| /* |
| * Copyright (C) 2000 Lars Knoll (knoll@kde.org) |
| * Copyright (C) 2003, 2004, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All right reserved. |
| * Copyright (C) 2010 Google Inc. All rights reserved. |
| * Copyright (C) 2014 Adobe Systems Inc. |
| * |
| * 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. |
| * |
| */ |
| |
| #ifndef SKY_ENGINE_CORE_RENDERING_LINE_TRAILINGOBJECTS_H_ |
| #define SKY_ENGINE_CORE_RENDERING_LINE_TRAILINGOBJECTS_H_ |
| |
| #include "sky/engine/wtf/Vector.h" |
| |
| namespace blink { |
| |
| class InlineIterator; |
| class RenderObject; |
| class RenderText; |
| |
| struct BidiRun; |
| |
| template <class Iterator, class Run> class BidiResolver; |
| template <class Iterator> class MidpointState; |
| typedef BidiResolver<InlineIterator, BidiRun> InlineBidiResolver; |
| typedef MidpointState<InlineIterator> LineMidpointState; |
| |
| // This class allows us to ensure lineboxes are created in the right place on the line when |
| // an out-of-flow positioned object or an empty inline is encountered between a trailing space |
| // and subsequent spaces and we want to ignore (i.e. collapse) surplus whitespace. So for example: |
| // <div>X <span></span> Y</div> |
| // or |
| // <div>X <div style="position: absolute"></div> Y</div> |
| // In both of the above snippets the inline and the positioned object occur after a trailing space |
| // and before a space that will cause our line breaking algorithm to start ignoring spaces. When it |
| // does that we want to ensure that the inline/positioned object gets a linebox and that it is part |
| // of the collapsed whitespace. So to achieve this we use appendObjectIfNeeded() to keep track of |
| // objects encountered after a trailing whitespace and updateMidpointsForTrailingObjects() to put |
| // them in the right place when we start ignoring surplus whitespace. |
| |
| class TrailingObjects { |
| public: |
| TrailingObjects() |
| : m_whitespace(0) |
| { |
| } |
| |
| void setTrailingWhitespace(RenderText* whitespace) |
| { |
| ASSERT(whitespace); |
| m_whitespace = whitespace; |
| } |
| |
| void clear() |
| { |
| m_whitespace = 0; |
| // Using resize(0) rather than clear() here saves 2% on |
| // PerformanceTests/Layout/line-layout.html because we avoid freeing and |
| // re-allocating the underlying buffer repeatedly. |
| m_objects.resize(0); |
| } |
| |
| void appendObjectIfNeeded(RenderObject* object) |
| { |
| if (m_whitespace) |
| m_objects.append(object); |
| } |
| |
| enum CollapseFirstSpaceOrNot { DoNotCollapseFirstSpace, CollapseFirstSpace }; |
| |
| void updateMidpointsForTrailingObjects(LineMidpointState&, const InlineIterator& lBreak, CollapseFirstSpaceOrNot); |
| |
| private: |
| RenderText* m_whitespace; |
| Vector<RenderObject*, 4> m_objects; |
| }; |
| |
| } |
| |
| #endif // SKY_ENGINE_CORE_RENDERING_LINE_TRAILINGOBJECTS_H_ |