*** DO NOT LAND *** Attempt to understand Regions complexity

Source/core/rendering/RootInlineBox.cpp

 /*
  * Copyright (C) 2003, 2006, 2008 Apple Inc. 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
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
 #include "config.h"
 #include "core/rendering/RootInlineBox.h"
 
 #include "core/dom/Document.h"
 #include "core/rendering/EllipsisBox.h"
 #include "core/rendering/HitTestResult.h"
 #include "core/rendering/InlineTextBox.h"
 #include "core/rendering/PaintInfo.h"
 #include "core/rendering/RenderBlockFlow.h"
-#include "core/rendering/RenderFlowThread.h"
 #include "core/rendering/RenderInline.h"
 #include "core/rendering/RenderView.h"
 #include "core/rendering/VerticalPositionCache.h"
 #include "platform/text/BidiResolver.h"
 #include "wtf/unicode/Unicode.h"
 
 using namespace std;
 
 namespace WebCore {
 
@@ skipping 162 matching lines @@
 {
     if (box->renderer() == m_lineBreakObj)
         setLineBreakInfo(0, 0, BidiStatus());
 
     for (RootInlineBox* prev = prevRootBox(); prev && prev->lineBreakObj() == box->renderer(); prev = prev->prevRootBox()) {
         prev->setLineBreakInfo(0, 0, BidiStatus());
         prev->markDirty();
     }
 }
 
-RenderRegion* RootInlineBox::containingRegion() const
-{
-    RenderRegion* region = m_fragmentationData ? m_fragmentationData->m_containingRegion : 0;
-
-#ifndef NDEBUG
-    if (region) {
-        RenderFlowThread* flowThread = block()->flowThreadContainingBlock();
-        const RenderRegionList& regionList = flowThread->renderRegionList();
-        ASSERT(regionList.contains(region));
-    }
-#endif
-
-    return region;
-}
-
-void RootInlineBox::setContainingRegion(RenderRegion* region)
-{
-    ASSERT(!isDirty());
-    ASSERT(block()->flowThreadContainingBlock());
-    LineFragmentationData* fragmentationData  = ensureLineFragmentationData();
-    fragmentationData->m_containingRegion = region;
-}
-
 LayoutUnit RootInlineBox::alignBoxesInBlockDirection(LayoutUnit heightOfBlock, GlyphOverflowAndFallbackFontsMap& textBoxDataMap, VerticalPositionCache& verticalPositionCache)
 {
     // SVG will handle vertical alignment on its own.
     if (isSVGRootInlineBox())
         return 0;
 
     LayoutUnit maxPositionTop = 0;
     LayoutUnit maxPositionBottom = 0;
     int maxAscent = 0;
     int maxDescent = 0;
@@ skipping 20 matching lines @@
     bool hasAnnotationsBefore = false;
     bool hasAnnotationsAfter = false;
     placeBoxesInBlockDirection(heightOfBlock, maxHeight, maxAscent, noQuirksMode, lineTop, lineBottom, setLineTop,
                                lineTopIncludingMargins, lineBottomIncludingMargins, hasAnnotationsBefore, hasAnnotationsAfter, baselineType());
     m_hasAnnotationsBefore = hasAnnotationsBefore;
     m_hasAnnotationsAfter = hasAnnotationsAfter;
 
     maxHeight = max<LayoutUnit>(0, maxHeight); // FIXME: Is this really necessary?
 
     setLineTopBottomPositions(lineTop, lineBottom, heightOfBlock, heightOfBlock + maxHeight);
-    setPaginatedLineWidth(block()->availableLogicalWidthForContent(heightOfBlock));
+    setPaginatedLineWidth(block()->availableLogicalWidthForContent());
 
     LayoutUnit annotationsAdjustment = beforeAnnotationsAdjustment();
     if (annotationsAdjustment) {
         // FIXME: Need to handle pagination here. We might have to move to the next page/column as a result of the
         // ruby expansion.
         adjustBlockDirectionPosition(annotationsAdjustment);
         heightOfBlock += annotationsAdjustment;
     }
 
     LayoutUnit gridSnapAdjustment = lineSnapAdjustment();
@@ skipping 703 matching lines @@
 }
 
 #ifndef NDEBUG
 const char* RootInlineBox::boxName() const
 {
     return "RootInlineBox";
 }
 #endif
 
 } // namespace WebCore