Move code for SelectionEditor in FrameSelection.cpp to SelectionEditor.cpp

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

Index: third_party/WebKit/Source/core/editing/SelectionEditor.cpp
diff --git a/third_party/WebKit/Source/core/editing/SelectionEditor.cpp b/third_party/WebKit/Source/core/editing/SelectionEditor.cpp
index 3cbe4ecee2d19bcee6490b58cb16a34655a86a29..3835d0678c75ee6ef0417df6d5821adde52c828a 100644
--- a/third_party/WebKit/Source/core/editing/SelectionEditor.cpp
+++ b/third_party/WebKit/Source/core/editing/SelectionEditor.cpp
@@ -178,6 +178,199 @@ void SelectionEditor::contextDestroyed(Document*) {
   m_cacheIsDirty = false;
 }
 
+static Position computePositionForChildrenRemoval(const Position& position,
+                                                  ContainerNode& container) {
+  Node* node = position.computeContainerNode();
+  if (container.containsIncludingHostElements(*node))
+    return Position::firstPositionInNode(&container);
+  return position;
+}
+
+void SelectionEditor::nodeChildrenWillBeRemoved(ContainerNode& container) {
+  if (m_selection.isNone())
+    return;
+  const Position oldBase = m_selection.m_base;
+  const Position oldExtent = m_selection.m_extent;
+  const Position& newBase =
+      computePositionForChildrenRemoval(oldBase, container);
+  const Position& newExtent =
+      computePositionForChildrenRemoval(oldExtent, container);
+  if (newBase == oldBase && newExtent == oldExtent)
+    return;
+  m_selection = SelectionInDOMTree::Builder()
+                    .setBaseAndExtent(newBase, newExtent)
+                    .build();
+  markCacheDirty();
+}
+
+static Position computePositionForNodeRemoval(const Position& position,
+                                              Node& nodeToBeRemoved) {
+  Position result = position;
+  // TODO(yosin): We should rename |updatePositionForNodeRemoval()|
+  // to |computePositionForNodeRemoval()| to avoid using output parameter.
+  updatePositionForNodeRemoval(result, nodeToBeRemoved);
+  return result;
+}
+
+void SelectionEditor::nodeWillBeRemoved(Node& nodeToBeRemoved) {
+  if (m_selection.isNone())
+    return;
+  const Position oldBase = m_selection.m_base;
+  const Position oldExtent = m_selection.m_extent;
+  const Position& newBase =
+      computePositionForNodeRemoval(oldBase, nodeToBeRemoved);
+  const Position& newExtent =
+      computePositionForNodeRemoval(oldExtent, nodeToBeRemoved);
+  if (newBase == oldBase && newExtent == oldExtent)
+    return;
+  m_selection = SelectionInDOMTree::Builder()
+                    .setBaseAndExtent(newBase, newExtent)
+                    .build();
+  markCacheDirty();
+}
+
+static Position updatePositionAfterAdoptingTextReplacement(
+    const Position& position,
+    CharacterData* node,
+    unsigned offset,
+    unsigned oldLength,
+    unsigned newLength) {
+  if (position.anchorNode() != node)
+    return position;
+
+  if (position.isBeforeAnchor()) {
+    return updatePositionAfterAdoptingTextReplacement(
+        Position(node, 0), node, offset, oldLength, newLength);
+  }
+  if (position.isAfterAnchor()) {
+    return updatePositionAfterAdoptingTextReplacement(
+        Position(node, oldLength), node, offset, oldLength, newLength);
+  }
+
+  // See:
+  // http://www.w3.org/TR/DOM-Level-2-Traversal-Range/ranges.html#Level-2-Range-Mutation
+  DCHECK_GE(position.offsetInContainerNode(), 0);
+  unsigned positionOffset =
+      static_cast<unsigned>(position.offsetInContainerNode());
+  // Replacing text can be viewed as a deletion followed by insertion.
+  if (positionOffset >= offset && positionOffset <= offset + oldLength)
+    positionOffset = offset;
+
+  // Adjust the offset if the position is after the end of the deleted contents
+  // (positionOffset > offset + oldLength) to avoid having a stale offset.
+  if (positionOffset > offset + oldLength)
+    positionOffset = positionOffset - oldLength + newLength;
+
+  // Due to case folding
+  // (http://unicode.org/Public/UCD/latest/ucd/CaseFolding.txt), LayoutText
+  // length may be different from Text length.  A correct implementation would
+  // translate the LayoutText offset to a Text offset; this is just a safety
+  // precaution to avoid offset values that run off the end of the Text.
+  if (positionOffset > node->length())
+    positionOffset = node->length();
+
+  return Position(node, positionOffset);
+}
+
+void SelectionEditor::didUpdateCharacterData(CharacterData* node,
+                                             unsigned offset,
+                                             unsigned oldLength,
+                                             unsigned newLength) {
+  // The fragment check is a performance optimization. See
+  // http://trac.webkit.org/changeset/30062.
+  if (m_selection.isNone() || !node || !node->isConnected()) {
+    didFinishDOMMutation();
+    return;
+  }
+  const Position& newBase = updatePositionAfterAdoptingTextReplacement(
+      m_selection.m_base, node, offset, oldLength, newLength);
+  const Position& newExtent = updatePositionAfterAdoptingTextReplacement(
+      m_selection.m_extent, node, offset, oldLength, newLength);
+  didFinishTextChange(newBase, newExtent);
+}
+
+// TODO(yosin): We should introduce |Position(const Text&, int)| to avoid
+// |const_cast<Text*>|.
+static Position updatePostionAfterAdoptingTextNodesMerged(
+    const Position& position,
+    const Text& mergedNode,
+    const NodeWithIndex& nodeToBeRemovedWithIndex,
+    unsigned oldLength) {
+  Node* const anchorNode = position.anchorNode();
+  const Node& nodeToBeRemoved = nodeToBeRemovedWithIndex.node();
+  switch (position.anchorType()) {
+    case PositionAnchorType::BeforeChildren:
+    case PositionAnchorType::AfterChildren:
+      return position;
+    case PositionAnchorType::BeforeAnchor:
+      if (anchorNode == nodeToBeRemoved)
+        return Position(const_cast<Text*>(&mergedNode), mergedNode.length());
+      return position;
+    case PositionAnchorType::AfterAnchor:
+      if (anchorNode == nodeToBeRemoved)
+        return Position(const_cast<Text*>(&mergedNode), mergedNode.length());
+      if (anchorNode == mergedNode)
+        return Position(const_cast<Text*>(&mergedNode), oldLength);
+      return position;
+    case PositionAnchorType::OffsetInAnchor: {
+      const int offset = position.offsetInContainerNode();
+      if (anchorNode == nodeToBeRemoved)
+        return Position(const_cast<Text*>(&mergedNode), oldLength + offset);
+      if (anchorNode == nodeToBeRemoved.parentNode() &&
+          offset == nodeToBeRemovedWithIndex.index()) {
+        return Position(const_cast<Text*>(&mergedNode), oldLength);
+      }
+      return position;
+    }
+  }
+  NOTREACHED() << position;
+  return position;
+}
+
+void SelectionEditor::didMergeTextNodes(
+    const Text& mergedNode,
+    const NodeWithIndex& nodeToBeRemovedWithIndex,
+    unsigned oldLength) {
+  if (m_selection.isNone()) {
+    didFinishDOMMutation();
+    return;
+  }
+  const Position& newBase = updatePostionAfterAdoptingTextNodesMerged(
+      m_selection.m_base, mergedNode, nodeToBeRemovedWithIndex, oldLength);
+  const Position& newExtent = updatePostionAfterAdoptingTextNodesMerged(
+      m_selection.m_extent, mergedNode, nodeToBeRemovedWithIndex, oldLength);
+  didFinishTextChange(newBase, newExtent);
+}
+
+static Position updatePostionAfterAdoptingTextNodeSplit(
+    const Position& position,
+    const Text& oldNode) {
+  if (!position.anchorNode() || position.anchorNode() != &oldNode ||
+      !position.isOffsetInAnchor())
+    return position;
+  // See:
+  // http://www.w3.org/TR/DOM-Level-2-Traversal-Range/ranges.html#Level-2-Range-Mutation
+  DCHECK_GE(position.offsetInContainerNode(), 0);
+  unsigned positionOffset =
+      static_cast<unsigned>(position.offsetInContainerNode());
+  unsigned oldLength = oldNode.length();
+  if (positionOffset <= oldLength)
+    return position;
+  return Position(toText(oldNode.nextSibling()), positionOffset - oldLength);
+}
+
+void SelectionEditor::didSplitTextNode(const Text& oldNode) {
+  if (m_selection.isNone() || !oldNode.isConnected()) {
+    didFinishDOMMutation();
+    return;
+  }
+  const Position& newBase =
+      updatePostionAfterAdoptingTextNodeSplit(m_selection.m_base, oldNode);
+  const Position& newExtent =
+      updatePostionAfterAdoptingTextNodeSplit(m_selection.m_extent, oldNode);
+  didFinishTextChange(newBase, newExtent);
+}
+
 void SelectionEditor::resetLogicalRange() {
   // Non-collapsed ranges are not allowed to start at the end of a line that
   // is wrapped, they start at the beginning of the next line instead