1 files changed, 118 insertions, 0 deletions
diff --git a/xbmc/windowing/OSScreenSaver.h b/xbmc/windowing/OSScreenSaver.h
new file mode 100644
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+++ b/xbmc/windowing/OSScreenSaver.h
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+/*
+ *  Copyright (C) 2017-2018 Team Kodi
+ *  This file is part of Kodi - https://kodi.tv
+ *
+ *  SPDX-License-Identifier: GPL-2.0-or-later
+ *  See LICENSES/README.md for more information.
+ */
+
+#pragma once
+
+#include <memory>
+#include <utility>
+
+namespace KODI
+{
+namespace WINDOWING
+{
+
+class COSScreenSaverManager;
+
+/**
+ * Inhibit the OS screen saver as long as this object is alive
+ *
+ * Destroy or call \ref Release to stop this inhibitor from being active.
+ * The OS screen saver may still be inhibited as long as other inhibitors are
+ * active though.
+ *
+ * \note Make sure to release or destroy the inhibitor before the \ref
+ *       COSScreenSaverManager is destroyed
+ */
+class COSScreenSaverInhibitor
+{
+public:
+  COSScreenSaverInhibitor() noexcept;
+  COSScreenSaverInhibitor(COSScreenSaverInhibitor&& other) noexcept;
+  COSScreenSaverInhibitor& operator=(COSScreenSaverInhibitor&& other) noexcept;
+  ~COSScreenSaverInhibitor() noexcept;
+  void Release();
+  bool IsActive() const;
+  operator bool() const;
+
+private:
+  friend class COSScreenSaverManager;
+  explicit COSScreenSaverInhibitor(COSScreenSaverManager* manager);
+  bool m_active;
+  COSScreenSaverManager* m_manager;
+
+  COSScreenSaverInhibitor(COSScreenSaverInhibitor const& other) = delete;
+  COSScreenSaverInhibitor& operator=(COSScreenSaverInhibitor const& other) = delete;
+};
+
+/**
+ * Interface for OS screen saver control implementations
+ */
+class IOSScreenSaver
+{
+public:
+  virtual ~IOSScreenSaver() = default;
+  /**
+   * Do not allow the OS screen saver to become active
+   *
+   * Calling this function multiple times without calling \ref Unhibit
+   * MUST NOT produce any side-effects.
+   */
+  virtual void Inhibit() = 0;
+  /**
+   * Allow the OS screen saver to become active again
+   *
+   * Calling this function multiple times or at all without calling \ref Inhibit
+   * MUST NOT produce any side-effects.
+   */
+  virtual void Uninhibit() = 0;
+};
+
+/**
+ * Dummy implementation of IOSScreenSaver
+ */
+class CDummyOSScreenSaver : public IOSScreenSaver
+{
+public:
+  void Inhibit() override {}
+  void Uninhibit() override {}
+};
+
+/**
+ * Manage the OS screen saver
+ *
+ * This class keeps track of a number of \ref COSScreenSaverInhibitor instances
+ * and keeps the OS screen saver inhibited as long as at least one of them
+ * exists and is active.
+ */
+class COSScreenSaverManager
+{
+public:
+  /**
+   * Create manager with backing OS-specific implementation
+   */
+  explicit COSScreenSaverManager(std::unique_ptr<IOSScreenSaver> impl);
+  /**
+   * Create inhibitor that prevents the OS screen saver from becoming active as
+   * long as it is alive
+   */
+  COSScreenSaverInhibitor CreateInhibitor();
+  /**
+   * Check whether the OS screen saver is currently inhibited
+   */
+  bool IsInhibited();
+
+private:
+  friend class COSScreenSaverInhibitor;
+  void RemoveInhibitor();
+
+  unsigned int m_inhibitionCount{0u};
+  std::unique_ptr<IOSScreenSaver> m_impl;
+};
+
+}
+}