Do not send redundant selectionchange-events (decouple focus)

third_party/WebKit/Source/core/editing/LayoutSelection.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2006 Apple Computer, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 15 matching lines @@
 #include "core/editing/VisibleSelection.h"
 #include "platform/heap/Handle.h"
 
 namespace blink {
 
 class FrameSelection;
 class LayoutView;
 
 class LayoutSelection final : public GarbageCollected<LayoutSelection> {
  public:
+  enum PaintHint { kHide, kKeep, kPaint };

[yosin_UTC9, 2017/04/13 09:31:50]

nit: s/enum/enum class/

[hugoh_UTC2, 2017/04/14 01:34:47]

Done.

+
   static LayoutSelection* Create(FrameSelection& frame_selection) {
     return new LayoutSelection(frame_selection);
   }
 
   bool HasPendingSelection() const { return has_pending_selection_; }
-  void SetHasPendingSelection() { has_pending_selection_ = true; }
+  void SetHasPendingSelection(PaintHint);
   void Commit(LayoutView&);
 
   IntRect SelectionBounds();
   void InvalidatePaintForSelection();
   enum SelectionPaintInvalidationMode {
     kPaintInvalidationNewXOROld,
     kPaintInvalidationNewMinusOld
   };
   void SetSelection(
       LayoutObject* start,
@@ skipping 10 matching lines @@
  private:
   LayoutSelection(FrameSelection&);
 
   const VisibleSelection& GetVisibleSelection() const;
 
   SelectionInFlatTree CalcVisibleSelection(
       const VisibleSelectionInFlatTree&) const;
 
   Member<FrameSelection> frame_selection_;
   bool has_pending_selection_ : 1;
+  bool force_hide_ : 1;
 
   // The current selection represented as 2 boundaries.
   // Selection boundaries are represented in LayoutView by a tuple
   // (LayoutObject, DOM node offset).
   // See http://www.w3.org/TR/dom/#range for more information.
   //
   // |m_selectionStartPos| and |m_selectionEndPos| are only valid for
   // |Text| node without 'transform' or 'first-letter'.
   //
   // Those are used for selection painting and paint invalidation upon
   // selection change.
   LayoutObject* selection_start_;
   LayoutObject* selection_end_;
 
   // TODO(yosin): Clarify the meaning of these variables. editing/ passes
   // them as offsets in the DOM tree  but layout uses them as offset in the
   // layout tree.
   int selection_start_pos_;
   int selection_end_pos_;
 };
 
 }  // namespace blink
 
 #endif