Application segfaults on close

cuddlykittens11

Hi, I wrote a small test of "layers," for a PyQt app that I'm working on. When I was using PyQt4, there were no segfualts, but as soon as I switched it to PyQt5, it segfaults on close.

It seems to be something with setting the scene for the QGraphicsView. If there is no scene, there is no segfault, yet if there is it will upon closing the app. Line 30 of the cod ebelow notes this.

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A simple example to implement a layer feature, it tests:

-- Layers

-- .gif load and aniamiton

-- Zooming

All if this should be done using the QGraphicsView Framework

import sys
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *

TODO, this is now segfaulting because of update to PyQt5, fix it

class LayerWidget(QWidget):

def __init__(self, parent=None):
    super(LayerWidget, self).__init__(parent)

    # Some Varibales
    self.scale = 2
    self.viewSize = QSize()         # Size we want for the view at all times

    # Get the scene
    self.scene = LayerScene(self)

    # Set the view
    self.view = QGraphicsView(self)
    self.view.setScene(self.scene)              # Doesn't segfault if a scene is not set
    self.view.setFrameShape(QFrame.NoFrame)
    self.view.scale(self.scale, self.scale)

    self.viewSize = self.scene.sceneRect().toRect().size() * self.scale

    # Other
    self.setWindowTitle('Simple Layers Test (w/ Animation)')
    self.resize(self.viewSize)


def resizeEvent(self, event):
    # Try to keep the view in the center of the window at all times
    widgetSize = self.size()
    viewSize = self.viewSize

    # Check the sizes
    widgetWidthSmaller = widgetSize.width() < viewSize.width()
    widgetHeightSmaller = widgetSize.height() < viewSize.height()
    if widgetWidthSmaller or widgetHeightSmaller:
        # too small, resize the view

        # Make the new sized view
        newSize = QSize()
        newSize.setWidth(widgetSize.width() if widgetWidthSmaller else viewSize.width())
        newSize.setHeight(widgetSize.height() if widgetHeightSmaller else viewSize.height())

        newLoc = QPoint()
        newLoc.setX(0 if widgetWidthSmaller else self.view.pos().x())
        newLoc.setY(0 if widgetHeightSmaller else self.view.pos().y())

        # Change the minimum size and resize the view
        self.view.resize(newSize)
        self.view.move(newLoc)
    else:
        # No scrolly-bars
        self.view.resize(self.viewSize)

        # Keep it centered
        viewRect = self.view.rect()
        viewRect.moveCenter(self.rect().center())
        self.view.move(viewRect.topLeft())

class LayerScene(QGraphicsScene):
# Represents a "frame," with multiple layers

def __init__(self, parent=None):
    super(LayerScene, self).__init__(parent)

    self.layer = []

    # Hard code in some images
    self.layer.append(QGraphicsPixmapItem(QPixmap.fromImage(QImage('orange_glow.png'))))
    self.layer.append(AnimatedGIF('blue_spirit.gif'))

    self.layer[1].moveBy(50, 50)

    self.addItem(self.layer[0])
    self.addItem(self.layer[1])
    
    self.layer[1].start()

class AnimatedGIF(QGraphicsPixmapItem):
# A small test of an animated gif playing in a graphics scene

def __init__(self, filename, parent=None):
    super(AnimatedGIF, self).__init__(parent)

    self.gif = QMovie(filename)
    self.gif.frameChanged[int].connect(self.nextFrame)


@pyqtSlot(int)
def nextFrame(self, n):
    self.setPixmap(self.gif.currentPixmap())


def start(self):
    self.gif.start()

def main():
app = QApplication(sys.argv)
lw = LayerWidget()
lw.show()

sys.exit(app.exec_())

main()
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Oddly enough, I had another test application that used QGraphicsView and QGraphicsScene in a similar manner. It used to segfault all the time in PyQt4, but it doesn't in PyQt5.

Any help here would be appreciated.