Do not send redundant selectionchange-events (decouple focus)

third_party/WebKit/Source/core/editing/PendingSelection.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights
  * reserved.
  *
  * 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.
  *
@@ skipping 20 matching lines @@
 
 namespace blink {
 
 PendingSelection::PendingSelection(FrameSelection& frameSelection)
     : m_frameSelection(&frameSelection), m_hasPendingSelection(false) {}
 
 const VisibleSelection& PendingSelection::visibleSelection() const {
   return m_frameSelection->computeVisibleSelectionInDOMTree();
 }
 
-static bool isSelectionInDocument(
-    const VisibleSelectionInFlatTree& visibleSelection,
-    const Document& document) {
-  const PositionInFlatTree& start = visibleSelection.start();
-  if (start.isNotNull() &&
-      (!start.isConnected() || start.document() != document))
-    return false;
-  const PositionInFlatTree& end = visibleSelection.end();
-  if (end.isNotNull() && (!end.isConnected() || end.document() != document))
-    return false;
-  const PositionInFlatTree extent = visibleSelection.extent();
-  if (extent.isNotNull() &&
-      (!extent.isConnected() || extent.document() != document))
-    return false;
-  return true;
-}
-
 SelectionInFlatTree PendingSelection::calcVisibleSelection(
     const VisibleSelectionInFlatTree& originalSelection) const {
   const PositionInFlatTree& start = originalSelection.start();
   const PositionInFlatTree& end = originalSelection.end();
   SelectionType selectionType = originalSelection.getSelectionType();
   const TextAffinity affinity = originalSelection.affinity();
 
   bool paintBlockCursor =
       m_frameSelection->shouldShowBlockCursor() &&
       selectionType == SelectionType::CaretSelection &&
@@ skipping 51 matching lines @@
   if (!isSelectionInDocument(originalSelection, layoutView.document()))
     return;
 
   // Construct a new VisibleSolution, since visibleSelection() is not
   // necessarily valid, and the following steps assume a valid selection. See
   // <https://bugs.webkit.org/show_bug.cgi?id=69563> and
   // <rdar://problem/10232866>.
   const VisibleSelectionInFlatTree& selection =
       createVisibleSelection(calcVisibleSelection(originalSelection));
 
-  if (!selection.isRange()) {
+  const LocalFrame& frame = *layoutView.document().frame();
+  if (!selection.isRange() || !selectionHasFocus(frame)) {
     layoutView.clearSelection();
     return;
   }
 
   // Use the rightmost candidate for the start of the selection, and the
   // leftmost candidate for the end of the selection. Example: foo <a>bar</a>.
   // Imagine that a line wrap occurs after 'foo', and that 'bar' is selected.
   // If we pass [foo, 3] as the start of the selection, the selection painting
   // code will think that content on the line containing 'foo' is selected
   // and will fill the gap before 'bar'.
@@ skipping 21 matching lines @@
   DCHECK(layoutView == endLayoutObject->view());
   layoutView.setSelection(startLayoutObject, startPos.computeEditingOffset(),
                           endLayoutObject, endPos.computeEditingOffset());
 }
 
 DEFINE_TRACE(PendingSelection) {
   visitor->trace(m_frameSelection);
 }
 
 }  // namespace blink