From 420a5ee428f90849f96814d65d01332b93cdb9de Mon Sep 17 00:00:00 2001
From: Anika Raemer <anika@raemer.net>
Date: Wed, 3 Apr 2019 17:44:46 +0200
Subject: [PATCH] Added MouseEventSpy as base for an auto shutdown

---
 LenaPi/LenaPi.pro        |  6 ++++--
 LenaPi/MouseEventSpy.cpp | 45 ++++++++++++++++++++++++++++++++++++++++
 LenaPi/MouseEventSpy.h   | 27 ++++++++++++++++++++++++
 LenaPi/main.cpp          |  3 +++
 4 files changed, 79 insertions(+), 2 deletions(-)
 create mode 100644 LenaPi/MouseEventSpy.cpp
 create mode 100644 LenaPi/MouseEventSpy.h

diff --git a/LenaPi/LenaPi.pro b/LenaPi/LenaPi.pro
index 56e316b..390855c 100644
--- a/LenaPi/LenaPi.pro
+++ b/LenaPi/LenaPi.pro
@@ -10,7 +10,8 @@ SOURCES += main.cpp \
     controllers/NavigationController.cpp \
     models/UiStateModel.cpp \
     controllers/MusicController.cpp \
-    models/MusicModel.cpp
+    models/MusicModel.cpp \
+    MouseEventSpy.cpp
 
 RESOURCES += qml.qrc \
     lenapi.qrc
@@ -43,6 +44,7 @@ HEADERS += \
     controllers/NavigationController.h \
     models/UiStateModel.h \
     controllers/MusicController.h \
-    models/MusicModel.h
+    models/MusicModel.h \
+    MouseEventSpy.h
 
 INCLUDEPATH+=/usr/local/include
diff --git a/LenaPi/MouseEventSpy.cpp b/LenaPi/MouseEventSpy.cpp
new file mode 100644
index 0000000..332a6ba
--- /dev/null
+++ b/LenaPi/MouseEventSpy.cpp
@@ -0,0 +1,45 @@
+#include "MouseEventSpy.h"
+
+#include <QEvent>
+#include <QGuiApplication>
+#include <QDebug>
+
+MouseEventSpy::MouseEventSpy(QObject *parent) : QObject(parent)
+{
+    qDebug() << "created Instance";
+}
+
+/**
+ * Implements the SINGLETON PATTERN
+ */
+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);
+    }
+    return inst;
+}
+
+/**
+ * This is the method is necessary for 'installEventFilter'
+ */
+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)
+            && event->spontaneous() // Take only mouse events from outside of Qt
+            )
+        emit mouseEventDetected();
+        qDebug("MouseEvent detected.");
+    return QObject::eventFilter(watched, event);
+}
diff --git a/LenaPi/MouseEventSpy.h b/LenaPi/MouseEventSpy.h
new file mode 100644
index 0000000..67012fc
--- /dev/null
+++ b/LenaPi/MouseEventSpy.h
@@ -0,0 +1,27 @@
+#ifndef MOUSEEVENTSPY_H
+#define MOUSEEVENTSPY_H
+
+#include <QObject>
+
+/**
+ * Catches all mouse event and starts timer -- basically behaves like a screensaver.
+* Based on
+* https://stackoverflow.com/questions/46173105/how-can-i-reset-a-timer-every-time-i-receive-a-touch-event-from-a-qml-page
+*
+* @todo implement timer and behavior on timeout.
+*/
+class MouseEventSpy : public QObject
+{
+    Q_OBJECT
+public:
+    explicit MouseEventSpy(QObject *parent = 0);
+    static MouseEventSpy* instance();
+
+protected:
+    bool eventFilter(QObject* watched, QEvent* event);
+
+signals:
+    void mouseEventDetected();
+};
+
+#endif // MOUSEEVENTSPY_H
diff --git a/LenaPi/main.cpp b/LenaPi/main.cpp
index bd0022e..f8ce39a 100644
--- a/LenaPi/main.cpp
+++ b/LenaPi/main.cpp
@@ -1,6 +1,7 @@
 #include <QGuiApplication>
 #include <QQmlApplicationEngine>
 #include "controllers/NavigationController.h"
+#include "MouseEventSpy.h"
 
 int main(int argc, char *argv[])
 {
@@ -28,6 +29,8 @@ int main(int argc, char *argv[])
     navController.setContext(engine.rootContext());
     navController.init("/home/ar/source/lenaMusic/");
 
+    // install MouseEventSpy used for auto shut down of RaspberryPi if not used for a predefined time.
+    MouseEventSpy::instance();
     engine.load(QUrl("qrc:/main.qml"));