Remove checks for older Qt versions

src/GUI/AirportDiagram.cxx

@@ -116,13 +116,7 @@ AirportDiagram::AirportDiagram(QQuickItem* pr) :
     f.setBold(true);
     QFontMetricsF metrics(f);
     qreal xOffset = metrics.width("H") * 0.5;
-#if QT_VERSION >= 0x050800
     qreal yOffset = metrics.capHeight() * 0.5;
-#else
-    // capHeight is not avaialble in 5.7 and lower, compute
-    // it using tightBoundingRect
-    qreal yOffset = -0.5 * metrics.tightBoundingRect("H").y();
-#endif
     m_helipadIconPath.addText(-xOffset, yOffset, f, "H");
 }
 

src/GUI/LauncherController.cxx

@@ -280,9 +280,6 @@ void LauncherController::collectAircraftArgs()
         QString state = m_aircraftState;
         if ((m_aircraftState == "auto") && !m_selectedAircraftInfo->haveExplicitAutoState()) {
             state = selectAircraftStateAutomatically();
-#if QT_VERSION >= 0x050600
-            qInfo() << "doing launcher auto state selection, picked:" + state;
-#endif
         }
 
         if (!state.isEmpty()) {

src/GUI/QQuickDrawable.cxx

@@ -226,13 +226,7 @@ public slots:
     void initRenderControl()
     {
         qtContext = flightgear::qtContextFromOSG(osgContext);
-                
-    #if QT_VERSION < 0x050600
-        SG_LOG(SG_GUI, SG_ALERT, "Qt < 5.6 was used to build FlightGear, multi-threading of QtQuick is not safe");
-    #else
-        renderControl->prepareThread(QThread::currentThread());
-    #endif
-                
+        renderControl->prepareThread(QThread::currentThread());                
         QOpenGLContextPrivate::setCurrentContext(qtContext);
         QOpenGLContextPrivate::get(qtContext)->surface = foreignOSGWindow;
         renderControl->initialize(qtContext);

src/GUI/QtLauncher.cxx

@@ -214,9 +214,7 @@ static void simgearMessageOutput(QtMsgType type, const QMessageLogContext &conte
     sgDebugPriority mappedPriority = SG_WARN;
     switch (type) {
     case QtDebugMsg:    mappedPriority = SG_DEBUG; break;
-#if QT_VERSION >= 0x050500
     case QtInfoMsg:     mappedPriority = SG_INFO; break;
-#endif
     case QtWarningMsg:  mappedPriority = SG_WARN; break;
     case QtCriticalMsg: mappedPriority = SG_ALERT; break;
     case QtFatalMsg:    mappedPriority = SG_POPUP; break;
@@ -272,18 +270,16 @@ void initApp(int& argc, char** argv, bool doInitQSettings)
 		// leave things unset here, so users can use env var
 		// QT_AUTO_SCREEN_SCALE_FACTOR=1 to enable it at runtime
 
-//#if QT_VERSION >= QT_VERSION_CHECK(5, 6, 0)
       //  QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
-//#endif
+        
         static_qApp.reset(new QApplication(s_argc, argv));
         static_qApp->setOrganizationName("FlightGear");
         static_qApp->setApplicationName("FlightGear");
         static_qApp->setOrganizationDomain("flightgear.org");
 
-#if QT_VERSION >= QT_VERSION_CHECK(5, 7, 0)
         static_qApp->setDesktopFileName(
           QStringLiteral("org.flightgear.FlightGear.desktop"));
-#endif
+
         QTranslator* fallbackTranslator = new QTranslator(static_qApp.get());
         if (!fallbackTranslator->load(QLatin1String(":/FlightGear_en_US.qm"))) {
             qWarning() << "Failed to load default (en) translations";

src/GUI/ThumbnailImageItem.cxx

@@ -83,11 +83,7 @@ QSGNode *ThumbnailImageItem::updatePaintNode(QSGNode* oldNode, QQuickItem::Updat
             textureNode = new QSGSimpleTextureNode;
             textureNode->setOwnsTexture(true);
         }
-#if QT_VERSION >= QT_VERSION_CHECK(5, 6, 0)
         QSGTexture* tex = window()->createTextureFromImage(m_image, QQuickWindow::TextureIsOpaque);
-#else
-        QSGTexture* tex = window()->createTextureFromImage(m_image);
-#endif
         textureNode->setTexture(tex);
         textureNode->markDirty(QSGBasicGeometryNode::DirtyMaterial);
         m_imageDirty = false;

src/Viewer/GraphicsWindowQt5.cpp

@@ -185,14 +185,6 @@ GLWindow::~GLWindow()
     }
 }
 
-#if QT_VERSION < 0x050500
-void GLWindow::requestUpdate()
-{
-    // mimic Qt 5.5's requestUpdate method
-    QTimer::singleShot(0, this, SLOT(processUpdateEvent()));
-}
-#endif
-
 bool GLWindow::event( QEvent* event )
 {
     if (event->type() == QEvent::WindowStateChange) {

src/Viewer/GraphicsWindowQt5.hxx

@@ -72,9 +72,6 @@ public:
     virtual void mouseMoveEvent( QMouseEvent* event );
     virtual void wheelEvent( QWheelEvent* event );
 
-#if QT_VERSION < 0x050500
-    void requestUpdate();
-#endif
 signals:
     void beforeRendering();
     void afterRendering();