Cleanup friends of LayoutObject

Source/core/layout/LayoutBlock.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 544 matching lines @@
 
 void LayoutBlock::promoteAllChildrenAndInsertAfter()
 {
     LayoutObject* firstPromotee = firstChild();
     if (!firstPromotee)
         return;
     LayoutObject* lastPromotee = lastChild();
     LayoutBlock* parent = toLayoutBlock(this->parent());
     LayoutObject* nextSiblingOfPromotees = nextSibling();
     for (LayoutObject* o = firstPromotee; o; o = o->nextSibling())
-        o->setParent(parent);
+        DangerousLayoutTreeMutator(*o).setParent(parent);
     children()->setFirstChild(nullptr);
     children()->setLastChild(nullptr);
-    firstPromotee->setPreviousSibling(this);
-    setNextSibling(firstPromotee);
-    lastPromotee->setNextSibling(nextSiblingOfPromotees);
+    DangerousLayoutTreeMutator(*firstPromotee).setPreviousSibling(this);
+    DangerousLayoutTreeMutator(*this).setNextSibling(firstPromotee);
+    DangerousLayoutTreeMutator(*lastPromotee).setNextSibling(nextSiblingOfPromotees);
     if (nextSiblingOfPromotees)
-        nextSiblingOfPromotees->setPreviousSibling(lastPromotee);
+        DangerousLayoutTreeMutator(*nextSiblingOfPromotees).setPreviousSibling(lastPromotee);

[esprehn, 2015/08/21 21:20:32]

Instead of having all methods I'd prefer it only had insertBefore() and
setParent() and we moved this tree mutation operation into the
LayoutObjectChildList or the DangerousLayoutTreeMutator.

setParent() should also ASSERT that nextSibling() and previousSibling() are
nullptr.

[Xianzhu, 2015/08/21 22:52:19]

Thanks for the finding. Actually I didn't look into the real logic here.

Changed the whole function body to moveAllChildrenTo(parent(), nextSibling()).

     if (parent->children()->lastChild() == this)
         parent->children()->setLastChild(lastPromotee);
 }
 
 void LayoutBlock::removeLeftoverAnonymousBlock(LayoutBlock* child)
 {
     ASSERT(child->isAnonymousBlock());
     ASSERT(!child->childrenInline());
     ASSERT(child->parent() == this);
 
     if (child->continuation())
         return;
 
     // Promote all the leftover anonymous block's children (to become children of this block
     // instead). We still want to keep the leftover block in the tree for a moment, for notification
     // purposes done further below (flow threads and grids).
     child->promoteAllChildrenAndInsertAfter();
 
     // Remove all the information in the flow thread associated with the leftover anonymous block.
-    child->removeFromLayoutFlowThread();
+    DangerousLayoutTreeMutator(*child).removeFromLayoutFlowThread();

[esprehn, 2015/08/21 21:20:31]

I think I would just make removeFromLayoutFlowThread public.

[Xianzhu, 2015/08/21 22:52:19]

Done.

 
     // LayoutGrid keeps track of its children, we must notify it about changes in the tree.
     if (child->parent()->isLayoutGrid())
         toLayoutGrid(child->parent())->dirtyGrid();
 
     // Now remove the leftover anonymous block from the tree, and destroy it. We'll rip it out
     // manually from the tree before destroying it, because we don't want to trigger any tree
     // adjustments with regards to anonymous blocks (or any other kind of undesired chain-reaction).
     children()->removeChildNode(this, child, false);
     child->destroy();
@@ skipping 2168 matching lines @@
     if (layoutObject->isOutOfFlowPositioned() || !layoutObject->needsOverflowRecalcAfterStyleChange())
         return false;
 
     ASSERT(layoutObject->isLayoutBlock());
     return toLayoutBlock(layoutObject)->recalcOverflowAfterStyleChange();
 }
 
 bool LayoutBlock::recalcChildOverflowAfterStyleChange()
 {
     ASSERT(childNeedsOverflowRecalcAfterStyleChange());
-    setChildNeedsOverflowRecalcAfterStyleChange(false);
+    clearChildNeedsOverflowRecalcAfterStyleChange();
 
     bool childrenOverflowChanged = false;
 
     if (childrenInline()) {
         ListHashSet<RootInlineBox*> lineBoxes;
         ASSERT_WITH_SECURITY_IMPLICATION(isLayoutBlockFlow());
         for (InlineWalker walker(toLayoutBlockFlow(this)); !walker.atEnd(); walker.advance()) {
             LayoutObject* layoutObject = walker.current();
             if (recalcNormalFlowChildOverflowIfNeeded(layoutObject)) {
                 childrenOverflowChanged = true;
@@ skipping 35 matching lines @@
 {
     ASSERT(needsOverflowRecalcAfterStyleChange());
 
     bool childrenOverflowChanged = false;
     if (childNeedsOverflowRecalcAfterStyleChange())
         childrenOverflowChanged = recalcChildOverflowAfterStyleChange();
 
     if (!selfNeedsOverflowRecalcAfterStyleChange() && !childrenOverflowChanged)
         return false;
 
-    setSelfNeedsOverflowRecalcAfterStyleChange(false);
+    clearSelfNeedsOverflowRecalcAfterStyleChange();
     // If the current block needs layout, overflow will be recalculated during
     // layout time anyway. We can safely exit here.
     if (needsLayout())
         return false;
 
     LayoutUnit oldClientAfterEdge = hasOverflowModel() ? m_overflow->layoutClientAfterEdge() : clientLogicalBottom();
     computeOverflow(oldClientAfterEdge);
 
     if (hasOverflowClip())
         layer()->scrollableArea()->updateAfterOverflowRecalc();
@@ skipping 70 matching lines @@
 void LayoutBlock::showLineTreeAndMark(const InlineBox* markedBox1, const char* markedLabel1, const InlineBox* markedBox2, const char* markedLabel2, const LayoutObject* obj) const
 {
     showLayoutObject();
     for (const RootInlineBox* root = firstRootBox(); root; root = root->nextRootBox())
         root->showLineTreeAndMark(markedBox1, markedLabel1, markedBox2, markedLabel2, obj, 1);
 }
 
 #endif
 
 } // namespace blink