Remove deprecated Qt version checks and unused code

Arrangement_on_surface_2/demo/Arrangement_on_surface_2/CurveInputMethods.cpp

@@ -109,15 +109,6 @@ void CurveInputMethod::beginInput_()
   for (auto& item : items) this->getScene()->addItem(item);
 }
 
-static inline void clearPainterPath(QPainterPath& ppath)
-{
-#if (QT_VERSION >= QT_VERSION_CHECK(5, 13, 0))
-  ppath.clear();
-#else
-  ppath = {};
-#endif
-}
-
 void CurveInputMethod::reset()
 {
   this->resetInput();
@@ -193,7 +184,6 @@ PolylineInputMethod::PolylineInputMethod() :
 
 void PolylineInputMethod::beginInput()
 {
-  clearPainterPath(this->painterPath);
   this->polylineGuide.setPath(this->painterPath);
   this->lastLine.setLine(0, 0, 0, 0);
   QPen pen = this->polylineGuide.pen();
@@ -356,8 +346,6 @@ BezierInputMethod::BezierInputMethod() : CurveInputMethod(CurveType::Bezier, -1)
 
 void BezierInputMethod::beginInput()
 {
-  clearPainterPath(this->painterOldPath);
-  clearPainterPath(this->painterPath);
   this->bezierGuide.setPath(this->painterPath);
   this->bezierOldGuide.setPath(this->painterOldPath);
 
@@ -407,7 +395,6 @@ static void updateBezierPainterPath(
   const std::vector<QPointF>& controlPoints, std::vector<QPointF>& cache,
   const QTransform& worldTransform, QPainterPath& painterPath)
 {
-  clearPainterPath(painterPath);
   if (controlPoints.size() < 2) return;
 
   float pixel_len = approx_pixel_length(controlPoints, worldTransform);

GraphicsView/include/CGAL/Qt/qglviewer.h

@@ -478,15 +478,6 @@ public:
   qreal bufferTextureMaxU() const { return bufferTextureMaxU_; }
   /*! Same as bufferTextureMaxU(), but for the v texture coordinate. */
   qreal bufferTextureMaxV() const { return bufferTextureMaxV_; }
-#if (QT_VERSION >= QT_VERSION_CHECK(5, 4, 0))
-  // These methods are part of the QGLWidget public API.
-  // As of version 2.7.0, the use of QOpenGLWidget instead means that they have
-  // to be provided for backward compatibility.
-  void renderText(int x, int y, const QString &str,
-                  const QFont &font = QFont());
-  void renderText(double x, double y, double z, const QString &str,
-                  const QFont &font = QFont());
-#endif
 
 public Q_SLOTS:
   void copyBufferToTexture(GLint, GLenum = GL_NONE);

GraphicsView/include/CGAL/Qt/qglviewer_impl.h

@@ -720,30 +720,6 @@ CGAL_INLINE_FUNCTION
 void CGAL::QGLViewer::drawLight(GLenum, qreal ) const {
 }
 
-#if (QT_VERSION >= QT_VERSION_CHECK(5, 4, 0))
-CGAL_INLINE_FUNCTION
-void CGAL::QGLViewer::renderText(int x, int y, const QString &str,
-                           const QFont &font) {
-  QColor fontColor = QColor(0, 0,
-                            0, 255);
-
-  // Render text
-  QPainter painter(this);
-  painter.setPen(fontColor);
-  painter.setFont(font);
-  painter.drawText(x, y, str);
-  painter.end();
-}
-
-CGAL_INLINE_FUNCTION
-void CGAL::QGLViewer::renderText(double x, double y, double z, const QString &str,
-                           const QFont &font) {
-  using CGAL::qglviewer::Vec;
-  const Vec proj = camera_->projectedCoordinatesOf(Vec(x, y, z));
-  renderText(int(proj.x), int(proj.y), str, font);
-}
-#endif
-
 /*! Draws \p text at position \p x, \p y (expressed in screen coordinates
 pixels, origin in the upper left corner of the widget).
 

Lab/demo/Lab/CGAL_Lab.cpp

@@ -27,11 +27,6 @@ int& code_to_call_before_creation_of_QCoreApplication(int& i) {
   fmt.setOption(QSurfaceFormat::DebugContext);
   QSurfaceFormat::setDefaultFormat(fmt);
 
-  //for windows
-#if (QT_VERSION >= QT_VERSION_CHECK(5, 3, 0))
-  QCoreApplication::setAttribute(Qt::AA_UseDesktopOpenGL);
-#endif
-
   return i;
 }
 

Lab/demo/Lab/MainWindow.cpp

@@ -663,15 +663,6 @@ void MainWindow::loadPlugins()
     }
   }
   QString env_path = qgetenv("LAB_DEMO_PLUGINS_PATH");
-#if (QT_VERSION >= QT_VERSION_CHECK(5, 6, 0))
-  QChar separator = QDir::listSeparator();
-#else
-#if defined(_WIN32)
-  QChar separator = ';';
-#else
-  QChar separator = ':';
-#endif
-#endif
   if(!env_path.isEmpty()) {
 #if defined(_WIN32)
     QString path = qgetenv("PATH");