1 /* 2 * Copyright (C) 2003, 2009, 2012 Apple Inc. All rights reserved. 3 * Copyright (C) 2013 Intel Corporation. All rights reserved. 4 * 5 * Portions are Copyright (C) 1998 Netscape Communications Corporation. 6 * 7 * Other contributors: 8 * Robert O'Callahan <roc+@cs.cmu.edu> 9 * David Baron <dbaron (at) fas.harvard.edu> 10 * Christian Biesinger <cbiesinger (at) web.de> 11 * Randall Jesup <rjesup (at) wgate.com> 12 * Roland Mainz <roland.mainz (at) informatik.med.uni-giessen.de> 13 * Josh Soref <timeless (at) mac.com> 14 * Boris Zbarsky <bzbarsky (at) mit.edu> 15 * 16 * This library is free software; you can redistribute it and/or 17 * modify it under the terms of the GNU Lesser General Public 18 * License as published by the Free Software Foundation; either 19 * version 2.1 of the License, or (at your option) any later version. 20 * 21 * This library is distributed in the hope that it will be useful, 22 * but WITHOUT ANY WARRANTY; without even the implied warranty of 23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 24 * Lesser General Public License for more details. 25 * 26 * You should have received a copy of the GNU Lesser General Public 27 * License along with this library; if not, write to the Free Software 28 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 29 * 30 * Alternatively, the contents of this file may be used under the terms 31 * of either the Mozilla Public License Version 1.1, found at 32 * http://www.mozilla.org/MPL/ (the "MPL") or the GNU General Public 33 * License Version 2.0, found at http://www.fsf.org/copyleft/gpl.html 34 * (the "GPL"), in which case the provisions of the MPL or the GPL are 35 * applicable instead of those above. If you wish to allow use of your 36 * version of this file only under the terms of one of those two 37 * licenses (the MPL or the GPL) and not to allow others to use your 38 * version of this file under the LGPL, indicate your decision by 39 * deletingthe provisions above and replace them with the notice and 40 * other provisions required by the MPL or the GPL, as the case may be. 41 * If you do not delete the provisions above, a recipient may use your 42 * version of this file under any of the LGPL, the MPL or the GPL. 43 */ 44 45 #ifndef RenderLayerStackingNode_h 46 #define RenderLayerStackingNode_h 47 48 #include "core/rendering/RenderLayerModelObject.h" 49 #include "wtf/Noncopyable.h" 50 #include "wtf/OwnPtr.h" 51 #include "wtf/Vector.h" 52 53 namespace WebCore { 54 55 class RenderLayer; 56 class RenderLayerCompositor; 57 class RenderStyle; 58 59 class RenderLayerStackingNode { 60 WTF_MAKE_NONCOPYABLE(RenderLayerStackingNode); 61 public: 62 explicit RenderLayerStackingNode(RenderLayer*); 63 ~RenderLayerStackingNode(); 64 65 int zIndex() const { return renderer()->style()->zIndex(); } 66 67 // A stacking context is a layer that has a non-auto z-index. 68 bool isStackingContext() const { return !renderer()->style()->hasAutoZIndex(); } 69 70 // Update our normal and z-index lists. 71 void updateLayerListsIfNeeded(); 72 73 bool zOrderListsDirty() const { return m_zOrderListsDirty; } 74 void dirtyZOrderLists(); 75 void updateZOrderLists(); 76 void clearZOrderLists(); 77 void dirtyStackingContextZOrderLists(); 78 79 bool hasPositiveZOrderList() const { return posZOrderList() && posZOrderList()->size(); } 80 bool hasNegativeZOrderList() const { return negZOrderList() && negZOrderList()->size(); } 81 82 // FIXME: should check for dirtiness here? 83 bool isNormalFlowOnly() const { return m_isNormalFlowOnly; } 84 void updateIsNormalFlowOnly(); 85 bool normalFlowListDirty() const { return m_normalFlowListDirty; } 86 void dirtyNormalFlowList(); 87 88 void updateStackingNodesAfterStyleChange(const RenderStyle* oldStyle); 89 90 RenderLayerStackingNode* ancestorStackingContextNode() const; 91 92 // Gets the enclosing stacking context for this node, possibly the node 93 // itself, if it is a stacking context. 94 RenderLayerStackingNode* enclosingStackingContextNode() { return isStackingContext() ? this : ancestorStackingContextNode(); } 95 96 RenderLayer* layer() const { return m_layer; } 97 98 #if ASSERT_ENABLED 99 bool layerListMutationAllowed() const { return m_layerListMutationAllowed; } 100 void setLayerListMutationAllowed(bool flag) { m_layerListMutationAllowed = flag; } 101 #endif 102 103 private: 104 friend class RenderLayerStackingNodeIterator; 105 friend class RenderLayerStackingNodeReverseIterator; 106 friend class RenderTreeAsText; 107 108 Vector<RenderLayerStackingNode*>* posZOrderList() const 109 { 110 ASSERT(!m_zOrderListsDirty); 111 ASSERT(isStackingContext() || !m_posZOrderList); 112 return m_posZOrderList.get(); 113 } 114 115 Vector<RenderLayerStackingNode*>* normalFlowList() const 116 { 117 ASSERT(!m_normalFlowListDirty); 118 return m_normalFlowList.get(); 119 } 120 121 Vector<RenderLayerStackingNode*>* negZOrderList() const 122 { 123 ASSERT(!m_zOrderListsDirty); 124 ASSERT(isStackingContext() || !m_negZOrderList); 125 return m_negZOrderList.get(); 126 } 127 128 void rebuildZOrderLists(); 129 void collectLayers(OwnPtr<Vector<RenderLayerStackingNode*> >& posZOrderList, OwnPtr<Vector<RenderLayerStackingNode*> >& negZOrderList); 130 131 #if ASSERT_ENABLED 132 bool isInStackingParentZOrderLists() const; 133 bool isInStackingParentNormalFlowList() const; 134 void updateStackingParentForZOrderLists(RenderLayerStackingNode* stackingParent); 135 void updateStackingParentForNormalFlowList(RenderLayerStackingNode* stackingParent); 136 void setStackingParent(RenderLayerStackingNode* stackingParent) { m_stackingParent = stackingParent; } 137 #endif 138 139 bool shouldBeNormalFlowOnly() const; 140 141 void updateNormalFlowList(); 142 143 bool isDirtyStackingContext() const { return m_zOrderListsDirty && isStackingContext(); } 144 145 RenderLayerCompositor* compositor() const; 146 // FIXME: Investigate changing this to Renderbox. 147 RenderLayerModelObject* renderer() const; 148 149 RenderLayer* m_layer; 150 151 // m_posZOrderList holds a sorted list of all the descendant nodes within 152 // that have z-indices of 0 or greater (auto will count as 0). 153 // m_negZOrderList holds descendants within our stacking context with 154 // negative z-indices. 155 OwnPtr<Vector<RenderLayerStackingNode*> > m_posZOrderList; 156 OwnPtr<Vector<RenderLayerStackingNode*> > m_negZOrderList; 157 158 // This list contains child nodes that cannot create stacking contexts. 159 OwnPtr<Vector<RenderLayerStackingNode*> > m_normalFlowList; 160 161 unsigned m_zOrderListsDirty : 1; 162 unsigned m_normalFlowListDirty: 1; 163 unsigned m_isNormalFlowOnly : 1; 164 165 #if ASSERT_ENABLED 166 unsigned m_layerListMutationAllowed : 1; 167 RenderLayerStackingNode* m_stackingParent; 168 #endif 169 }; 170 171 inline void RenderLayerStackingNode::clearZOrderLists() 172 { 173 ASSERT(!isStackingContext()); 174 175 #if ASSERT_ENABLED 176 updateStackingParentForZOrderLists(0); 177 #endif 178 179 m_posZOrderList.clear(); 180 m_negZOrderList.clear(); 181 } 182 183 inline void RenderLayerStackingNode::updateZOrderLists() 184 { 185 if (!m_zOrderListsDirty) 186 return; 187 188 if (!isStackingContext()) { 189 clearZOrderLists(); 190 m_zOrderListsDirty = false; 191 return; 192 } 193 194 rebuildZOrderLists(); 195 } 196 197 #if ASSERT_ENABLED 198 class LayerListMutationDetector { 199 public: 200 explicit LayerListMutationDetector(RenderLayerStackingNode* stackingNode) 201 : m_stackingNode(stackingNode) 202 , m_previousMutationAllowedState(stackingNode->layerListMutationAllowed()) 203 { 204 m_stackingNode->setLayerListMutationAllowed(false); 205 } 206 207 ~LayerListMutationDetector() 208 { 209 m_stackingNode->setLayerListMutationAllowed(m_previousMutationAllowedState); 210 } 211 212 private: 213 RenderLayerStackingNode* m_stackingNode; 214 bool m_previousMutationAllowedState; 215 }; 216 #endif 217 218 } // namespace WebCore 219 220 #endif // RenderLayerStackingNode_h 221
