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 41afe11c85185d22f509ddc551141887d1ae33c5..bd062d535a23184d1af44bc9cb0186d5fb8584b0 100644
--- a/third_party/WebKit/Source/core/editing/markers/DocumentMarkerController.cpp
+++ b/third_party/WebKit/Source/core/editing/markers/DocumentMarkerController.cpp
@@ -84,8 +84,10 @@ 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();
@@ -178,11 +180,6 @@ 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();
@@ -588,6 +585,7 @@ void DocumentMarkerController::invalidateRectsForAllMarkers() {
 DEFINE_TRACE(DocumentMarkerController) {
   visitor->trace(m_markers);
   visitor->trace(m_document);
+  SynchronousMutationObserver::trace(visitor);
 }
 
 void DocumentMarkerController::removeMarkers(
@@ -697,6 +695,30 @@ void DocumentMarkerController::removeMarkersFromList(
   }
 }
 
+void DocumentMarkerController::removeZeroLengthMarkers() {
+  for (auto& nodeMarkers : m_markers) {
+    const Node& node = *nodeMarkers.key;
+    MarkerLists& markers = *nodeMarkers.value;
+    for (size_t markerListIndex = 0;
+         markerListIndex < DocumentMarker::MarkerTypeIndexesCount;
+         ++markerListIndex) {
+      Member<MarkerList>& list = markers[markerListIndex];

[yosin_UTC9, 2017/02/20 07:26:27]

nit: s/&//

+      if (!list)
+        continue;
+      bool removedMarkers = false;
+      for (size_t j = list->size(); j > 0; --j) {
+        if (list->at(j - 1)->startOffset() == list->at(j - 1)->endOffset()) {
+          list->remove(j - 1);
+          removedMarkers = true;
+        }
+      }
+      if (removedMarkers &&

[yosin_UTC9, 2017/02/20 07:26:27]

We prefer early-return-style.

if (!removeMarkers)
  continue;
if (markerListIndex != DocumentMarker::TextMatchMarkerIndex)
  continue;
invalidatePaintForTickmarks(node);

+          markerListIndex == DocumentMarker::TextMatchMarkerIndex)
+        invalidatePaintForTickmarks(node);
+    }
+  }
+}
+
 void DocumentMarkerController::repaintMarkers(
     DocumentMarker::MarkerTypes markerTypes) {
   if (!possiblyHasMarkers(markerTypes))
@@ -727,45 +749,6 @@ 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.get(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()))
@@ -858,6 +841,90 @@ 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) {

[yosin_UTC9, 2017/02/20 07:26:27]

nit: no need to have "{}"

+    removeMarkers(node, offset, oldLength);
+  }
+
+  if (!possiblyHasMarkers(DocumentMarker::AllMarkers()))
+    return;
+  DCHECK(!m_markers.isEmpty());
+
+  MarkerLists* markers = m_markers.get(node);
+  if (!markers)
+    return;
+
+  bool didShiftMarker = false;
+  for (size_t markerListIndex = 0;
+       markerListIndex < DocumentMarker::MarkerTypeIndexesCount;
+       ++markerListIndex) {
+    Member<MarkerList>& list = (*markers)[markerListIndex];

[yosin_UTC9, 2017/02/20 07:26:27]

nit: s/&//

+    if (!list)
+      continue;
+
+    for (MarkerList::iterator marker = list->begin(); marker != list->end();
+         ++marker) {
+      // if marker is contained by but not equal to the replaced range, remove
+      // the marker
+      if ((offset <= (*marker)->startOffset() &&
+           (*marker)->endOffset() < offset + oldLength) ||
+          (offset < (*marker)->startOffset() &&
+           (*marker)->endOffset() <= offset + oldLength)) {
+        list->remove(marker - list->begin());
+        marker--;
+        continue;
+      }
+
+      // 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 beginning of new
+          // text
+          (*marker)->setStartOffset(offset);
+        } else {
+          // Marker start was after the replaced text. Shift by length
+          // difference
+          unsigned oldStartOffset = (*marker)->startOffset();
+          (*marker)->setStartOffset(oldStartOffset + newLength - oldLength);
+        }
+      }
+
+      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 (didShiftMarker) {
+    removeZeroLengthMarkers();
+    invalidateRectsForMarkersInNode(*node);
+    // repaint the affected node
+    if (node->layoutObject())
+      node->layoutObject()->setShouldDoFullPaintInvalidation();
+  }
+}
+
 }  // namespace blink
 
 #ifndef NDEBUG