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28
29#ifndef GraphicsContextState_h
30#define GraphicsContextState_h
31
32#include "platform/graphics/DrawLooperBuilder.h"
33#include "platform/graphics/Gradient.h"
34#include "platform/graphics/GraphicsTypes.h"
35#include "platform/graphics/Path.h"
36#include "platform/graphics/Pattern.h"
37#include "platform/graphics/StrokeData.h"
38#include "third_party/skia/include/core/SkColorFilter.h"
39#include "third_party/skia/include/core/SkPaint.h"
40#include "wtf/PassOwnPtr.h"
41#include "wtf/RefPtr.h"
42
43namespace blink {
44
45// Encapsulates the state information we store for each pushed graphics state.
46// Only GraphicsContext can use this class.
47class PLATFORM_EXPORT GraphicsContextState FINAL {
48public:
49    static PassOwnPtr<GraphicsContextState> create()
50    {
51        return adoptPtr(new GraphicsContextState());
52    }
53
54    static PassOwnPtr<GraphicsContextState> createAndCopy(const GraphicsContextState& other)
55    {
56        return adoptPtr(new GraphicsContextState(other));
57    }
58
59    void copy(const GraphicsContextState&);
60
61    // SkPaint objects that reflect the current state. If the length of the
62    // path to be stroked is known, pass it in for correct dash or dot placement.
63    const SkPaint& strokePaint(int strokedPathLength = 0) const;
64    const SkPaint& fillPaint() const;
65
66    uint16_t saveCount() const { return m_saveCount; }
67    void incrementSaveCount() { ++m_saveCount; }
68    void decrementSaveCount() { --m_saveCount; }
69
70    // Stroke data
71    Color strokeColor() const { return m_strokeColor; }
72    SkColor effectiveStrokeColor() const { return applyAlpha(m_strokeColor.rgb()); }
73    void setStrokeColor(const Color&);
74
75    Gradient* strokeGradient() const { return m_strokeGradient.get(); }
76    void setStrokeGradient(const PassRefPtr<Gradient>);
77    void clearStrokeGradient();
78
79    Pattern* strokePattern() const { return m_strokePattern.get(); }
80    void setStrokePattern(const PassRefPtr<Pattern>);
81    void clearStrokePattern();
82
83    const StrokeData& strokeData() const { return m_strokeData; }
84    void setStrokeStyle(StrokeStyle);
85    void setStrokeThickness(float);
86    void setLineCap(LineCap);
87    void setLineJoin(LineJoin);
88    void setMiterLimit(float);
89    void setLineDash(const DashArray&, float);
90
91    // Fill data
92    Color fillColor() const { return m_fillColor; }
93    SkColor effectiveFillColor() const { return applyAlpha(m_fillColor.rgb()); }
94    void setFillColor(const Color&);
95
96    Gradient* fillGradient() const { return m_fillGradient.get(); }
97    void setFillGradient(const PassRefPtr<Gradient>);
98    void clearFillGradient();
99
100    Pattern* fillPattern() const { return m_fillPattern.get(); }
101    void setFillPattern(const PassRefPtr<Pattern>);
102    void clearFillPattern();
103
104    // Path fill rule
105    WindRule fillRule() const { return m_fillRule; }
106    void setFillRule(WindRule rule) { m_fillRule = rule; }
107
108    // Shadow. (This will need tweaking if we use draw loopers for other things.)
109    SkDrawLooper* drawLooper() const { return m_looper.get(); }
110    void setDrawLooper(PassRefPtr<SkDrawLooper>);
111    void clearDrawLooper();
112
113    // Text. (See TextModeFill & friends.)
114    TextDrawingModeFlags textDrawingMode() const { return m_textDrawingMode; }
115    void setTextDrawingMode(TextDrawingModeFlags mode) { m_textDrawingMode = mode; }
116
117    // Common shader state.
118    int alpha() const { return m_alpha; }
119    void setAlphaAsFloat(float);
120
121    SkColorFilter* colorFilter() const { return m_colorFilter.get(); }
122    void setColorFilter(PassRefPtr<SkColorFilter>);
123
124    // Compositing control, for the CSS and Canvas compositing spec.
125    void setCompositeOperation(CompositeOperator, WebBlendMode);
126    CompositeOperator compositeOperator() const { return m_compositeOperator; }
127    WebBlendMode blendMode() const { return m_blendMode; }
128
129    // Image interpolation control.
130    InterpolationQuality interpolationQuality() const { return m_interpolationQuality; }
131    void setInterpolationQuality(InterpolationQuality);
132
133    bool shouldAntialias() const { return m_shouldAntialias; }
134    void setShouldAntialias(bool);
135
136    bool shouldClampToSourceRect() const { return m_shouldClampToSourceRect; }
137    void setShouldClampToSourceRect(bool shouldClampToSourceRect) { m_shouldClampToSourceRect = shouldClampToSourceRect; }
138
139private:
140    GraphicsContextState();
141    explicit GraphicsContextState(const GraphicsContextState&);
142    GraphicsContextState& operator=(const GraphicsContextState&);
143
144    // Helper function for applying the state's alpha value to the given input
145    // color to produce a new output color.
146    SkColor applyAlpha(SkColor c) const
147    {
148        int a = SkAlphaMul(SkColorGetA(c), m_alpha);
149        return (c & 0x00FFFFFF) | (a << 24);
150    }
151
152    // These are mutbale to enable gradient updates when the paints are fetched for use.
153    mutable SkPaint m_strokePaint;
154    mutable SkPaint m_fillPaint;
155
156    StrokeData m_strokeData;
157
158    Color m_strokeColor;
159    RefPtr<Gradient> m_strokeGradient;
160    RefPtr<Pattern> m_strokePattern;
161
162    Color m_fillColor;
163    WindRule m_fillRule;
164    RefPtr<Gradient> m_fillGradient;
165    RefPtr<Pattern> m_fillPattern;
166
167    RefPtr<SkDrawLooper> m_looper;
168
169    TextDrawingModeFlags m_textDrawingMode;
170
171    int m_alpha;
172    RefPtr<SkColorFilter> m_colorFilter;
173
174    CompositeOperator m_compositeOperator;
175    WebBlendMode m_blendMode;
176
177    InterpolationQuality m_interpolationQuality;
178
179    uint16_t m_saveCount;
180
181    bool m_shouldAntialias : 1;
182    bool m_shouldClampToSourceRect : 1;
183};
184
185} // namespace blink
186
187#endif // GraphicsContextState_h
188