layout/generic/nsHTMLCanvasFrame.cpp@b8a032363ba2
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
1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 /* This Source Code Form is subject to the terms of the Mozilla Public
3 * License, v. 2.0. If a copy of the MPL was not distributed with this
4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6 /* rendering object for the HTML <canvas> element */
8 #include "nsHTMLCanvasFrame.h"
10 #include "nsGkAtoms.h"
11 #include "mozilla/dom/HTMLCanvasElement.h"
12 #include "nsDisplayList.h"
13 #include "nsLayoutUtils.h"
14 #include "Layers.h"
15 #include "ActiveLayerTracker.h"
17 #include <algorithm>
19 using namespace mozilla;
20 using namespace mozilla::dom;
21 using namespace mozilla::layers;
23 class nsDisplayCanvas : public nsDisplayItem {
24 public:
25 nsDisplayCanvas(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame)
26 : nsDisplayItem(aBuilder, aFrame)
27 {
28 MOZ_COUNT_CTOR(nsDisplayCanvas);
29 }
30 #ifdef NS_BUILD_REFCNT_LOGGING
31 virtual ~nsDisplayCanvas() {
32 MOZ_COUNT_DTOR(nsDisplayCanvas);
33 }
34 #endif
36 NS_DISPLAY_DECL_NAME("nsDisplayCanvas", TYPE_CANVAS)
38 virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
39 bool* aSnap) MOZ_OVERRIDE {
40 *aSnap = false;
41 nsIFrame* f = Frame();
42 HTMLCanvasElement *canvas =
43 HTMLCanvasElement::FromContent(f->GetContent());
44 nsRegion result;
45 if (canvas->GetIsOpaque()) {
46 result = GetBounds(aBuilder, aSnap);
47 }
48 return result;
49 }
51 virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder,
52 bool* aSnap) MOZ_OVERRIDE {
53 *aSnap = true;
54 nsHTMLCanvasFrame* f = static_cast<nsHTMLCanvasFrame*>(Frame());
55 return f->GetInnerArea() + ToReferenceFrame();
56 }
58 virtual already_AddRefed<Layer> BuildLayer(nsDisplayListBuilder* aBuilder,
59 LayerManager* aManager,
60 const ContainerLayerParameters& aContainerParameters) MOZ_OVERRIDE
61 {
62 return static_cast<nsHTMLCanvasFrame*>(mFrame)->
63 BuildLayer(aBuilder, aManager, this, aContainerParameters);
64 }
65 virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder,
66 LayerManager* aManager,
67 const ContainerLayerParameters& aParameters) MOZ_OVERRIDE
68 {
69 if (HTMLCanvasElement::FromContent(mFrame->GetContent())->ShouldForceInactiveLayer(aManager))
70 return LAYER_INACTIVE;
72 // If compositing is cheap, just do that
73 if (aManager->IsCompositingCheap() ||
74 ActiveLayerTracker::IsContentActive(mFrame))
75 return mozilla::LAYER_ACTIVE;
77 return LAYER_INACTIVE;
78 }
79 };
82 nsIFrame*
83 NS_NewHTMLCanvasFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
84 {
85 return new (aPresShell) nsHTMLCanvasFrame(aContext);
86 }
88 NS_QUERYFRAME_HEAD(nsHTMLCanvasFrame)
89 NS_QUERYFRAME_ENTRY(nsHTMLCanvasFrame)
90 NS_QUERYFRAME_TAIL_INHERITING(nsContainerFrame)
92 NS_IMPL_FRAMEARENA_HELPERS(nsHTMLCanvasFrame)
94 void
95 nsHTMLCanvasFrame::Init(nsIContent* aContent,
96 nsIFrame* aParent,
97 nsIFrame* aPrevInFlow)
98 {
99 nsContainerFrame::Init(aContent, aParent, aPrevInFlow);
101 // We can fill in the canvas before the canvas frame is created, in
102 // which case we never get around to marking the content as active. Therefore,
103 // we mark it active here when we create the frame.
104 ActiveLayerTracker::NotifyContentChange(this);
105 }
107 nsHTMLCanvasFrame::~nsHTMLCanvasFrame()
108 {
109 }
111 nsIntSize
112 nsHTMLCanvasFrame::GetCanvasSize()
113 {
114 nsIntSize size(0,0);
115 HTMLCanvasElement *canvas =
116 HTMLCanvasElement::FromContentOrNull(GetContent());
117 if (canvas) {
118 size = canvas->GetSize();
119 } else {
120 NS_NOTREACHED("couldn't get canvas size");
121 }
123 return size;
124 }
126 /* virtual */ nscoord
127 nsHTMLCanvasFrame::GetMinWidth(nsRenderingContext *aRenderingContext)
128 {
129 // XXX The caller doesn't account for constraints of the height,
130 // min-height, and max-height properties.
131 nscoord result = nsPresContext::CSSPixelsToAppUnits(GetCanvasSize().width);
132 DISPLAY_MIN_WIDTH(this, result);
133 return result;
134 }
136 /* virtual */ nscoord
137 nsHTMLCanvasFrame::GetPrefWidth(nsRenderingContext *aRenderingContext)
138 {
139 // XXX The caller doesn't account for constraints of the height,
140 // min-height, and max-height properties.
141 nscoord result = nsPresContext::CSSPixelsToAppUnits(GetCanvasSize().width);
142 DISPLAY_PREF_WIDTH(this, result);
143 return result;
144 }
146 /* virtual */ nsSize
147 nsHTMLCanvasFrame::GetIntrinsicRatio()
148 {
149 nsIntSize size(GetCanvasSize());
150 return nsSize(nsPresContext::CSSPixelsToAppUnits(size.width),
151 nsPresContext::CSSPixelsToAppUnits(size.height));
152 }
154 /* virtual */ nsSize
155 nsHTMLCanvasFrame::ComputeSize(nsRenderingContext *aRenderingContext,
156 nsSize aCBSize, nscoord aAvailableWidth,
157 nsSize aMargin, nsSize aBorder, nsSize aPadding,
158 uint32_t aFlags)
159 {
160 nsIntSize size = GetCanvasSize();
162 IntrinsicSize intrinsicSize;
163 intrinsicSize.width.SetCoordValue(nsPresContext::CSSPixelsToAppUnits(size.width));
164 intrinsicSize.height.SetCoordValue(nsPresContext::CSSPixelsToAppUnits(size.height));
166 nsSize intrinsicRatio = GetIntrinsicRatio(); // won't actually be used
168 return nsLayoutUtils::ComputeSizeWithIntrinsicDimensions(
169 aRenderingContext, this,
170 intrinsicSize, intrinsicRatio, aCBSize,
171 aMargin, aBorder, aPadding);
172 }
174 nsresult
175 nsHTMLCanvasFrame::Reflow(nsPresContext* aPresContext,
176 nsHTMLReflowMetrics& aMetrics,
177 const nsHTMLReflowState& aReflowState,
178 nsReflowStatus& aStatus)
179 {
180 DO_GLOBAL_REFLOW_COUNT("nsHTMLCanvasFrame");
181 DISPLAY_REFLOW(aPresContext, this, aReflowState, aMetrics, aStatus);
182 NS_FRAME_TRACE(NS_FRAME_TRACE_CALLS,
183 ("enter nsHTMLCanvasFrame::Reflow: availSize=%d,%d",
184 aReflowState.AvailableWidth(), aReflowState.AvailableHeight()));
186 NS_PRECONDITION(mState & NS_FRAME_IN_REFLOW, "frame is not in reflow");
188 aStatus = NS_FRAME_COMPLETE;
190 aMetrics.Width() = aReflowState.ComputedWidth();
191 aMetrics.Height() = aReflowState.ComputedHeight();
193 // stash this away so we can compute our inner area later
194 mBorderPadding = aReflowState.ComputedPhysicalBorderPadding();
196 aMetrics.Width() += mBorderPadding.left + mBorderPadding.right;
197 aMetrics.Height() += mBorderPadding.top + mBorderPadding.bottom;
199 if (GetPrevInFlow()) {
200 nscoord y = GetContinuationOffset(&aMetrics.Width());
201 aMetrics.Height() -= y + mBorderPadding.top;
202 aMetrics.Height() = std::max(0, aMetrics.Height());
203 }
205 aMetrics.SetOverflowAreasToDesiredBounds();
206 FinishAndStoreOverflow(&aMetrics);
208 // Reflow the single anon block child.
209 nsReflowStatus childStatus;
210 nsSize availSize(aReflowState.ComputedWidth(), NS_UNCONSTRAINEDSIZE);
211 nsIFrame* childFrame = mFrames.FirstChild();
212 NS_ASSERTION(!childFrame->GetNextSibling(), "HTML canvas should have 1 kid");
213 nsHTMLReflowMetrics childDesiredSize(aReflowState.GetWritingMode(), aMetrics.mFlags);
214 nsHTMLReflowState childReflowState(aPresContext, aReflowState, childFrame,
215 availSize);
216 ReflowChild(childFrame, aPresContext, childDesiredSize, childReflowState,
217 0, 0, 0, childStatus, nullptr);
218 FinishReflowChild(childFrame, aPresContext, childDesiredSize,
219 &childReflowState, 0, 0, 0);
221 NS_FRAME_TRACE(NS_FRAME_TRACE_CALLS,
222 ("exit nsHTMLCanvasFrame::Reflow: size=%d,%d",
223 aMetrics.Width(), aMetrics.Height()));
224 NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aMetrics);
226 return NS_OK;
227 }
229 // FIXME taken from nsImageFrame, but then had splittable frame stuff
230 // removed. That needs to be fixed.
231 nsRect
232 nsHTMLCanvasFrame::GetInnerArea() const
233 {
234 nsRect r;
235 r.x = mBorderPadding.left;
236 r.y = mBorderPadding.top;
237 r.width = mRect.width - mBorderPadding.left - mBorderPadding.right;
238 r.height = mRect.height - mBorderPadding.top - mBorderPadding.bottom;
239 return r;
240 }
242 already_AddRefed<Layer>
243 nsHTMLCanvasFrame::BuildLayer(nsDisplayListBuilder* aBuilder,
244 LayerManager* aManager,
245 nsDisplayItem* aItem,
246 const ContainerLayerParameters& aContainerParameters)
247 {
248 nsRect area = GetContentRect() - GetPosition() + aItem->ToReferenceFrame();
249 HTMLCanvasElement* element = static_cast<HTMLCanvasElement*>(GetContent());
250 nsIntSize canvasSize = GetCanvasSize();
252 nsPresContext* presContext = PresContext();
253 element->HandlePrintCallback(presContext->Type());
255 if (canvasSize.width <= 0 || canvasSize.height <= 0 || area.IsEmpty())
256 return nullptr;
258 CanvasLayer* oldLayer = static_cast<CanvasLayer*>
259 (aManager->GetLayerBuilder()->GetLeafLayerFor(aBuilder, aItem));
260 nsRefPtr<CanvasLayer> layer = element->GetCanvasLayer(aBuilder, oldLayer, aManager);
261 if (!layer)
262 return nullptr;
264 gfxRect r = gfxRect(presContext->AppUnitsToGfxUnits(area.x),
265 presContext->AppUnitsToGfxUnits(area.y),
266 presContext->AppUnitsToGfxUnits(area.width),
267 presContext->AppUnitsToGfxUnits(area.height));
269 // Transform the canvas into the right place
270 gfx::Matrix transform;
271 gfxPoint p = r.TopLeft() + aContainerParameters.mOffset;
272 transform.Translate(p.x, p.y);
273 transform.Scale(r.Width()/canvasSize.width, r.Height()/canvasSize.height);
274 layer->SetBaseTransform(gfx::Matrix4x4::From2D(transform));
275 layer->SetFilter(nsLayoutUtils::GetGraphicsFilterForFrame(this));
276 layer->SetVisibleRegion(nsIntRect(0, 0, canvasSize.width, canvasSize.height));
278 return layer.forget();
279 }
281 void
282 nsHTMLCanvasFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
283 const nsRect& aDirtyRect,
284 const nsDisplayListSet& aLists)
285 {
286 if (!IsVisibleForPainting(aBuilder))
287 return;
289 DisplayBorderBackgroundOutline(aBuilder, aLists);
291 DisplayListClipState::AutoClipContainingBlockDescendantsToContentBox
292 clip(aBuilder, this, DisplayListClipState::ASSUME_DRAWING_RESTRICTED_TO_CONTENT_RECT);
294 aLists.Content()->AppendNewToTop(
295 new (aBuilder) nsDisplayCanvas(aBuilder, this));
297 DisplaySelectionOverlay(aBuilder, aLists.Content(),
298 nsISelectionDisplay::DISPLAY_IMAGES);
299 }
301 nsIAtom*
302 nsHTMLCanvasFrame::GetType() const
303 {
304 return nsGkAtoms::HTMLCanvasFrame;
305 }
307 // get the offset into the content area of the image where aImg starts if it is a continuation.
308 // from nsImageFrame
309 nscoord
310 nsHTMLCanvasFrame::GetContinuationOffset(nscoord* aWidth) const
311 {
312 nscoord offset = 0;
313 if (aWidth) {
314 *aWidth = 0;
315 }
317 if (GetPrevInFlow()) {
318 for (nsIFrame* prevInFlow = GetPrevInFlow() ; prevInFlow; prevInFlow = prevInFlow->GetPrevInFlow()) {
319 nsRect rect = prevInFlow->GetRect();
320 if (aWidth) {
321 *aWidth = rect.width;
322 }
323 offset += rect.height;
324 }
325 offset -= mBorderPadding.top;
326 offset = std::max(0, offset);
327 }
328 return offset;
329 }
331 #ifdef ACCESSIBILITY
332 a11y::AccType
333 nsHTMLCanvasFrame::AccessibleType()
334 {
335 return a11y::eHTMLCanvasType;
336 }
337 #endif
339 #ifdef DEBUG_FRAME_DUMP
340 nsresult
341 nsHTMLCanvasFrame::GetFrameName(nsAString& aResult) const
342 {
343 return MakeFrameName(NS_LITERAL_STRING("HTMLCanvas"), aResult);
344 }
345 #endif
