1 /* 2 * Copyright (C) 2000 Lars Knoll (knoll (at) kde.org) 3 * Copyright (C) 2003, 2004, 2006, 2007, 2009, 2010 Apple Inc. All right reserved. 4 * 5 * This library is free software; you can redistribute it and/or 6 * modify it under the terms of the GNU Library General Public 7 * License as published by the Free Software Foundation; either 8 * version 2 of the License, or (at your option) any later version. 9 * 10 * This library is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 * Library General Public License for more details. 14 * 15 * You should have received a copy of the GNU Library General Public License 16 * along with this library; see the file COPYING.LIB. If not, write to 17 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 18 * Boston, MA 02110-1301, USA. 19 * 20 */ 21 22 #include "config.h" 23 #include "BidiContext.h" 24 #include <wtf/Vector.h> 25 26 namespace WebCore { 27 28 using namespace WTF::Unicode; 29 30 inline PassRefPtr<BidiContext> BidiContext::createUncached(unsigned char level, Direction direction, bool override, BidiEmbeddingSource source, BidiContext* parent) 31 { 32 return adoptRef(new BidiContext(level, direction, override, source, parent)); 33 } 34 35 PassRefPtr<BidiContext> BidiContext::create(unsigned char level, Direction direction, bool override, BidiEmbeddingSource source, BidiContext* parent) 36 { 37 ASSERT(direction == (level % 2 ? RightToLeft : LeftToRight)); 38 39 if (parent) 40 return createUncached(level, direction, override, source, parent); 41 42 ASSERT(level <= 1); 43 if (!level) { 44 if (!override) { 45 static BidiContext* ltrContext = createUncached(0, LeftToRight, false, FromStyleOrDOM, 0).releaseRef(); 46 return ltrContext; 47 } 48 49 static BidiContext* ltrOverrideContext = createUncached(0, LeftToRight, true, FromStyleOrDOM, 0).releaseRef(); 50 return ltrOverrideContext; 51 } 52 53 if (!override) { 54 static BidiContext* rtlContext = createUncached(1, RightToLeft, false, FromStyleOrDOM, 0).releaseRef(); 55 return rtlContext; 56 } 57 58 static BidiContext* rtlOverrideContext = createUncached(1, RightToLeft, true, FromStyleOrDOM, 0).releaseRef(); 59 return rtlOverrideContext; 60 } 61 62 static inline PassRefPtr<BidiContext> copyContextAndRebaselineLevel(BidiContext* context, BidiContext* parent) 63 { 64 ASSERT(context); 65 unsigned char newLevel = parent ? parent->level() : 0; 66 if (context->dir() == RightToLeft) 67 newLevel = nextGreaterOddLevel(newLevel); 68 else if (parent) 69 newLevel = nextGreaterEvenLevel(newLevel); 70 71 return BidiContext::create(newLevel, context->dir(), context->override(), context->source(), parent); 72 } 73 74 // The BidiContext stack must be immutable -- they're re-used for re-layout after 75 // DOM modification/editing -- so we copy all the non-unicode contexts, and 76 // recalculate their levels. 77 PassRefPtr<BidiContext> BidiContext::copyStackRemovingUnicodeEmbeddingContexts() 78 { 79 Vector<BidiContext*, 64> contexts; 80 for (BidiContext* iter = this; iter; iter = iter->parent()) { 81 if (iter->source() != FromUnicode) 82 contexts.append(iter); 83 } 84 ASSERT(contexts.size()); 85 86 RefPtr<BidiContext> topContext = copyContextAndRebaselineLevel(contexts.last(), 0); 87 for (int i = contexts.size() - 1; i > 0; --i) 88 topContext = copyContextAndRebaselineLevel(contexts[i - 1], topContext.get()); 89 90 return topContext.release(); 91 } 92 93 bool operator==(const BidiContext& c1, const BidiContext& c2) 94 { 95 if (&c1 == &c2) 96 return true; 97 if (c1.level() != c2.level() || c1.override() != c2.override() || c1.dir() != c2.dir() || c1.source() != c2.source()) 98 return false; 99 if (!c1.parent()) 100 return !c2.parent(); 101 return c2.parent() && *c1.parent() == *c2.parent(); 102 } 103 104 } // namespace WebCore 105
