Sensible opengl widget values for better scrolling when dragging

CHANGELOG

@@ -7,6 +7,7 @@ External contributors notice at the end of the line: (LastName, FirstName / nick
 
 ## 2022-07-15 2.1.0
 Add functions to move block to start or end of track.
+Scroll view when dragging blocks and tracks with the mouse.
 Add 3/2 to metrical instruction.
 Autosave when exporting Lilypond .ly or PDF.
 Command to quickly add text below or above a staff.

qtgui/scoreview.py

@@ -23,7 +23,7 @@ import logging; logger = logging.getLogger(__name__); logger.info("import")
 
 
 #Third Party
-from PyQt5 import QtCore, QtGui, QtWidgets, QtOpenGL
+from PyQt5 import QtCore, QtGui, QtWidgets
 
 #Template Modules
 from template.helper import onlyOne
@@ -42,24 +42,28 @@ class ScoreView(QtWidgets.QGraphicsView):
         self.scoreScene = GuiScore(parentView=self)
         self.setScene(self.scoreScene)
 
-        viewport = QtOpenGL.QGLWidget(QtOpenGL.QGLFormat(QtOpenGL.QGL.SampleBuffers))
-        viewport.format().setSwapInterval(0) #disable VSync.
-        viewport.setAutoFillBackground(False)
-
-        viewport = QtWidgets.QOpenGLWidget()
-        #These special parameters should not matter. Run with the default.
-        #viewportFormat = QtGui.QSurfaceFormat()
-        #viewportFormat.setSwapInterval(0) #disable VSync
-        #viewportFormat.setSamples(2**8)
-        #viewportFormat.setDefaultFormat(viewportFormat)
-        #viewport.setFormat(viewportFormat)
-        self.setViewport(viewport)
+        opengl = True
+        if opengl:
+            #Scrolling without openGl is sluggish. This is a sure improvement. -2022.
+            from PyQt5 import QtOpenGL
+            viewport = QtWidgets.QOpenGLWidget()
+            #viewport = QtOpenGL.QGLWidget(QtOpenGL.QGLFormat(QtOpenGL.QGL.SampleBuffers))
+            #These special parameters should not matter. Run with the default.
+            viewportFormat = QtGui.QSurfaceFormat()
+            viewportFormat.setSwapInterval(0) #disable VSync
+            viewportFormat.setDefaultFormat(viewportFormat)
+            viewport.setFormat(viewportFormat)
+            self.setViewport(viewport)
+
+        self.viewport().setAutoFillBackground(False)
 
         self.setAlignment(QtCore.Qt.AlignLeft|QtCore.Qt.AlignTop)
 
         #self.setDragMode(QtWidgets.QGraphicsView.RubberBandDrag)
+        #self.setDragMode(QtWidgets.QGraphicsView.ScrollHandDrag)
         self.setDragMode(QtWidgets.QGraphicsView.NoDrag)
 
+
         api.callbacks.setCursor.append(self.centerOnCursor) #returns a dict
         api.callbacks.updateBlockTrack.append(self.updateMode) # We need  this after every update because the track is redrawn after each update and we don't know what to show