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

Source/core/dom/NamedFlow.cpp

-/*
- * Copyright (C) 2011 Adobe Systems Incorporated. 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 notice, this list of conditions and the following
- *    disclaimer in the documentation and/or other materials
- *    provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER "AS IS" AND ANY
- * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE
- * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
- * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
- * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
- * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
- * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
-
-#include "config.h"
-#include "core/dom/NamedFlow.h"
-
-#include "RuntimeEnabledFeatures.h"
-#include "core/dom/NamedFlowCollection.h"
-#include "core/dom/StaticNodeList.h"
-#include "core/events/ThreadLocalEventNames.h"
-#include "core/events/UIEvent.h"
-#include "core/rendering/RenderNamedFlowFragment.h"
-#include "core/rendering/RenderNamedFlowThread.h"
-
-namespace WebCore {
-
-NamedFlow::NamedFlow(PassRefPtr<NamedFlowCollection> manager, const AtomicString& flowThreadName)
-    : m_flowThreadName(flowThreadName)
-    , m_flowManager(manager)
-    , m_parentFlowThread(0)
-{
-    ASSERT(RuntimeEnabledFeatures::cssRegionsEnabled());
-    ScriptWrappable::init(this);
-}
-
-NamedFlow::~NamedFlow()
-{
-    // The named flow is not "strong" referenced from anywhere at this time so it shouldn't be reused if the named flow is recreated.
-    m_flowManager->discardNamedFlow(this);
-}
-
-PassRefPtr<NamedFlow> NamedFlow::create(PassRefPtr<NamedFlowCollection> manager, const AtomicString& flowThreadName)
-{
-    return adoptRef(new NamedFlow(manager, flowThreadName));
-}
-
-const AtomicString& NamedFlow::name() const
-{
-    return m_flowThreadName;
-}
-
-bool NamedFlow::overset() const
-{
-    if (m_flowManager->document())
-        m_flowManager->document()->updateLayoutIgnorePendingStylesheets();
-
-    // The renderer may be destroyed or created after the style update.
-    // Because this is called from JS, where the wrapper keeps a reference to the NamedFlow, no guard is necessary.
-    return m_parentFlowThread ? m_parentFlowThread->overset() : true;
-}
-
-static inline bool inFlowThread(RenderObject* renderer, RenderNamedFlowThread* flowThread)
-{
-    if (!renderer)
-        return false;
-    RenderFlowThread* currentFlowThread = renderer->flowThreadContainingBlock();
-    if (flowThread == currentFlowThread)
-        return true;
-    if (renderer->flowThreadState() != RenderObject::InsideInFlowThread)
-        return false;
-
-    // An in-flow flow thread can be nested inside an out-of-flow one, so we have to recur up to check.
-    return inFlowThread(currentFlowThread->containingBlock(), flowThread);
-}
-
-int NamedFlow::firstEmptyRegionIndex() const
-{
-    if (m_flowManager->document())
-        m_flowManager->document()->updateLayoutIgnorePendingStylesheets();
-
-    if (!m_parentFlowThread)
-        return -1;
-
-    const RenderRegionList& regionList = m_parentFlowThread->renderRegionList();
-    if (regionList.isEmpty())
-        return -1;
-
-    int countNonPseudoRegions = -1;
-    RenderRegionList::const_iterator iter = regionList.begin();
-    for (int index = 0; iter != regionList.end(); ++index, ++iter) {
-        const RenderNamedFlowFragment* renderRegion = toRenderNamedFlowFragment(*iter);
-        // FIXME: Pseudo-elements are not included in the list.
-        // They will be included when we will properly support the Region interface
-        // http://dev.w3.org/csswg/css-regions/#the-region-interface
-        if (!renderRegion->isElementBasedRegion())
-            continue;
-        countNonPseudoRegions++;
-        if (renderRegion->regionOversetState() == RegionEmpty)
-            return countNonPseudoRegions;
-    }
-    return -1;
-}
-
-PassRefPtr<NodeList> NamedFlow::getRegionsByContent(Node* contentNode)
-{
-    Vector<RefPtr<Node> > regionNodes;
-
-    if (!contentNode)
-        return StaticNodeList::adopt(regionNodes);
-
-    if (m_flowManager->document())
-        m_flowManager->document()->updateLayoutIgnorePendingStylesheets();
-
-    // The renderer may be destroyed or created after the style update.
-    // Because this is called from JS, where the wrapper keeps a reference to the NamedFlow, no guard is necessary.
-    if (!m_parentFlowThread)
-        return StaticNodeList::adopt(regionNodes);
-
-    if (inFlowThread(contentNode->renderer(), m_parentFlowThread)) {
-        const RenderRegionList& regionList = m_parentFlowThread->renderRegionList();
-        for (RenderRegionList::const_iterator iter = regionList.begin(); iter != regionList.end(); ++iter) {
-            const RenderNamedFlowFragment* renderRegion = toRenderNamedFlowFragment(*iter);
-            // They will be included when we will properly support the Region interface
-            // http://dev.w3.org/csswg/css-regions/#the-region-interface
-            if (!renderRegion->isElementBasedRegion())
-                continue;
-            if (m_parentFlowThread->objectInFlowRegion(contentNode->renderer(), renderRegion))
-                regionNodes.append(renderRegion->nodeForRegion());
-        }
-    }
-
-    return StaticNodeList::adopt(regionNodes);
-}
-
-PassRefPtr<NodeList> NamedFlow::getRegions()
-{
-    Vector<RefPtr<Node> > regionNodes;
-
-    if (m_flowManager->document())
-        m_flowManager->document()->updateLayoutIgnorePendingStylesheets();
-
-    // The renderer may be destroyed or created after the style update.
-    // Because this is called from JS, where the wrapper keeps a reference to the NamedFlow, no guard is necessary.
-    if (!m_parentFlowThread)
-        return StaticNodeList::adopt(regionNodes);
-
-    const RenderRegionList& regionList = m_parentFlowThread->renderRegionList();
-    for (RenderRegionList::const_iterator iter = regionList.begin(); iter != regionList.end(); ++iter) {
-        const RenderNamedFlowFragment* renderRegion = toRenderNamedFlowFragment(*iter);
-        // They will be included when we will properly support the Region interface
-        // http://dev.w3.org/csswg/css-regions/#the-region-interface
-        if (!renderRegion->isElementBasedRegion())
-            continue;
-        regionNodes.append(renderRegion->nodeForRegion());
-    }
-
-    return StaticNodeList::adopt(regionNodes);
-}
-
-PassRefPtr<NodeList> NamedFlow::getContent()
-{
-    Vector<RefPtr<Node> > contentNodes;
-
-    if (m_flowManager->document())
-        m_flowManager->document()->updateLayoutIgnorePendingStylesheets();
-
-    // The renderer may be destroyed or created after the style update.
-    // Because this is called from JS, where the wrapper keeps a reference to the NamedFlow, no guard is necessary.
-    if (!m_parentFlowThread)
-        return StaticNodeList::adopt(contentNodes);
-
-    const NamedFlowContentNodes& contentNodesList = m_parentFlowThread->contentNodes();
-    for (NamedFlowContentNodes::const_iterator it = contentNodesList.begin(); it != contentNodesList.end(); ++it) {
-        Node* node = *it;
-        ASSERT(node->computedStyle()->flowThread() == m_parentFlowThread->flowThreadName());
-        contentNodes.append(node);
-    }
-
-    return StaticNodeList::adopt(contentNodes);
-}
-
-void NamedFlow::setRenderer(RenderNamedFlowThread* parentFlowThread)
-{
-    // The named flow can either go from a no_renderer->renderer or renderer->no_renderer state; anything else could indicate a bug.
-    ASSERT((!m_parentFlowThread && parentFlowThread) || (m_parentFlowThread && !parentFlowThread));
-
-    // If parentFlowThread is 0, the flow thread will move in the "NULL" state.
-    m_parentFlowThread = parentFlowThread;
-}
-
-void NamedFlow::dispatchRegionLayoutUpdateEvent()
-{
-    ASSERT(!NoEventDispatchAssertion::isEventDispatchForbidden());
-
-    // If the flow is in the "NULL" state the event should not be dispatched any more.
-    if (flowState() == FlowStateNull)
-        return;
-
-    RefPtr<Event> event = UIEvent::create(EventTypeNames::webkitregionlayoutupdate, false, false, m_flowManager->document()->domWindow(), 0);
-
-    dispatchEvent(event);
-}
-
-void NamedFlow::dispatchRegionOversetChangeEvent()
-{
-    ASSERT(!NoEventDispatchAssertion::isEventDispatchForbidden());
-
-    // If the flow is in the "NULL" state the event should not be dispatched any more.
-    if (flowState() == FlowStateNull)
-        return;
-
-    RefPtr<Event> event = UIEvent::create(EventTypeNames::webkitregionoversetchange, false, false, m_flowManager->document()->domWindow(), 0);
-
-    dispatchEvent(event);
-}
-
-const AtomicString& NamedFlow::interfaceName() const
-{
-    return EventTargetNames::NamedFlow;
-}
-
-ExecutionContext* NamedFlow::executionContext() const
-{
-    return m_flowManager->document();
-}
-
-Node* NamedFlow::ownerNode() const
-{
-    return m_flowManager->document();
-}
-
-} // namespace WebCore
-