third_party/WebKit/Source/platform/graphics/GraphicsContextStateSaver.h

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  28
  29 #ifndef GraphicsContextStateSaver_h
  30 #define GraphicsContextStateSaver_h
  31
  32 #include "platform/PlatformExport.h"
  33 #include "platform/graphics/GraphicsContext.h"
  34
  35 namespace blink {
  36
  37 class PLATFORM_EXPORT GraphicsContextStateSaver {
  38     WTF_MAKE_FAST_ALLOCATED(GraphicsContextStateSaver);
  39 public:
  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
  78 private:
  79     GraphicsContext& m_context;
  80     bool m_saveAndRestore;
  81 };
  82
  83 } // namespace blink
  84
  85 #endif // GraphicsContextStateSaver_h