PyQt: setCentralWidget clashes with QPushButton function

Question

So I deduced down to this problem from my project that the setCentralWidget from the Slides Widget class I injected in the Main Window class causes the function of the buttons (i.e. opening a new Widget window) from the Main Window to not work at all.

If I remove the setCentralWidget the buttons work fine so without compromising any of the functions, what approach should I use for this? Should I use a different form of calling the Slides Widget class?

Any help would be appreciated, as always! Thanks!

from PyQt4 import QtCore, QtGui
import sys
from functools import partial


class MainWindow(QtGui.QMainWindow):
    def __init__(self, image_files, parent=None):
        super(MainWindow, self).__init__()

        self.setupUi(self)
        self.slides_widget = Slides(image_files, self)
#If you enable this down below, pushButton will not function 
#and instead the slideshow will pop up and function correctly
        #self.setCentralWidget(self.slides_widget)

    def setupUi(self, MainWindow):

        MainWindow.resize(1278, 688)
        #MainWindow.setStyleSheet(self.styledata)

        self.groupBox = QtGui.QGroupBox(MainWindow)
        self.groupBox.setGeometry(QtCore.QRect(490, 220, 120, 371))
        self.groupBox.setAlignment(QtCore.Qt.AlignHCenter|QtCore.Qt.AlignTop)
        self.groupBox.setFlat(False)
        self.groupBox.setCheckable(False)


        self.pushButton_Desc = QtGui.QPushButton(self.groupBox)
        self.pushButton_Desc.setGeometry(QtCore.QRect(20, 30, 71, 61))

        self.pushButton_Desc.clicked.connect(partial(self.DescWindow))

        self.groupBox.raise_()

        self.NewWindow = QtGui.QWidget()

    def DescWindow(self):
        self.NewWindow.show();


class Slides(QtGui.QWidget):
    def __init__(self, image_files, parent=None):
        super(Slides, self).__init__(parent)

        self.image_files = image_files
        self.label = QtGui.QLabel("", self)
        self.label.setGeometry(65, 225, 423, 363)

        #buttons to rewind and forward
        self.button = QtGui.QPushButton(". . .", self)
        self.button.setGeometry(200, 100, 140, 30)
        self.button.clicked.connect(self.timerEvent)

        self.timer = QtCore.QBasicTimer()
        self.step = 0
        self.delay = 3000 #ms

    def timerEvent(self, e=None):
        if self.step >= len(self.image_files):
            self.timer.start(self.delay, self)
            self.step = 0
            return
        self.timer.start(self.delay, self)
        file = self.image_files[self.step]
        image = QtGui.QPixmap(file)
        self.label.setPixmap(image)
        #self.setWindowTitle("{} --> {}".format(str(self.step), file))
        self.step += 1


image_files = ["images\slide1.jpg", "images\slide2.jpg", "images\slide3.jpg",
 "images\slide4.jpg", "images\slide5.jpg"]

if __name__ == "__main__":
    app = QtGui.QApplication(sys.argv)
    Form = MainWindow(image_files)
    Form.show()
    sys.exit(app.exec_())

Answer 1

The problem arises because first place the button and on this is placed the CentralWidget, the solution is to place the button in the CentralWidget, ie in Slides.

You must change:

def __init__(self, image_files, parent=None):
    super(MainWindow, self).__init__()
    self.setupUi(self)
    self.slides_widget = Slides(image_files, self)

to:

def __init__(self, image_files, parent=None):
    super(MainWindow, self).__init__()
    self.slides_widget = Slides(image_files, self)
    self.setupUi(self)

and

self.groupBox = QtGui.QGroupBox(MainWindow)

to:

self.groupBox = QtGui.QGroupBox(MainWindow.slides_widget)

Complete code:

from PyQt4 import QtCore, QtGui
import sys


class MainWindow(QtGui.QMainWindow):
    def __init__(self, image_files, parent=None):
        super(MainWindow, self).__init__()
        self.slides_widget = Slides(image_files, self)
        self.setupUi(self)

    def setupUi(self, MainWindow):

        MainWindow.resize(1278, 688)
        #MainWindow.setStyleSheet(self.styledata)

        self.groupBox = QtGui.QGroupBox(MainWindow.slides_widget)
        self.groupBox.setGeometry(QtCore.QRect(490, 220, 120, 371))
        self.groupBox.setAlignment(QtCore.Qt.AlignHCenter|QtCore.Qt.AlignTop)
        self.groupBox.setFlat(False)
        self.groupBox.setCheckable(False)


        self.pushButton_Desc = QtGui.QPushButton(self.groupBox)
        self.pushButton_Desc.setGeometry(QtCore.QRect(20, 30, 71, 61))

        self.pushButton_Desc.clicked.connect(self.DescWindow)
        self.setCentralWidget(self.slides_widget)

        self.groupBox.raise_()

        self.NewWindow = QtGui.QWidget()

    def DescWindow(self):
        self.NewWindow.show();


class Slides(QtGui.QWidget):
    def __init__(self, image_files, parent=None):
        super(Slides, self).__init__(parent)

        self.image_files = image_files
        self.label = QtGui.QLabel("", self)
        self.label.setGeometry(65, 225, 423, 363)

        #buttons to rewind and forward
        self.button = QtGui.QPushButton(". . .", self)
        self.button.setGeometry(200, 100, 140, 30)
        self.button.clicked.connect(self.timerEvent)

        self.timer = QtCore.QBasicTimer()
        self.step = 0
        self.delay = 3000 #ms

    def timerEvent(self, e=None):
        if self.step >= len(self.image_files):
            self.timer.start(self.delay, self)
            self.step = 0
            return
        self.timer.start(self.delay, self)
        file = self.image_files[self.step]
        image = QtGui.QPixmap(file)
        self.label.setPixmap(image)
        #self.setWindowTitle("{} --> {}".format(str(self.step), file))
        self.step += 1


image_files = ["images\slide1.jpg", "images\slide2.jpg", "images\slide3.jpg",
 "images\slide4.jpg", "images\slide5.jpg"]

if __name__ == "__main__":
    app = QtGui.QApplication(sys.argv)
    Form = MainWindow(image_files)
    Form.show()
    sys.exit(app.exec_())