title: Wanted: Directions/ideas for a custom tree-to-tree drag'n'drop implementation in ExtJS
body: <p>I need some combined functionality regarding drag'n'drop between two trees in <em>ExtJS</em>.</p>
  
  <p><strong>The first</strong> required feature is very simple and is just the builtin drag'n'drop features isolated to a single <em>tree</em> only.</p>
  
  <p><img src="https://i.stack.imgur.com/f5x0u.jpg" alt="Standard tree drag&#39;n&#39;drop"></p>
  
  <p><strong>The second</strong> required feature is that I wan't the user to be able to drag a node from the <em>left tree</em> and drop it at any node in the <em>right tree</em>. </p>
  
  <p><img src="https://i.stack.imgur.com/294oC.jpg" alt="One way non destructive drag&#39;n&#39;drop"></p>
  
  <p>The action should not remove the node from the <em>left tree</em>, thus creating the possibility of dragging the same node from the <em>left tree</em> to multiple places in the <em>right tree</em>.</p>
  
  <p><strong>My question is:</strong> Which approach should I take to combine these two functionalities, utilizing the existing possibilities in the <code>TreePanel</code> object without inventing the wheel again? I am not looking for a complete solution (it would be nice though ;-) ), but rather how to handle drag/drop-zones, events and so on.</p>