third_party/blink/renderer/platform/exported/web_scrollbar_impl.h

/*
 * Copyright (C) 2012 Google 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. AND ITS CONTRIBUTORS ``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 ITS 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.
 */

#ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_EXPORTED_WEB_SCROLLBAR_IMPL_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_EXPORTED_WEB_SCROLLBAR_IMPL_H_

#include "base/memory/ptr_util.h"
#include "third_party/blink/public/platform/web_scrollbar.h"
#include "third_party/blink/renderer/platform/heap/handle.h"
#include "third_party/blink/renderer/platform/platform_export.h"
#include "third_party/blink/renderer/platform/wtf/allocator.h"
#include "third_party/blink/renderer/platform/wtf/noncopyable.h"

#include <memory>

namespace blink {

class Scrollbar;
class PLATFORM_EXPORT WebScrollbarImpl final : public WebScrollbar {
  USING_FAST_MALLOC(WebScrollbarImpl);
  WTF_MAKE_NONCOPYABLE(WebScrollbarImpl);

 public:
  static std::unique_ptr<WebScrollbarImpl> Create(Scrollbar* scrollbar) {
    return base::WrapUnique(new WebScrollbarImpl(scrollbar));
  }

  // Implement WebScrollbar methods
  bool IsOverlay() const override;
  int Value() const override;
  WebPoint Location() const override;
  WebSize Size() const override;
  bool Enabled() const override;
  int Maximum() const override;
  int TotalSize() const override;
  bool IsScrollableAreaActive() const override;
  bool HasTickmarks() const override;
  void GetTickmarks(WebVector<WebRect>& tickmarks) const override;
  ScrollbarControlSize GetControlSize() const override;
  ScrollbarPart PressedPart() const override;
  ScrollbarPart HoveredPart() const override;
  WebScrollbarOverlayColorTheme ScrollbarOverlayColorTheme() const override;
  bool IsCustomScrollbar() const override;
  Orientation GetOrientation() const override;
  bool IsLeftSideVerticalScrollbar() const override;
  float ElasticOverscroll() const override;
  void SetElasticOverscroll(float) override;

 private:
  explicit WebScrollbarImpl(Scrollbar*);

  // Accessed by main and compositor threads, e.g., the compositor thread
  // checks |orientation()|.
  //
  // TODO: minimize or avoid cross-thread use, if possible.
  CrossThreadPersistent<Scrollbar> scrollbar_;
};

}  // namespace blink

#endif