third_party/WebKit/Source/modules/canvas2d/CanvasRenderingContext2D.h

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#ifndef CanvasRenderingContext2D_h
#define CanvasRenderingContext2D_h

#include "bindings/core/v8/ScriptWrappable.h"
#include "bindings/modules/v8/UnionTypesModules.h"
#include "core/html/canvas/CanvasContextCreationAttributes.h"
#include "core/html/canvas/CanvasRenderingContext.h"
#include "core/html/canvas/CanvasRenderingContextFactory.h"
#include "modules/ModulesExport.h"
#include "modules/canvas2d/Canvas2DContextAttributes.h"
#include "modules/canvas2d/CanvasPathMethods.h"
#include "modules/canvas2d/CanvasRenderingContext2DState.h"
#include "platform/graphics/GraphicsTypes.h"
#include "public/platform/WebThread.h"
#include "wtf/Vector.h"
#include "wtf/text/WTFString.h"

namespace blink { class WebLayer; }

namespace blink {

class CanvasImageSource;
class Element;
class ExceptionState;
class FloatRect;
class FloatSize;
class Font;
class FontMetrics;
class HitRegion;
class HitRegionOptions;
class HitRegionManager;
class ImageData;
class Path2D;
class SVGMatrixTearOff;
class TextMetrics;

typedef HTMLImageElementOrHTMLVideoElementOrHTMLCanvasElementOrImageBitmap CanvasImageSourceUnion;

class MODULES_EXPORT CanvasRenderingContext2D final : public CanvasRenderingContext, public CanvasPathMethods, public WebThread::TaskObserver {
    DEFINE_WRAPPERTYPEINFO();
public:
    class Factory : public CanvasRenderingContextFactory {
        WTF_MAKE_NONCOPYABLE(Factory);
    public:
        Factory() {}
        ~Factory() override {}

        PassOwnPtrWillBeRawPtr<CanvasRenderingContext> create(HTMLCanvasElement* canvas, const CanvasContextCreationAttributes& attrs, Document& document) override
        {
            return adoptPtrWillBeNoop(new CanvasRenderingContext2D(canvas, attrs, document));
        }
        CanvasRenderingContext::ContextType contextType() const override { return CanvasRenderingContext::Context2d; }
        void onError(HTMLCanvasElement*, const String& error) override { }
    };

    ~CanvasRenderingContext2D() override;

    void strokeStyle(StringOrCanvasGradientOrCanvasPattern&) const;
    void setStrokeStyle(const StringOrCanvasGradientOrCanvasPattern&);

    void fillStyle(StringOrCanvasGradientOrCanvasPattern&) const;
    void setFillStyle(const StringOrCanvasGradientOrCanvasPattern&);

    double lineWidth() const;
    void setLineWidth(double);

    String lineCap() const;
    void setLineCap(const String&);

    String lineJoin() const;
    void setLineJoin(const String&);

    double miterLimit() const;
    void setMiterLimit(double);

    const Vector<double>& getLineDash() const;
    void setLineDash(const Vector<double>&);

    double lineDashOffset() const;
    void setLineDashOffset(double);

    double shadowOffsetX() const;
    void setShadowOffsetX(double);

    double shadowOffsetY() const;
    void setShadowOffsetY(double);

    double shadowBlur() const;
    void setShadowBlur(double);

    String shadowColor() const;
    void setShadowColor(const String&);

    double globalAlpha() const;
    void setGlobalAlpha(double);

    bool isContextLost() const override;

    bool shouldAntialias() const;
    void setShouldAntialias(bool) override;

    String globalCompositeOperation() const;
    void setGlobalCompositeOperation(const String&);

    String filter() const;
    void setFilter(const String&);

    void save();
    void restore();

    PassRefPtrWillBeRawPtr<SVGMatrixTearOff> currentTransform() const;
    void setCurrentTransform(PassRefPtrWillBeRawPtr<SVGMatrixTearOff>);

    void scale(double sx, double sy);
    void rotate(double angleInRadians);
    void translate(double tx, double ty);
    void transform(double m11, double m12, double m21, double m22, double dx, double dy);
    void setTransform(double m11, double m12, double m21, double m22, double dx, double dy);
    void resetTransform();

    void beginPath();

    void fill(const String& winding = "nonzero");
    void fill(Path2D*, const String& winding = "nonzero");
    void stroke();
    void stroke(Path2D*);
    void clip(const String& winding = "nonzero");
    void clip(Path2D*, const String& winding = "nonzero");

    bool isPointInPath(const double x, const double y, const String& winding = "nonzero");
    bool isPointInPath(Path2D*, const double x, const double y, const String& winding = "nonzero");
    bool isPointInStroke(const double x, const double y);
    bool isPointInStroke(Path2D*, const double x, const double y);

    void scrollPathIntoView();
    void scrollPathIntoView(Path2D*);

    void clearRect(double x, double y, double width, double height) override;
    void fillRect(double x, double y, double width, double height);
    void strokeRect(double x, double y, double width, double height);

    void drawImage(const CanvasImageSourceUnion&, double x, double y, ExceptionState&);
    void drawImage(const CanvasImageSourceUnion&, double x, double y, double width, double height, ExceptionState&);
    void drawImage(const CanvasImageSourceUnion&, double sx, double sy, double sw, double sh, double dx, double dy, double dw, double dh, ExceptionState&);
    void drawImage(CanvasImageSource*, double sx, double sy, double sw, double sh, double dx, double dy, double dw, double dh, ExceptionState&);

    CanvasGradient* createLinearGradient(double x0, double y0, double x1, double y1);
    CanvasGradient* createRadialGradient(double x0, double y0, double r0, double x1, double y1, double r1, ExceptionState&);
    CanvasPattern* createPattern(const CanvasImageSourceUnion&, const String& repetitionType, ExceptionState&);

    ImageData* createImageData(ImageData*) const;
    ImageData* createImageData(double width, double height, ExceptionState&) const;
    ImageData* getImageData(double sx, double sy, double sw, double sh, ExceptionState&) const;
    void putImageData(ImageData*, double dx, double dy, ExceptionState&);
    void putImageData(ImageData*, double dx, double dy, double dirtyX, double dirtyY, double dirtyWidth, double dirtyHeight, ExceptionState&);

    void reset() override;

    String font() const;
    void setFont(const String&) override;

    String textAlign() const;
    void setTextAlign(const String&);

    String textBaseline() const;
    void setTextBaseline(const String&);

    String direction() const;
    void setDirection(const String&);

    void fillText(const String& text, double x, double y);
    void fillText(const String& text, double x, double y, double maxWidth);
    void strokeText(const String& text, double x, double y);
    void strokeText(const String& text, double x, double y, double maxWidth);
    TextMetrics* measureText(const String& text);

    bool imageSmoothingEnabled() const;
    void setImageSmoothingEnabled(bool);
    String imageSmoothingQuality() const;
    void setImageSmoothingQuality(const String&);

    void getContextAttributes(Canvas2DContextAttributes&) const;

    void drawFocusIfNeeded(Element*);
    void drawFocusIfNeeded(Path2D*, Element*);

    void addHitRegion(const HitRegionOptions&, ExceptionState&);
    void removeHitRegion(const String& id);
    void clearHitRegions();
    HitRegion* hitRegionAtPoint(const FloatPoint&);
    unsigned hitRegionsCount() const override;

    void loseContext(LostContextMode) override;
    void didSetSurfaceSize() override;

    void restoreCanvasMatrixClipStack(SkCanvas*) const override;

    // TaskObserver implementation
    void didProcessTask() override;
    void willProcessTask() override { }

    void styleDidChange(const ComputedStyle* oldStyle, const ComputedStyle& newStyle) override;

private:
    friend class CanvasRenderingContext2DAutoRestoreSkCanvas;

    CanvasRenderingContext2D(HTMLCanvasElement*, const CanvasContextCreationAttributes& attrs, Document&);

    CanvasRenderingContext2DState& modifiableState();
    const CanvasRenderingContext2DState& state() const { return *m_stateStack.last(); }

    void setShadow(const FloatSize& offset, double blur, RGBA32 color);

    void dispatchContextLostEvent(Timer<CanvasRenderingContext2D>*);
    void dispatchContextRestoredEvent(Timer<CanvasRenderingContext2D>*);
    void tryRestoreContextEvent(Timer<CanvasRenderingContext2D>*);

    bool computeDirtyRect(const FloatRect& localBounds, SkIRect*);
    bool computeDirtyRect(const FloatRect& localBounds, const SkIRect& transformedClipBounds, SkIRect*);
    void didDraw(const SkIRect&);

    SkCanvas* drawingCanvas() const;

    void unwindStateStack();
    void realizeSaves();

    void pruneLocalFontCache(size_t targetSize);
    void schedulePruneLocalFontCacheIfNeeded();

    bool shouldDrawImageAntialiased(const FloatRect& destRect) const;

    template<typename DrawFunc, typename ContainsFunc>
    bool draw(const DrawFunc&, const ContainsFunc&, const SkRect& bounds, CanvasRenderingContext2DState::PaintType, CanvasRenderingContext2DState::ImageType = CanvasRenderingContext2DState::NoImage);
    void drawPathInternal(const Path&, CanvasRenderingContext2DState::PaintType, SkPath::FillType = SkPath::kWinding_FillType);
    void drawImageInternal(SkCanvas*, CanvasImageSource*, Image*, const FloatRect& srcRect, const FloatRect& dstRect, const SkPaint*);
    void clipInternal(const Path&, const String& windingRuleString);

    bool isPointInPathInternal(const Path&, const double x, const double y, const String& windingRuleString);
    bool isPointInStrokeInternal(const Path&, const double x, const double y);

    void scrollPathIntoViewInternal(const Path&);

    void drawTextInternal(const String&, double x, double y, CanvasRenderingContext2DState::PaintType, double* maxWidth = nullptr);

    const Font& accessFont();
    int getFontBaseline(const FontMetrics&) const;

    void clearCanvas();
    bool rectContainsTransformedRect(const FloatRect&, const SkIRect&) const;

    void inflateStrokeRect(FloatRect&) const;

    template<typename DrawFunc>
    void compositedDraw(const DrawFunc&, SkCanvas*, CanvasRenderingContext2DState::PaintType, CanvasRenderingContext2DState::ImageType);

    void drawFocusIfNeededInternal(const Path&, Element*);
    bool focusRingCallIsValid(const Path&, Element*);
    void drawFocusRing(const Path&);
    void updateElementAccessibility(const Path&, Element*);

    void validateStateStack();

    enum DrawType {
        ClipFill, // Fill that is already known to cover the current clip
        UntransformedUnclippedFill
    };

    void checkOverdraw(const SkRect&, const SkPaint*, CanvasRenderingContext2DState::ImageType, DrawType);

    CanvasRenderingContext::ContextType contextType() const override { return CanvasRenderingContext::Context2d; }
    bool is2d() const override { return true; }
    bool isAccelerated() const override;
    bool hasAlpha() const override { return m_hasAlpha; }
    void setIsHidden(bool) override;
    void stop() final;
    DECLARE_VIRTUAL_TRACE();

    virtual bool isTransformInvertible() const;

    WebLayer* platformLayer() const override;

    WillBeHeapVector<OwnPtrWillBeMember<CanvasRenderingContext2DState>> m_stateStack;
    PersistentWillBeMember<HitRegionManager> m_hitRegionManager;
    AntiAliasingMode m_clipAntialiasing;
    bool m_hasAlpha;
    LostContextMode m_contextLostMode;
    bool m_contextRestorable;
    unsigned m_tryRestoreContextAttemptCount;
    Timer<CanvasRenderingContext2D> m_dispatchContextLostEventTimer;
    Timer<CanvasRenderingContext2D> m_dispatchContextRestoredEventTimer;
    Timer<CanvasRenderingContext2D> m_tryRestoreContextEventTimer;

    HashMap<String, Font> m_fontsResolvedUsingCurrentStyle;
    bool m_pruneLocalFontCacheScheduled;
    ListHashSet<String> m_fontLRUList;
};

DEFINE_TYPE_CASTS(CanvasRenderingContext2D, CanvasRenderingContext, context, context->is2d(), context.is2d());

} // namespace blink

#endif // CanvasRenderingContext2D_h