Home | History | Annotate | Download | only in dom
      1 /*
      2  * Copyright (C) 1999 Lars Knoll (knoll (at) kde.org)
      3  *           (C) 1999 Antti Koivisto (koivisto (at) kde.org)
      4  *           (C) 2001 Dirk Mueller (mueller (at) kde.org)
      5  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
      6  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
      7  * Copyright (C) 2011 Google Inc. All rights reserved.
      8  *
      9  * This library is free software; you can redistribute it and/or
     10  * modify it under the terms of the GNU Library General Public
     11  * License as published by the Free Software Foundation; either
     12  * version 2 of the License, or (at your option) any later version.
     13  *
     14  * This library is distributed in the hope that it will be useful,
     15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
     16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     17  * Library General Public License for more details.
     18  *
     19  * You should have received a copy of the GNU Library General Public License
     20  * along with this library; see the file COPYING.LIB.  If not, write to
     21  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
     22  * Boston, MA 02110-1301, USA.
     23  *
     24  */
     25 
     26 #include "config.h"
     27 #include "core/dom/NodeRenderingContext.h"
     28 
     29 #include "RuntimeEnabledFeatures.h"
     30 #include "core/css/resolver/StyleResolver.h"
     31 #include "core/dom/ContainerNode.h"
     32 #include "core/dom/FullscreenElementStack.h"
     33 #include "core/dom/Node.h"
     34 #include "core/dom/Text.h"
     35 #include "core/dom/shadow/InsertionPoint.h"
     36 #include "core/rendering/FlowThreadController.h"
     37 #include "core/rendering/RenderFullScreen.h"
     38 #include "core/rendering/RenderNamedFlowThread.h"
     39 #include "core/rendering/RenderObject.h"
     40 #include "core/rendering/RenderText.h"
     41 #include "core/rendering/RenderView.h"
     42 
     43 namespace WebCore {
     44 
     45 static bool isRendererReparented(const RenderObject* renderer)
     46 {
     47     if (!renderer->node()->isElementNode())
     48         return false;
     49     if (renderer->style() && !renderer->style()->flowThread().isEmpty())
     50         return true;
     51     if (toElement(renderer->node())->shouldBeReparentedUnderRenderView(renderer->style()))
     52         return true;
     53     return false;
     54 }
     55 
     56 RenderObject* NodeRenderingContext::nextRenderer() const
     57 {
     58     if (RenderObject* renderer = m_node->renderer())
     59         return renderer->nextSibling();
     60 
     61     Element* element = m_node->isElementNode() ? toElement(m_node) : 0;
     62     if (element && element->shouldBeReparentedUnderRenderView(m_style.get())) {
     63         // FIXME: Reparented renderers not in the top layer should probably be
     64         // ordered in DOM tree order. We don't have a good way to do that yet,
     65         // since NodeRenderingTraversal isn't aware of reparenting. It's safe to
     66         // just append for now; it doesn't disrupt the top layer rendering as
     67         // the layer collection in RenderLayer only requires that top layer
     68         // renderers are orderered correctly relative to each other.
     69         if (!element->isInTopLayer())
     70             return 0;
     71 
     72         const Vector<RefPtr<Element> >& topLayerElements = element->document().topLayerElements();
     73         size_t position = topLayerElements.find(element);
     74         ASSERT(position != kNotFound);
     75         for (size_t i = position + 1; i < topLayerElements.size(); ++i) {
     76             if (RenderObject* renderer = topLayerElements[i]->renderer())
     77                 return renderer;
     78         }
     79         return 0;
     80     }
     81 
     82     if (m_parentFlowRenderer)
     83         return m_parentFlowRenderer->nextRendererForNode(m_node);
     84 
     85     // Avoid an O(N^2) walk over the children when reattaching all children of a node.
     86     if (m_renderingParent && m_renderingParent->needsAttach())
     87         return 0;
     88 
     89     for (Node* sibling = NodeRenderingTraversal::nextSibling(m_node); sibling; sibling = NodeRenderingTraversal::nextSibling(sibling)) {
     90         RenderObject* renderer = sibling->renderer();
     91         if (renderer && !isRendererReparented(renderer))
     92             return renderer;
     93     }
     94 
     95     return 0;
     96 }
     97 
     98 RenderObject* NodeRenderingContext::previousRenderer() const
     99 {
    100     if (RenderObject* renderer = m_node->renderer())
    101         return renderer->previousSibling();
    102 
    103     // FIXME: This doesn't work correctly for reparented elements that are
    104     // display: none. We'd need to duplicate the logic in nextRenderer, but since
    105     // nothing needs that yet just assert.
    106     ASSERT(!m_node->isElementNode() || !toElement(m_node)->shouldBeReparentedUnderRenderView(m_style.get()));
    107 
    108     if (m_parentFlowRenderer)
    109         return m_parentFlowRenderer->previousRendererForNode(m_node);
    110 
    111     // FIXME: We should have the same O(N^2) avoidance as nextRenderer does
    112     // however, when I tried adding it, several tests failed.
    113     for (Node* sibling = NodeRenderingTraversal::previousSibling(m_node); sibling; sibling = NodeRenderingTraversal::previousSibling(sibling)) {
    114         RenderObject* renderer = sibling->renderer();
    115         if (renderer && !isRendererReparented(renderer))
    116             return renderer;
    117     }
    118 
    119     return 0;
    120 }
    121 
    122 RenderObject* NodeRenderingContext::parentRenderer() const
    123 {
    124     if (RenderObject* renderer = m_node->renderer())
    125         return renderer->parent();
    126 
    127     if (m_node->isElementNode() && toElement(m_node)->shouldBeReparentedUnderRenderView(m_style.get())) {
    128         // The parent renderer of reparented elements is the RenderView, but only
    129         // if the normal parent would have had a renderer.
    130         // FIXME: This behavior isn't quite right as the spec for top layer
    131         // only talks about display: none ancestors so putting a <dialog> inside
    132         // an <optgroup> seems like it should still work even though this check
    133         // will prevent it.
    134         if (!m_renderingParent || !m_renderingParent->renderer())
    135             return 0;
    136         return m_node->document().renderView();
    137     }
    138 
    139     if (m_parentFlowRenderer)
    140         return m_parentFlowRenderer;
    141 
    142     return m_renderingParent ? m_renderingParent->renderer() : 0;
    143 }
    144 
    145 bool NodeRenderingContext::shouldCreateRenderer() const
    146 {
    147     if (!m_renderingParent)
    148         return false;
    149     RenderObject* parentRenderer = this->parentRenderer();
    150     if (!parentRenderer)
    151         return false;
    152     if (!parentRenderer->canHaveChildren())
    153         return false;
    154     if (!m_renderingParent->childShouldCreateRenderer(*m_node))
    155         return false;
    156     return true;
    157 }
    158 
    159 // Check the specific case of elements that are children of regions but are flowed into a flow thread themselves.
    160 bool NodeRenderingContext::elementInsideRegionNeedsRenderer()
    161 {
    162     Element* element = toElement(m_node);
    163     bool elementInsideRegionNeedsRenderer = false;
    164     RenderObject* parentRenderer = this->parentRenderer();
    165     if ((parentRenderer && !parentRenderer->canHaveChildren() && parentRenderer->isRenderNamedFlowFragmentContainer())
    166         || (!parentRenderer && element->parentElement() && element->parentElement()->isInsideRegion())) {
    167 
    168         if (!m_style)
    169             m_style = element->styleForRenderer();
    170 
    171         elementInsideRegionNeedsRenderer = element->shouldMoveToFlowThread(m_style.get());
    172 
    173         // Children of this element will only be allowed to be flowed into other flow-threads if display is NOT none.
    174         if (element->rendererIsNeeded(*m_style))
    175             element->setIsInsideRegion(true);
    176     }
    177 
    178     return elementInsideRegionNeedsRenderer;
    179 }
    180 
    181 void NodeRenderingContext::moveToFlowThreadIfNeeded()
    182 {
    183     if (!RuntimeEnabledFeatures::cssRegionsEnabled())
    184         return;
    185 
    186     Element* element = toElement(m_node);
    187 
    188     if (!element->shouldMoveToFlowThread(m_style.get()))
    189         return;
    190 
    191     ASSERT(m_node->document().renderView());
    192     FlowThreadController* flowThreadController = m_node->document().renderView()->flowThreadController();
    193     m_parentFlowRenderer = flowThreadController->ensureRenderFlowThreadWithName(m_style->flowThread());
    194     flowThreadController->registerNamedFlowContentNode(m_node, m_parentFlowRenderer);
    195 }
    196 
    197 void NodeRenderingContext::createRendererForElementIfNeeded()
    198 {
    199     ASSERT(!m_node->renderer());
    200 
    201     Element* element = toElement(m_node);
    202 
    203     element->setIsInsideRegion(false);
    204 
    205     if (!shouldCreateRenderer() && !elementInsideRegionNeedsRenderer())
    206         return;
    207 
    208     if (!m_style)
    209         m_style = element->styleForRenderer();
    210 
    211     moveToFlowThreadIfNeeded();
    212 
    213     if (!element->rendererIsNeeded(*m_style))
    214         return;
    215 
    216     RenderObject* newRenderer = element->createRenderer(m_style.get());
    217     if (!newRenderer)
    218         return;
    219 
    220     RenderObject* parentRenderer = this->parentRenderer();
    221 
    222     if (!parentRenderer->isChildAllowed(newRenderer, m_style.get())) {
    223         newRenderer->destroy();
    224         return;
    225     }
    226 
    227     // Make sure the RenderObject already knows it is going to be added to a RenderFlowThread before we set the style
    228     // for the first time. Otherwise code using inRenderFlowThread() in the styleWillChange and styleDidChange will fail.
    229     newRenderer->setFlowThreadState(parentRenderer->flowThreadState());
    230 
    231     RenderObject* nextRenderer = this->nextRenderer();
    232     element->setRenderer(newRenderer);
    233     newRenderer->setAnimatableStyle(m_style.release()); // setAnimatableStyle() can depend on renderer() already being set.
    234 
    235     if (FullscreenElementStack::isActiveFullScreenElement(element)) {
    236         newRenderer = RenderFullScreen::wrapRenderer(newRenderer, parentRenderer, &element->document());
    237         if (!newRenderer)
    238             return;
    239     }
    240 
    241     // Note: Adding newRenderer instead of renderer(). renderer() may be a child of newRenderer.
    242     parentRenderer->addChild(newRenderer, nextRenderer);
    243 }
    244 
    245 void NodeRenderingContext::createRendererForTextIfNeeded()
    246 {
    247     ASSERT(!m_node->renderer());
    248 
    249     Text* textNode = toText(m_node);
    250 
    251     if (!shouldCreateRenderer())
    252         return;
    253 
    254     RenderObject* parentRenderer = this->parentRenderer();
    255 
    256     if (m_parentDetails.resetStyleInheritance())
    257         m_style = textNode->document().ensureStyleResolver().defaultStyleForElement();
    258     else
    259         m_style = parentRenderer->style();
    260 
    261     if (!textNode->textRendererIsNeeded(*this))
    262         return;
    263 
    264     RenderText* newRenderer = textNode->createTextRenderer(m_style.get());
    265     if (!parentRenderer->isChildAllowed(newRenderer, m_style.get())) {
    266         newRenderer->destroy();
    267         return;
    268     }
    269 
    270     // Make sure the RenderObject already knows it is going to be added to a RenderFlowThread before we set the style
    271     // for the first time. Otherwise code using inRenderFlowThread() in the styleWillChange and styleDidChange will fail.
    272     newRenderer->setFlowThreadState(parentRenderer->flowThreadState());
    273 
    274     RenderObject* nextRenderer = this->nextRenderer();
    275     textNode->setRenderer(newRenderer);
    276     // Parent takes care of the animations, no need to call setAnimatableStyle.
    277     newRenderer->setStyle(m_style.release());
    278     parentRenderer->addChild(newRenderer, nextRenderer);
    279 }
    280 
    281 }
    282