title: Cannot use ApplicationWindow (QML) on PySide2
body: <p>I'm trying to run a simple Qt application using QML and more specifically ApplicationWindow.</p>
  
  <p>My Python code is a simple QML caller:</p>
  
  <pre><code>import sys
  from PySide2.QtWidgets import QApplication
  from PySide2.QtQuick import QQuickView
  from PySide2.QtCore import QUrl
  
  if __name__ == '__main__':
  
      app = QApplication(sys.argv)
  
      view = QQuickView()
      url = QUrl('view.qml')
      view.setSource(url)
      view.show()
  
      sys.exit(app.exec_())
  </code></pre>
  
  <p>and my QML file is a simple ApplicationWindow with Title, width and height:</p>
  
  <pre><code>import QtQuick 2.0
  
  ApplicationWindow {
  
      title: "Qt Quick Controls Gallery"
  
      width: 640
      height: 480
  }
  </code></pre>
  
  <p>Running the code results in a blank screen, with default title ("gui.py", instead of the title given on QML), and with default width and height (not the specified on the QML file):</p>
  
  <p><a href="https://i.stack.imgur.com/keb6d.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/keb6d.png" alt="enter image description here"></a></p>
  
  <p>I can run other components, like rectangles, buttons and canvas without problems. My problem is specifically with the ApplicationWindow component, that I would like to use since it's the standard for QML apps.</p>
  
  <p>I'm trying to stick with PySide2 as it's becoming the supported for Python Qt, but I'm accepting PyQt solutions as well, of course.</p>