View synchronization

mojo/services/public/cpp/view_manager/view_observer.h

+// Copyright 2014 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 MOJO_SERVICES_PUBLIC_CPP_VIEW_MANAGER_VIEW_OBSERVER_H_
+#define MOJO_SERVICES_PUBLIC_CPP_VIEW_MANAGER_VIEW_OBSERVER_H_
+
+#include <vector>
+
+#include "base/basictypes.h"
+
+namespace mojo {
+namespace services {
+namespace view_manager {
+
+class View;
+
+class ViewObserver {
+ public:
+  enum DispositionChangePhase {
+    DISPOSITION_CHANGING,
+    DISPOSITION_CHANGED
+  };
+
+  virtual void OnViewDestroy(View* view, DispositionChangePhase phase) {}
+
+ protected:
+  virtual ~ViewObserver() {}
+};
+
+}  // namespace view_manager
+}  // namespace services
+}  // namespace mojo
+
+#endif  // MOJO_SERVICES_PUBLIC_CPP_VIEW_MANAGER_VIEW_OBSERVER_H_