Rewrite DocumentMarkerController to use SynchronousMutationObserver

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

Index: third_party/WebKit/Source/core/editing/markers/DocumentMarkerController.cpp
diff --git a/third_party/WebKit/Source/core/editing/markers/DocumentMarkerController.cpp b/third_party/WebKit/Source/core/editing/markers/DocumentMarkerController.cpp
index 0db8cc87179a923581b191c0ff2b131c7154db5a..8a3e2f4056c34826f2299e169fac32df7c2fe956 100644
--- a/third_party/WebKit/Source/core/editing/markers/DocumentMarkerController.cpp
+++ b/third_party/WebKit/Source/core/editing/markers/DocumentMarkerController.cpp
@@ -82,8 +82,10 @@ inline bool DocumentMarkerController::possiblyHasMarkers(
   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();
@@ -175,11 +177,6 @@ static bool startsFurther(const Member<RenderedDocumentMarker>& lhv,
   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();
@@ -305,10 +302,7 @@ void DocumentMarkerController::copyMarkers(Node* srcNode,
     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;
 
@@ -585,6 +579,7 @@ void DocumentMarkerController::invalidateRectsForAllMarkers() {
 DEFINE_TRACE(DocumentMarkerController) {
   visitor->trace(m_markers);
   visitor->trace(m_document);
+  SynchronousMutationObserver::trace(visitor);
 }
 
 void DocumentMarkerController::removeMarkers(
@@ -724,45 +719,6 @@ void DocumentMarkerController::repaintMarkers(
   }
 }
 
-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()))
@@ -855,6 +811,81 @@ void DocumentMarkerController::showMarkers() const {
 }
 #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 it = list->begin(); it != list->end(); ++it) {
+      RenderedDocumentMarker& marker = **it;
+      // 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())
+        continue;
+      list->remove(it - list->begin());
+      --it;
+    }
+  }
+
+  if (!didShiftMarker)
+    return;
+  if (!node->layoutObject())
+    return;
+  invalidateRectsForMarkersInNode(*node);
+  // repaint the affected node
+  node->layoutObject()->setShouldDoFullPaintInvalidation();
+}
+
 }  // namespace blink
 
 #ifndef NDEBUG