1 /* 2 * Copyright (C) 2013 Google Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions are 6 * met: 7 * 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above 11 * copyright notice, this list of conditions and the following disclaimer 12 * in the documentation and/or other materials provided with the 13 * distribution. 14 * * Neither the name of Google Inc. nor the names of its 15 * contributors may be used to endorse or promote products derived from 16 * this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #ifndef SubtreeLayoutScope_h 32 #define SubtreeLayoutScope_h 33 34 #include "wtf/HashSet.h" 35 36 // This is the way to mark a subtree as needing layout during layout, 37 // e.g. for the purposes of doing a multipass layout. 38 // 39 // It should only be used during layout. Outside of layout, you should 40 // just call renderer->setNeedsLayout() directly. 41 // 42 // It ensures that you don't accidentally mark part of the tree as 43 // needing layout and not actually lay it out. 44 45 namespace blink { 46 47 class RenderObject; 48 49 class SubtreeLayoutScope { 50 public: 51 SubtreeLayoutScope(RenderObject& root); 52 ~SubtreeLayoutScope(); 53 54 void setNeedsLayout(RenderObject* descendant); 55 void setChildNeedsLayout(RenderObject* descendant); 56 root()57 RenderObject& root() { return m_root; } 58 void addRendererToLayout(RenderObject* renderer); 59 60 private: 61 RenderObject& m_root; 62 63 #if ENABLE(ASSERT) 64 HashSet<RenderObject*> m_renderersToLayout; 65 #endif 66 }; 67 68 } 69 70 #endif 71