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@fas.harvard.edu> 10 * Christian Biesinger <cbiesinger@web.de> 11 * Randall Jesup <rjesup@wgate.com> 12 * Roland Mainz <roland.mainz@informatik.med.uni-giessen.de> 13 * Josh Soref <timeless@mac.com> 14 * Boris Zbarsky <bzbarsky@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 RenderLayerClipper_h 46 #define RenderLayerClipper_h 47 48 #include "core/rendering/ClipRectsCache.h" 49 #include "core/rendering/RenderBox.h" 50 51 namespace blink { 52 53 class RenderLayer; 54 55 enum ShouldRespectOverflowClip { 56 IgnoreOverflowClip, 57 RespectOverflowClip 58 }; 59 60 class ClipRectsContext { 61 public: 62 ClipRectsContext(const RenderLayer* root, ClipRectsCacheSlot slot, OverlayScrollbarSizeRelevancy relevancy = IgnoreOverlayScrollbarSize, const LayoutSize& accumulation = LayoutSize()) rootLayer(root)63 : rootLayer(root) 64 , scrollbarRelevancy(relevancy) 65 , cacheSlot(slot) 66 , subPixelAccumulation(accumulation) 67 , respectOverflowClip(slot == PaintingClipRectsIgnoringOverflowClip ? IgnoreOverflowClip : RespectOverflowClip) 68 { 69 } 70 setIgnoreOverflowClip()71 void setIgnoreOverflowClip() 72 { 73 ASSERT(!usesCache() || cacheSlot == PaintingClipRects); 74 ASSERT(respectOverflowClip == RespectOverflowClip); 75 if (usesCache()) 76 cacheSlot = PaintingClipRectsIgnoringOverflowClip; 77 respectOverflowClip = IgnoreOverflowClip; 78 } 79 usesCache()80 bool usesCache() const 81 { 82 return cacheSlot != UncachedClipRects; 83 } 84 85 const RenderLayer* const rootLayer; 86 const OverlayScrollbarSizeRelevancy scrollbarRelevancy; 87 88 private: 89 friend class RenderLayerClipper; 90 91 ClipRectsCacheSlot cacheSlot; 92 LayoutSize subPixelAccumulation; 93 ShouldRespectOverflowClip respectOverflowClip; 94 }; 95 96 class RenderLayerClipper { 97 WTF_MAKE_NONCOPYABLE(RenderLayerClipper); 98 public: 99 explicit RenderLayerClipper(RenderLayerModelObject&); 100 101 void clearClipRectsIncludingDescendants(); 102 void clearClipRectsIncludingDescendants(ClipRectsCacheSlot); 103 104 LayoutRect childrenClipRect() const; // Returns the foreground clip rect of the layer in the document's coordinate space. 105 LayoutRect localClipRect() const; // Returns the background clip rect of the layer in the local coordinate space. 106 107 ClipRects* getClipRects(const ClipRectsContext&) const; 108 109 ClipRect backgroundClipRect(const ClipRectsContext&) const; 110 111 // This method figures out our layerBounds in coordinates relative to 112 // |rootLayer|. It also computes our background and foreground clip rects 113 // for painting/event handling. 114 // Pass offsetFromRoot if known. 115 void calculateRects(const ClipRectsContext&, const LayoutRect& paintDirtyRect, LayoutRect& layerBounds, 116 ClipRect& backgroundRect, ClipRect& foregroundRect, ClipRect& outlineRect, const LayoutPoint* offsetFromRoot = 0) const; 117 118 private: 119 void calculateClipRects(const ClipRectsContext&, ClipRects&) const; 120 121 ClipRects* clipRectsIfCached(const ClipRectsContext&) const; 122 ClipRects* storeClipRectsInCache(const ClipRectsContext&, ClipRects* parentClipRects, const ClipRects&) const; 123 124 // cachedClipRects looks buggy: It doesn't check whether context.rootLayer and entry.root match. 125 // FIXME: Move callers to clipRectsIfCached, which does the proper checks. cachedClipRects(const ClipRectsContext & context)126 ClipRects* cachedClipRects(const ClipRectsContext& context) const 127 { 128 return m_cache ? m_cache->get(context.cacheSlot).clipRects.get() : 0; 129 } 130 131 void getOrCalculateClipRects(const ClipRectsContext&, ClipRects&) const; 132 133 RenderLayer* clippingRootForPainting() const; 134 cache()135 ClipRectsCache& cache() const 136 { 137 if (!m_cache) 138 m_cache = adoptPtr(new ClipRectsCache); 139 return *m_cache; 140 } 141 142 // FIXME: Could this be a RenderBox? 143 RenderLayerModelObject& m_renderer; 144 mutable OwnPtr<ClipRectsCache> m_cache; 145 }; 146 147 } // namespace blink 148 149 #endif // RenderLayerClipper_h 150