.Height()));
   NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aMetrics);
   return NS_OK;
 }
 // FIXME taken from nsImageFrame, but then had splittable frame stuff
 // removed.  That needs to be fixed.
 nsRect
 nsHTMLCanvasFrame::GetInnerArea() const
 {
   nsRect r;
   r.x = mBorderPadding.left;
   r.y = mBorderPadding.top;
   r.width = mRect.width - mBorderPadding.left - mBorderPadding.right;
   r.height = mRect.height - mBorderPadding.top - mBorderPadding.bottom;
   return r;
 }
 already_AddRefed<Layer>
 nsHTMLCanvasFrame::BuildLayer(nsDisplayListBuilder* aBuilder,
                               LayerManager* aManager,
                               nsDisplayItem* aItem,
                               const ContainerLayerParameters& aContainerParameters)
 {
   nsRect area = GetContentRect() - GetPosition() + aItem->ToReferenceFrame();
   HTMLCanvasElement* element = static_cast<HTMLCanvasElement*>(GetContent());
   nsIntSize canvasSize = GetCanvasSize();
   nsPresContext* presContext = PresContext();
   element->HandlePrintCallback(presContext->Type());
   if (canvasSize.width <= 0 || canvasSize.height <= 0 || area.IsEmpty())
     return nullptr;
   CanvasLayer* oldLayer = static_cast<CanvasLayer*>
     (aManager->GetLayerBuilder()->GetLeafLayerFor(aBuilder, aItem));
   nsRefPtr<CanvasLayer> layer = element->GetCanvasLayer(aBuilder, oldLayer, aManager);
   if (!layer)
     return nullptr;
   gfxRect r = gfxRect(presContext->AppUnitsToGfxUnits(area.x),
                       presContext->AppUnitsToGfxUnits(area.y),
                       presContext->AppUnitsToGfxUnits(area.width),
                       presContext->AppUnitsToGfxUnits(area.height));
   // Transform the canvas into the right place
   gfx::Matrix transform;
   gfxPoint p = r.TopLeft() + aContainerParameters.mOffset;
   transform.Translate(p.x, p.y);
   transform.Scale(r.Width()/canvasSize.width, r.Height()/canvasSize.height);
   layer->SetBaseTransform(gfx::Matrix4x4::From2D(transform));
   layer->SetFilter(nsLayoutUtils::GetGraphicsFilterForFrame(this));
   layer->SetVisibleRegion(nsIntRect(0, 0, canvasSize.width, canvasSize.height));
   return layer.forget();
 }
 void
 nsHTMLCanvasFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
                                     const nsRect&           aDirtyRect,
                                     const nsDisplayListSet& aLists)
 {
   if (!IsVisibleForPainting(aBuilder))
     return;
   DisplayBorderBackgroundOutline(aBuilder, aLists);
   DisplayListClipState::AutoClipContainingBlockDescendantsToContentBox
     clip(aBuilder, this, DisplayListClipState::ASSUME_DRAWING_RESTRICTED_TO_CONTENT_RECT);
   aLists.Content()->AppendNewToTop(
     new (aBuilder) nsDisplayCanvas(aBuilder, this));
   DisplaySelectionOverlay(aBuilder, aLists.Content(),
                           nsISelectionDisplay::DISPLAY_IMAGES);
 }
 nsIAtom*
 nsHTMLCanvasFrame::GetType() const
 {
   return nsGkAtoms::HTMLCanvasFrame;
 }
 // get the offset into the content area of the image where aImg starts if it is a continuation.
 // from nsImageFrame
 nscoord
 nsHTMLCanvasFrame::GetContinuationOffset(nscoord* aWidth) const
 {
   nscoord offset = 0;
   if (aWidth) {
     *aWidth = 0;
   }
   if (GetPrevInFlow()) {
     for (nsIFrame* prevInFlow = GetPrevInFlow() ; prevInFlow; prevInFlow = prevInFlow->GetPrevInFlow()) {
       nsRect rect = prevInFlow->GetRect();
       if (aWidth) {
         *aWidth = rect.width;
       }
       offset += rect.height;
     }
     offset -= mBorderPadding.top;
     offset = std::max(0, offset);
   }
   return offset;
 }
 #ifdef ACCESSIBILITY
 a11y::AccType
 nsHTMLCanvasFrame::AccessibleType()
 {
   return a11y::eHTMLCanvasType;
 }
 #endif
 #ifdef DEBUG_FRAME_DUMP
 nsresult
 nsHTMLCanvasFrame::GetFrameName(nsAString& aResult) const
 {
   return MakeFrameName(NS_LITERAL_STRING("HTMLCanvas"), aResult);
 }
 #endif

The Tor Browser / annotate

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

layout/generic/nsHTMLCanvasFrame.cpp