Allow selection to skip over contenteditable

Source/core/editing/VisiblePosition.cpp

Index: Source/core/editing/VisiblePosition.cpp
diff --git a/Source/core/editing/VisiblePosition.cpp b/Source/core/editing/VisiblePosition.cpp
index 0aafd6c0831558336d3c969d60d830da2db2c439..0ecd02cccb40f79e6a65e2005504a5671a295b79 100644
--- a/Source/core/editing/VisiblePosition.cpp
+++ b/Source/core/editing/VisiblePosition.cpp
@@ -63,21 +63,20 @@ void VisiblePosition::init(const Position& position, EAffinity affinity)
 
 VisiblePosition VisiblePosition::next(EditingBoundaryCrossingRule rule) const
 {
-    // FIXME: Support CanSkipEditingBoundary
-    ASSERT(rule == CanCrossEditingBoundary || rule == CannotCrossEditingBoundary);
     VisiblePosition next(nextVisuallyDistinctCandidate(m_deepPosition), m_affinity);
 
-    if (rule == CanCrossEditingBoundary)
+    switch (rule) {
+    case CanCrossEditingBoundary:
         return next;
-
-    return honorEditingBoundaryAtOrAfter(next);
+    case CannotCrossEditingBoundary:
+        return honorEditingBoundaryAtOrAfter(next);
+    case CanSkipOverEditingBoundary:
+        return skipToEndOfEditingBoundary(next);
+    }
 }
 
 VisiblePosition VisiblePosition::previous(EditingBoundaryCrossingRule rule) const
 {
-    // FIXME: Support CanSkipEditingBoundary
-    ASSERT(rule == CanCrossEditingBoundary || rule == CannotCrossEditingBoundary);
-    // find first previous DOM position that is visible
     Position pos = previousVisuallyDistinctCandidate(m_deepPosition);
 
     // return null visible position if there is no previous visible position
@@ -97,10 +96,14 @@ VisiblePosition VisiblePosition::previous(EditingBoundaryCrossingRule rule) cons
     }
 #endif
 
-    if (rule == CanCrossEditingBoundary)
+    switch (rule) {
+    case CanCrossEditingBoundary:
         return prev;
-
-    return honorEditingBoundaryAtOrBefore(prev);
+    case CannotCrossEditingBoundary:
+        return honorEditingBoundaryAtOrBefore(prev);
+    case CanSkipOverEditingBoundary:
+        return skipToStartOfEditingBoundary(prev);
+    }
 }
 
 Position VisiblePosition::leftVisuallyDistinctCandidate() const
@@ -488,6 +491,46 @@ VisiblePosition VisiblePosition::honorEditingBoundaryAtOrAfter(const VisiblePosi
     return firstEditablePositionAfterPositionInRoot(pos.deepEquivalent(), highestRoot);
 }
 
+VisiblePosition VisiblePosition::skipToStartOfEditingBoundary(const VisiblePosition &pos) const
+{
+    if (pos.isNull())
+        return pos;
+
+    Node* highestRoot = highestEditableRoot(deepEquivalent());
+    Node* highestRootOfPos = highestEditableRoot(pos.deepEquivalent());
+
+    // Return pos itself if the two are from the very same editable region, or both are non-editable.
+    if (highestRootOfPos == highestRoot)
+        return pos;
+
+    // If |pos| has an editable root, skip to the start
+    if (highestRootOfPos)
+        return previousVisuallyDistinctCandidate(Position(highestRootOfPos, Position::PositionIsBeforeAnchor).parentAnchoredEquivalent());
+
+    // That must mean that |pos| is not editable. Return the last position before pos that is in the same editable region as this position
+    return lastEditablePositionBeforePositionInRoot(pos.deepEquivalent(), highestRoot);
+}
+
+VisiblePosition VisiblePosition::skipToEndOfEditingBoundary(const VisiblePosition &pos) const
+{
+    if (pos.isNull())
+        return pos;
+
+    Node* highestRoot = highestEditableRoot(deepEquivalent());
+    Node* highestRootOfPos = highestEditableRoot(pos.deepEquivalent());
+
+    // Return pos itself if the two are from the very same editable region, or both are non-editable.
+    if (highestRootOfPos == highestRoot)
+        return pos;
+
+    // If |pos| has an editable root, skip to the end
+    if (highestRootOfPos)
+        return Position(highestRootOfPos, Position::PositionIsAfterAnchor).parentAnchoredEquivalent();
+
+    // That must mean that |pos| is not editable. Return the next position after pos that is in the same editable region as this position
+    return firstEditablePositionAfterPositionInRoot(pos.deepEquivalent(), highestRoot);
+}
+
 static Position canonicalizeCandidate(const Position& candidate)
 {
     if (candidate.isNull())