From ce8c3262f810290f3db4a06358c1e868412d86d7 Mon Sep 17 00:00:00 2001
From: pijyoi <nixchuan@gmail.com>
Date: Sun, 31 Jan 2021 00:59:29 +0800
Subject: [PATCH] switch to use of QOpenGLWidget in GraphicsView.py (#1525)

* switch to use of QOpenGLWidget in GraphicsView.py

experimental plotting in PlotCurveItem gets broken by this. so we allow
Qt5 users to opt back to using QGLWidget with the enableExperimental
option.

* allow Qt6 users to turn on enableExperimental

to more easily allow users to see the broken-ness.

* drop QGLWidget, use only QOpenGLWidget
---
 pyqtgraph/Qt.py                          | 11 ++---------
 pyqtgraph/graphicsItems/PlotCurveItem.py | 15 ++++++---------
 pyqtgraph/widgets/GraphicsView.py        | 17 ++++++-----------
 3 files changed, 14 insertions(+), 29 deletions(-)

diff --git a/pyqtgraph/Qt.py b/pyqtgraph/Qt.py
index 9709a482..83654c93 100644
--- a/pyqtgraph/Qt.py
+++ b/pyqtgraph/Qt.py
@@ -211,10 +211,6 @@ elif QT_LIB == PYQT5:
         from PyQt5 import QtSvg
     except ImportError as err:
         QtSvg = FailedImport(err)
-    try:
-        from PyQt5 import QtOpenGL
-    except ImportError as err:
-        QtOpenGL = FailedImport(err)
     try:
         from PyQt5 import QtTest
         QtTest.QTest.qWaitForWindowShown = QtTest.QTest.qWaitForWindowExposed
@@ -249,10 +245,6 @@ elif QT_LIB == PYSIDE2:
         from PySide2 import QtSvg
     except ImportError as err:
         QtSvg = FailedImport(err)
-    try:
-        from PySide2 import QtOpenGL
-    except ImportError as err:
-        QtOpenGL = FailedImport(err)
     try:
         from PySide2 import QtTest
         QtTest.QTest.qWaitForWindowShown = QtTest.QTest.qWaitForWindowExposed
@@ -354,7 +346,8 @@ if QT_LIB in [PYQT6, PYSIDE6]:
     # We're using Qt6 which has a different structure so we're going to use a shim to
     # recreate the Qt5 structure
 
-    QtWidgets.QOpenGLWidget = QtOpenGLWidgets.QOpenGLWidget
+    if not isinstance(QtOpenGLWidgets, FailedImport):
+        QtWidgets.QOpenGLWidget = QtOpenGLWidgets.QOpenGLWidget
 
 
 # Common to PySide, PySide2 and PySide6
diff --git a/pyqtgraph/graphicsItems/PlotCurveItem.py b/pyqtgraph/graphicsItems/PlotCurveItem.py
index b56d3d4d..39003813 100644
--- a/pyqtgraph/graphicsItems/PlotCurveItem.py
+++ b/pyqtgraph/graphicsItems/PlotCurveItem.py
@@ -1,10 +1,6 @@
 # -*- coding: utf-8 -*-
-from ..Qt import QtGui, QtCore
-try:
-    from ..Qt import QtOpenGL
-    HAVE_OPENGL = True
-except:
-    HAVE_OPENGL = False
+from ..Qt import QtCore, QtGui, QtWidgets
+HAVE_OPENGL = hasattr(QtWidgets, 'QOpenGLWidget')
 
 import warnings
 import numpy as np
@@ -483,9 +479,10 @@ class PlotCurveItem(GraphicsObject):
         if self.xData is None or len(self.xData) == 0:
             return
 
-        if HAVE_OPENGL and getConfigOption('enableExperimental') and isinstance(widget, QtOpenGL.QGLWidget):
-            self.paintGL(p, opt, widget)
-            return
+        if getConfigOption('enableExperimental'):
+            if HAVE_OPENGL and isinstance(widget, QtWidgets.QOpenGLWidget):
+                self.paintGL(p, opt, widget)
+                return
 
         x = None
         y = None
diff --git a/pyqtgraph/widgets/GraphicsView.py b/pyqtgraph/widgets/GraphicsView.py
index 4490d4de..6e93aa45 100644
--- a/pyqtgraph/widgets/GraphicsView.py
+++ b/pyqtgraph/widgets/GraphicsView.py
@@ -5,14 +5,7 @@ Copyright 2010  Luke Campagnola
 Distributed under MIT/X11 license. See license.txt for more information.
 """
 
-from ..Qt import QtCore, QtGui, QT_LIB
-
-try:
-    from ..Qt import QtOpenGL
-    HAVE_OPENGL = True
-except ImportError:
-    HAVE_OPENGL = False
-
+from ..Qt import QtCore, QtGui, QtWidgets, QT_LIB
 from ..Point import Point
 import sys, os
 import warnings
@@ -58,7 +51,7 @@ class GraphicsView(QtGui.QGraphicsView):
         useOpenGL       If True, the GraphicsView will use OpenGL to do all of its
                         rendering. This can improve performance on some systems,
                         but may also introduce bugs (the combination of 
-                        QGraphicsView and QGLWidget is still an 'experimental' 
+                        QGraphicsView and QOpenGLWidget is still an 'experimental'
                         feature of Qt)
         background      Set the background color of the GraphicsView. Accepts any
                         single argument accepted by 
@@ -176,9 +169,11 @@ class GraphicsView(QtGui.QGraphicsView):
 
     def useOpenGL(self, b=True):
         if b:
+            HAVE_OPENGL = hasattr(QtWidgets, 'QOpenGLWidget')
             if not HAVE_OPENGL:
-                raise Exception("Requested to use OpenGL with QGraphicsView, but QtOpenGL module is not available.")
-            v = QtOpenGL.QGLWidget()
+                raise Exception("Requested to use OpenGL with QGraphicsView, but QOpenGLWidget is not available.")
+
+            v = QtWidgets.QOpenGLWidget()
         else:
             v = QtGui.QWidget()