Add ScreenSaver.

src/utilities/Locker.h

@@ -10,7 +10,9 @@ class Locker : public QObject
 public:
     static Locker* getInstance();
     void start();
+    void stop();
     void setTimer(int aInterval);
+    void setIsEnable(bool aIsEnable);
 
 public slots:
     void refreshTimer();
@@ -21,6 +23,7 @@ private:
 
     QTimer* mScreenTimer;
     int mCounter;
+    bool mIsEnable;
 };
 
 #endif // LOCKER_H