Refactoring and documentation

LenaPi/MouseEventSpy.h

@@ -15,19 +15,44 @@ class MouseEventSpy : public QObject
     Q_OBJECT
 
 protected:
-    explicit MouseEventSpy(QObject *parent = 0);
+    explicit MouseEventSpy(QObject *parent = nullptr) : QObject(parent) { /* nothing */ }
 
 signals:
     void mouseEventDetected();
 
 public:
+    /**
+     * @brief Create instance if necessary.
+     *
+     * If no instance has been created yet, create new instance and install it as event filter
+     * in QGuiApplication.
+     *
+     * @see MouseEventSpy::instance()
+     */
     static void init();
+    /**
+     * @brief Implements the singleton pattern.
+     * @return Instance of MouseEventSpy
+     *
+     * If no instance has been created yet, create new instance and install it as event filter
+     * in QGuiApplication.
+     */
     static MouseEventSpy* instance();
 
 protected:
+    /**
+     * @brief Expand QObject::eventFilter to react to MouseEvents.
+     *
+     * Restart timer each time a mouse event is detected.
+     */
     bool eventFilter(QObject* watched, QEvent* event);
 
 private:
+    /**
+     * @brief Checks whether the event type is a mouse event.
+     * @param t Event type
+     * @return Returns whether the event type is a mouse event.
+     */
     bool isMouseEvent(QEvent::Type t);
 
 };