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1 /*
2  * Copyright (C) 2003, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
3  * Copyright (C) 2008-2009 Torch Mobile, Inc.
4  * Copyright (C) 2013 Google Inc. All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
16  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
19  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
22  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
23  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
25  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #ifndef GraphicsContext_h
29 #define GraphicsContext_h
30 
31 #include "platform/PlatformExport.h"
32 #include "platform/fonts/Font.h"
33 #include "platform/geometry/FloatRect.h"
34 #include "platform/graphics/DashArray.h"
35 #include "platform/graphics/DrawLooperBuilder.h"
36 #include "platform/graphics/ImageBufferSurface.h"
37 #include "platform/graphics/ImageFilter.h"
38 #include "platform/graphics/ImageOrientation.h"
39 #include "platform/graphics/GraphicsContextAnnotation.h"
40 #include "platform/graphics/GraphicsContextState.h"
41 #include "platform/graphics/RegionTracker.h"
42 #include "platform/graphics/skia/SkiaUtils.h"
43 #include "wtf/FastAllocBase.h"
44 #include "wtf/Forward.h"
45 #include "wtf/Noncopyable.h"
46 #include "wtf/PassOwnPtr.h"
47 
48 class SkBitmap;
49 class SkPaint;
50 class SkPath;
51 class SkRRect;
52 class SkTextBlob;
53 struct SkRect;
54 
55 namespace blink {
56 
57 class DisplayList;
58 class ImageBuffer;
59 class KURL;
60 
61 class PLATFORM_EXPORT GraphicsContext {
62     WTF_MAKE_NONCOPYABLE(GraphicsContext); WTF_MAKE_FAST_ALLOCATED;
63 public:
64     enum AntiAliasingMode {
65         NotAntiAliased,
66         AntiAliased
67     };
68     enum AccessMode {
69         ReadOnly,
70         ReadWrite
71     };
72 
73     enum DisabledMode {
74         NothingDisabled = 0, // Run as normal.
75         FullyDisabled = 1 // Do absolutely minimal work to remove the cost of the context from performance tests.
76     };
77 
78     // A 0 canvas is allowed, but in such cases the context must only have canvas
79     // related commands called when within a beginRecording/endRecording block.
80     // Furthermore, save/restore calls must be balanced any time the canvas is 0.
81     explicit GraphicsContext(SkCanvas*, DisabledMode = NothingDisabled);
82 
83     ~GraphicsContext();
84 
85     // Returns the canvas used for painting. Must not be called if painting is disabled.
86     // Accessing the backing canvas this way flushes all queued save ops,
87     // so it should be avoided. Use the corresponding draw/matrix/clip methods instead.
canvas()88     SkCanvas* canvas()
89     {
90         // Flush any pending saves.
91         realizeCanvasSave();
92 
93         return m_canvas;
94     }
canvas()95     const SkCanvas* canvas() const
96     {
97         return m_canvas;
98     }
99 
100     void resetCanvas(SkCanvas*);
101 
contextDisabled()102     bool contextDisabled() const { return m_disabledState; }
103 
104     // ---------- State management methods -----------------
105     void save();
106     void restore();
saveCount()107     unsigned saveCount() { return m_canvasStateStack.size(); }
108 #if ENABLE(ASSERT)
disableDestructionChecks()109     void disableDestructionChecks() { m_disableDestructionChecks = true; }
110 #endif
111 
112     void saveLayer(const SkRect* bounds, const SkPaint*);
113     void restoreLayer();
114 
hasStroke()115     bool hasStroke() const { return strokeStyle() != NoStroke && strokeThickness() > 0; }
116 
strokeThickness()117     float strokeThickness() const { return immutableState()->strokeData().thickness(); }
setStrokeThickness(float thickness)118     void setStrokeThickness(float thickness) { mutableState()->setStrokeThickness(thickness); }
119 
strokeStyle()120     StrokeStyle strokeStyle() const { return immutableState()->strokeData().style(); }
setStrokeStyle(StrokeStyle style)121     void setStrokeStyle(StrokeStyle style) { mutableState()->setStrokeStyle(style); }
122 
strokeColor()123     Color strokeColor() const { return immutableState()->strokeColor(); }
setStrokeColor(const Color & color)124     void setStrokeColor(const Color& color) { mutableState()->setStrokeColor(color); }
effectiveStrokeColor()125     SkColor effectiveStrokeColor() const { return immutableState()->effectiveStrokeColor(); }
126 
strokePattern()127     Pattern* strokePattern() const { return immutableState()->strokePattern(); }
128     void setStrokePattern(PassRefPtr<Pattern>);
129 
strokeGradient()130     Gradient* strokeGradient() const { return immutableState()->strokeGradient(); }
131     void setStrokeGradient(PassRefPtr<Gradient>);
132 
setLineCap(LineCap cap)133     void setLineCap(LineCap cap) { mutableState()->setLineCap(cap); }
setLineDash(const DashArray & dashes,float dashOffset)134     void setLineDash(const DashArray& dashes, float dashOffset) { mutableState()->setLineDash(dashes, dashOffset); }
setLineJoin(LineJoin join)135     void setLineJoin(LineJoin join) { mutableState()->setLineJoin(join); }
setMiterLimit(float limit)136     void setMiterLimit(float limit) { mutableState()->setMiterLimit(limit); }
137 
fillRule()138     WindRule fillRule() const { return immutableState()->fillRule(); }
setFillRule(WindRule fillRule)139     void setFillRule(WindRule fillRule) { mutableState()->setFillRule(fillRule); }
140 
fillColor()141     Color fillColor() const { return immutableState()->fillColor(); }
setFillColor(const Color & color)142     void setFillColor(const Color& color) { mutableState()->setFillColor(color); }
effectiveFillColor()143     SkColor effectiveFillColor() const { return immutableState()->effectiveFillColor(); }
144 
145     void setFillPattern(PassRefPtr<Pattern>);
fillPattern()146     Pattern* fillPattern() const { return immutableState()->fillPattern(); }
147 
148     void setFillGradient(PassRefPtr<Gradient>);
fillGradient()149     Gradient* fillGradient() const { return immutableState()->fillGradient(); }
150 
drawLooper()151     SkDrawLooper* drawLooper() const { return immutableState()->drawLooper(); }
152 
153     bool getTransformedClipBounds(FloatRect* bounds) const;
154     SkMatrix getTotalMatrix() const;
155 
setShouldAntialias(bool antialias)156     void setShouldAntialias(bool antialias) { mutableState()->setShouldAntialias(antialias); }
shouldAntialias()157     bool shouldAntialias() const { return immutableState()->shouldAntialias(); }
158 
159     // Disable the anti-aliasing optimization for scales/multiple-of-90-degrees
160     // rotations of thin ("hairline") images.
161     // Note: This will only be reliable when the device pixel scale/ratio is
162     // fixed (e.g. when drawing to context backed by an ImageBuffer).
disableAntialiasingOptimizationForHairlineImages()163     void disableAntialiasingOptimizationForHairlineImages() { ASSERT(!isRecording()); m_antialiasHairlineImages = true; }
shouldAntialiasHairlineImages()164     bool shouldAntialiasHairlineImages() const { return m_antialiasHairlineImages; }
165 
setShouldClampToSourceRect(bool clampToSourceRect)166     void setShouldClampToSourceRect(bool clampToSourceRect) { mutableState()->setShouldClampToSourceRect(clampToSourceRect); }
shouldClampToSourceRect()167     bool shouldClampToSourceRect() const { return immutableState()->shouldClampToSourceRect(); }
168 
169     // FIXME: the setter is only used once, at construction time; convert to a constructor param,
170     // and possibly consolidate with other flags (paintDisabled, isPrinting, ...)
setShouldSmoothFonts(bool smoothFonts)171     void setShouldSmoothFonts(bool smoothFonts) { m_shouldSmoothFonts = smoothFonts; }
shouldSmoothFonts()172     bool shouldSmoothFonts() const { return m_shouldSmoothFonts; }
173 
174     // Turn off LCD text for the paint if not supported on this context.
175     void adjustTextRenderMode(SkPaint*) const;
176     bool couldUseLCDRenderedText() const;
177 
setTextDrawingMode(TextDrawingModeFlags mode)178     void setTextDrawingMode(TextDrawingModeFlags mode) { mutableState()->setTextDrawingMode(mode); }
textDrawingMode()179     TextDrawingModeFlags textDrawingMode() const { return immutableState()->textDrawingMode(); }
180 
setAlphaAsFloat(float alpha)181     void setAlphaAsFloat(float alpha) { mutableState()->setAlphaAsFloat(alpha);}
getNormalizedAlpha()182     int getNormalizedAlpha() const
183     {
184         int alpha = immutableState()->alpha();
185         return alpha > 255 ? 255 : alpha;
186     }
187 
setImageInterpolationQuality(InterpolationQuality quality)188     void setImageInterpolationQuality(InterpolationQuality quality) { mutableState()->setInterpolationQuality(quality); }
imageInterpolationQuality()189     InterpolationQuality imageInterpolationQuality() const { return immutableState()->interpolationQuality(); }
190 
191     void setCompositeOperation(CompositeOperator, WebBlendMode = WebBlendModeNormal);
compositeOperation()192     CompositeOperator compositeOperation() const { return immutableState()->compositeOperator(); }
blendModeOperation()193     WebBlendMode blendModeOperation() const { return immutableState()->blendMode(); }
194 
195     // Speicy the device scale factor which may change the way document markers
196     // and fonts are rendered.
setDeviceScaleFactor(float factor)197     void setDeviceScaleFactor(float factor) { m_deviceScaleFactor = factor; }
deviceScaleFactor()198     float deviceScaleFactor() const { return m_deviceScaleFactor; }
199 
200     // If true we are (most likely) rendering to a web page and the
201     // canvas has been prepared with an opaque background. If false,
202     // the canvas may have transparency (as is the case when rendering
203     // to a canvas object).
setCertainlyOpaque(bool isOpaque)204     void setCertainlyOpaque(bool isOpaque) { m_isCertainlyOpaque = isOpaque; }
isCertainlyOpaque()205     bool isCertainlyOpaque() const { return m_isCertainlyOpaque; }
206 
207     // Returns if the context is a printing context instead of a display
208     // context. Bitmap shouldn't be resampled when printing to keep the best
209     // possible quality.
printing()210     bool printing() const { return m_printing; }
setPrinting(bool printing)211     void setPrinting(bool printing) { m_printing = printing; }
212 
isAccelerated()213     bool isAccelerated() const { return m_accelerated; }
setAccelerated(bool accelerated)214     void setAccelerated(bool accelerated) { m_accelerated = accelerated; }
215 
216     // The opaque region is empty until tracking is turned on.
217     // It is never clerared by the context.
218     enum RegionTrackingMode {
219         RegionTrackingDisabled = 0,
220         RegionTrackingOpaque,
221         RegionTrackingOverwrite
222     };
223     void setRegionTrackingMode(RegionTrackingMode);
regionTrackingEnabled()224     bool regionTrackingEnabled() { return m_regionTrackingMode != RegionTrackingDisabled; }
opaqueRegion()225     const RegionTracker& opaqueRegion() const { return m_trackedRegion; }
226 
227     // The text region is empty until tracking is turned on.
228     // It is never clerared by the context.
setTrackTextRegion(bool track)229     void setTrackTextRegion(bool track) { m_trackTextRegion = track; }
textRegion()230     const SkRect& textRegion() const { return m_textRegion; }
231 
annotationMode()232     AnnotationModeFlags annotationMode() const { return m_annotationMode; }
setAnnotationMode(const AnnotationModeFlags mode)233     void setAnnotationMode(const AnnotationModeFlags mode) { m_annotationMode = mode; }
234 
235     SkColorFilter* colorFilter() const;
236     void setColorFilter(ColorFilter);
237     // ---------- End state management methods -----------------
238 
239     // Get the contents of the image buffer
240     bool readPixels(const SkImageInfo&, void* pixels, size_t rowBytes, int x, int y);
241 
242     // Get the current fill style.
fillPaint()243     const SkPaint& fillPaint() const { return immutableState()->fillPaint(); }
244 
245     // Get the current stroke style.
strokePaint()246     const SkPaint& strokePaint() const { return immutableState()->strokePaint(); }
247 
248     // These draw methods will do both stroking and filling.
249     // FIXME: ...except drawRect(), which fills properly but always strokes
250     // using a 1-pixel stroke inset from the rect borders (of the correct
251     // stroke color).
252     void drawRect(const IntRect&);
253     void drawLine(const IntPoint&, const IntPoint&);
254     void drawConvexPolygon(size_t numPoints, const FloatPoint*, bool shouldAntialias = false);
255 
256     void fillPath(const Path&);
257     void strokePath(const Path&);
258 
259     void fillEllipse(const FloatRect&);
260     void strokeEllipse(const FloatRect&);
261 
262     void fillRect(const FloatRect&);
263     void fillRect(const FloatRect&, const Color&);
264     void fillRect(const FloatRect&, const Color&, CompositeOperator);
265     void fillRoundedRect(const IntRect&, const IntSize& topLeft, const IntSize& topRight, const IntSize& bottomLeft, const IntSize& bottomRight, const Color&);
266     void fillRoundedRect(const RoundedRect&, const Color&);
267 
268     void clearRect(const FloatRect&);
269 
270     void strokeRect(const FloatRect&);
271     void strokeRect(const FloatRect&, float lineWidth);
272 
273     void fillBetweenRoundedRects(const IntRect&, const IntSize& outerTopLeft, const IntSize& outerTopRight, const IntSize& outerBottomLeft, const IntSize& outerBottomRight,
274         const IntRect&, const IntSize& innerTopLeft, const IntSize& innerTopRight, const IntSize& innerBottomLeft, const IntSize& innerBottomRight, const Color&);
275     void fillBetweenRoundedRects(const RoundedRect&, const RoundedRect&, const Color&);
276 
277     void drawDisplayList(DisplayList*);
278 
279     void drawImage(Image*, const IntPoint&, CompositeOperator = CompositeSourceOver, RespectImageOrientationEnum = DoNotRespectImageOrientation);
280     void drawImage(Image*, const IntRect&, CompositeOperator = CompositeSourceOver, RespectImageOrientationEnum = DoNotRespectImageOrientation);
281     void drawImage(Image*, const FloatRect& destRect);
282     void drawImage(Image*, const FloatRect& destRect, const FloatRect& srcRect, CompositeOperator = CompositeSourceOver, RespectImageOrientationEnum = DoNotRespectImageOrientation);
283     void drawImage(Image*, const FloatRect& destRect, const FloatRect& srcRect, CompositeOperator, WebBlendMode, RespectImageOrientationEnum = DoNotRespectImageOrientation);
284 
285     void drawTiledImage(Image*, const IntRect& destRect, const IntPoint& srcPoint, const IntSize& tileSize,
286         CompositeOperator = CompositeSourceOver, WebBlendMode = WebBlendModeNormal, const IntSize& repeatSpacing = IntSize());
287     void drawTiledImage(Image*, const IntRect& destRect, const IntRect& srcRect,
288         const FloatSize& tileScaleFactor, Image::TileRule hRule = Image::StretchTile, Image::TileRule vRule = Image::StretchTile,
289         CompositeOperator = CompositeSourceOver);
290 
291     void drawImageBuffer(ImageBuffer*, const FloatRect& destRect, const FloatRect* srcRect = 0, CompositeOperator = CompositeSourceOver, WebBlendMode = WebBlendModeNormal);
292 
293     void drawPicture(PassRefPtr<SkPicture>, const FloatRect& dest, const FloatRect& src, CompositeOperator, WebBlendMode);
294 
295     // These methods write to the canvas and modify the opaque region, if tracked.
296     // Also drawLine(const IntPoint& point1, const IntPoint& point2) and fillRoundedRect
297     void writePixels(const SkImageInfo&, const void* pixels, size_t rowBytes, int x, int y);
298     void writePixels(const SkBitmap&, int x, int y);
299     void drawBitmap(const SkBitmap&, SkScalar, SkScalar, const SkPaint* = 0);
300     void drawBitmapRect(const SkBitmap&, const SkRect*, const SkRect&, const SkPaint* = 0);
301     void drawOval(const SkRect&, const SkPaint&);
302     void drawPath(const SkPath&, const SkPaint&);
303     // After drawing directly to the context's canvas, use this function to notify the context so
304     // it can track the opaque region.
305     // FIXME: this is still needed only because ImageSkia::paintSkBitmap() may need to notify for a
306     //        smaller rect than the one drawn to, due to its clipping logic.
307     void didDrawRect(const SkRect&, const SkPaint&, const SkBitmap* = 0);
308     void drawRect(const SkRect&, const SkPaint&);
309     void drawPosText(const void* text, size_t byteLength, const SkPoint pos[], const SkRect& textRect, const SkPaint&);
310     void drawPosTextH(const void* text, size_t byteLength, const SkScalar xpos[], SkScalar constY, const SkRect& textRect, const SkPaint&);
311     void drawTextBlob(const SkTextBlob*, const SkPoint& origin, const SkPaint&);
312 
clip(const IntRect & rect)313     void clip(const IntRect& rect) { clipRect(rect); }
clip(const FloatRect & rect)314     void clip(const FloatRect& rect) { clipRect(rect); }
315     void clipRoundedRect(const RoundedRect&, SkRegion::Op = SkRegion::kIntersect_Op);
clipOut(const IntRect & rect)316     void clipOut(const IntRect& rect) { clipRect(rect, NotAntiAliased, SkRegion::kDifference_Op); }
317     void clipOut(const Path&);
318     void clipOutRoundedRect(const RoundedRect&);
319     void clipPath(const Path&, WindRule = RULE_EVENODD);
320     void clipConvexPolygon(size_t numPoints, const FloatPoint*, bool antialias = true);
321     void clipRect(const SkRect&, AntiAliasingMode = NotAntiAliased, SkRegion::Op = SkRegion::kIntersect_Op);
322     // This clip function is used only by <canvas> code. It allows
323     // implementations to handle clipping on the canvas differently since
324     // the discipline is different.
325     void canvasClip(const Path&, WindRule = RULE_EVENODD);
326 
327     void drawText(const Font&, const TextRunPaintInfo&, const FloatPoint&);
328     void drawEmphasisMarks(const Font&, const TextRunPaintInfo&, const AtomicString& mark, const FloatPoint&);
329     void drawBidiText(const Font&, const TextRunPaintInfo&, const FloatPoint&, Font::CustomFontNotReadyAction = Font::DoNotPaintIfFontNotReady);
330     void drawHighlightForText(const Font&, const TextRun&, const FloatPoint&, int h, const Color& backgroundColor, int from = 0, int to = -1);
331 
332     void drawLineForText(const FloatPoint&, float width, bool printing);
333     enum DocumentMarkerLineStyle {
334         DocumentMarkerSpellingLineStyle,
335         DocumentMarkerGrammarLineStyle
336     };
337     void drawLineForDocumentMarker(const FloatPoint&, float width, DocumentMarkerLineStyle);
338 
339     void beginTransparencyLayer(float opacity, const FloatRect* = 0);
340     void beginLayer(float opacity, CompositeOperator, const FloatRect* = 0, ColorFilter = ColorFilterNone, ImageFilter* = 0);
341     void endLayer();
342 
343     void beginCull(const FloatRect&);
344     void endCull();
345 
346     // Instead of being dispatched to the active canvas, draw commands following beginRecording()
347     // are stored in a display list that can be replayed at a later time. Pass in the bounding
348     // rectangle for the content in the list.
349     void beginRecording(const FloatRect&, uint32_t = 0);
350     PassRefPtr<DisplayList> endRecording();
351 
352     bool hasShadow() const;
353     void setShadow(const FloatSize& offset, float blur, const Color&,
354         DrawLooperBuilder::ShadowTransformMode = DrawLooperBuilder::ShadowRespectsTransforms,
355         DrawLooperBuilder::ShadowAlphaMode = DrawLooperBuilder::ShadowRespectsAlpha);
clearShadow()356     void clearShadow() { clearDrawLooper(); }
357 
358     // It is assumed that this draw looper is used only for shadows
359     // (i.e. a draw looper is set if and only if there is a shadow).
360     // The builder passed into this method will be destroyed.
361     void setDrawLooper(PassOwnPtr<DrawLooperBuilder>);
362     void clearDrawLooper();
363 
364     void drawFocusRing(const Vector<IntRect>&, int width, int offset, const Color&);
365     void drawFocusRing(const Path&, int width, int offset, const Color&);
366 
367     enum Edge {
368         NoEdge = 0,
369         TopEdge = 1 << 1,
370         RightEdge = 1 << 2,
371         BottomEdge = 1 << 3,
372         LeftEdge = 1 << 4
373     };
374     typedef unsigned Edges;
375     void drawInnerShadow(const RoundedRect&, const Color& shadowColor, const IntSize shadowOffset, int shadowBlur, int shadowSpread, Edges clippedEdges = NoEdge);
376 
377     // ---------- Transformation methods -----------------
378     // Note that the getCTM method returns only the current transform from Blink's perspective,
379     // which is not the final transform used to place content on screen. It cannot be relied upon
380     // for testing where a point will appear on screen or how large it will be.
381     AffineTransform getCTM() const;
concatCTM(const AffineTransform & affine)382     void concatCTM(const AffineTransform& affine) { concat(affineTransformToSkMatrix(affine)); }
setCTM(const AffineTransform & affine)383     void setCTM(const AffineTransform& affine) { setMatrix(affineTransformToSkMatrix(affine)); }
384     void setMatrix(const SkMatrix&);
385 
386     void scale(float x, float y);
387     void rotate(float angleInRadians);
388     void translate(float x, float y);
389 
390     // This function applies the device scale factor to the context, making the context capable of
391     // acting as a base-level context for a HiDPI environment.
applyDeviceScaleFactor(float deviceScaleFactor)392     void applyDeviceScaleFactor(float deviceScaleFactor) { scale(deviceScaleFactor, deviceScaleFactor); }
393     // ---------- End transformation methods -----------------
394 
395     // URL drawing
396     void setURLForRect(const KURL&, const IntRect&);
397     void setURLFragmentForRect(const String& name, const IntRect&);
398     void addURLTargetAtPoint(const String& name, const IntPoint&);
399 
400     // Create an image buffer compatible with this context, with suitable resolution
401     // for drawing into the buffer and then into this context.
402     PassOwnPtr<ImageBuffer> createRasterBuffer(const IntSize&, OpacityMode = NonOpaque) const;
403 
404     static void adjustLineToPixelBoundaries(FloatPoint& p1, FloatPoint& p2, float strokeWidth, StrokeStyle);
405 
406     void beginAnnotation(const AnnotationList&);
407     void endAnnotation();
408 
409     void preparePaintForDrawRectToRect(
410         SkPaint*,
411         const SkRect& srcRect,
412         const SkRect& destRect,
413         CompositeOperator,
414         WebBlendMode,
415         bool isLazyDecoded = false,
416         bool isDataComplete = true) const;
417 
focusRingOutsetExtent(int offset,int width)418     static int focusRingOutsetExtent(int offset, int width)
419     {
420         return focusRingOutset(offset) + (focusRingWidth(width) + 1) / 2;
421     }
422 
423 private:
immutableState()424     const GraphicsContextState* immutableState() const { return m_paintState; }
425 
mutableState()426     GraphicsContextState* mutableState()
427     {
428         realizePaintSave();
429         return m_paintState;
430     }
431 
432     static void setPathFromConvexPoints(SkPath*, size_t, const FloatPoint*);
433     static void setRadii(SkVector*, IntSize, IntSize, IntSize, IntSize);
434 
435     static PassRefPtr<SkColorFilter> WebCoreColorFilterToSkiaColorFilter(ColorFilter);
436 
437 #if OS(MACOSX)
focusRingOutset(int offset)438     static inline int focusRingOutset(int offset) { return offset + 2; }
focusRingWidth(int width)439     static inline int focusRingWidth(int width) { return width; }
440 #else
focusRingOutset(int offset)441     static inline int focusRingOutset(int offset) { return 0; }
focusRingWidth(int width)442     static inline int focusRingWidth(int width) { return 1; }
443     static SkPMColor lineColors(int);
444     static SkPMColor antiColors1(int);
445     static SkPMColor antiColors2(int);
446     static void draw1xMarker(SkBitmap*, int);
447     static void draw2xMarker(SkBitmap*, int);
448 #endif
449 
450     // Helpers for drawing a focus ring (drawFocusRing)
451     float prepareFocusRingPaint(SkPaint&, const Color&, int width) const;
452     void drawFocusRingPath(const SkPath&, const Color&, int width);
453     void drawFocusRingRect(const SkRect&, const Color&, int width);
454 
455     // SkCanvas wrappers.
456     void clipPath(const SkPath&, AntiAliasingMode = NotAntiAliased, SkRegion::Op = SkRegion::kIntersect_Op);
457     void clipRRect(const SkRRect&, AntiAliasingMode = NotAntiAliased, SkRegion::Op = SkRegion::kIntersect_Op);
458     void concat(const SkMatrix&);
459     void drawRRect(const SkRRect&, const SkPaint&);
460 
461     // Apply deferred paint state saves
realizePaintSave()462     void realizePaintSave()
463     {
464         if (contextDisabled())
465             return;
466 
467         if (m_paintState->saveCount()) {
468             m_paintState->decrementSaveCount();
469             ++m_paintStateIndex;
470             if (m_paintStateStack.size() == m_paintStateIndex) {
471                 m_paintStateStack.append(GraphicsContextState::createAndCopy(*m_paintState));
472                 m_paintState = m_paintStateStack[m_paintStateIndex].get();
473             } else {
474                 GraphicsContextState* priorPaintState = m_paintState;
475                 m_paintState = m_paintStateStack[m_paintStateIndex].get();
476                 m_paintState->copy(*priorPaintState);
477             }
478         }
479     }
480 
481     // Apply deferred canvas state saves
realizeCanvasSave()482     void realizeCanvasSave()
483     {
484         if (!m_pendingCanvasSave || contextDisabled())
485             return;
486 
487         ASSERT(m_canvas); // m_pendingCanvasSave should never be true when no canvas.
488         m_canvas->save();
489         m_pendingCanvasSave = false;
490     }
491 
492     void didDrawTextInRect(const SkRect& textRect);
493 
494     void fillRectWithRoundedHole(const IntRect&, const RoundedRect& roundedHoleRect, const Color&);
495 
496     bool isRecording() const;
497 
498     // null indicates painting is contextDisabled. Never delete this object.
499     SkCanvas* m_canvas;
500 
501     // Paint states stack. Enables local drawing state change with save()/restore() calls.
502     // This state controls the appearance of drawn content.
503     // We do not delete from this stack to avoid memory churn.
504     Vector<OwnPtr<GraphicsContextState> > m_paintStateStack;
505     // Current index on the stack. May not be the last thing on the stack.
506     unsigned m_paintStateIndex;
507     // Raw pointer to the current state.
508     GraphicsContextState* m_paintState;
509 
510     // Currently pending save flags for Skia Canvas state.
511     // Canvas state includes the canavs, it's matrix and clips. Think of it as _where_
512     // the draw operations will happen.
513     struct CanvasSaveState;
514     Vector<CanvasSaveState> m_canvasStateStack;
515     bool m_pendingCanvasSave;
516 
517     AnnotationModeFlags m_annotationMode;
518 
519     struct RecordingState;
520     Vector<RecordingState> m_recordingStateStack;
521 
522 #if ENABLE(ASSERT)
523     unsigned m_annotationCount;
524     unsigned m_layerCount;
525     bool m_disableDestructionChecks;
526 #endif
527     // Tracks the region painted opaque via the GraphicsContext.
528     RegionTracker m_trackedRegion;
529 
530     // Tracks the region where text is painted via the GraphicsContext.
531     SkRect m_textRegion;
532 
533     unsigned m_disabledState;
534 
535     float m_deviceScaleFactor;
536 
537     // Activation for the above region tracking features
538     unsigned m_regionTrackingMode : 2;
539     bool m_trackTextRegion : 1;
540 
541     bool m_accelerated : 1;
542     bool m_isCertainlyOpaque : 1;
543     bool m_printing : 1;
544     bool m_antialiasHairlineImages : 1;
545     bool m_shouldSmoothFonts : 1;
546 };
547 
548 } // namespace blink
549 
550 #endif // GraphicsContext_h
551