cleaned up and commented code

shell/src/main.cpp

@@ -6,26 +6,31 @@
 
 int main(int argc, char *argv[])
 {
+    // creates our Qt GUI app
     QGuiApplication app(argc, argv);
 
+    // creats InputManager and installs it as an application-wide event filter so it can observe input events before normal delivery
     InputManager inputManager;
     app.installEventFilter(&inputManager);
 
-    qmlRegisterUncreatableMetaObject(
-        InputManager::staticMetaObject,
-        "NomadInput",
-        1, 0,
-        "InputManager",
-        "InputManager is created by nomad"
-    );
+    // Expose InputManager's Qt meta-object to QML under the NomadInput module, for ease of reading code.
+    // This lets us refer to inputs as InputManager.Left, InputManager.Right, et cetera
+    // QML isn't allowed to create it's own
+    qmlRegisterUncreatableMetaObject(InputManager::staticMetaObject, "NomadInput", 1, 0, "InputManager", "InputManager is created by nomad");
 
+    // start up the QML engine
     QQmlApplicationEngine engine;
+    // make our InputManager instance available to QML for signals
     engine.rootContext()->setContextProperty("inputManager", &inputManager);
 
+    // load our Main.qml into the engine to start things off
     engine.loadFromModule("nomad", "Main");
 
-    if (engine.rootObjects().isEmpty())
+    // makes sure we've got QML objects
+    if (engine.rootObjects().isEmpty()) {
         return -1;
+    }
 
+    // Start the event loop and keeps nomad running until it exits
     return app.exec();
 }