Style sheets / Qt Designer support for high dpi screens?
<p>Today I have ported my application from Qt5.5 to Qt5.6RC. Running it on my high dpi screen the widgets appeared tiny. After reading <a href="http://doc.qt.io/qt-5/highdpi.html" rel="noreferrer">this</a> and setting <code>QT_AUTO_SCREEN_SCALE_FACTOR to "1"</code> at least it is usable again.</p>

<p>However <a href="http://doc.qt.io/qt-5/highdpi.html" rel="noreferrer">they say</a>:</p>

<blockquote>
  <p>In the longer term, the application should be adapted to run
  unmodified:</p>
  
  <p>1) Always use the qreal versions of the QPainter drawing API.<br>
  2) Size windows and dialogs in relation to the screen size.<br> 
  3) Replace hard-coded sizes in layouts and drawing code by values calculated from font metrics or screen size.</p>
</blockquote>

<p>Not all style sheet attributes support <code>em</code> (".. from font metrics"). No idea how I would use "screen size" relative in style sheets. Also Qt Designer only supports <code>px</code> in many places, like shown below.</p>

<p><a href="https://i.stack.imgur.com/MnUlmm.png" rel="noreferrer"><img src="https://i.stack.imgur.com/MnUlmm.png" alt="icon size"></a></p>

<p>Considered I do not want to give up designer and stylesheets, what are my options to create genuine Qt hires applications?</p>

<hr>

<p>Related (but no answer to my question)</p>

<ul>
<li>It is even a bit unclear what <code>1em</code> means in the Qt world: <a href="https://stackoverflow.com/q/33963809/356726">What does size &quot;1em&quot; in Qt qss mean, if there is no font size em?</a></li>
<li><a href="https://stackoverflow.com/q/34407001/356726">Qt and high dpi screens</a> </li>
<li><a href="https://stackoverflow.com/q/32313658/356726">QT High DPI Support on Windows</a></li>
</ul>