| /* |
| * Copyright (C) 2000 Lars Knoll (knoll@kde.org) |
| * Copyright (C) 2003, 2004, 2006, 2007, 2009, 2010 Apple Inc. |
| * All right reserved. |
| * |
| * This library is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Library General Public |
| * License as published by the Free Software Foundation; either |
| * version 2 of the License, or (at your option) any later version. |
| * |
| * This library is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Library General Public License for more details. |
| * |
| * You should have received a copy of the GNU Library General Public License |
| * along with this library; see the file COPYING.LIB. If not, write to |
| * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
| * Boston, MA 02110-1301, USA. |
| * |
| */ |
| |
| #include "platform/text/BidiContext.h" |
| |
| #include "wtf/StdLibExtras.h" |
| #include "wtf/Vector.h" |
| |
| namespace blink { |
| |
| using namespace WTF::Unicode; |
| |
| struct SameSizeAsBidiContext : public RefCounted<SameSizeAsBidiContext> { |
| uint32_t bitfields : 16; |
| void* parent; |
| }; |
| |
| static_assert(sizeof(BidiContext) == sizeof(SameSizeAsBidiContext), |
| "BidiContext should stay small"); |
| |
| inline PassRefPtr<BidiContext> BidiContext::createUncached( |
| unsigned char level, |
| CharDirection direction, |
| bool override, |
| BidiEmbeddingSource source, |
| BidiContext* parent) { |
| return adoptRef(new BidiContext(level, direction, override, source, parent)); |
| } |
| |
| PassRefPtr<BidiContext> BidiContext::create(unsigned char level, |
| CharDirection direction, |
| bool override, |
| BidiEmbeddingSource source, |
| BidiContext* parent) { |
| ASSERT(direction == (level % 2 ? RightToLeft : LeftToRight)); |
| |
| if (parent || level >= 2) |
| return createUncached(level, direction, override, source, parent); |
| |
| ASSERT(level <= 1); |
| if (!level) { |
| if (!override) { |
| DEFINE_STATIC_REF( |
| BidiContext, ltrContext, |
| (createUncached(0, LeftToRight, false, FromStyleOrDOM, 0))); |
| return ltrContext; |
| } |
| |
| DEFINE_STATIC_REF( |
| BidiContext, ltrOverrideContext, |
| (createUncached(0, LeftToRight, true, FromStyleOrDOM, 0))); |
| return ltrOverrideContext; |
| } |
| |
| if (!override) { |
| DEFINE_STATIC_REF( |
| BidiContext, rtlContext, |
| (createUncached(1, RightToLeft, false, FromStyleOrDOM, 0))); |
| return rtlContext; |
| } |
| |
| DEFINE_STATIC_REF(BidiContext, rtlOverrideContext, |
| (createUncached(1, RightToLeft, true, FromStyleOrDOM, 0))); |
| return rtlOverrideContext; |
| } |
| |
| static inline PassRefPtr<BidiContext> copyContextAndRebaselineLevel( |
| BidiContext* context, |
| BidiContext* parent) { |
| ASSERT(context); |
| unsigned char newLevel = parent ? parent->level() : 0; |
| if (context->dir() == RightToLeft) |
| newLevel = nextGreaterOddLevel(newLevel); |
| else if (parent) |
| newLevel = nextGreaterEvenLevel(newLevel); |
| |
| return BidiContext::create(newLevel, context->dir(), context->override(), |
| context->source(), parent); |
| } |
| |
| // The BidiContext stack must be immutable -- they're re-used for re-layout |
| // after DOM modification/editing -- so we copy all the non-unicode contexts, |
| // and recalculate their levels. |
| PassRefPtr<BidiContext> |
| BidiContext::copyStackRemovingUnicodeEmbeddingContexts() { |
| Vector<BidiContext*, 64> contexts; |
| for (BidiContext* iter = this; iter; iter = iter->parent()) { |
| if (iter->source() != FromUnicode) |
| contexts.append(iter); |
| } |
| ASSERT(contexts.size()); |
| |
| RefPtr<BidiContext> topContext = |
| copyContextAndRebaselineLevel(contexts.last(), 0); |
| for (int i = contexts.size() - 1; i > 0; --i) |
| topContext = |
| copyContextAndRebaselineLevel(contexts[i - 1], topContext.get()); |
| |
| return topContext.release(); |
| } |
| |
| bool operator==(const BidiContext& c1, const BidiContext& c2) { |
| if (&c1 == &c2) |
| return true; |
| if (c1.level() != c2.level() || c1.override() != c2.override() || |
| c1.dir() != c2.dir() || c1.source() != c2.source()) |
| return false; |
| if (!c1.parent()) |
| return !c2.parent(); |
| return c2.parent() && *c1.parent() == *c2.parent(); |
| } |
| |
| } // namespace blink |