chromium/src/third_party/blink/renderer/core/scroll/scrollbar_theme.h - manifest_repos/chromium_src - Git at Google

 /*
  * Copyright (C) 2008 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.
  */

 #ifndef THIRD_PARTY_BLINK_RENDERER_CORE_SCROLL_SCROLLBAR_THEME_H_
 #define THIRD_PARTY_BLINK_RENDERER_CORE_SCROLL_SCROLLBAR_THEME_H_

 #include "third_party/blink/renderer/core/core_export.h"
 #include "third_party/blink/renderer/core/scroll/scroll_types.h"
 #include "third_party/blink/renderer/core/scroll/scrollbar.h"
 #include "third_party/blink/renderer/platform/geometry/int_rect.h"
 #include "third_party/blink/renderer/platform/graphics/paint/display_item.h"
 #include "third_party/blink/renderer/platform/graphics/scrollbar_theme_settings.h"

 namespace blink {

 class GraphicsContext;
 class WebMouseEvent;

 class CORE_EXPORT ScrollbarTheme {
   USING_FAST_MALLOC(ScrollbarTheme);

  public:
   ScrollbarTheme() = default;
   ScrollbarTheme(const ScrollbarTheme&) = delete;
   ScrollbarTheme& operator=(const ScrollbarTheme&) = delete;
   virtual ~ScrollbarTheme() = default;

   // If true, then scrollbars with this theme will be painted every time
   // Scrollbar::SetNeedsPaintInvalidation is called. If false, then only parts
   // which are explicitly invalidated will be repainted.
   virtual bool ShouldRepaintAllPartsOnInvalidation() const { return true; }

   virtual void UpdateEnabledState(const Scrollbar&) {}

   // |context|'s current space is the space of the scrollbar's FrameRect().
   void Paint(const Scrollbar&,
              GraphicsContext& context,
              const IntPoint& paint_offset);

   ScrollbarPart HitTestRootFramePosition(const Scrollbar&, const IntPoint&);

   virtual int ScrollbarThickness(float scale_from_dip) { return 0; }
   virtual int ScrollbarMargin(float scale_from_dip) const { return 0; }

   virtual bool IsSolidColor() const { return false; }
   virtual bool UsesOverlayScrollbars() const { return false; }
   virtual void UpdateScrollbarOverlayColorTheme(const Scrollbar&) {}

   // If true, scrollbars that become invisible (i.e. overlay scrollbars that
   // fade out) should be marked as disabled. This option exists since Mac and
   // Aura overlays implement the fade out differently, with Mac painting code
   // fading out the scrollbars. Aura scrollbars require disabling the scrollbar
   // to prevent painting it.
   virtual bool ShouldDisableInvisibleScrollbars() const { return true; }

   // If true, Blink is in charge of hiding/showing of overlay scrollbars.  As
   // above, this option exists because on Mac the visibility is controlled by
   // Mac painting code which Blink doesn't have an input into. In order to
   // prevent the two from getting out of sync we disable setting the Blink-side
   // parameter on Mac.
   virtual bool BlinkControlsOverlayVisibility() const { return true; }

   virtual bool InvalidateOnMouseEnterExit() { return false; }

   // Returns parts of the scrollbar which must be repainted following a change
   // in the thumb position, given scroll positions before and after.
   virtual ScrollbarPart PartsToInvalidateOnThumbPositionChange(
       const Scrollbar&,
       float old_position,
       float new_position) const {
     return kAllParts;
   }

   virtual void PaintScrollCorner(GraphicsContext&,
                                  const Scrollbar* vertical_scrollbar,
                                  const DisplayItemClient&,
                                  const IntRect& corner_rect,
                                  mojom::blink::ColorScheme color_scheme);
   virtual void PaintTickmarks(GraphicsContext&,
                               const Scrollbar&,
                               const IntRect&);

   virtual bool ShouldCenterOnThumb(const Scrollbar&, const WebMouseEvent&) {
     return false;
   }
   virtual bool ShouldSnapBackToDragOrigin(const Scrollbar&,
                                           const WebMouseEvent&) {
     return false;
   }
   virtual bool ShouldDragDocumentInsteadOfThumb(const Scrollbar&,
                                                 const WebMouseEvent&) {
     return false;
   }

   virtual bool SupportsDragSnapBack() const { return false; }
   virtual bool JumpOnTrackClick() const { return false; }

   // The position of the thumb relative to the track.
   int ThumbPosition(const Scrollbar& scrollbar) {
     return ThumbPosition(scrollbar, scrollbar.CurrentPos());
   }
   virtual base::TimeDelta OverlayScrollbarFadeOutDelay() const;
   virtual base::TimeDelta OverlayScrollbarFadeOutDuration() const;
   // The position the thumb would have, relative to the track, at the specified
   // scroll position.
   virtual int ThumbPosition(const Scrollbar&, float scroll_position);
   // The length of the thumb along the axis of the scrollbar.
   virtual int ThumbLength(const Scrollbar&);
   // The position of the track relative to the scrollbar.
   virtual int TrackPosition(const Scrollbar&);
   // The length of the track along the axis of the scrollbar.
   virtual int TrackLength(const Scrollbar&);
   // The opacity to be applied to the scrollbar. A theme overriding Opacity()
   // should also override PaintThumbWithOpacity().
   virtual float Opacity(const Scrollbar&) const { return 1.0f; }

   // Whether the native theme of the OS has scrollbar buttons.
   virtual bool NativeThemeHasButtons() = 0;
   // Whether the scrollbar has buttons. It's the same as NativeThemeHasButtons()
   // except for custom scrollbars which can override the OS settings.
   virtual bool HasButtons(const Scrollbar&) { return NativeThemeHasButtons(); }

   virtual bool HasThumb(const Scrollbar&) = 0;

   // All these rects are in the same coordinate space as the scrollbar's
   // FrameRect.
   virtual IntRect BackButtonRect(const Scrollbar&) = 0;
   virtual IntRect ForwardButtonRect(const Scrollbar&) = 0;
   virtual IntRect TrackRect(const Scrollbar&) = 0;
   virtual IntRect ThumbRect(const Scrollbar&);

   virtual int MinimumThumbLength(const Scrollbar&) = 0;

   virtual void SplitTrack(const Scrollbar&,
                           const IntRect& track,
                           IntRect& start_track,
                           IntRect& thumb,
                           IntRect& end_track);

   virtual void PaintThumb(GraphicsContext&, const Scrollbar&, const IntRect&) {}

   // |offset| is from the space of the scrollbar's FrameRect() to |context|'s
   // current space.
   void PaintTrackButtonsTickmarks(GraphicsContext& context,
                                   const Scrollbar&,
                                   const IntPoint& offset);

   virtual int MaxOverlapBetweenPages() {
     return std::numeric_limits<int>::max();
   }

   virtual base::TimeDelta InitialAutoscrollTimerDelay();
   virtual base::TimeDelta AutoscrollTimerDelay();

   virtual IntRect ConstrainTrackRectToTrackPieces(const Scrollbar&,
                                                   const IntRect& rect) {
     return rect;
   }

   virtual void RegisterScrollbar(Scrollbar&) {}

   virtual bool IsMockTheme() const { return false; }

   virtual bool UsesNinePatchThumbResource() const { return false; }

   // For a nine-patch scrollbar, this defines the painting canvas size which the
   // painting code will use to paint the scrollbar into. The actual scrollbar
   // dimensions will be ignored for purposes of painting since the resource can
   // be then resized without a repaint.
   virtual IntSize NinePatchThumbCanvasSize(const Scrollbar&) const {
     NOTREACHED();
     return IntSize();
   }

   // For a nine-patch resource, the aperture defines the center patch that will
   // be stretched out.
   virtual IntRect NinePatchThumbAperture(const Scrollbar&) const {
     NOTREACHED();
     return IntRect();
   }

   virtual bool AllowsHitTest() const { return true; }

  protected:
   // The point is in the same coordinate space as the scrollbar's FrameRect.
   virtual ScrollbarPart HitTest(const Scrollbar&, const IntPoint&);

   virtual int TickmarkBorderWidth() { return 0; }
   virtual void PaintTrack(GraphicsContext&, const Scrollbar&, const IntRect&) {}
   virtual void PaintButton(GraphicsContext&,
                            const Scrollbar&,
                            const IntRect&,
                            ScrollbarPart) {}

   // |offset| is the offset of the |context|'s current space to the space of
   // scrollbar's FrameRect().
   virtual void PaintTrackAndButtons(GraphicsContext& context,
                                     const Scrollbar&,
                                     const IntPoint& offset);

   // Paint the thumb with Opacity() applied.
   virtual void PaintThumbWithOpacity(GraphicsContext& context,
                                      const Scrollbar& scrollbar,
                                      const IntRect& rect) {
     // By default this method just calls PaintThumb(). A theme with custom
     // Opacity() should override this method to apply the opacity.
     DCHECK_EQ(1.0f, Opacity(scrollbar));
     PaintThumb(context, scrollbar, rect);
   }

  protected:
   // For GetTheme().
   friend class MockScrollableArea;
   friend class MockScrollableAreaForAnimatorTest;
   friend class Page;

   // Get the theme based on global scrollbar settings. We should always use
   // Page::GetScrollbarTheme() to get scrollbar theme because we support
   // different native scrollbar theme base on page settings.
   // See http://crrev.com/c/646727.
   static ScrollbarTheme& GetTheme();

   static bool OverlayScrollbarsEnabled() {
     return ScrollbarThemeSettings::OverlayScrollbarsEnabled();
   }
   static bool MockScrollbarsEnabled() {
     return ScrollbarThemeSettings::MockScrollbarsEnabled();
   }

  private:
   // Must be implemented to return the correct theme subclass.
   static ScrollbarTheme& NativeTheme();
 };

 }  // namespace blink
 #endif
	/*
	* Copyright (C) 2008 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.
	*/

	#ifndef THIRD_PARTY_BLINK_RENDERER_CORE_SCROLL_SCROLLBAR_THEME_H_
	#define THIRD_PARTY_BLINK_RENDERER_CORE_SCROLL_SCROLLBAR_THEME_H_

	#include "third_party/blink/renderer/core/core_export.h"
	#include "third_party/blink/renderer/core/scroll/scroll_types.h"
	#include "third_party/blink/renderer/core/scroll/scrollbar.h"
	#include "third_party/blink/renderer/platform/geometry/int_rect.h"
	#include "third_party/blink/renderer/platform/graphics/paint/display_item.h"
	#include "third_party/blink/renderer/platform/graphics/scrollbar_theme_settings.h"

	namespace blink {

	class GraphicsContext;
	class WebMouseEvent;

	class CORE_EXPORT ScrollbarTheme {
	USING_FAST_MALLOC(ScrollbarTheme);

	public:
	ScrollbarTheme() = default;
	ScrollbarTheme(const ScrollbarTheme&) = delete;
	ScrollbarTheme& operator=(const ScrollbarTheme&) = delete;
	virtual ~ScrollbarTheme() = default;

	// If true, then scrollbars with this theme will be painted every time
	// Scrollbar::SetNeedsPaintInvalidation is called. If false, then only parts
	// which are explicitly invalidated will be repainted.
	virtual bool ShouldRepaintAllPartsOnInvalidation() const { return true; }

	virtual void UpdateEnabledState(const Scrollbar&) {}

	// \|context\|'s current space is the space of the scrollbar's FrameRect().
	void Paint(const Scrollbar&,
	GraphicsContext& context,
	const IntPoint& paint_offset);

	ScrollbarPart HitTestRootFramePosition(const Scrollbar&, const IntPoint&);

	virtual int ScrollbarThickness(float scale_from_dip) { return 0; }
	virtual int ScrollbarMargin(float scale_from_dip) const { return 0; }

	virtual bool IsSolidColor() const { return false; }
	virtual bool UsesOverlayScrollbars() const { return false; }
	virtual void UpdateScrollbarOverlayColorTheme(const Scrollbar&) {}

	// If true, scrollbars that become invisible (i.e. overlay scrollbars that
	// fade out) should be marked as disabled. This option exists since Mac and
	// Aura overlays implement the fade out differently, with Mac painting code
	// fading out the scrollbars. Aura scrollbars require disabling the scrollbar
	// to prevent painting it.
	virtual bool ShouldDisableInvisibleScrollbars() const { return true; }

	// If true, Blink is in charge of hiding/showing of overlay scrollbars. As
	// above, this option exists because on Mac the visibility is controlled by
	// Mac painting code which Blink doesn't have an input into. In order to
	// prevent the two from getting out of sync we disable setting the Blink-side
	// parameter on Mac.
	virtual bool BlinkControlsOverlayVisibility() const { return true; }

	virtual bool InvalidateOnMouseEnterExit() { return false; }

	// Returns parts of the scrollbar which must be repainted following a change
	// in the thumb position, given scroll positions before and after.
	virtual ScrollbarPart PartsToInvalidateOnThumbPositionChange(
	const Scrollbar&,
	float old_position,
	float new_position) const {
	return kAllParts;
	}

	virtual void PaintScrollCorner(GraphicsContext&,
	const Scrollbar* vertical_scrollbar,
	const DisplayItemClient&,
	const IntRect& corner_rect,
	mojom::blink::ColorScheme color_scheme);
	virtual void PaintTickmarks(GraphicsContext&,
	const Scrollbar&,
	const IntRect&);

	virtual bool ShouldCenterOnThumb(const Scrollbar&, const WebMouseEvent&) {
	return false;
	}
	virtual bool ShouldSnapBackToDragOrigin(const Scrollbar&,
	const WebMouseEvent&) {
	return false;
	}
	virtual bool ShouldDragDocumentInsteadOfThumb(const Scrollbar&,
	const WebMouseEvent&) {
	return false;
	}

	virtual bool SupportsDragSnapBack() const { return false; }
	virtual bool JumpOnTrackClick() const { return false; }

	// The position of the thumb relative to the track.
	int ThumbPosition(const Scrollbar& scrollbar) {
	return ThumbPosition(scrollbar, scrollbar.CurrentPos());
	}
	virtual base::TimeDelta OverlayScrollbarFadeOutDelay() const;
	virtual base::TimeDelta OverlayScrollbarFadeOutDuration() const;
	// The position the thumb would have, relative to the track, at the specified
	// scroll position.
	virtual int ThumbPosition(const Scrollbar&, float scroll_position);
	// The length of the thumb along the axis of the scrollbar.
	virtual int ThumbLength(const Scrollbar&);
	// The position of the track relative to the scrollbar.
	virtual int TrackPosition(const Scrollbar&);
	// The length of the track along the axis of the scrollbar.
	virtual int TrackLength(const Scrollbar&);
	// The opacity to be applied to the scrollbar. A theme overriding Opacity()
	// should also override PaintThumbWithOpacity().
	virtual float Opacity(const Scrollbar&) const { return 1.0f; }

	// Whether the native theme of the OS has scrollbar buttons.
	virtual bool NativeThemeHasButtons() = 0;
	// Whether the scrollbar has buttons. It's the same as NativeThemeHasButtons()
	// except for custom scrollbars which can override the OS settings.
	virtual bool HasButtons(const Scrollbar&) { return NativeThemeHasButtons(); }

	virtual bool HasThumb(const Scrollbar&) = 0;

	// All these rects are in the same coordinate space as the scrollbar's
	// FrameRect.
	virtual IntRect BackButtonRect(const Scrollbar&) = 0;
	virtual IntRect ForwardButtonRect(const Scrollbar&) = 0;
	virtual IntRect TrackRect(const Scrollbar&) = 0;
	virtual IntRect ThumbRect(const Scrollbar&);

	virtual int MinimumThumbLength(const Scrollbar&) = 0;

	virtual void SplitTrack(const Scrollbar&,
	const IntRect& track,
	IntRect& start_track,
	IntRect& thumb,
	IntRect& end_track);

	virtual void PaintThumb(GraphicsContext&, const Scrollbar&, const IntRect&) {}

	// \|offset\| is from the space of the scrollbar's FrameRect() to \|context\|'s
	// current space.
	void PaintTrackButtonsTickmarks(GraphicsContext& context,
	const Scrollbar&,
	const IntPoint& offset);

	virtual int MaxOverlapBetweenPages() {
	return std::numeric_limits<int>::max();
	}

	virtual base::TimeDelta InitialAutoscrollTimerDelay();
	virtual base::TimeDelta AutoscrollTimerDelay();

	virtual IntRect ConstrainTrackRectToTrackPieces(const Scrollbar&,
	const IntRect& rect) {
	return rect;
	}

	virtual void RegisterScrollbar(Scrollbar&) {}

	virtual bool IsMockTheme() const { return false; }

	virtual bool UsesNinePatchThumbResource() const { return false; }

	// For a nine-patch scrollbar, this defines the painting canvas size which the
	// painting code will use to paint the scrollbar into. The actual scrollbar
	// dimensions will be ignored for purposes of painting since the resource can
	// be then resized without a repaint.
	virtual IntSize NinePatchThumbCanvasSize(const Scrollbar&) const {
	NOTREACHED();
	return IntSize();
	}

	// For a nine-patch resource, the aperture defines the center patch that will
	// be stretched out.
	virtual IntRect NinePatchThumbAperture(const Scrollbar&) const {
	NOTREACHED();
	return IntRect();
	}

	virtual bool AllowsHitTest() const { return true; }

	protected:
	// The point is in the same coordinate space as the scrollbar's FrameRect.
	virtual ScrollbarPart HitTest(const Scrollbar&, const IntPoint&);

	virtual int TickmarkBorderWidth() { return 0; }
	virtual void PaintTrack(GraphicsContext&, const Scrollbar&, const IntRect&) {}
	virtual void PaintButton(GraphicsContext&,
	const Scrollbar&,
	const IntRect&,
	ScrollbarPart) {}

	// \|offset\| is the offset of the \|context\|'s current space to the space of
	// scrollbar's FrameRect().
	virtual void PaintTrackAndButtons(GraphicsContext& context,
	const Scrollbar&,
	const IntPoint& offset);

	// Paint the thumb with Opacity() applied.
	virtual void PaintThumbWithOpacity(GraphicsContext& context,
	const Scrollbar& scrollbar,
	const IntRect& rect) {
	// By default this method just calls PaintThumb(). A theme with custom
	// Opacity() should override this method to apply the opacity.
	DCHECK_EQ(1.0f, Opacity(scrollbar));
	PaintThumb(context, scrollbar, rect);
	}

	protected:
	// For GetTheme().
	friend class MockScrollableArea;
	friend class MockScrollableAreaForAnimatorTest;
	friend class Page;

	// Get the theme based on global scrollbar settings. We should always use
	// Page::GetScrollbarTheme() to get scrollbar theme because we support
	// different native scrollbar theme base on page settings.
	// See http://crrev.com/c/646727.
	static ScrollbarTheme& GetTheme();

	static bool OverlayScrollbarsEnabled() {
	return ScrollbarThemeSettings::OverlayScrollbarsEnabled();
	}
	static bool MockScrollbarsEnabled() {
	return ScrollbarThemeSettings::MockScrollbarsEnabled();
	}

	private:
	// Must be implemented to return the correct theme subclass.
	static ScrollbarTheme& NativeTheme();
	};

	} // namespace blink
	#endif