| // Copyright 2020 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_UPGRADE_DETECTOR_INSTALLED_VERSION_MONITOR_H_ |
| #define CHROME_BROWSER_UPGRADE_DETECTOR_INSTALLED_VERSION_MONITOR_H_ |
| |
| #include <memory> |
| |
| #include "base/callback_forward.h" |
| |
| // An abstract base for an object that monitors the browser's installation for |
| // updates. |
| class InstalledVersionMonitor { |
| public: |
| // A callback run to indicate either a monitored change or an error. The |
| // single boolean argument is true in case of error, or false in case of a |
| // change. |
| using Callback = base::RepeatingCallback<void(bool)>; |
| |
| // Returns a new instance. |
| static std::unique_ptr<InstalledVersionMonitor> Create(); |
| |
| InstalledVersionMonitor(const InstalledVersionMonitor&) = delete; |
| InstalledVersionMonitor& operator=(const InstalledVersionMonitor&) = delete; |
| virtual ~InstalledVersionMonitor() = default; |
| |
| // Starts the monitor; may only be called once per instance. |callback| will |
| // be run zero or more times with a false argument to report changes in the |
| // installation, and at most one time with a true argument to report an error. |
| // In case of error, no further notifications will be made. There is no |
| // guarantee that |callback| will not be run after this instance is destroyed. |
| virtual void Start(Callback callback) = 0; |
| |
| protected: |
| InstalledVersionMonitor() = default; |
| }; |
| |
| #endif // CHROME_BROWSER_UPGRADE_DETECTOR_INSTALLED_VERSION_MONITOR_H_ |