third_party/blink/renderer/platform/graphics/graphics_context_state_saver.h

// Copyright (C) 2013 Google Inc. All rights reserved.
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#ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_GRAPHICS_GRAPHICS_CONTEXT_STATE_SAVER_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_GRAPHICS_GRAPHICS_CONTEXT_STATE_SAVER_H_

#include "base/macros.h"
#include "third_party/blink/renderer/platform/graphics/graphics_context.h"
#include "third_party/blink/renderer/platform/platform_export.h"
#include "third_party/blink/renderer/platform/wtf/allocator.h"

namespace blink {

class PLATFORM_EXPORT GraphicsContextStateSaver final {
  USING_FAST_MALLOC(GraphicsContextStateSaver);

 public:
  GraphicsContextStateSaver(GraphicsContext& context,
                            bool save_and_restore = true)
      : context_(context), save_and_restore_(save_and_restore) {
    if (save_and_restore_)
      context_.Save();
  }

  ~GraphicsContextStateSaver() {
    if (save_and_restore_)
      context_.Restore();
  }

  void Save() {
    DCHECK(!save_and_restore_);
    context_.Save();
    save_and_restore_ = true;
  }

  void SaveIfNeeded() {
    if (Saved())
      return;
    Save();
  }

  void Restore() {
    DCHECK(save_and_restore_);
    context_.Restore();
    save_and_restore_ = false;
  }

  GraphicsContext& Context() const { return context_; }
  bool Saved() const { return save_and_restore_; }

 private:
  GraphicsContext& context_;
  bool save_and_restore_;

  DISALLOW_COPY_AND_ASSIGN(GraphicsContextStateSaver);
};

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_PLATFORM_GRAPHICS_GRAPHICS_CONTEXT_STATE_SAVER_H_