1 /* 2 * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved. 3 * 4 * Portions are Copyright (C) 1998 Netscape Communications Corporation. 5 * 6 * Other contributors: 7 * Robert O'Callahan <roc+@cs.cmu.edu> 8 * David Baron <dbaron (at) fas.harvard.edu> 9 * Christian Biesinger <cbiesinger (at) web.de> 10 * Randall Jesup <rjesup (at) wgate.com> 11 * Roland Mainz <roland.mainz (at) informatik.med.uni-giessen.de> 12 * Josh Soref <timeless (at) mac.com> 13 * Boris Zbarsky <bzbarsky (at) mit.edu> 14 * 15 * This library is free software; you can redistribute it and/or 16 * modify it under the terms of the GNU Lesser General Public 17 * License as published by the Free Software Foundation; either 18 * version 2.1 of the License, or (at your option) any later version. 19 * 20 * This library is distributed in the hope that it will be useful, 21 * but WITHOUT ANY WARRANTY; without even the implied warranty of 22 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 23 * Lesser General Public License for more details. 24 * 25 * You should have received a copy of the GNU Lesser General Public 26 * License along with this library; if not, write to the Free Software 27 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 28 * 29 * Alternatively, the contents of this file may be used under the terms 30 * of either the Mozilla Public License Version 1.1, found at 31 * http://www.mozilla.org/MPL/ (the "MPL") or the GNU General Public 32 * License Version 2.0, found at http://www.fsf.org/copyleft/gpl.html 33 * (the "GPL"), in which case the provisions of the MPL or the GPL are 34 * applicable instead of those above. If you wish to allow use of your 35 * version of this file only under the terms of one of those two 36 * licenses (the MPL or the GPL) and not to allow others to use your 37 * version of this file under the LGPL, indicate your decision by 38 * deletingthe provisions above and replace them with the notice and 39 * other provisions required by the MPL or the GPL, as the case may be. 40 * If you do not delete the provisions above, a recipient may use your 41 * version of this file under any of the LGPL, the MPL or the GPL. 42 */ 43 44 #include "config.h" 45 #include "core/rendering/RenderLayerClipper.h" 46 47 #include "core/rendering/RenderLayer.h" 48 #include "core/rendering/RenderView.h" 49 50 namespace WebCore { 51 52 void RenderLayerClipper::updateClipRects(const ClipRectsContext& clipRectsContext) 53 { 54 ClipRectsType clipRectsType = clipRectsContext.clipRectsType; 55 ASSERT(clipRectsType < NumCachedClipRectsTypes); 56 if (m_clipRectsCache && m_clipRectsCache->getClipRects(clipRectsType, clipRectsContext.respectOverflowClip)) { 57 // FIXME: these asserts trigger for squashing. Need to update this code to support squashing as appropriate. 58 ASSERT(clipRectsContext.rootLayer == m_clipRectsCache->m_clipRectsRoot[clipRectsType]); 59 ASSERT(m_clipRectsCache->m_scrollbarRelevancy[clipRectsType] == clipRectsContext.overlayScrollbarSizeRelevancy); 60 61 #ifdef CHECK_CACHED_CLIP_RECTS 62 // This code is useful to check cached clip rects, but is too expensive to leave enabled in debug builds by default. 63 ClipRectsContext tempContext(clipRectsContext); 64 tempContext.clipRectsType = TemporaryClipRects; 65 ClipRects clipRects; 66 calculateClipRects(tempContext, clipRects); 67 ASSERT(clipRects == *m_clipRectsCache->getClipRects(clipRectsType, clipRectsContext.respectOverflowClip).get()); 68 #endif 69 return; // We have the correct cached value. 70 } 71 72 // For transformed layers, the root layer was shifted to be us, so there is no need to 73 // examine the parent. We want to cache clip rects with us as the root. 74 RenderLayer* parentLayer = clipRectsContext.rootLayer != m_renderer->layer() ? m_renderer->layer()->parent() : 0; 75 if (parentLayer) 76 parentLayer->clipper().updateClipRects(clipRectsContext); 77 78 ClipRects clipRects; 79 calculateClipRects(clipRectsContext, clipRects); 80 81 if (!m_clipRectsCache) 82 m_clipRectsCache = adoptPtr(new ClipRectsCache); 83 84 if (parentLayer && parentLayer->clipper().clipRects(clipRectsContext) && clipRects == *parentLayer->clipper().clipRects(clipRectsContext)) 85 m_clipRectsCache->setClipRects(clipRectsType, clipRectsContext.respectOverflowClip, parentLayer->clipper().clipRects(clipRectsContext)); 86 else 87 m_clipRectsCache->setClipRects(clipRectsType, clipRectsContext.respectOverflowClip, ClipRects::create(clipRects)); 88 89 #ifndef NDEBUG 90 m_clipRectsCache->m_clipRectsRoot[clipRectsType] = clipRectsContext.rootLayer; 91 m_clipRectsCache->m_scrollbarRelevancy[clipRectsType] = clipRectsContext.overlayScrollbarSizeRelevancy; 92 #endif 93 } 94 95 void RenderLayerClipper::clearClipRectsIncludingDescendants(ClipRectsType typeToClear) 96 { 97 // FIXME: it's not clear how this layer not having clip rects guarantees that no descendants have any. 98 if (!m_clipRectsCache) 99 return; 100 101 clearClipRects(typeToClear); 102 103 for (RenderLayer* layer = m_renderer->layer()->firstChild(); layer; layer = layer->nextSibling()) 104 layer->clipper().clearClipRectsIncludingDescendants(typeToClear); 105 } 106 107 void RenderLayerClipper::clearClipRects(ClipRectsType typeToClear) 108 { 109 if (typeToClear == AllClipRectTypes) { 110 m_clipRectsCache = nullptr; 111 } else { 112 ASSERT(typeToClear < NumCachedClipRectsTypes); 113 RefPtr<ClipRects> dummy; 114 m_clipRectsCache->setClipRects(typeToClear, RespectOverflowClip, dummy); 115 m_clipRectsCache->setClipRects(typeToClear, IgnoreOverflowClip, dummy); 116 } 117 } 118 119 void RenderLayerClipper::calculateClipRects(const ClipRectsContext& clipRectsContext, ClipRects& clipRects) const 120 { 121 if (!m_renderer->layer()->parent()) { 122 // The root layer's clip rect is always infinite. 123 clipRects.reset(PaintInfo::infiniteRect()); 124 return; 125 } 126 127 ClipRectsType clipRectsType = clipRectsContext.clipRectsType; 128 bool useCached = clipRectsType != TemporaryClipRects; 129 130 // For transformed layers, the root layer was shifted to be us, so there is no need to 131 // examine the parent. We want to cache clip rects with us as the root. 132 RenderLayer* parentLayer = clipRectsContext.rootLayer != m_renderer->layer() ? m_renderer->layer()->parent() : 0; 133 134 // Ensure that our parent's clip has been calculated so that we can examine the values. 135 if (parentLayer) { 136 if (useCached && parentLayer->clipper().clipRects(clipRectsContext)) { 137 clipRects = *parentLayer->clipper().clipRects(clipRectsContext); 138 } else { 139 ClipRectsContext parentContext(clipRectsContext); 140 parentContext.overlayScrollbarSizeRelevancy = IgnoreOverlayScrollbarSize; // FIXME: why? 141 parentLayer->clipper().calculateClipRects(parentContext, clipRects); 142 } 143 } else { 144 clipRects.reset(PaintInfo::infiniteRect()); 145 } 146 147 // A fixed object is essentially the root of its containing block hierarchy, so when 148 // we encounter such an object, we reset our clip rects to the fixedClipRect. 149 if (m_renderer->style()->position() == FixedPosition) { 150 clipRects.setPosClipRect(clipRects.fixedClipRect()); 151 clipRects.setOverflowClipRect(clipRects.fixedClipRect()); 152 clipRects.setFixed(true); 153 } else if (m_renderer->style()->hasInFlowPosition()) { 154 clipRects.setPosClipRect(clipRects.overflowClipRect()); 155 } else if (m_renderer->style()->position() == AbsolutePosition) { 156 clipRects.setOverflowClipRect(clipRects.posClipRect()); 157 } 158 159 // Update the clip rects that will be passed to child layers. 160 if ((m_renderer->hasOverflowClip() && (clipRectsContext.respectOverflowClip == RespectOverflowClip || m_renderer->layer() != clipRectsContext.rootLayer)) || m_renderer->hasClip()) { 161 // This layer establishes a clip of some kind. 162 163 // This offset cannot use convertToLayerCoords, because sometimes our rootLayer may be across 164 // some transformed layer boundary, for example, in the RenderLayerCompositor overlapMap, where 165 // clipRects are needed in view space. 166 LayoutPoint offset; 167 offset = roundedLayoutPoint(m_renderer->localToContainerPoint(FloatPoint(), clipRectsContext.rootLayer->renderer())); 168 RenderView* view = m_renderer->view(); 169 ASSERT(view); 170 if (view && clipRects.fixed() && clipRectsContext.rootLayer->renderer() == view) { 171 offset -= view->frameView()->scrollOffsetForFixedPosition(); 172 } 173 174 if (m_renderer->hasOverflowClip()) { 175 ClipRect newOverflowClip = toRenderBox(m_renderer)->overflowClipRect(offset, clipRectsContext.region, clipRectsContext.overlayScrollbarSizeRelevancy); 176 if (m_renderer->style()->hasBorderRadius()) 177 newOverflowClip.setHasRadius(true); 178 clipRects.setOverflowClipRect(intersection(newOverflowClip, clipRects.overflowClipRect())); 179 if (m_renderer->isPositioned()) 180 clipRects.setPosClipRect(intersection(newOverflowClip, clipRects.posClipRect())); 181 } 182 if (m_renderer->hasClip()) { 183 LayoutRect newPosClip = toRenderBox(m_renderer)->clipRect(offset, clipRectsContext.region); 184 clipRects.setPosClipRect(intersection(newPosClip, clipRects.posClipRect())); 185 clipRects.setOverflowClipRect(intersection(newPosClip, clipRects.overflowClipRect())); 186 clipRects.setFixedClipRect(intersection(newPosClip, clipRects.fixedClipRect())); 187 } 188 } 189 } 190 191 } // namespace WebCore 192
