Merge branch 'feature/JAL-3080clearTreeGroups' into Jalview-BH/JAL-3026

diff --combined src/jalview/gui/TreeCanvas.java
index b83dc12,fa30e13..f7faa6c
--- 1/src/jalview/gui/TreeCanvas.java
--- 2/src/jalview/gui/TreeCanvas.java
+++ b/src/jalview/gui/TreeCanvas.java
@@@ -27,7 -27,6 +27,7 @@@ import jalview.datamodel.Sequence
  import jalview.datamodel.SequenceGroup;
  import jalview.datamodel.SequenceI;
  import jalview.datamodel.SequenceNode;
 +import jalview.gui.JalviewColourChooser.ColourChooserListener;
  import jalview.schemes.ColourSchemeI;
  import jalview.schemes.ColourSchemeProperty;
  import jalview.schemes.UserColourScheme;
@@@ -842,17 -841,15 +842,17 @@@ public class TreeCanvas extends JPanel 
     */
    void chooseSubtreeColour()
    {
 -    Color col = JColorChooser.showDialog(this,
 -            MessageManager.getString("label.select_subtree_colour"),
 -            highlightNode.color);
 -    if (col != null)
 -    {
 -      setColor(highlightNode, col);
 -      PaintRefresher.Refresh(tp, ap.av.getSequenceSetId());
 -      repaint();
 -    }
 +    String ttl = MessageManager.getString("label.select_subtree_colour");
 +    ColourChooserListener listener = new ColourChooserListener() {
 +      @Override
 +      public void colourSelected(Color c)
 +      {
 +        setColor(highlightNode, c);
 +        PaintRefresher.Refresh(tp, ap.av.getSequenceSetId());
 +        repaint();
 +      }
 +    };
 +    JalviewColourChooser.showColourChooser(this, ttl,  highlightNode.color, listener);
    }
  
    @Override
@@@ -965,6 -962,15 +965,15 @@@
            }
          }
          colourGroups(groups);
+ 
+         /*
+          * clear partition (don't show vertical line) if
+          * it is to the right of all nodes
+          */
+         if (groups.isEmpty())
+         {
+           threshold = 0f;
+         }
        }
  
        PaintRefresher.Refresh(tp, ap.av.getSequenceSetId());
@@@ -984,7 -990,7 +993,7 @@@
  
        Vector<SequenceNode> l = tree.findLeaves(groups.get(i));
  
-       Vector<SequenceI> sequences = new Vector<SequenceI>();
+       Vector<SequenceI> sequences = new Vector<>();
  
        for (int j = 0; j < l.size(); j++)
        {