Rewrite DocumentMarkerController to use SynchronousMutationObserver

third_party/WebKit/Source/core/editing/markers/DocumentMarkerController.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights
  * reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
@@ skipping 66 matching lines @@
   return DocumentMarker::SpellingMarkerIndex;
 }
 
 }  // namespace
 
 inline bool DocumentMarkerController::possiblyHasMarkers(
     DocumentMarker::MarkerTypes types) {
   return m_possiblyExistingMarkerTypes.intersects(types);
 }
 
-DocumentMarkerController::DocumentMarkerController(const Document& document)
-    : m_possiblyExistingMarkerTypes(0), m_document(&document) {}
+DocumentMarkerController::DocumentMarkerController(Document& document)
+    : m_possiblyExistingMarkerTypes(0), m_document(&document) {
+  setContext(&document);
+}
 
 void DocumentMarkerController::clear() {
   m_markers.clear();
   m_possiblyExistingMarkerTypes = 0;
 }
 
 void DocumentMarkerController::addMarker(const Position& start,
                                          const Position& end,
                                          DocumentMarker::MarkerType type,
                                          const String& description,
@@ skipping 72 matching lines @@
   TextIterator markedText(range.startPosition(), range.endPosition());
   DocumentMarkerController::removeMarkers(
       markedText, markerTypes, shouldRemovePartiallyOverlappingMarker);
 }
 
 static bool startsFurther(const Member<RenderedDocumentMarker>& lhv,
                           const DocumentMarker* rhv) {
   return lhv->startOffset() < rhv->startOffset();
 }
 
-static bool startsAfter(const Member<RenderedDocumentMarker>& marker,
-                        size_t startOffset) {
-  return marker->startOffset() < startOffset;
-}
-
 static bool endsBefore(size_t startOffset,
                        const Member<RenderedDocumentMarker>& rhv) {
   return startOffset < rhv->endOffset();
 }
 
 static bool compareByStart(const Member<DocumentMarker>& lhv,
                            const Member<DocumentMarker>& rhv) {
   return lhv->startOffset() < rhv->startOffset();
 }
 
@@ skipping 105 matching lines @@
 
   if (!possiblyHasMarkers(DocumentMarker::AllMarkers()))
     return;
   DCHECK(!m_markers.isEmpty());
 
   MarkerLists* markers = m_markers.at(srcNode);
   if (!markers)
     return;
 
   bool docDirty = false;
-  for (size_t markerListIndex = 0;
-       markerListIndex < DocumentMarker::MarkerTypeIndexesCount;
-       ++markerListIndex) {
-    Member<MarkerList>& list = (*markers)[markerListIndex];
+  for (Member<MarkerList> list : *markers) {
     if (!list)
       continue;
 
     unsigned endOffset = startOffset + length - 1;
     MarkerList::iterator startPos = std::lower_bound(
         list->begin(), list->end(), startOffset, doesNotInclude);
     for (MarkerList::iterator i = startPos; i != list->end(); ++i) {
       DocumentMarker* marker = i->get();
 
       // stop if we are now past the specified range
@@ skipping 256 matching lines @@
 
       if (markerList->front()->type() == DocumentMarker::TextMatch)
         invalidatePaintForTickmarks(node);
     }
   }
 }
 
 DEFINE_TRACE(DocumentMarkerController) {
   visitor->trace(m_markers);
   visitor->trace(m_document);
+  SynchronousMutationObserver::trace(visitor);
 }
 
 void DocumentMarkerController::removeMarkers(
     Node* node,
     DocumentMarker::MarkerTypes markerTypes) {
   if (!possiblyHasMarkers(markerTypes))
     return;
   DCHECK(!m_markers.isEmpty());
 
   MarkerMap::iterator iterator = m_markers.find(node);
@@ skipping 119 matching lines @@
 
       // cause the node to be redrawn
       if (LayoutObject* layoutObject = node->layoutObject()) {
         layoutObject->setShouldDoFullPaintInvalidation();
         break;
       }
     }
   }
 }
 
-void DocumentMarkerController::shiftMarkers(Node* node,
-                                            unsigned startOffset,
-                                            int delta) {
-  if (!possiblyHasMarkers(DocumentMarker::AllMarkers()))
-    return;
-  DCHECK(!m_markers.isEmpty());
-
-  MarkerLists* markers = m_markers.at(node);
-  if (!markers)
-    return;
-
-  bool didShiftMarker = false;
-  for (size_t markerListIndex = 0;
-       markerListIndex < DocumentMarker::MarkerTypeIndexesCount;
-       ++markerListIndex) {
-    Member<MarkerList>& list = (*markers)[markerListIndex];
-    if (!list)
-      continue;
-    MarkerList::iterator startPos =
-        std::lower_bound(list->begin(), list->end(), startOffset, startsAfter);
-    for (MarkerList::iterator marker = startPos; marker != list->end();
-         ++marker) {
-#if DCHECK_IS_ON()
-      int startOffset = (*marker)->startOffset();
-      DCHECK_GE(startOffset + delta, 0);
-#endif
-      (*marker)->shiftOffsets(delta);
-      didShiftMarker = true;
-    }
-  }
-
-  if (didShiftMarker) {
-    invalidateRectsForMarkersInNode(*node);
-    // repaint the affected node
-    if (node->layoutObject())
-      node->layoutObject()->setShouldDoFullPaintInvalidation();
-  }
-}
-
 bool DocumentMarkerController::setMarkersActive(const EphemeralRange& range,
                                                 bool active) {
   if (!possiblyHasMarkers(DocumentMarker::AllMarkers()))
     return false;
 
   DCHECK(!m_markers.isEmpty());
 
   Node* const startContainer = range.startPosition().computeContainerNode();
   DCHECK(startContainer);
   Node* const endContainer = range.endPosition().computeContainerNode();
@@ skipping 72 matching lines @@
         builder.append(")");
       }
     }
     builder.append("\n");
   }
   LOG(INFO) << m_markers.size() << " nodes have markers:\n"
             << builder.toString().utf8().data();
 }
 #endif
 
+// SynchronousMutationObserver
+void DocumentMarkerController::didUpdateCharacterData(CharacterData* node,
+                                                      unsigned offset,
+                                                      unsigned oldLength,
+                                                      unsigned newLength) {
+  // If we're doing a pure remove operation, remove the markers in the range
+  // being removed (markers containing, but larger than, the range, will be
+  // split)
+  if (newLength == 0)
+    removeMarkers(node, offset, oldLength);
+
+  if (!possiblyHasMarkers(DocumentMarker::AllMarkers()))
+    return;
+  DCHECK(!m_markers.isEmpty());
+
+  MarkerLists* markers = m_markers.at(node);
+  if (!markers)
+    return;
+
+  bool didShiftMarker = false;
+  for (MarkerList* list : *markers) {
+    if (!list)
+      continue;
+
+    for (MarkerList::iterator marker = list->begin(); marker != list->end();

[yosin_UTC9, 2017/02/24 04:36:18]

nit: s/marker/it/ or s/marker/marker_it/ since it is MarkerList::iterator.

Then add:
Marker& marker = *it;

+         ++marker) {
+      // algorithm inspired by https://dom.spec.whatwg.org/#concept-cd-replace
+      // but with some changes
+      if ((*marker)->startOffset() > offset) {
+        // Deviation from the concept-cd-replace algorithm: < instead of <= in
+        // the next line
+        if ((*marker)->startOffset() < offset + oldLength) {
+          // Marker start was in the replaced text. Move to end of new text
+          // (Deviation from the concept-cd-replace algorithm: that algorithm
+          // would move to the beginning of the new text here)
+          (*marker)->setStartOffset(offset + newLength);
+        } else {
+          // Marker start was after the replaced text. Shift by length
+          // difference
+          unsigned oldStartOffset = (*marker)->startOffset();
+          (*marker)->setStartOffset(oldStartOffset + newLength - oldLength);
+        }
+        didShiftMarker = true;
+      }
+
+      if ((*marker)->endOffset() > offset) {
+        // Deviation from the concept-cd-replace algorithm: < instead of <= in
+        // the next line
+        if ((*marker)->endOffset() < offset + oldLength) {
+          // Marker end was in the replaced text. Move to beginning of new text
+          (*marker)->setEndOffset(offset);
+        } else {
+          // Marker end was after the replaced text. Shift by length difference
+          unsigned oldEndOffset = (*marker)->endOffset();
+          (*marker)->setEndOffset(oldEndOffset + newLength - oldLength);
+        }
+        didShiftMarker = true;
+      }
+
+      if ((*marker)->startOffset() >= (*marker)->endOffset()) {
+        list->remove(marker - list->begin());
+        --marker;
+        continue;
+      }
+    }
+  }
+
+  if (didShiftMarker) {

[yosin_UTC9, 2017/02/24 04:36:18]

Let's use early-return style

if (!didShiftMarker)
  return;
invalidateRectsForMarkersInNode(*node);
if (!node->layoutObject())
  return;
node->layoutObject()->setShouldDoFullPaintInvalidation();

+    invalidateRectsForMarkersInNode(*node);

[yosin_UTC9, 2017/02/24 04:36:18]

I think we don't need to call invalidateRectsForMarkersInNode() if
node->layoutObject() == nullptr.

+    // repaint the affected node
+    if (node->layoutObject())
+      node->layoutObject()->setShouldDoFullPaintInvalidation();
+  }
+}
+
 }  // namespace blink
 
 #ifndef NDEBUG
 void showDocumentMarkers(const blink::DocumentMarkerController* controller) {
   if (controller)
     controller->showMarkers();
 }
 #endif