title: Selecting only leafs in JTree
body: <p>So I want to be able to only select leafs in JTree. There are some solutions online, but they don't work on multiple selection...</p>
  
  <p>What I would like is to find the part of the code that fires when user clicks on a node and modify that part to suit my needs.</p>
  
  <p>I have found a listener within DefaultTreeCellEditor, but that code seem to apply to when only one node is selected at a time...</p>
  
  <p>The bottom line is, where can I find the code that, when nodes gets clicked, decides if it will select it or not, and will it or not deselect all the other selected nodes?</p>