title: Using ApplicationWindow in qml with PyQt5 results in a blank window, but the same code without it doesn't
body: <p>I am trying to write a simple Hello World app in PyQt5 using qml.</p>
  <p>This is my code with</p>
  <pre><code>import QtQuick 2.0
  
      
  ApplicationWindow {
      visible: true
      width: 400
      height: 500
      title: &quot;Hello App&quot;
  
      Rectangle {
          width: 400; height: 500
          color: &quot;gray&quot;
  
          Text {
              id: helloworld
              text: &quot;Hello world!&quot;
              color: &quot;blue&quot;
              font.pointSize: 32
          }
      }
  }
  </code></pre>
  <p>This results in a blank window.</p>
  <p>This code is my code without ApplicationWindow, and this one works:</p>
  <pre><code>Rectangle {
      width: 400; height: 500
      color: &quot;gray&quot;
       Text {
          id: helloworld
          text: &quot;Hello world!&quot;
          color: &quot;blue&quot;
          font.pointSize: 32
      }
  }
  </code></pre>
  <p>Why is using ApplicationWindow breaking the code?</p>
  <pre><code>from PyQt5.QtCore import QUrlfrom PyQt5.QtWidgets import QApplication
  from PyQt5.QtQuick import QQuickView
  import sys
  
  app = QApplication(sys.argv)
  
  view = QQuickView()
  view.setSource(QUrl(&quot;file2_working.qml&quot;))
  view.show()
  
  app.exec()
  </code></pre>