title: QWidget setGeometry show without use of a QLayout
body: <p>The target is to paint a QWidget subclass in a other QWidget. By give only the coords.</p>
  
  <pre><code>#include &lt;QApplication&gt;
  #include &lt;QWidget&gt;
  #include &lt;QLabel&gt;
  int main(int argc, char *argv[])
  {
      QApplication a(argc, argv);
      QWidget* w = new QWidget;
      w-&gt;show();
      QLabel* l = new QLabel;
      l-&gt;setText("Hello World!");
      l-&gt;setParent(w);
      l-&gt;setGeometry(0,0,100,100);
  
      return a.exec();
  }
  </code></pre>
  
  <p>Why i see nothing on the window.</p>