Segfaulting layers

simple_layers.py

# 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()