Ash: Implement Toasts

ash/system/toast/toast_manager.h

+// Copyright 2016 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 ASH_SYSTEM_TOAST_TOAST_MANAGER_H_
+#define ASH_SYSTEM_TOAST_TOAST_MANAGER_H_
+
+#include <queue>
+#include <string>
+
+#include "ash/ash_export.h"
+#include "ash/system/toast/toast_overlay.h"
+#include "base/memory/singleton.h"
+#include "base/threading/thread_checker.h"
+
+namespace ash {
+
+class ASH_EXPORT ToastManager : public ToastOverlay::Delegate {
+ public:
+  static ToastManager* GetInstance();
+
+  void Show(const std::string& text, uint64_t duration_ms);
+
+  void OnClosed() override;
+
+ private:
+  friend struct base::DefaultSingletonTraits<ToastManager>;
+
+  ToastManager();  // private ctor
+  virtual ~ToastManager();
+
+  void ShowLatest();
+  void OnDurationPassed(int toast_id);
+
+  int toast_id_ = 0;
+  std::queue<std::pair<std::string, uint64_t>> queue_;
+  scoped_ptr<ToastOverlay> overlay_;
+
+  base::ThreadChecker thread_checker_;
+
+  DISALLOW_COPY_AND_ASSIGN(ToastManager);
+};
+
+}  // namespace ash
+
+#endif  // ASH_SYSTEM_TOAST_TOAST_MANAGER_H_