Make RenderObject::style() return a const object

Source/core/editing/ApplyBlockElementCommand.cpp

 /*
  * Copyright (C) 2006, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 155 matching lines @@
         return false;
 
     TrackExceptionState exceptionState;
     String textAtPosition = toText(textNode)->substringData(offset, 1, exceptionState);
     if (exceptionState.hadException())
         return false;
 
     return textAtPosition[0] == '\n';
 }
 
-static LayoutStyle* layoutStyleOfEnclosingTextNode(const Position& position)
+static const LayoutStyle* layoutStyleOfEnclosingTextNode(const Position& position)
 {
     if (position.anchorType() != Position::PositionIsOffsetInAnchor || !position.containerNode() || !position.containerNode()->isTextNode())
         return 0;
     return position.containerNode()->layoutStyle();
 }
 
 void ApplyBlockElementCommand::rangeForParagraphSplittingTextNodesIfNeeded(const VisiblePosition& endOfCurrentParagraph, Position& start, Position& end)
 {
     start = startOfParagraph(endOfCurrentParagraph).deepEquivalent();
     end = endOfCurrentParagraph.deepEquivalent();
 
     document().updateRenderTreeIfNeeded();
 
     bool isStartAndEndOnSameNode = false;
-    if (LayoutStyle* startStyle = layoutStyleOfEnclosingTextNode(start)) {
+    if (const LayoutStyle* startStyle = layoutStyleOfEnclosingTextNode(start)) {
         isStartAndEndOnSameNode = layoutStyleOfEnclosingTextNode(end) && start.containerNode() == end.containerNode();
         bool isStartAndEndOfLastParagraphOnSameNode = layoutStyleOfEnclosingTextNode(m_endOfLastParagraph) && start.containerNode() == m_endOfLastParagraph.containerNode();
 
         // Avoid obtanining the start of next paragraph for start
         if (startStyle->preserveNewline() && isNewLineAtPosition(start) && !isNewLineAtPosition(start.previous()) && start.offsetInContainerNode() > 0)
             start = startOfParagraph(VisiblePosition(end.previous())).deepEquivalent();
 
         // If start is in the middle of a text node, split.
         if (!startStyle->collapseWhiteSpace() && start.offsetInContainerNode() > 0) {
             int startOffset = start.offsetInContainerNode();
             Text* startText = start.containerText();
             splitTextNode(startText, startOffset);
             start = firstPositionInNode(startText);
             if (isStartAndEndOnSameNode) {
                 ASSERT(end.offsetInContainerNode() >= startOffset);
                 end = Position(startText, end.offsetInContainerNode() - startOffset);
             }
             if (isStartAndEndOfLastParagraphOnSameNode) {
                 ASSERT(m_endOfLastParagraph.offsetInContainerNode() >= startOffset);
                 m_endOfLastParagraph = Position(startText, m_endOfLastParagraph.offsetInContainerNode() - startOffset);
             }
         }
     }
 
     document().updateRenderTreeIfNeeded();
 
-    if (LayoutStyle* endStyle = layoutStyleOfEnclosingTextNode(end)) {
+    if (const LayoutStyle* endStyle = layoutStyleOfEnclosingTextNode(end)) {
         bool isEndAndEndOfLastParagraphOnSameNode = layoutStyleOfEnclosingTextNode(m_endOfLastParagraph) && end.deprecatedNode() == m_endOfLastParagraph.deprecatedNode();
         // Include \n at the end of line if we're at an empty paragraph
         if (endStyle->preserveNewline() && start == end && end.offsetInContainerNode() < end.containerNode()->maxCharacterOffset()) {
             int endOffset = end.offsetInContainerNode();
             if (!isNewLineAtPosition(end.previous()) && isNewLineAtPosition(end))
                 end = Position(end.containerText(), endOffset + 1);
             if (isEndAndEndOfLastParagraphOnSameNode && end.offsetInContainerNode() >= m_endOfLastParagraph.offsetInContainerNode())
                 m_endOfLastParagraph = end;
         }
 
@@ skipping 11 matching lines @@
             }
             end = lastPositionInNode(endContainer->previousSibling());
         }
     }
 }
 
 VisiblePosition ApplyBlockElementCommand::endOfNextParagrahSplittingTextNodesIfNeeded(VisiblePosition& endOfCurrentParagraph, Position& start, Position& end)
 {
     VisiblePosition endOfNextParagraph = endOfParagraph(endOfCurrentParagraph.next());
     Position position = endOfNextParagraph.deepEquivalent();
-    LayoutStyle* style = layoutStyleOfEnclosingTextNode(position);
+    const LayoutStyle* style = layoutStyleOfEnclosingTextNode(position);
     if (!style)
         return endOfNextParagraph;
 
     RefPtrWillBeRawPtr<Text> text = position.containerText();
     if (!style->preserveNewline() || !position.offsetInContainerNode() || !isNewLineAtPosition(firstPositionInNode(text.get())))
         return endOfNextParagraph;
 
     // \n at the beginning of the text node immediately following the current paragraph is trimmed by moveParagraphWithClones.
     // If endOfNextParagraph was pointing at this same text node, endOfNextParagraph will be shifted by one paragraph.
     // Avoid this by splitting "\n"
@@ skipping 28 matching lines @@
     return element.release();
 }
 
 void ApplyBlockElementCommand::trace(Visitor* visitor)
 {
     visitor->trace(m_endOfLastParagraph);
     CompositeEditCommand::trace(visitor);
 }
 
 }