Restart timer on mouse event.

Todo: call shut down script on timeout

LenaPi/MouseEventSpy.cpp

@@ -1,25 +1,29 @@
 #include "MouseEventSpy.h"
 
-#include <QEvent>
 #include <QGuiApplication>
 #include <QDebug>
 
+/**
+ * @brief Initialize timer.
+ * @param parent Parent object
+ */
 MouseEventSpy::MouseEventSpy(QObject *parent) : QObject(parent)
 {
-    qDebug() << "created Instance";
+    initTimer(10000);
+    mTimer.start();
 }
 
 /**
- * Implements the SINGLETON PATTERN
+ * @brief Implements the singleton pattern
+ *
+ * If no instance has been created yet, create new instance and install it as event filter
+ * in QGuiApplication.
  */
 MouseEventSpy* MouseEventSpy::instance()
 {
     static MouseEventSpy* inst;
     if (inst == nullptr)
     {
-        // If no instance has been created yet, create a new and install it as event filter.
-        // Uppon first use of the instance, it will automatically
-        // install itself in the QGuiApplication
         inst = new MouseEventSpy();
         QGuiApplication* app = qGuiApp;
         app->installEventFilter(inst);
@@ -28,18 +32,57 @@ MouseEventSpy* MouseEventSpy::instance()
 }
 
 /**
- * This is the method is necessary for 'installEventFilter'
+ * @brief Expand QObject::eventFilter to react to MouseEvents.
+ *
+ * Restart timer each time a mouse event is detected.
  */
 bool MouseEventSpy::eventFilter(QObject* watched, QEvent* event)
 {
     QEvent::Type t = event->type();
-    if ((t == QEvent::MouseButtonDblClick
-         || t == QEvent::MouseButtonPress
-         || t == QEvent::MouseButtonRelease
-         || t == QEvent::MouseMove)
+    if (isMouseEvent(t)
             && event->spontaneous() // Take only mouse events from outside of Qt
             )
+    {
         emit mouseEventDetected();
-        qDebug("MouseEvent detected.");
-    return QObject::eventFilter(watched, event);
+    }
+
+        if(mTimer.isActive()){
+            mTimer.stop();
+        }
+        mTimer.start();
+
+        return QObject::eventFilter(watched, event);
+}
+
+/**
+ * @brief Initialize and connect timer.
+ * @param interval Timeout interval in millisecond.
+ */
+void MouseEventSpy::initTimer(int interval)
+{
+    connect(&mTimer, &QTimer::timeout, this, &MouseEventSpy::onTimeout);
+    mTimer.setInterval(interval);
+    mTimer.setSingleShot(true);
+}
+
+/**
+ * @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 MouseEventSpy::isMouseEvent(QEvent::Type t)
+{
+    return (t == QEvent::MouseButtonDblClick
+            || t == QEvent::MouseButtonPress
+            || t == QEvent::MouseButtonRelease
+            || t == QEvent::MouseMove);
+}
+
+/**
+ * @brief Behavior on timeout: shut down RaspberryPi.
+ * @todo Call shutdown script.
+ */
+void MouseEventSpy::onTimeout()
+{
+    qDebug() << "shutting down.";
 }

LenaPi/MouseEventSpy.h

@@ -2,6 +2,8 @@
 #define MOUSEEVENTSPY_H
 
 #include <QObject>
+#include <QTimer>
+#include <QEvent>
 
 /**
  * Catches all mouse event and starts timer -- basically behaves like a screensaver.
@@ -20,6 +22,14 @@ public:
 protected:
     bool eventFilter(QObject* watched, QEvent* event);
 
+private:
+    void initTimer(int interval);
+    bool isMouseEvent(QEvent::Type t);
+    QTimer mTimer;
+
+private slots:
+    void onTimeout();
+
 signals:
     void mouseEventDetected();
 };