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

Source/core/rendering/RenderInline.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 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.
  *
@@ skipping 13 matching lines @@
 #include "core/rendering/RenderInline.h"
 
 #include "core/dom/FullscreenElementStack.h"
 #include "core/page/Chrome.h"
 #include "core/page/Page.h"
 #include "core/rendering/GraphicsContextAnnotator.h"
 #include "core/rendering/HitTestResult.h"
 #include "core/rendering/InlineTextBox.h"
 #include "core/rendering/LayoutRectRecorder.h"
 #include "core/rendering/RenderBlock.h"
-#include "core/rendering/RenderFlowThread.h"
 #include "core/rendering/RenderFullScreen.h"
 #include "core/rendering/RenderGeometryMap.h"
 #include "core/rendering/RenderLayer.h"
 #include "core/rendering/RenderTheme.h"
 #include "core/rendering/RenderView.h"
 #include "core/rendering/style/StyleInheritedData.h"
 #include "platform/geometry/FloatQuad.h"
 #include "platform/geometry/TransformState.h"
 #include "platform/graphics/GraphicsContext.h"
 
@@ skipping 158 matching lines @@
 void RenderInline::updateAlwaysCreateLineBoxes(bool fullLayout)
 {
     // Once we have been tainted once, just assume it will happen again. This way effects like hover highlighting that change the
     // background color will only cause a layout on the first rollover.
     if (m_alwaysCreateLineBoxes)
         return;
 
     RenderStyle* parentStyle = parent()->style();
     RenderInline* parentRenderInline = parent()->isRenderInline() ? toRenderInline(parent()) : 0;
     bool checkFonts = document().inNoQuirksMode();
-    RenderFlowThread* flowThread = flowThreadContainingBlock();
     bool alwaysCreateLineBoxes = (parentRenderInline && parentRenderInline->alwaysCreateLineBoxes())
         || (parentRenderInline && parentStyle->verticalAlign() != BASELINE)
         || style()->verticalAlign() != BASELINE
         || style()->textEmphasisMark() != TextEmphasisMarkNone
         || (checkFonts && (!parentStyle->font().fontMetrics().hasIdenticalAscentDescentAndLineGap(style()->font().fontMetrics())
-        || parentStyle->lineHeight() != style()->lineHeight()))
-        || (flowThread && flowThread->hasRegionsWithStyling());
+            || parentStyle->lineHeight() != style()->lineHeight()));
 
     if (!alwaysCreateLineBoxes && checkFonts && document().styleEngine()->usesFirstLineRules()) {
         // Have to check the first line style as well.
         parentStyle = parent()->style(true);
         RenderStyle* childStyle = style(true);
         alwaysCreateLineBoxes = !parentStyle->font().fontMetrics().hasIdenticalAscentDescentAndLineGap(childStyle->font().fontMetrics())
         || childStyle->verticalAlign() != BASELINE
         || parentStyle->lineHeight() != childStyle->lineHeight();
     }
 
@@ skipping 96 matching lines @@
 
     RenderBoxModelObject::addChild(newChild, beforeChild);
 
     newChild->setNeedsLayoutAndPrefWidthsRecalc();
 }
 
 RenderInline* RenderInline::clone() const
 {
     RenderInline* cloneInline = new RenderInline(node());
     cloneInline->setStyle(style());
-    cloneInline->setFlowThreadState(flowThreadState());
     return cloneInline;
 }
 
 void RenderInline::splitInlines(RenderBlock* fromBlock, RenderBlock* toBlock,
                                 RenderBlock* middleBlock,
                                 RenderObject* beforeChild, RenderBoxModelObject* oldCont)
 {
     // Create a clone of this inline.
     RenderInline* cloneInline = clone();
     cloneInline->setContinuation(oldCont);
@@ skipping 778 matching lines @@
     if (isInFlowPositioned())
         offset += offsetForInFlowPosition();
 
     container->adjustForColumns(offset, point);
 
     if (container->hasOverflowClip())
         offset -= toRenderBox(container)->scrolledContentOffset();
 
     if (offsetDependsOnPoint) {
         *offsetDependsOnPoint = container->hasColumns()
-            || (container->isBox() && container->style()->isFlippedBlocksWritingMode())
-            || container->isRenderFlowThread();
+            || (container->isBox() && container->style()->isFlippedBlocksWritingMode());
     }
 
     return offset;
 }
 
 void RenderInline::mapLocalToContainer(const RenderLayerModelObject* repaintContainer, TransformState& transformState, MapCoordinatesFlags mode, bool* wasFixed) const
 {
     if (repaintContainer == this)
         return;
 
@@ skipping 426 matching lines @@
         container = this;
 
     FloatPoint absPos = container->localToAbsolute();
     region.bounds.setX(absPos.x() + region.bounds.x());
     region.bounds.setY(absPos.y() + region.bounds.y());
 
     regions.append(region);
 }
 
 } // namespace WebCore