title: Qt: How to display selected text in an inactive window
body: <p>I have an inactive <code>QMainWindow</code> with a <code>QTabWidget</code> as <code>CentralWidget</code> which holds multiple <code>QPlainTextEdits</code>. Beside that I have a seperate <code>QWidget</code> flagged with <code>Qt::WindowStaysOnTopHint</code> and <code>Qt::Tool</code> which I want to use as a find/replace tool for the <code>QPlainTextEdits</code>.</p>
  
  <p>Now when I use the tool widget the <code>QMainWindow</code> is shown as inactive like it should and the selection background of the selected text in the active <code>QPlainTextEdit</code> is rendered as inactive (slightly grey) but I want the selection to be rendered like the <code>QMainWindow</code> would be active, with the default selection color w/o loosing the focus on the tool widget.</p>
  
  <p>How do I achieve that?</p>