1// Copyright (C) 2013 Google Inc. All rights reserved. 2// 3// Redistribution and use in source and binary forms, with or without 4// modification, are permitted provided that the following conditions are 5// met: 6// 7// * Redistributions of source code must retain the above copyright 8// notice, this list of conditions and the following disclaimer. 9// * Redistributions in binary form must reproduce the above 10// copyright notice, this list of conditions and the following disclaimer 11// in the documentation and/or other materials provided with the 12// distribution. 13// * Neither the name of Google Inc. nor the names of its 14// contributors may be used to endorse or promote products derived from 15// this software without specific prior written permission. 16// 17// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 18// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 19// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 20// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 21// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 22// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 23// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 27// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 29#ifndef GraphicsContextStateSaver_h 30#define GraphicsContextStateSaver_h 31 32#include "platform/PlatformExport.h" 33#include "platform/graphics/GraphicsContext.h" 34 35namespace blink { 36 37class PLATFORM_EXPORT GraphicsContextStateSaver { 38 WTF_MAKE_FAST_ALLOCATED; 39public: 40 GraphicsContextStateSaver(GraphicsContext& context, bool saveAndRestore = true) 41 : m_context(context) 42 , m_saveAndRestore(saveAndRestore) 43 { 44 if (m_saveAndRestore) 45 m_context.save(); 46 } 47 48 ~GraphicsContextStateSaver() 49 { 50 if (m_saveAndRestore) 51 m_context.restore(); 52 } 53 54 void save() 55 { 56 ASSERT(!m_saveAndRestore); 57 m_context.save(); 58 m_saveAndRestore = true; 59 } 60 61 void saveIfNeeded() 62 { 63 if (saved()) 64 return; 65 save(); 66 } 67 68 void restore() 69 { 70 ASSERT(m_saveAndRestore); 71 m_context.restore(); 72 m_saveAndRestore = false; 73 } 74 75 GraphicsContext* context() const { return &m_context; } 76 bool saved() const { return m_saveAndRestore; } 77 78private: 79 GraphicsContext& m_context; 80 bool m_saveAndRestore; 81}; 82 83} // namespace blink 84 85#endif // GraphicsContextStateSaver_h 86