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31 #ifndef PlatformContextSkia_h
32 #define PlatformContextSkia_h
34 #include "GraphicsContext.h"
35 #include "Noncopyable.h"
38 #include "SkDashPathEffect.h"
39 #include "SkDrawLooper.h"
43 #include <wtf/Vector.h>
47 enum CompositeOperator;
48 class GraphicsContext3D;
51 // This class holds the platform-specific state for GraphicsContext. We put
52 // most of our Skia wrappers on this class. In theory, a lot of this stuff could
53 // be moved to GraphicsContext directly, except that some code external to this
54 // would like to poke at our graphics layer as well (like the Image and Font
55 // stuff, which needs some amount of our wrappers and state around SkCanvas).
57 // So in general, this class uses just Skia types except when there's no easy
58 // conversion. GraphicsContext is responsible for converting the WebKit types to
59 // Skia types and setting up the eventual call to the Skia functions.
61 // This class then keeps track of all the current Skia state. WebKit expects
62 // that the graphics state that is pushed and popped by save() and restore()
63 // includes things like colors and pen styles. Skia does this differently, where
64 // push and pop only includes transforms and bitmaps, and the application is
65 // responsible for managing the painting state which is store in separate
66 // SkPaint objects. This class provides the adaptor that allows the painting
67 // state to be pushed and popped along with the bitmap.
68 class PlatformContextSkia {
69 WTF_MAKE_NONCOPYABLE(PlatformContextSkia);
71 // For printing, there shouldn't be any canvas. canvas can be NULL. If you
72 // supply a NULL canvas, you can also call setCanvas later.
73 PlatformContextSkia(SkCanvas*);
74 ~PlatformContextSkia();
76 // Sets the graphics context associated with this context.
77 // GraphicsContextSkia calls this from its constructor.
78 void setGraphicsContext(const GraphicsContext* gc) { m_gc = gc; }
80 // Sets the canvas associated with this context. Use when supplying NULL
81 // to the constructor.
82 void setCanvas(SkCanvas*);
84 // If false we're rendering to a GraphicsContext for a web page, if false
85 // we're not (as is the case when rendering to a canvas object).
86 // If this is true the contents have not been marked up with the magic
87 // color and all text drawing needs to go to a layer so that the alpha is
89 void setDrawingToImageBuffer(bool);
90 bool isDrawingToImageBuffer() const;
95 // Begins a layer that is clipped to the image |imageBuffer| at the location
96 // |rect|. This layer is implicitly restored when the next restore is
98 // NOTE: |imageBuffer| may be deleted before the |restore| is invoked.
99 void beginLayerClippedToImage(const FloatRect&, const ImageBuffer*);
100 void clipPathAntiAliased(const SkPath&);
102 // Sets up the common flags on a paint for antialiasing, effects, etc.
103 // This is implicitly called by setupPaintFill and setupPaintStroke, but
104 // you may wish to call it directly sometimes if you don't want that other
106 void setupPaintCommon(SkPaint*) const;
108 // Sets up the paint for the current fill style.
109 void setupPaintForFilling(SkPaint*) const;
111 // Sets up the paint for stroking. Returns an int representing the width of
112 // the pen, or 1 if the pen's width is 0 if a non-zero length is provided,
113 // the number of dashes/dots on a dashed/dotted line will be adjusted to
114 // start and end that length with a dash/dot.
115 float setupPaintForStroking(SkPaint*, SkRect*, int length) const;
117 // State setting functions.
118 void setDrawLooper(SkDrawLooper*); // Note: takes an additional ref.
119 void setMiterLimit(float);
120 void setAlpha(float);
121 void setLineCap(SkPaint::Cap);
122 void setLineJoin(SkPaint::Join);
123 void setXfermodeMode(SkXfermode::Mode);
124 void setFillColor(SkColor);
125 void setStrokeStyle(StrokeStyle);
126 void setStrokeColor(SkColor);
127 void setStrokeThickness(float thickness);
128 void setTextDrawingMode(TextDrawingModeFlags mode);
129 void setUseAntialiasing(bool enable);
130 void setDashPathEffect(SkDashPathEffect*);
132 SkDrawLooper* getDrawLooper() const;
133 StrokeStyle getStrokeStyle() const;
134 float getStrokeThickness() const;
135 TextDrawingModeFlags getTextDrawingMode() const;
136 float getAlpha() const;
137 int getNormalizedAlpha() const;
138 SkXfermode::Mode getXfermodeMode() const;
140 void canvasClipPath(const SkPath&);
142 // Returns the fill color. The returned color has it's alpha adjusted
143 // by the current alpha.
144 SkColor effectiveFillColor() const;
146 // Returns the stroke color. The returned color has it's alpha adjusted
147 // by the current alpha.
148 SkColor effectiveStrokeColor() const;
150 // Returns the canvas used for painting, NOT guaranteed to be non-null.
151 SkCanvas* canvas() { return m_canvas; }
153 InterpolationQuality interpolationQuality() const;
154 void setInterpolationQuality(InterpolationQuality interpolationQuality);
156 // FIXME: This should be pushed down to GraphicsContext.
157 void drawRect(SkRect rect);
159 // FIXME: I'm still unsure how I will serialize this call.
160 void paintSkPaint(const SkRect&, const SkPaint&);
162 const SkBitmap* bitmap() const;
164 // Returns if the context is a printing context instead of a display
165 // context. Bitmap shouldn't be resampled when printing to keep the best
167 bool printing() const { return m_printing; }
168 void setPrinting(bool p) { m_printing = p; }
170 void getImageResamplingHint(IntSize* srcSize, FloatSize* dstSize) const;
171 void setImageResamplingHint(const IntSize& srcSize, const FloatSize& dstSize);
172 void clearImageResamplingHint();
173 bool hasImageResamplingHint() const;
175 bool isAccelerated() const { return m_gpuContext; }
176 void setGraphicsContext3D(GraphicsContext3D*);
179 // Used when restoring and the state has an image clip. Only shows the pixels in
180 // m_canvas that are also in imageBuffer.
181 void applyClipFromImage(const FloatRect&, const SkBitmap&);
182 void applyAntiAliasedClipPaths(WTF::Vector<SkPath>& paths);
184 // common code between setupPaintFor[Filling,Stroking]
185 void setupShader(SkPaint*, Gradient*, Pattern*, SkColor) const;
187 // Defines drawing style.
190 // NULL indicates painting is disabled. Never delete this object.
192 const GraphicsContext* m_gc;
194 // States stack. Enables local drawing state change with save()/restore()
196 WTF::Vector<State> m_stateStack;
197 // Pointer to the current drawing state. This is a cached value of
198 // mStateStack.back().
201 // Stores image sizes for a hint to compute image resampling modes.
202 // Values are used in ImageSkia.cpp
203 IntSize m_imageResamplingHintSrcSize;
204 FloatSize m_imageResamplingHintDstSize;
206 bool m_drawingToImageBuffer;
207 GraphicsContext3D* m_gpuContext;
211 #endif // PlatformContextSkia_h