title: How to use QCoreApplication::postEvent to inject synthetic input events
body: <p>I'm injecting Keyboard and Mouse events which are comming over the network into my Qt Application and use <code>QCoreApplication::postEvent</code> for this. The mouse coordinates are absolute screen pixel coordinates.</p>
  
  <pre><code>QMouseEvent *event = new QMouseEvent(type, QPoint(x, y), mouse_button, mouse_buttons,
      Qt::NoModifier);
  QCoreApplication::postEvent(g_qtdraw.main.widget, event);
  </code></pre>
  
  <p>Initially I had just one widget (referenced by <code>g_qtdraw.main.widget</code>) so I simply used that one as the receiver argument for <code>postEvent</code>. Now my application has more than one widget and the above code does not do what I want any longer.</p>
  
  <p>A second widget is shown in fullscreen mode and I know that all mouse events have to go to this window but with the above code they are still routed to the main widget.</p>
  
  <p>How do I choose the correct widget as the receiver (the one under the mouse x,y coords)? Is there a standard way, so that Qt chooses the right widget or do I have to track this myself?</p>