chromium/src/third_party/blink/renderer/core/scroll/scrollbar_theme_aura.h

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#ifndef THIRD_PARTY_BLINK_RENDERER_CORE_SCROLL_SCROLLBAR_THEME_AURA_H_
#define THIRD_PARTY_BLINK_RENDERER_CORE_SCROLL_SCROLLBAR_THEME_AURA_H_

#include "base/gtest_prod_util.h"
#include "third_party/blink/renderer/core/scroll/scrollbar_theme.h"

namespace blink {

class CORE_EXPORT ScrollbarThemeAura : public ScrollbarTheme {
 public:
  int ScrollbarThickness(float scale_from_dip) override;

 protected:
  bool NativeThemeHasButtons() override { return true; }
  bool HasThumb(const Scrollbar&) override;

  IntRect BackButtonRect(const Scrollbar&) override;
  IntRect ForwardButtonRect(const Scrollbar&) override;
  IntRect TrackRect(const Scrollbar&) override;
  int MinimumThumbLength(const Scrollbar&) override;

  void PaintTrack(GraphicsContext&, const Scrollbar&, const IntRect&) override;
  void PaintButton(GraphicsContext&,
                   const Scrollbar&,
                   const IntRect&,
                   ScrollbarPart) override;
  void PaintThumb(GraphicsContext&, const Scrollbar&, const IntRect&) override;

  bool ShouldRepaintAllPartsOnInvalidation() const override;
  ScrollbarPart PartsToInvalidateOnThumbPositionChange(
      const Scrollbar&,
      float old_position,
      float new_position) const override;

  bool ShouldCenterOnThumb(const Scrollbar&, const WebMouseEvent&) override;

  // During a thumb drag, if the pointer moves outside a certain threshold in
  // the non-scrolling direction, the scroller is expected to "snap back" to the
  // location where the drag first originated from.
  bool SupportsDragSnapBack() const override;
  bool ShouldSnapBackToDragOrigin(const Scrollbar&,
                                  const WebMouseEvent&) override;

 private:
  FRIEND_TEST_ALL_PREFIXES(ScrollbarThemeAuraTest, ButtonSizeHorizontal);
  FRIEND_TEST_ALL_PREFIXES(ScrollbarThemeAuraTest, ButtonSizeVertical);
  FRIEND_TEST_ALL_PREFIXES(ScrollbarThemeAuraTest, NoButtonsReturnsSize0);

  virtual bool HasScrollbarButtons(ScrollbarOrientation) const;
  IntSize ButtonSize(const Scrollbar&);
};

}  // namespace blink

#endif