PySide2/PyQt5: Graphics issues in QScrollArea for OSX #14160
Description
Bug report
Bug summary
Figure graphics aren't re-drawn correctly in a QScrollArea when using matplotlib>2.2.4 on OSX. I've put together a short program based on one of the examples which demonstrates this.
This seems specific to Macs as I've run the same code on Ubuntu without these issues.
Code for reproduction
import sys
import os
import random
import numpy as np
# PySide2 here gives the same result
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *
import matplotlib
# Make sure that we are using QT5
matplotlib.use('Qt5Agg')
from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.figure import Figure
class MyMplCanvas(FigureCanvas):
"""Ultimately, this is a QWidget (as well as a FigureCanvasAgg, etc.)."""
def __init__(self, parent=None, width=5, height=4, dpi=100):
fig = Figure(figsize=(width, height), dpi=dpi)
self.axes = fig.add_subplot(111)
self.compute_initial_figure()
FigureCanvas.__init__(self, fig)
self.setParent(parent)
FigureCanvas.setSizePolicy(self,
QSizePolicy.Expanding,
QSizePolicy.Expanding)
FigureCanvas.updateGeometry(self)
def compute_initial_figure(self):
pass
class MyStaticMplCanvas(MyMplCanvas):
"""Simple canvas with a sine plot."""
def compute_initial_figure(self):
t = np.linspace(0.0, 3.0, 2000)
s = np.sin(2*np.pi*t)
self.axes.plot(t, s)
class Widget(QWidget):
def __init__(self, parent= None):
super(Widget, self).__init__()
#Container Widget
widget = QWidget()
#Layout of Container Widget
layout = QVBoxLayout(self)
fc = MyStaticMplCanvas()
layout.addWidget(fc)
widget.setLayout(layout)
#Scroll Area Properties
scroll = QScrollArea()
scroll.setVerticalScrollBarPolicy(Qt.ScrollBarAlwaysOn)
scroll.setHorizontalScrollBarPolicy(Qt.ScrollBarAlwaysOn)
scroll.setWidgetResizable(False)
scroll.setWidget(widget)
#Scroll Area Layer add
vLayout = QVBoxLayout(self)
vLayout.addWidget(scroll)
self.setLayout(vLayout)
if __name__ == '__main__':
app = QApplication(sys.argv)
dialog = Widget()
dialog.show()
app.exec_()The plot looks like this with window larger than the plot:
Actual outcome
After resizing the window and scrolling to see the rest of the canvs, parts of the plot aren't drawn correctly both during and after the scroll event:
This is true for any version of matplotlib>=2.2.4.
Expected outcome
When reverting the matplotlib version to 2.2.4 using pip3, the plot appears normally during and after scrolling:
Matplotlib version
Matplotlib version >= 2.2.4 installed with pip3.
Python 3.7
OSX 10.14.3
Backend: backend_qt5agg
Other libraries (installed with pip3)
- PySide2 (5.12.3)
- PyQt5.QtCore.QT_VERSION_STR (5.12.2)
- PyQt5.QtCore.PYQT_VERSION_STR (5.12.2)