title: Combo box items are hidden behind other controls.
body: <p>error screenshot:</p>
  
  <p><a href="https://i.stack.imgur.com/3keuR.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/3keuR.png" alt="https://i.stack.imgur.com/3keuR.png"></a></p>
  
  <p>The <code>JComboBox</code> items are obscured by <code>RSyntaxTextArea</code> in programs created with Java Swing.</p>
  
  <p>This symptom does not occur when running the same program on a mac.
  It only occurs in the windows environment.</p>
  
  <p>Could someone give me some hint about the solution?</p>