1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/layout/generic/nsHTMLCanvasFrame.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,346 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +/* rendering object for the HTML <canvas> element */
1.10 +
1.11 +#include "nsHTMLCanvasFrame.h"
1.12 +
1.13 +#include "nsGkAtoms.h"
1.14 +#include "mozilla/dom/HTMLCanvasElement.h"
1.15 +#include "nsDisplayList.h"
1.16 +#include "nsLayoutUtils.h"
1.17 +#include "Layers.h"
1.18 +#include "ActiveLayerTracker.h"
1.19 +
1.20 +#include <algorithm>
1.21 +
1.22 +using namespace mozilla;
1.23 +using namespace mozilla::dom;
1.24 +using namespace mozilla::layers;
1.25 +
1.26 +class nsDisplayCanvas : public nsDisplayItem {
1.27 +public:
1.28 + nsDisplayCanvas(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame)
1.29 + : nsDisplayItem(aBuilder, aFrame)
1.30 + {
1.31 + MOZ_COUNT_CTOR(nsDisplayCanvas);
1.32 + }
1.33 +#ifdef NS_BUILD_REFCNT_LOGGING
1.34 + virtual ~nsDisplayCanvas() {
1.35 + MOZ_COUNT_DTOR(nsDisplayCanvas);
1.36 + }
1.37 +#endif
1.38 +
1.39 + NS_DISPLAY_DECL_NAME("nsDisplayCanvas", TYPE_CANVAS)
1.40 +
1.41 + virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
1.42 + bool* aSnap) MOZ_OVERRIDE {
1.43 + *aSnap = false;
1.44 + nsIFrame* f = Frame();
1.45 + HTMLCanvasElement *canvas =
1.46 + HTMLCanvasElement::FromContent(f->GetContent());
1.47 + nsRegion result;
1.48 + if (canvas->GetIsOpaque()) {
1.49 + result = GetBounds(aBuilder, aSnap);
1.50 + }
1.51 + return result;
1.52 + }
1.53 +
1.54 + virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder,
1.55 + bool* aSnap) MOZ_OVERRIDE {
1.56 + *aSnap = true;
1.57 + nsHTMLCanvasFrame* f = static_cast<nsHTMLCanvasFrame*>(Frame());
1.58 + return f->GetInnerArea() + ToReferenceFrame();
1.59 + }
1.60 +
1.61 + virtual already_AddRefed<Layer> BuildLayer(nsDisplayListBuilder* aBuilder,
1.62 + LayerManager* aManager,
1.63 + const ContainerLayerParameters& aContainerParameters) MOZ_OVERRIDE
1.64 + {
1.65 + return static_cast<nsHTMLCanvasFrame*>(mFrame)->
1.66 + BuildLayer(aBuilder, aManager, this, aContainerParameters);
1.67 + }
1.68 + virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder,
1.69 + LayerManager* aManager,
1.70 + const ContainerLayerParameters& aParameters) MOZ_OVERRIDE
1.71 + {
1.72 + if (HTMLCanvasElement::FromContent(mFrame->GetContent())->ShouldForceInactiveLayer(aManager))
1.73 + return LAYER_INACTIVE;
1.74 +
1.75 + // If compositing is cheap, just do that
1.76 + if (aManager->IsCompositingCheap() ||
1.77 + ActiveLayerTracker::IsContentActive(mFrame))
1.78 + return mozilla::LAYER_ACTIVE;
1.79 +
1.80 + return LAYER_INACTIVE;
1.81 + }
1.82 +};
1.83 +
1.84 +
1.85 +nsIFrame*
1.86 +NS_NewHTMLCanvasFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
1.87 +{
1.88 + return new (aPresShell) nsHTMLCanvasFrame(aContext);
1.89 +}
1.90 +
1.91 +NS_QUERYFRAME_HEAD(nsHTMLCanvasFrame)
1.92 + NS_QUERYFRAME_ENTRY(nsHTMLCanvasFrame)
1.93 +NS_QUERYFRAME_TAIL_INHERITING(nsContainerFrame)
1.94 +
1.95 +NS_IMPL_FRAMEARENA_HELPERS(nsHTMLCanvasFrame)
1.96 +
1.97 +void
1.98 +nsHTMLCanvasFrame::Init(nsIContent* aContent,
1.99 + nsIFrame* aParent,
1.100 + nsIFrame* aPrevInFlow)
1.101 +{
1.102 + nsContainerFrame::Init(aContent, aParent, aPrevInFlow);
1.103 +
1.104 + // We can fill in the canvas before the canvas frame is created, in
1.105 + // which case we never get around to marking the content as active. Therefore,
1.106 + // we mark it active here when we create the frame.
1.107 + ActiveLayerTracker::NotifyContentChange(this);
1.108 +}
1.109 +
1.110 +nsHTMLCanvasFrame::~nsHTMLCanvasFrame()
1.111 +{
1.112 +}
1.113 +
1.114 +nsIntSize
1.115 +nsHTMLCanvasFrame::GetCanvasSize()
1.116 +{
1.117 + nsIntSize size(0,0);
1.118 + HTMLCanvasElement *canvas =
1.119 + HTMLCanvasElement::FromContentOrNull(GetContent());
1.120 + if (canvas) {
1.121 + size = canvas->GetSize();
1.122 + } else {
1.123 + NS_NOTREACHED("couldn't get canvas size");
1.124 + }
1.125 +
1.126 + return size;
1.127 +}
1.128 +
1.129 +/* virtual */ nscoord
1.130 +nsHTMLCanvasFrame::GetMinWidth(nsRenderingContext *aRenderingContext)
1.131 +{
1.132 + // XXX The caller doesn't account for constraints of the height,
1.133 + // min-height, and max-height properties.
1.134 + nscoord result = nsPresContext::CSSPixelsToAppUnits(GetCanvasSize().width);
1.135 + DISPLAY_MIN_WIDTH(this, result);
1.136 + return result;
1.137 +}
1.138 +
1.139 +/* virtual */ nscoord
1.140 +nsHTMLCanvasFrame::GetPrefWidth(nsRenderingContext *aRenderingContext)
1.141 +{
1.142 + // XXX The caller doesn't account for constraints of the height,
1.143 + // min-height, and max-height properties.
1.144 + nscoord result = nsPresContext::CSSPixelsToAppUnits(GetCanvasSize().width);
1.145 + DISPLAY_PREF_WIDTH(this, result);
1.146 + return result;
1.147 +}
1.148 +
1.149 +/* virtual */ nsSize
1.150 +nsHTMLCanvasFrame::GetIntrinsicRatio()
1.151 +{
1.152 + nsIntSize size(GetCanvasSize());
1.153 + return nsSize(nsPresContext::CSSPixelsToAppUnits(size.width),
1.154 + nsPresContext::CSSPixelsToAppUnits(size.height));
1.155 +}
1.156 +
1.157 +/* virtual */ nsSize
1.158 +nsHTMLCanvasFrame::ComputeSize(nsRenderingContext *aRenderingContext,
1.159 + nsSize aCBSize, nscoord aAvailableWidth,
1.160 + nsSize aMargin, nsSize aBorder, nsSize aPadding,
1.161 + uint32_t aFlags)
1.162 +{
1.163 + nsIntSize size = GetCanvasSize();
1.164 +
1.165 + IntrinsicSize intrinsicSize;
1.166 + intrinsicSize.width.SetCoordValue(nsPresContext::CSSPixelsToAppUnits(size.width));
1.167 + intrinsicSize.height.SetCoordValue(nsPresContext::CSSPixelsToAppUnits(size.height));
1.168 +
1.169 + nsSize intrinsicRatio = GetIntrinsicRatio(); // won't actually be used
1.170 +
1.171 + return nsLayoutUtils::ComputeSizeWithIntrinsicDimensions(
1.172 + aRenderingContext, this,
1.173 + intrinsicSize, intrinsicRatio, aCBSize,
1.174 + aMargin, aBorder, aPadding);
1.175 +}
1.176 +
1.177 +nsresult
1.178 +nsHTMLCanvasFrame::Reflow(nsPresContext* aPresContext,
1.179 + nsHTMLReflowMetrics& aMetrics,
1.180 + const nsHTMLReflowState& aReflowState,
1.181 + nsReflowStatus& aStatus)
1.182 +{
1.183 + DO_GLOBAL_REFLOW_COUNT("nsHTMLCanvasFrame");
1.184 + DISPLAY_REFLOW(aPresContext, this, aReflowState, aMetrics, aStatus);
1.185 + NS_FRAME_TRACE(NS_FRAME_TRACE_CALLS,
1.186 + ("enter nsHTMLCanvasFrame::Reflow: availSize=%d,%d",
1.187 + aReflowState.AvailableWidth(), aReflowState.AvailableHeight()));
1.188 +
1.189 + NS_PRECONDITION(mState & NS_FRAME_IN_REFLOW, "frame is not in reflow");
1.190 +
1.191 + aStatus = NS_FRAME_COMPLETE;
1.192 +
1.193 + aMetrics.Width() = aReflowState.ComputedWidth();
1.194 + aMetrics.Height() = aReflowState.ComputedHeight();
1.195 +
1.196 + // stash this away so we can compute our inner area later
1.197 + mBorderPadding = aReflowState.ComputedPhysicalBorderPadding();
1.198 +
1.199 + aMetrics.Width() += mBorderPadding.left + mBorderPadding.right;
1.200 + aMetrics.Height() += mBorderPadding.top + mBorderPadding.bottom;
1.201 +
1.202 + if (GetPrevInFlow()) {
1.203 + nscoord y = GetContinuationOffset(&aMetrics.Width());
1.204 + aMetrics.Height() -= y + mBorderPadding.top;
1.205 + aMetrics.Height() = std::max(0, aMetrics.Height());
1.206 + }
1.207 +
1.208 + aMetrics.SetOverflowAreasToDesiredBounds();
1.209 + FinishAndStoreOverflow(&aMetrics);
1.210 +
1.211 + // Reflow the single anon block child.
1.212 + nsReflowStatus childStatus;
1.213 + nsSize availSize(aReflowState.ComputedWidth(), NS_UNCONSTRAINEDSIZE);
1.214 + nsIFrame* childFrame = mFrames.FirstChild();
1.215 + NS_ASSERTION(!childFrame->GetNextSibling(), "HTML canvas should have 1 kid");
1.216 + nsHTMLReflowMetrics childDesiredSize(aReflowState.GetWritingMode(), aMetrics.mFlags);
1.217 + nsHTMLReflowState childReflowState(aPresContext, aReflowState, childFrame,
1.218 + availSize);
1.219 + ReflowChild(childFrame, aPresContext, childDesiredSize, childReflowState,
1.220 + 0, 0, 0, childStatus, nullptr);
1.221 + FinishReflowChild(childFrame, aPresContext, childDesiredSize,
1.222 + &childReflowState, 0, 0, 0);
1.223 +
1.224 + NS_FRAME_TRACE(NS_FRAME_TRACE_CALLS,
1.225 + ("exit nsHTMLCanvasFrame::Reflow: size=%d,%d",
1.226 + aMetrics.Width(), aMetrics.Height()));
1.227 + NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aMetrics);
1.228 +
1.229 + return NS_OK;
1.230 +}
1.231 +
1.232 +// FIXME taken from nsImageFrame, but then had splittable frame stuff
1.233 +// removed. That needs to be fixed.
1.234 +nsRect
1.235 +nsHTMLCanvasFrame::GetInnerArea() const
1.236 +{
1.237 + nsRect r;
1.238 + r.x = mBorderPadding.left;
1.239 + r.y = mBorderPadding.top;
1.240 + r.width = mRect.width - mBorderPadding.left - mBorderPadding.right;
1.241 + r.height = mRect.height - mBorderPadding.top - mBorderPadding.bottom;
1.242 + return r;
1.243 +}
1.244 +
1.245 +already_AddRefed<Layer>
1.246 +nsHTMLCanvasFrame::BuildLayer(nsDisplayListBuilder* aBuilder,
1.247 + LayerManager* aManager,
1.248 + nsDisplayItem* aItem,
1.249 + const ContainerLayerParameters& aContainerParameters)
1.250 +{
1.251 + nsRect area = GetContentRect() - GetPosition() + aItem->ToReferenceFrame();
1.252 + HTMLCanvasElement* element = static_cast<HTMLCanvasElement*>(GetContent());
1.253 + nsIntSize canvasSize = GetCanvasSize();
1.254 +
1.255 + nsPresContext* presContext = PresContext();
1.256 + element->HandlePrintCallback(presContext->Type());
1.257 +
1.258 + if (canvasSize.width <= 0 || canvasSize.height <= 0 || area.IsEmpty())
1.259 + return nullptr;
1.260 +
1.261 + CanvasLayer* oldLayer = static_cast<CanvasLayer*>
1.262 + (aManager->GetLayerBuilder()->GetLeafLayerFor(aBuilder, aItem));
1.263 + nsRefPtr<CanvasLayer> layer = element->GetCanvasLayer(aBuilder, oldLayer, aManager);
1.264 + if (!layer)
1.265 + return nullptr;
1.266 +
1.267 + gfxRect r = gfxRect(presContext->AppUnitsToGfxUnits(area.x),
1.268 + presContext->AppUnitsToGfxUnits(area.y),
1.269 + presContext->AppUnitsToGfxUnits(area.width),
1.270 + presContext->AppUnitsToGfxUnits(area.height));
1.271 +
1.272 + // Transform the canvas into the right place
1.273 + gfx::Matrix transform;
1.274 + gfxPoint p = r.TopLeft() + aContainerParameters.mOffset;
1.275 + transform.Translate(p.x, p.y);
1.276 + transform.Scale(r.Width()/canvasSize.width, r.Height()/canvasSize.height);
1.277 + layer->SetBaseTransform(gfx::Matrix4x4::From2D(transform));
1.278 + layer->SetFilter(nsLayoutUtils::GetGraphicsFilterForFrame(this));
1.279 + layer->SetVisibleRegion(nsIntRect(0, 0, canvasSize.width, canvasSize.height));
1.280 +
1.281 + return layer.forget();
1.282 +}
1.283 +
1.284 +void
1.285 +nsHTMLCanvasFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
1.286 + const nsRect& aDirtyRect,
1.287 + const nsDisplayListSet& aLists)
1.288 +{
1.289 + if (!IsVisibleForPainting(aBuilder))
1.290 + return;
1.291 +
1.292 + DisplayBorderBackgroundOutline(aBuilder, aLists);
1.293 +
1.294 + DisplayListClipState::AutoClipContainingBlockDescendantsToContentBox
1.295 + clip(aBuilder, this, DisplayListClipState::ASSUME_DRAWING_RESTRICTED_TO_CONTENT_RECT);
1.296 +
1.297 + aLists.Content()->AppendNewToTop(
1.298 + new (aBuilder) nsDisplayCanvas(aBuilder, this));
1.299 +
1.300 + DisplaySelectionOverlay(aBuilder, aLists.Content(),
1.301 + nsISelectionDisplay::DISPLAY_IMAGES);
1.302 +}
1.303 +
1.304 +nsIAtom*
1.305 +nsHTMLCanvasFrame::GetType() const
1.306 +{
1.307 + return nsGkAtoms::HTMLCanvasFrame;
1.308 +}
1.309 +
1.310 +// get the offset into the content area of the image where aImg starts if it is a continuation.
1.311 +// from nsImageFrame
1.312 +nscoord
1.313 +nsHTMLCanvasFrame::GetContinuationOffset(nscoord* aWidth) const
1.314 +{
1.315 + nscoord offset = 0;
1.316 + if (aWidth) {
1.317 + *aWidth = 0;
1.318 + }
1.319 +
1.320 + if (GetPrevInFlow()) {
1.321 + for (nsIFrame* prevInFlow = GetPrevInFlow() ; prevInFlow; prevInFlow = prevInFlow->GetPrevInFlow()) {
1.322 + nsRect rect = prevInFlow->GetRect();
1.323 + if (aWidth) {
1.324 + *aWidth = rect.width;
1.325 + }
1.326 + offset += rect.height;
1.327 + }
1.328 + offset -= mBorderPadding.top;
1.329 + offset = std::max(0, offset);
1.330 + }
1.331 + return offset;
1.332 +}
1.333 +
1.334 +#ifdef ACCESSIBILITY
1.335 +a11y::AccType
1.336 +nsHTMLCanvasFrame::AccessibleType()
1.337 +{
1.338 + return a11y::eHTMLCanvasType;
1.339 +}
1.340 +#endif
1.341 +
1.342 +#ifdef DEBUG_FRAME_DUMP
1.343 +nsresult
1.344 +nsHTMLCanvasFrame::GetFrameName(nsAString& aResult) const
1.345 +{
1.346 + return MakeFrameName(NS_LITERAL_STRING("HTMLCanvas"), aResult);
1.347 +}
1.348 +#endif
1.349 +
