-static int PositionUpdate_Type = QEvent::User + 6;
-static int ItemChanged_Type = QEvent::User + 7;
-static int ItemRateChanged_Type = QEvent::User + 8;
-static int ItemTitleChanged_Type = QEvent::User + 9;
-static int ItemStateChanged_Type = QEvent::User + 10;
-static int VolumeChanged_Type = QEvent::User + 11;
+static int const PositionUpdate_Type = QEvent::User + 6;
+static int const ItemChanged_Type = QEvent::User + 7;
+static int const ItemRateChanged_Type = QEvent::User + 8;
+static int const ItemTitleChanged_Type = QEvent::User + 9;
+static int const ItemStateChanged_Type = QEvent::User + 10;
+static int const VolumeChanged_Type = QEvent::User + 11;