third_party/WebKit/Source/modules/offscreencanvas2d/OffscreenCanvasRenderingContext2D.h

// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef OffscreenCanvasRenderingContext2D_h
#define OffscreenCanvasRenderingContext2D_h

#include "core/html/canvas/CanvasContextCreationAttributes.h"
#include "core/html/canvas/CanvasRenderingContext.h"
#include "core/html/canvas/CanvasRenderingContextFactory.h"
#include "modules/canvas2d/BaseRenderingContext2D.h"
#include <memory>

namespace blink {

class MODULES_EXPORT OffscreenCanvasRenderingContext2D final : public CanvasRenderingContext, public BaseRenderingContext2D {
    DEFINE_WRAPPERTYPEINFO();
    USING_GARBAGE_COLLECTED_MIXIN(OffscreenCanvasRenderingContext2D);
public:
    class Factory : public CanvasRenderingContextFactory {
    public:
        Factory() {}
        ~Factory() override {}

        CanvasRenderingContext* create(ScriptState* scriptState, OffscreenCanvas* canvas, const CanvasContextCreationAttributes& attrs) override
        {
            return new OffscreenCanvasRenderingContext2D(scriptState, canvas, attrs);
        }

        CanvasRenderingContext::ContextType getContextType() const override
        {
            return CanvasRenderingContext::Context2d;
        }
    };

    void commit(ExceptionState&);

    // CanvasRenderingContext implementation
    ~OffscreenCanvasRenderingContext2D() override;
    ContextType getContextType() const override { return Context2d; }
    bool is2d() const override { return true; }
    void setOffscreenCanvasGetContextResult(OffscreenRenderingContext&) final;
    void setIsHidden(bool) final { ASSERT_NOT_REACHED(); }
    void stop() final { ASSERT_NOT_REACHED(); }
    void setCanvasGetContextResult(RenderingContext&) final {}
    void clearRect(double x, double y, double width, double height) override { BaseRenderingContext2D::clearRect(x, y, width, height); }
    PassRefPtr<Image> getImage(AccelerationHint, SnapshotReason) const final;

    // BaseRenderingContext2D implementation
    bool originClean() const final;
    void setOriginTainted() final;
    bool wouldTaintOrigin(CanvasImageSource*, ExecutionContext*) final;

    int width() const final;
    int height() const final;

    bool hasImageBuffer() const final;
    ImageBuffer* imageBuffer() const final;

    bool parseColorOrCurrentColor(Color&, const String& colorString) const final;

    SkCanvas* drawingCanvas() const final;
    SkCanvas* existingDrawingCanvas() const final;
    void disableDeferral(DisableDeferralReason) final;

    AffineTransform baseTransform() const final;
    void didDraw(const SkIRect& dirtyRect) final;

    bool stateHasFilter() final;
    SkImageFilter* stateGetFilter() final;
    void snapshotStateForFilter() final { }

    void validateStateStack() const final;

    bool hasAlpha() const final { return creationAttributes().alpha(); }
    bool isContextLost() const override;

    ImageBitmap* transferToImageBitmap(ExceptionState&) final;

protected:
    OffscreenCanvasRenderingContext2D(ScriptState*, OffscreenCanvas*, const CanvasContextCreationAttributes& attrs);
    DECLARE_VIRTUAL_TRACE();

private:
    bool m_needsMatrixClipRestore = false;
    std::unique_ptr<ImageBuffer> m_imageBuffer;

    bool isPaintable() const final;

    RefPtr<StaticBitmapImage> transferToStaticBitmapImage();
};

DEFINE_TYPE_CASTS(OffscreenCanvasRenderingContext2D, CanvasRenderingContext, context,
    context->is2d() && context->getOffscreenCanvas(),
    context.is2d() && context.getOffscreenCanvas());

} // namespace blink

#endif // OffscreenCanvasRenderingContext2D_h