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      1 /*
      2  * Copyright (C) 2006, 2007, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  * 1. Redistributions of source code must retain the above copyright
      8  *    notice, this list of conditions and the following disclaimer.
      9  * 2. Redistributions in binary form must reproduce the above copyright
     10  *    notice, this list of conditions and the following disclaimer in the
     11  *    documentation and/or other materials provided with the distribution.
     12  *
     13  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
     14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
     17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
     21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     24  */
     25 
     26 #ifndef CanvasRenderingContext2D_h
     27 #define CanvasRenderingContext2D_h
     28 
     29 #include "core/html/canvas/Canvas2DContextAttributes.h"
     30 #include "core/html/canvas/CanvasPathMethods.h"
     31 #include "core/html/canvas/CanvasRenderingContext.h"
     32 #include "core/svg/SVGMatrix.h"
     33 #include "platform/fonts/Font.h"
     34 #include "platform/graphics/Color.h"
     35 #include "platform/geometry/FloatSize.h"
     36 #include "platform/graphics/GraphicsTypes.h"
     37 #include "platform/graphics/ImageBuffer.h"
     38 #include "platform/graphics/Path.h"
     39 #include "platform/transforms/AffineTransform.h"
     40 #include "wtf/HashMap.h"
     41 #include "wtf/Vector.h"
     42 #include "wtf/text/WTFString.h"
     43 
     44 namespace blink { class WebLayer; }
     45 
     46 namespace WebCore {
     47 
     48 class CanvasGradient;
     49 class CanvasPattern;
     50 class CanvasStyle;
     51 class DOMPath;
     52 class Element;
     53 class ExceptionState;
     54 class FloatRect;
     55 class GraphicsContext;
     56 class HTMLCanvasElement;
     57 class HTMLImageElement;
     58 class HTMLVideoElement;
     59 class ImageBitmap;
     60 class ImageData;
     61 class TextMetrics;
     62 
     63 typedef HashMap<String, RefPtr<MutableStylePropertySet> > MutableStylePropertyMap;
     64 
     65 class CanvasRenderingContext2D : public CanvasRenderingContext, public CanvasPathMethods {
     66 public:
     67     static PassOwnPtr<CanvasRenderingContext2D> create(HTMLCanvasElement* canvas, const Canvas2DContextAttributes* attrs, bool usesCSSCompatibilityParseMode)
     68     {
     69         return adoptPtr(new CanvasRenderingContext2D(canvas, attrs, usesCSSCompatibilityParseMode));
     70     }
     71     virtual ~CanvasRenderingContext2D();
     72 
     73     CanvasStyle* strokeStyle() const;
     74     void setStrokeStyle(PassRefPtr<CanvasStyle>);
     75 
     76     CanvasStyle* fillStyle() const;
     77     void setFillStyle(PassRefPtr<CanvasStyle>);
     78 
     79     float lineWidth() const;
     80     void setLineWidth(float);
     81 
     82     String lineCap() const;
     83     void setLineCap(const String&);
     84 
     85     String lineJoin() const;
     86     void setLineJoin(const String&);
     87 
     88     float miterLimit() const;
     89     void setMiterLimit(float);
     90 
     91     const Vector<float>& getLineDash() const;
     92     void setLineDash(const Vector<float>&);
     93     void setWebkitLineDash(const Vector<float>&);
     94 
     95     float lineDashOffset() const;
     96     void setLineDashOffset(float);
     97     float webkitLineDashOffset() const;
     98     void setWebkitLineDashOffset(float);
     99 
    100     float shadowOffsetX() const;
    101     void setShadowOffsetX(float);
    102 
    103     float shadowOffsetY() const;
    104     void setShadowOffsetY(float);
    105 
    106     float shadowBlur() const;
    107     void setShadowBlur(float);
    108 
    109     String shadowColor() const;
    110     void setShadowColor(const String&);
    111 
    112     float globalAlpha() const;
    113     void setGlobalAlpha(float);
    114 
    115     String globalCompositeOperation() const;
    116     void setGlobalCompositeOperation(const String&);
    117 
    118     void save() { ++m_unrealizedSaveCount; }
    119     void restore();
    120 
    121     SVGMatrix currentTransform() const
    122     {
    123         return SVGMatrix(state().m_transform);
    124     }
    125     void setCurrentTransform(const SVGMatrix&);
    126 
    127     void scale(float sx, float sy);
    128     void rotate(float angleInRadians);
    129     void translate(float tx, float ty);
    130     void transform(float m11, float m12, float m21, float m22, float dx, float dy);
    131     void setTransform(float m11, float m12, float m21, float m22, float dx, float dy);
    132     void resetTransform();
    133 
    134     void setStrokeColor(const String& color);
    135     void setStrokeColor(float grayLevel);
    136     void setStrokeColor(const String& color, float alpha);
    137     void setStrokeColor(float grayLevel, float alpha);
    138     void setStrokeColor(float r, float g, float b, float a);
    139     void setStrokeColor(float c, float m, float y, float k, float a);
    140 
    141     void setFillColor(const String& color);
    142     void setFillColor(float grayLevel);
    143     void setFillColor(const String& color, float alpha);
    144     void setFillColor(float grayLevel, float alpha);
    145     void setFillColor(float r, float g, float b, float a);
    146     void setFillColor(float c, float m, float y, float k, float a);
    147 
    148     void beginPath();
    149 
    150     PassRefPtr<DOMPath> currentPath();
    151     void setCurrentPath(DOMPath*);
    152     void fill(const String& winding = "nonzero");
    153     void stroke();
    154     void clip(const String& winding = "nonzero");
    155 
    156     bool isPointInPath(const float x, const float y, const String& winding = "nonzero");
    157     bool isPointInStroke(const float x, const float y);
    158 
    159     void clearRect(float x, float y, float width, float height);
    160     void fillRect(float x, float y, float width, float height);
    161     void strokeRect(float x, float y, float width, float height);
    162 
    163     void setShadow(float width, float height, float blur);
    164     void setShadow(float width, float height, float blur, const String& color);
    165     void setShadow(float width, float height, float blur, float grayLevel);
    166     void setShadow(float width, float height, float blur, const String& color, float alpha);
    167     void setShadow(float width, float height, float blur, float grayLevel, float alpha);
    168     void setShadow(float width, float height, float blur, float r, float g, float b, float a);
    169     void setShadow(float width, float height, float blur, float c, float m, float y, float k, float a);
    170 
    171     void clearShadow();
    172 
    173     void drawImage(ImageBitmap*, float x, float y, ExceptionState&);
    174     void drawImage(ImageBitmap*, float x, float y, float width, float height, ExceptionState&);
    175     void drawImage(ImageBitmap*, float sx, float sy, float sw, float sh, float dx, float dy, float dw, float dh, ExceptionState&);
    176     void drawImage(HTMLImageElement*, float x, float y, ExceptionState&);
    177     void drawImage(HTMLImageElement*, float x, float y, float width, float height, ExceptionState&);
    178     void drawImage(HTMLImageElement*, float sx, float sy, float sw, float sh, float dx, float dy, float dw, float dh, ExceptionState&);
    179     void drawImage(HTMLImageElement*, const FloatRect& srcRect, const FloatRect& dstRect, ExceptionState&);
    180     void drawImage(HTMLImageElement*, const FloatRect& srcRect, const FloatRect& dstRect, const CompositeOperator&, const blink::WebBlendMode&, ExceptionState&);
    181     void drawImage(HTMLCanvasElement*, float x, float y, ExceptionState&);
    182     void drawImage(HTMLCanvasElement*, float x, float y, float width, float height, ExceptionState&);
    183     void drawImage(HTMLCanvasElement*, float sx, float sy, float sw, float sh, float dx, float dy, float dw, float dh, ExceptionState&);
    184     void drawImage(HTMLCanvasElement*, const FloatRect& srcRect, const FloatRect& dstRect, ExceptionState&);
    185     void drawImage(HTMLVideoElement*, float x, float y, ExceptionState&);
    186     void drawImage(HTMLVideoElement*, float x, float y, float width, float height, ExceptionState&);
    187     void drawImage(HTMLVideoElement*, float sx, float sy, float sw, float sh, float dx, float dy, float dw, float dh, ExceptionState&);
    188     void drawImage(HTMLVideoElement*, const FloatRect& srcRect, const FloatRect& dstRect, ExceptionState&);
    189 
    190     void drawImageFromRect(HTMLImageElement*, float sx = 0, float sy = 0, float sw = 0, float sh = 0,
    191                            float dx = 0, float dy = 0, float dw = 0, float dh = 0, const String& compositeOperation = emptyString());
    192 
    193     void setAlpha(float);
    194 
    195     void setCompositeOperation(const String&);
    196 
    197     PassRefPtr<CanvasGradient> createLinearGradient(float x0, float y0, float x1, float y1, ExceptionState&);
    198     PassRefPtr<CanvasGradient> createRadialGradient(float x0, float y0, float r0, float x1, float y1, float r1, ExceptionState&);
    199     PassRefPtr<CanvasPattern> createPattern(HTMLImageElement*, const String& repetitionType, ExceptionState&);
    200     PassRefPtr<CanvasPattern> createPattern(HTMLCanvasElement*, const String& repetitionType, ExceptionState&);
    201 
    202     PassRefPtr<ImageData> createImageData(PassRefPtr<ImageData>, ExceptionState&) const;
    203     PassRefPtr<ImageData> createImageData(float width, float height, ExceptionState&) const;
    204     PassRefPtr<ImageData> getImageData(float sx, float sy, float sw, float sh, ExceptionState&) const;
    205     void putImageData(ImageData*, float dx, float dy, ExceptionState&);
    206     void putImageData(ImageData*, float dx, float dy, float dirtyX, float dirtyY, float dirtyWidth, float dirtyHeight, ExceptionState&);
    207 
    208     // Slated for deprecation:
    209     void webkitPutImageDataHD(ImageData* image, float dx, float dy, ExceptionState& e) { putImageData(image, dx, dy, e); }
    210     void webkitPutImageDataHD(ImageData* image, float dx, float dy, float dirtyX, float dirtyY, float dirtyWidth, float dirtyHeight, ExceptionState& e) { putImageData(image, dx, dy, dirtyX, dirtyY, dirtyWidth, dirtyHeight, e); }
    211     PassRefPtr<ImageData> webkitGetImageDataHD(float sx, float sy, float sw, float sh, ExceptionState&) const;
    212     float webkitBackingStorePixelRatio() const { return 1; }
    213 
    214     void reset();
    215 
    216     String font() const;
    217     void setFont(const String&);
    218 
    219     String textAlign() const;
    220     void setTextAlign(const String&);
    221 
    222     String textBaseline() const;
    223     void setTextBaseline(const String&);
    224 
    225     void fillText(const String& text, float x, float y);
    226     void fillText(const String& text, float x, float y, float maxWidth);
    227     void strokeText(const String& text, float x, float y);
    228     void strokeText(const String& text, float x, float y, float maxWidth);
    229     PassRefPtr<TextMetrics> measureText(const String& text);
    230 
    231     LineCap getLineCap() const { return state().m_lineCap; }
    232     LineJoin getLineJoin() const { return state().m_lineJoin; }
    233 
    234     bool imageSmoothingEnabled() const;
    235     void setImageSmoothingEnabled(bool);
    236 
    237     PassRefPtr<Canvas2DContextAttributes> getContextAttributes() const;
    238 
    239     void drawSystemFocusRing(Element*);
    240     bool drawCustomFocusRing(Element*);
    241 
    242 private:
    243     struct State : FontSelectorClient {
    244         State();
    245         virtual ~State();
    246 
    247         State(const State&);
    248         State& operator=(const State&);
    249 
    250         virtual void fontsNeedUpdate(FontSelector*) OVERRIDE;
    251 
    252         String m_unparsedStrokeColor;
    253         String m_unparsedFillColor;
    254         RefPtr<CanvasStyle> m_strokeStyle;
    255         RefPtr<CanvasStyle> m_fillStyle;
    256         float m_lineWidth;
    257         LineCap m_lineCap;
    258         LineJoin m_lineJoin;
    259         float m_miterLimit;
    260         FloatSize m_shadowOffset;
    261         float m_shadowBlur;
    262         RGBA32 m_shadowColor;
    263         float m_globalAlpha;
    264         CompositeOperator m_globalComposite;
    265         blink::WebBlendMode m_globalBlend;
    266         AffineTransform m_transform;
    267         bool m_invertibleCTM;
    268         Vector<float> m_lineDash;
    269         float m_lineDashOffset;
    270         bool m_imageSmoothingEnabled;
    271 
    272         // Text state.
    273         TextAlign m_textAlign;
    274         TextBaseline m_textBaseline;
    275 
    276         String m_unparsedFont;
    277         Font m_font;
    278         bool m_realizedFont;
    279     };
    280 
    281     CanvasRenderingContext2D(HTMLCanvasElement*, const Canvas2DContextAttributes* attrs, bool usesCSSCompatibilityParseMode);
    282 
    283     State& modifiableState() { ASSERT(!m_unrealizedSaveCount); return m_stateStack.last(); }
    284     const State& state() const { return m_stateStack.last(); }
    285 
    286     void applyLineDash() const;
    287     void setShadow(const FloatSize& offset, float blur, RGBA32 color);
    288     void applyShadow();
    289     bool shouldDrawShadows() const;
    290 
    291     void drawImageInternal(Image*, const FloatRect&, const FloatRect&, const CompositeOperator&, const blink::WebBlendMode&);
    292     bool computeDirtyRect(const FloatRect& localBounds, FloatRect*);
    293     bool computeDirtyRect(const FloatRect& localBounds, const FloatRect& transformedClipBounds, FloatRect*);
    294     void didDraw(const FloatRect&);
    295 
    296     GraphicsContext* drawingContext() const;
    297 
    298     void unwindStateStack();
    299     void realizeSaves()
    300     {
    301         if (m_unrealizedSaveCount)
    302             realizeSavesLoop();
    303     }
    304     void realizeSavesLoop();
    305 
    306     void applyStrokePattern();
    307     void applyFillPattern();
    308 
    309     void drawTextInternal(const String& text, float x, float y, bool fill, float maxWidth = 0, bool useMaxWidth = false);
    310 
    311     const Font& accessFont();
    312 
    313     void clearCanvas();
    314     bool rectContainsTransformedRect(const FloatRect&, const FloatRect&) const;
    315 
    316     void inflateStrokeRect(FloatRect&) const;
    317 
    318     template<class T> void fullCanvasCompositedFill(const T&);
    319     template<class T> void fullCanvasCompositedDrawImage(T*, const FloatRect&, const FloatRect&, CompositeOperator);
    320 
    321     bool focusRingCallIsValid(const Path&, Element*);
    322     void updateFocusRingAccessibility(const Path&, Element*);
    323     void drawFocusRing(const Path&);
    324 
    325     virtual bool is2d() const OVERRIDE { return true; }
    326     virtual bool isAccelerated() const OVERRIDE;
    327     virtual bool hasAlpha() const OVERRIDE { return m_hasAlpha; }
    328 
    329     virtual bool isTransformInvertible() const { return state().m_invertibleCTM; }
    330 
    331     virtual blink::WebLayer* platformLayer() const OVERRIDE;
    332 
    333     Vector<State, 1> m_stateStack;
    334     unsigned m_unrealizedSaveCount;
    335     bool m_usesCSSCompatibilityParseMode;
    336     bool m_hasAlpha;
    337     MutableStylePropertyMap m_fetchedFonts;
    338 };
    339 
    340 DEFINE_TYPE_CASTS(CanvasRenderingContext2D, CanvasRenderingContext, context, context->is2d(), context.is2d());
    341 
    342 } // namespace WebCore
    343 
    344 #endif
    345