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 * Copyright (C) 2013 Google Inc. All rights reserved.
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 * modification, are permitted provided that the following conditions are
 * met:
 *
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 * notice, this list of conditions and the following disclaimer.
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 * in the documentation and/or other materials provided with the
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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#ifndef ShadowList_h
#define ShadowList_h

#include "core/style/ComputedStyle.h"
#include "core/style/ShadowData.h"
#include "platform/geometry/FloatRectOutsets.h"
#include "platform/geometry/LayoutRect.h"
#include "platform/graphics/DrawLooperBuilder.h"
#include "wtf/RefCounted.h"
#include "wtf/Vector.h"
#include <memory>

namespace blink {

class FloatRect;
class LayoutRect;

typedef Vector<ShadowData, 1> ShadowDataVector;

// These are used to store shadows in specified order, but we usually want to
// iterate over them backwards as the first-specified shadow is painted on top.
class ShadowList : public RefCounted<ShadowList> {
 public:
  // This consumes passed in vector.
  static PassRefPtr<ShadowList> adopt(ShadowDataVector& shadows) {
    return adoptRef(new ShadowList(shadows));
  }
  const ShadowDataVector& shadows() const { return m_shadows; }
  bool operator==(const ShadowList& o) const {
    return m_shadows == o.m_shadows;
  }
  bool operator!=(const ShadowList& o) const { return !(*this == o); }

  static PassRefPtr<ShadowList> blend(const ShadowList* from,
                                      const ShadowList* to,
                                      double progress,
                                      const Color& currentColor);

  // Outsets needed to include all shadows in this list, as well as the
  // source (i.e. no outsets will be negative).
  FloatRectOutsets rectOutsetsIncludingOriginal() const;

  void adjustRectForShadow(FloatRect&) const;

  sk_sp<SkDrawLooper> createDrawLooper(DrawLooperBuilder::ShadowAlphaMode,
                                       const Color& currentColor,
                                       bool isHorizontal = true) const;

 private:
  ShadowList(ShadowDataVector& shadows) {
    // If we have no shadows, we use a null ShadowList
    ASSERT(!shadows.isEmpty());
    m_shadows.swap(shadows);
    m_shadows.shrinkToFit();
  }
  ShadowDataVector m_shadows;
};

}  // namespace blink

#endif  // ShadowList_h