title: Show shortcut in tooltip of QToolBar
body: <p>I have <code>QActions</code> added to a <code>QToolBar</code> using <code>addAction()</code>.</p>
  
  <p>I want the toolbar button tooltips to show the shortcuts. e.g. <em>Copy (Ctrl+C)</em>.
  Of course, i could statically set</p>
  
  <pre><code>action-&gt;setTooltip(QString("%1 (%2)").arg(action.toolTip(), action-&gt;shortcut().toString(QKeySequence::NativeText)));
  </code></pre>
  
  <p>However, this is quite cumbersome because there are lots of actions and the user can modify the shortcuts so that I would have to keep track of that and update accordingly. It would be much nicer if I could simply modify the <code>QToolBar</code> tooltip behavior by subclassing <code>QToolBar</code> similar to <a href="http://doc.qt.io/qt-5/qtwidgets-widgets-tooltips-example.html" rel="nofollow noreferrer">http://doc.qt.io/qt-5/qtwidgets-widgets-tooltips-example.html</a>.</p>
  
  <p>Unfortunately, it's not that simple. The tooltip is not generated by the <code>QToolBar</code> itself, but apparently by a <code>QToolButton</code> which is created internally when using <code>addAction()</code>. So ideally I would inject my own subclass of <code>QToolButton</code>. But that seems imposible because the actual instantiation of the toolbutton is done inside the private QToolBarLayout which I cannot access.</p>
  
  <p>Any ideas how to solve this?</p>