Add and use gfx::ScopedNSGraphicsContextState (ui/gfx/scoped_ns_graphics_context_state_mac.h).

ui/gfx/scoped_ns_graphics_context_state_mac.h

+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef UI_GFX_SCOPED_NS_GRAPHICS_CONTEXT_STATE_MAC_H_
+#define UI_GFX_SCOPED_NS_GRAPHICS_CONTEXT_STATE_MAC_H_
+
+#include "base/basictypes.h"
+
+#import <AppKit/AppKit.h>
+
+namespace gfx {
+
+// What this class does should be self-evident and self-documenting.
+class ScopedNSGraphicsContextState {
+ public:
+  explicit ScopedNSGraphicsContextState(NSGraphicsContext* context = nil)
+      : context_(context) {
+    if (!context_)
+      context_ = [NSGraphicsContext currentContext];
+    [context_ saveGraphicsState];
+  }
+
+  ~ScopedNSGraphicsContextState() {
+    [context_ restoreGraphicsState];
+  }
+
+ private:
+  NSGraphicsContext* context_;

[Nico, 2011/04/26 17:56:28]

If you keep this in a variable, this should probably be a scoped_nsobject with a
retain in the constructor?

Out-of-line things?

[Robert Sesek, 2011/04/26 18:50:53]

Done.
Done.

+
+  DISALLOW_COPY_AND_ASSIGN(ScopedNSGraphicsContextState);
+};
+
+}  // namespace gfx

[Avi (use Gerrit), 2011/04/26 17:50:29]

Can't you just do [NSGraphicsContext saveGraphicsState] in the constructor,
[NSGraphicsContext restoreGraphicsState] in the destructor, and drop the member
variable entirely?

[Robert Sesek, 2011/04/26 17:51:25]

Sure. Would you ever want to operate on a separate context, though?

+
+#endif  // UI_GFX_SCOPED_NS_GRAPHICS_CONTEXT_STATE_MAC_H_