title: How to adjust a QSlider's handle?
body: <p>I'm writing an app for a touchscreen, and the default handle is too small to grab reliably, so I want to make it bigger.  According to the official documentation, several answers on SE, and a couple of other forums, this ought to work in a QWidget's constructor:</p>
  
  <pre><code>sliderGrandMaster = new QSlider(Qt::Vertical, panelRight);
  sliderGrandMaster-&gt;setGeometry(          appdata-&gt;buttonBorder ,    //Left
                     buttonTopRight +      appdata-&gt;buttonBorder ,    //Top
                          halfwidth - (2 * appdata-&gt;buttonBorder),    //Width
              buttonRemainingHeight - (2 * appdata-&gt;buttonBorder));   //Height
  sliderGrandMaster-&gt;setRange(0, RANGE_MAX);
  sliderGrandMaster-&gt;setTickInterval(RANGE_MAX / 10);
  sliderGrandMaster-&gt;setTickPosition(QSlider::TicksBothSides);
  QString temp =  QString("handle:vertical { background: green; height: %1px; margin: 0 -%2px; }")
                  .arg(buttonRemainingHeight / 5)
                  .arg(halfwidth / 3);
  sliderGrandMaster-&gt;setStyleSheet(temp);
  </code></pre>
  
  <p>But it seems to have no effect.  The handle is the same small size regardless of what values I put in the stylesheet, and it's not even green.</p>
  
  <p>With my values at runtime, <code>temp</code> ends up being <code>handle:vertical { background: green; height: 66px; margin: 0 -32px; }</code>.  The size of the slider is <code>94px wide by 331px tall</code>.</p>
  
  <p>Am I missing something?</p>
  
  <hr>
  
  <h2>Edit:</h2>
  
  <p>This:</p>
  
  <pre><code>QString temp =  QString("QSlider::handle { background: green; height: %1px; width: %1px; margin: 0 -%2px; }")
                  .arg(buttonRemainingHeight / 5)
                  .arg(halfwidth / 3);
  sliderGrandMaster-&gt;setStyleSheet(temp);
  </code></pre>
  
  <p>at least got it green.  But the size is still wrong.  Qt version 5.4.2</p>