Full Screen Magnifier: Add MagnificationManager

chrome/browser/chromeos/accessibility/magnification_manager.h

+// Copyright (c) 2012 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 CHROME_BROWSER_CHROMEOS_ACCESSIBILITY_MAGNIFICATION_MANAGER_H_
+#define CHROME_BROWSER_CHROMEOS_ACCESSIBILITY_MAGNIFICATION_MANAGER_H_
+
+namespace chromeos {
+
+
+// MagnificationManager controls the full screen magnifier from chrome-browser
+// side (not ash side).
+//
+// MagnificationManager does:
+//   - Watch logged-in. Changes the behavior between the login screen and user
+//     desktop.
+//   - Watch change of the pref. When the pref changes, the setting of the
+//     magnifier will interlock with it.
+
+class MagnificationManager {
+ public:
+  // Creates an instance of MagnificationManager. This should be called once,
+  // because only one instance should exist at the same time.
+  static MagnificationManager* CreateInstance();
+  // Returns the existing instance. If there is no instance, returns NULL.
+  static MagnificationManager* GetInstance();
+
+  virtual ~MagnificationManager() {}
+
+  // Returns if the magnifier is enabled or not.
+  virtual bool IsEnabled() = 0;
+  // Enables (or disables if |enabled| is false) the magnifierh.
+  virtual void SetEnabled(bool enabled) = 0;
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_ACCESSIBILITY_MAGNIFICATION_MANAGER_H_