/*
 * Copyright (C) 2011-2021 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#include "CachedImageClient.h"
#include "CachedResourceHandle.h"
#include "CSSImageGeneratorValue.h"
#include <wtf/Function.h>

namespace WebCore {

namespace Style {
class BuilderState;
}

struct BlendingContext;
class CSSPrimitiveValue;

namespace Style {
class BuilderState;
} // namespace Style

class CSSCrossfadeValue final : public CSSImageGeneratorValue {
public:
    static Ref<CSSCrossfadeValue> create(Ref<CSSValue>&& fromValue, Ref<CSSValue>&& toValue, Ref<CSSPrimitiveValue>&& percentageValue, bool prefixed = false);

    ~CSSCrossfadeValue();

    String customCSSText() const;

    Image* image(RenderElement&, const FloatSize&);
    bool isFixedSize() const { return true; }
    FloatSize fixedSize(const RenderElement&);

    bool isPrefixed() const { return m_isPrefixed; }
    bool isPending() const;
    bool knownToBeOpaque(const RenderElement&) const;

    void loadSubimages(CachedResourceLoader&, const ResourceLoaderOptions&);

    bool traverseSubresources(const Function<bool(const CachedResource&)>& handler) const;

    RefPtr<CSSCrossfadeValue> blend(const CSSCrossfadeValue&, const BlendingContext&) const;

    bool equals(const CSSCrossfadeValue&) const;
    bool equalInputImages(const CSSCrossfadeValue&) const;

    Ref<CSSCrossfadeValue> valueWithStylesResolved(Style::BuilderState&);

private:
    CSSCrossfadeValue(Ref<CSSValue>&& fromValue, Ref<CSSValue>&& toValue, Ref<CSSPrimitiveValue>&& percentageValue, bool prefixed);

    class SubimageObserver final : public CachedImageClient {
    public:
        SubimageObserver(CSSCrossfadeValue&);
    private:
        void imageChanged(CachedImage*, const IntRect*) final;
        CSSCrossfadeValue& m_owner;
    };

    void crossfadeChanged();

    Ref<CSSValue> m_fromValue;
    Ref<CSSValue> m_toValue;
    Ref<CSSPrimitiveValue> m_percentageValue;

    CachedResourceHandle<CachedImage> m_cachedFromImage;
    CachedResourceHandle<CachedImage> m_cachedToImage;

    RefPtr<Image> m_generatedImage;

    SubimageObserver m_subimageObserver;
    bool m_isPrefixed { false };
    bool m_subimagesAreReady { false };
};

} // namespace WebCore

SPECIALIZE_TYPE_TRAITS_CSS_VALUE(CSSCrossfadeValue, isCrossfadeValue())