Fix redraw issues with OpenGL canvases when link states change.

src/ui/MainWindow.cc

@@ -205,6 +205,10 @@ MainWindow::MainWindow(QSplashScreen* splashScreen)
     connect(this, SIGNAL(x11EventOccured(XEvent*)), mouse, SLOT(handleX11Event(XEvent*)));
 #endif //QGC_MOUSE_ENABLED_LINUX
 
+    // These also cause the screen to redraw so we need to update any OpenGL canvases in QML controls
+    connect(LinkManager::instance(), &LinkManager::linkConnected,    this, &MainWindow::_linkStateChange);
+    connect(LinkManager::instance(), &LinkManager::linkDisconnected, this, &MainWindow::_linkStateChange);
+
     // Connect link
     if (_autoReconnect)
     {
@@ -1348,6 +1352,11 @@ void MainWindow::restoreLastUsedConnection()
     }
 }
 
+void MainWindow::_linkStateChange(LinkInterface*)
+{
+    emit repaintCanvas();
+}
+
 #ifdef QGC_MOUSE_ENABLED_LINUX
 bool MainWindow::x11Event(XEvent *event)
 {

src/ui/MainWindow.h

@@ -294,6 +294,7 @@ private slots:
     void _showDockWidgetAction(bool show);
     void _loadCustomWidgetFromFile(void);
     void _createNewCustomWidget(void);
+    void _linkStateChange(LinkInterface*);
 #ifdef UNITTEST_BUILD
     void _showQmlTestWidget(void);
 #endif