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

Source/core/rendering/RenderObject.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 31 matching lines @@
 #include "core/html/HTMLTableElement.h"
 #include "core/page/AutoscrollController.h"
 #include "core/page/EventHandler.h"
 #include "core/frame/Frame.h"
 #include "core/frame/FrameView.h"
 #include "core/page/Page.h"
 #include "core/frame/Settings.h"
 #include "core/frame/UseCounter.h"
 #include "core/frame/animation/AnimationController.h"
 #include "core/rendering/CompositedLayerMapping.h"
-#include "core/rendering/FlowThreadController.h"
 #include "core/rendering/HitTestResult.h"
 #include "core/rendering/LayoutRectRecorder.h"
 #include "core/rendering/RenderCounter.h"
 #include "core/rendering/RenderDeprecatedFlexibleBox.h"
 #include "core/rendering/RenderFlexibleBox.h"
 #include "core/rendering/RenderGeometryMap.h"
 #include "core/rendering/RenderGrid.h"
 #include "core/rendering/RenderImage.h"
 #include "core/rendering/RenderImageResourceStyleImage.h"
 #include "core/rendering/RenderInline.h"
 #include "core/rendering/RenderLayer.h"
 #include "core/rendering/RenderLayerCompositor.h"
 #include "core/rendering/RenderListItem.h"
 #include "core/rendering/RenderMarquee.h"
-#include "core/rendering/RenderMultiColumnBlock.h"
-#include "core/rendering/RenderNamedFlowThread.h"
-#include "core/rendering/RenderRegion.h"
 #include "core/rendering/RenderRuby.h"
 #include "core/rendering/RenderRubyText.h"
 #include "core/rendering/RenderScrollbarPart.h"
 #include "core/rendering/RenderTableCaption.h"
 #include "core/rendering/RenderTableCell.h"
 #include "core/rendering/RenderTableCol.h"
 #include "core/rendering/RenderTableRow.h"
 #include "core/rendering/RenderTextControlPlaceholder.h"
 #include "core/rendering/RenderTheme.h"
 #include "core/rendering/RenderView.h"
@@ skipping 54 matching lines @@
 }
 
 void RenderObject::operator delete(void* ptr)
 {
     ASSERT(isMainThread());
     partitionFree(ptr);
 }
 
 RenderObject* RenderObject::createObject(Element* element, RenderStyle* style)
 {
-    Document& doc = element->document();
-
     // Minimal support for content properties replacing an entire element.
     // Works only if we have exactly one piece of content and it's a URL.
     // Otherwise acts as if we didn't support this feature.
     const ContentData* contentData = style->contentData();
     if (contentData && !contentData->next() && contentData->isImage() && !element->isPseudoElement()) {
         RenderImage* image = new RenderImage(element);
         // RenderImageResourceStyleImage requires a style being present on the image but we don't want to
         // trigger a style change now as the node is not fully attached. Moving this code to style change
         // doesn't make sense as it should be run once at renderer creation.
         image->setStyleInternal(style);
@@ skipping 19 matching lines @@
     if (element->hasTagName(rtTag) && style->display() == BLOCK)
         return new RenderRubyText(element);
 
     switch (style->display()) {
     case NONE:
         return 0;
     case INLINE:
         return new RenderInline(element);
     case BLOCK:
     case INLINE_BLOCK:
-        if ((!style->hasAutoColumnCount() || !style->hasAutoColumnWidth()) && doc.regionBasedColumnsEnabled())
-            return new RenderMultiColumnBlock(element);
         return new RenderBlockFlow(element);
     case LIST_ITEM:
         return new RenderListItem(element);
     case TABLE:
     case INLINE_TABLE:
         return new RenderTable(element);
     case TABLE_ROW_GROUP:
     case TABLE_HEADER_GROUP:
     case TABLE_FOOTER_GROUP:
         return new RenderTableSection(element);
@@ skipping 78 matching lines @@
 bool RenderObject::isHR() const
 {
     return node() && node()->hasTagName(hrTag);
 }
 
 bool RenderObject::isLegend() const
 {
     return node() && node()->hasTagName(legendTag);
 }
 
-void RenderObject::setFlowThreadStateIncludingDescendants(FlowThreadState state)
-{
-    setFlowThreadState(state);
-
-    for (RenderObject* child = firstChild(); child; child = child->nextSibling()) {
-        // If the child is a fragmentation context it already updated the descendants flag accordingly.
-        if (child->isRenderFlowThread())
-            continue;
-        ASSERT(state != child->flowThreadState());
-        child->setFlowThreadStateIncludingDescendants(state);
-    }
-}
-
 bool RenderObject::requiresAnonymousTableWrappers(const RenderObject* newChild) const
 {
     // Check should agree with:
     // CSS 2.1 Tables: 17.2.1 Anonymous table objects
     // http://www.w3.org/TR/CSS21/tables.html#anonymous-boxes
     if (newChild->isRenderTableCol()) {
         const RenderTableCol* newTableColumn = toRenderTableCol(newChild);
         bool isColumnInColumnGroup = newTableColumn->isTableColumn() && isRenderTableCol();
         return !isTable() && !isColumnInColumnGroup;
     } else if (newChild->isTableCaption())
@@ skipping 292 matching lines @@
             continue;
 
         RenderBox* ancestorBox = toRenderBox(ancestor);
         if (ancestorBox->canBeScrolledAndHasScrollableArea())
             return ancestorBox;
     }
 
     return 0;
 }
 
-RenderFlowThread* RenderObject::locateFlowThreadContainingBlock() const
-{
-    ASSERT(flowThreadState() != NotInsideFlowThread);
-
-    // See if we have the thread cached because we're in the middle of layout.
-    RenderFlowThread* flowThread = view()->flowThreadController()->currentRenderFlowThread();
-    if (flowThread)
-        return flowThread;
-
-    // Not in the middle of layout so have to find the thread the slow way.
-    RenderObject* curr = const_cast<RenderObject*>(this);
-    while (curr) {
-        if (curr->isRenderFlowThread())
-            return toRenderFlowThread(curr);
-        curr = curr->containingBlock();
-    }
-    return 0;
-}
-
-RenderNamedFlowThread* RenderObject::renderNamedFlowThreadWrapper() const
-{
-    RenderObject* object = const_cast<RenderObject*>(this);
-    while (object && object->isAnonymousBlock() && !object->isRenderNamedFlowThread())
-        object = object->parent();
-
-    return object && object->isRenderNamedFlowThread() ? toRenderNamedFlowThread(object) : 0;
-}
-
 RenderBlock* RenderObject::firstLineBlock() const
 {
     return 0;
 }
 
 static inline bool objectIsRelayoutBoundary(const RenderObject* object)
 {
     // FIXME: In future it may be possible to broaden these conditions in order to improve performance.
     if (object->isTextControl())
         return true;
@@ skipping 707 matching lines @@
         }
     }
 
     if (document().view()->hasSoftwareFilters()) {
         if (RenderLayer* parentLayer = enclosingLayer()) {
             RenderLayer* enclosingFilterLayer = parentLayer->enclosingFilterLayer();
             if (enclosingFilterLayer)
                 return enclosingFilterLayer->renderer();
         }
     }
-
-    // If we have a flow thread, then we need to do individual repaints within the RenderRegions instead.
-    // Return the flow thread as a repaint container in order to create a chokepoint that allows us to change
-    // repainting to do individual region repaints.
-    RenderFlowThread* parentRenderFlowThread = flowThreadContainingBlock();
-    if (parentRenderFlowThread) {
-        // The ancestor document will do the reparenting when the repaint propagates further up.
-        // We're just a seamless child document, and we don't need to do the hacking.
-        if (parentRenderFlowThread->document() != document())
-            return repaintContainer;
-        // If we have already found a repaint container then we will repaint into that container only if it is part of the same
-        // flow thread. Otherwise we will need to catch the repaint call and send it to the flow thread.
-        RenderFlowThread* repaintContainerFlowThread = repaintContainer ? repaintContainer->flowThreadContainingBlock() : 0;
-        if (!repaintContainerFlowThread || repaintContainerFlowThread != parentRenderFlowThread)
-            repaintContainer = parentRenderFlowThread;
-    }
     return repaintContainer;
 }
 
 void RenderObject::repaintUsingContainer(const RenderLayerModelObject* repaintContainer, const IntRect& r) const
 {
     if (!repaintContainer) {
         view()->repaintViewRectangle(r);
         return;
     }
 
@@ skipping 18 matching lines @@
         // directly to the next chunk of code.
 
         // Then, convert the repaint rect from repaintConainer space into the squashing GraphicsLayer's coordinates.
         if (repaintContainer->hasTransform())
             offsetRect = repaintContainer->layer()->transform()->mapRect(r);
         offsetRect.move(-repaintContainer->layer()->offsetFromSquashingLayerOrigin());
         repaintContainer->groupedMapping()->squashingLayer()->setNeedsDisplayInRect(offsetRect);
         return;
     }
 
-    if (repaintContainer->isRenderFlowThread()) {
-        toRenderFlowThread(repaintContainer)->repaintRectangleInRegions(r);
-        return;
-    }
-
     if (repaintContainer->hasFilter() && repaintContainer->layer()->requiresFullLayerImageForFilters()) {
         repaintContainer->layer()->repainter().setFilterBackendNeedsRepaintingInRect(r);
         return;
     }
 
     RenderView* v = view();
     if (repaintContainer->isRenderView()) {
         ASSERT(repaintContainer == v);
         bool viewHasCompositedLayer = v->hasLayer() && v->layer()->compositingState() == PaintsIntoOwnBacking;
         if (!viewHasCompositedLayer) {
@@ skipping 882 matching lines @@
     ASSERT(o == container());
 
     LayoutSize offset;
 
     o->adjustForColumns(offset, point);
 
     if (o->hasOverflowClip())
         offset -= toRenderBox(o)->scrolledContentOffset();
 
     if (offsetDependsOnPoint)
-        *offsetDependsOnPoint = hasColumns() || o->isRenderFlowThread();
+        *offsetDependsOnPoint = hasColumns();
 
     return offset;
 }
 
 LayoutSize RenderObject::offsetFromAncestorContainer(RenderObject* container) const
 {
     LayoutSize offset;
     LayoutPoint referencePoint;
     const RenderObject* currContainer = this;
     do {
@@ skipping 234 matching lines @@
     if (AXObjectCache* cache = document().existingAXObjectCache())
         cache->childrenChanged(this->parent());
 
     remove();
 
     // The remove() call above may invoke axObjectCache()->childrenChanged() on the parent, which may require the AX render
     // object for this renderer. So we remove the AX render object now, after the renderer is removed.
     if (AXObjectCache* cache = document().existingAXObjectCache())
         cache->remove(this);
 
-#ifndef NDEBUG
-    if (!documentBeingDestroyed() && view() && view()->hasRenderNamedFlowThreads()) {
-        // After remove, the object and the associated information should not be in any flow thread.
-        const RenderNamedFlowThreadList* flowThreadList = view()->flowThreadController()->renderNamedFlowThreadList();
-        for (RenderNamedFlowThreadList::const_iterator iter = flowThreadList->begin(); iter != flowThreadList->end(); ++iter) {
-            const RenderNamedFlowThread* renderFlowThread = *iter;
-            ASSERT(!renderFlowThread->hasChild(this));
-            ASSERT(!renderFlowThread->hasChildInfo(this));
-        }
-    }
-#endif
-
     // If this renderer had a parent, remove should have destroyed any counters
     // attached to this renderer and marked the affected other counters for
     // reevaluation. This apparently redundant check is here for the case when
     // this renderer had no parent at the time remove() was called.
 
     if (hasCounterNodeMap())
         RenderCounter::destroyCounterNodes(*this);
 
     setAncestorLineBoxDirty(false);
 
@@ skipping 16 matching lines @@
     // that needs to be drawn and layer visibility optimization can't be used
     if (parent()->style()->visibility() != VISIBLE && style()->visibility() == VISIBLE && !hasLayer()) {
         if (!layer)
             layer = parent()->enclosingLayer();
         if (layer)
             layer->setHasVisibleContent();
     }
 
     if (!isFloating() && parent()->childrenInline())
         parent()->dirtyLinesFromChangedChild(this);
-
-    if (RenderNamedFlowThread* containerFlowThread = parent()->renderNamedFlowThreadWrapper())
-        containerFlowThread->addFlowChild(this);
 }
 
 void RenderObject::willBeRemovedFromTree()
 {
     // FIXME: We should ASSERT(isRooted()) but we have some out-of-order removals which would need to be fixed first.
 
     // If we remove a visible child from an invisible parent, we don't know the layer visibility any more.
     RenderLayer* layer = 0;
     if (parent()->style()->visibility() != VISIBLE && style()->visibility() == VISIBLE && !hasLayer()) {
         if ((layer = parent()->enclosingLayer()))
             layer->dirtyVisibleContentStatus();
     }
 
     // Keep our layer hierarchy updated.
     if (firstChild() || hasLayer()) {
         if (!layer)
             layer = parent()->enclosingLayer();
         removeLayers(layer);
     }
 
     if (isOutOfFlowPositioned() && parent()->childrenInline())
         parent()->dirtyLinesFromChangedChild(this);
 
-    removeFromRenderFlowThread();
-
-    if (RenderNamedFlowThread* containerFlowThread = parent()->renderNamedFlowThreadWrapper())
-        containerFlowThread->removeFlowChild(this);
-
     // Update cached boundaries in SVG renderers if a child is removed.
     if (parent()->isSVG())
         parent()->setNeedsBoundariesUpdate();
 }
 
-void RenderObject::removeFromRenderFlowThread()
-{
-    if (flowThreadState() == NotInsideFlowThread)
-        return;
-
-    // Sometimes we remove the element from the flow, but it's not destroyed at that time.
-    // It's only until later when we actually destroy it and remove all the children from it.
-    // Currently, that happens for firstLetter elements and list markers.
-    // Pass in the flow thread so that we don't have to look it up for all the children.
-    removeFromRenderFlowThreadRecursive(flowThreadContainingBlock());
-}
-
-void RenderObject::removeFromRenderFlowThreadRecursive(RenderFlowThread* renderFlowThread)
-{
-    if (const RenderObjectChildList* children = virtualChildren()) {
-        for (RenderObject* child = children->firstChild(); child; child = child->nextSibling())
-            child->removeFromRenderFlowThreadRecursive(renderFlowThread);
-    }
-
-    RenderFlowThread* localFlowThread = renderFlowThread;
-    if (flowThreadState() == InsideInFlowThread)
-        localFlowThread = flowThreadContainingBlock(); // We have to ask. We can't just assume we are in the same flow thread.
-    if (localFlowThread)
-        localFlowThread->removeFlowChildInfo(this);
-    setFlowThreadState(NotInsideFlowThread);
-}
-
 void RenderObject::destroyAndCleanupAnonymousWrappers()
 {
     // If the tree is destroyed, there is no need for a clean-up phase.
     if (documentBeingDestroyed()) {
         destroy();
         return;
     }
 
     RenderObject* destroyRoot = this;
     for (RenderObject* destroyRootParent = destroyRoot->parent(); destroyRootParent && destroyRootParent->isAnonymous(); destroyRoot = destroyRootParent, destroyRootParent = destroyRootParent->parent()) {
         // Anonymous block continuations are tracked and destroyed elsewhere (see the bottom of RenderBlock::removeChild)
         if (destroyRootParent->isRenderBlock() && toRenderBlock(destroyRootParent)->isAnonymousBlockContinuation())
             break;
-        // Render flow threads are tracked by the FlowThreadController, so we can't destroy them here.
         // Column spans are tracked elsewhere.
-        if (destroyRootParent->isRenderFlowThread() || destroyRootParent->isAnonymousColumnSpanBlock())
+        if (destroyRootParent->isAnonymousColumnSpanBlock())
             break;
 
         if (destroyRootParent->firstChild() != this || destroyRootParent->lastChild() != this)
             break;
     }
 
     destroyRoot->destroy();
 
     // WARNING: |this| is deleted here.
 }
@@ skipping 437 matching lines @@
     return renderer->node()->isInert();
 }
 
 void RenderObject::imageChanged(ImageResource* image, const IntRect* rect)
 {
     imageChanged(static_cast<WrappedImagePtr>(image), rect);
 }
 
 RenderObject* RenderObject::hoverAncestor() const
 {
-    // When searching for the hover ancestor and encountering a named flow thread,
-    // the search will continue with the DOM ancestor of the top-most element
-    // in the named flow thread.
-    // See https://code.google.com/p/chromium/issues/detail?id=243278
-    RenderObject* hoverAncestor = parent();
-
-    // Skip anonymous blocks directly flowed into flow threads as it would
-    // prevent us from continuing the search on the DOM tree when reaching the named flow thread.
-    if (hoverAncestor && hoverAncestor->isAnonymousBlock() && hoverAncestor->parent() && hoverAncestor->parent()->isRenderNamedFlowThread())
-        hoverAncestor = hoverAncestor->parent();
-
-    if (hoverAncestor && hoverAncestor->isRenderNamedFlowThread()) {
-        hoverAncestor = 0;
-
-        Node* node = this->node();
-        if (node) {
-            Node* domAncestorNode = node->parentNode();
-            if (domAncestorNode)
-                hoverAncestor = domAncestorNode->renderer();
-        }
-    }
-
-    return hoverAncestor;
+    // FIXME: Remove.
+    return parent();
 }
 
 Element* RenderObject::offsetParent() const
 {
     if (isRoot() || isBody())
         return 0;
 
     if (isOutOfFlowPositioned() && style()->position() == FixedPosition)
         return 0;
 
     // If A is an area HTML element which has a map HTML element somewhere in the ancestor
     // chain return the nearest ancestor map HTML element and stop this algorithm.
     // FIXME: Implement!
 
     float effectiveZoom = style()->effectiveZoom();
     Node* node = 0;
     for (RenderObject* ancestor = parent(); ancestor; ancestor = ancestor->parent()) {
         // Spec: http://www.w3.org/TR/cssom-view/#offset-attributes
 
-        // CSS regions specification says that region flows should return the body element as their offsetParent.
-        if (ancestor->isRenderNamedFlowThread())
-            return document().body();
-
         node = ancestor->node();
 
         if (!node)
             continue;
 
         if (ancestor->isPositioned())
             break;
 
         if (node->hasTagName(bodyTag))
             break;
@@ skipping 137 matching lines @@
 {
     ASSERT_NOT_REACHED();
     return false;
 }
 
 bool RenderObject::isRelayoutBoundaryForInspector() const
 {
     return objectIsRelayoutBoundary(this);
 }
 
-bool RenderObject::isRenderNamedFlowFragmentContainer() const
-{
-    return isRenderBlockFlow() && toRenderBlockFlow(this)->renderNamedFlowFragment();
-}
-
 } // namespace WebCore
 
 #ifndef NDEBUG
 
 void showTree(const WebCore::RenderObject* object)
 {
     if (object)
         object->showTreeForThis();
 }
 
@@ skipping 12 matching lines @@
 {
     if (object1) {
         const WebCore::RenderObject* root = object1;
         while (root->parent())
             root = root->parent();
         root->showRenderTreeAndMark(object1, "*", object2, "-", 0);
     }
 }
 
 #endif