🚀 go-pugleaf

In article <37837FF6.654DDC32@sema4.com>, ahumphreys@sema4.com says...
> What is the best way to populate a java tree from a dataset (or just on
> the fly)?  I don't know how many nodes we're going to have, so I can't
> really set up the appropriate number of GraphLocations in the code -- it
> needs to be done dynamically.  Thanks. -alex
> 
> 
Loop through the dataset, grab the info you need and build the tree.  
Here is a fragment where I am adding database metadata (column 
information) to a tree that describes a database table.

while (rsColumnList.next())
{
  // Now add a description for this particular column
  columnDescNode = new DefaultMutableTreeNode( 
                    new Pair( imageCol,
                              rsColumnList.getString( "COLUMN_NAME" )));
  treeModel.insertNodeInto( columnDescNode,
                            columnsNode,
                            columnsNode.getChildCount() );
}

The DefaultMutableTree node takes an object that it stores in its 
'userObject' instance variable.  This is usually a string, but in my 
example I am using a JGL Pair object.  This means I also need to have a 
renderer assigned to my tree that knows how to get into that Pair() 
object and update a renderer component appropriately:

class PairTreeCellRenderer extends DefaultTreeCellRenderer
{

   public void PairTreeCellRenderer()
   {

      setLeafIcon( null );
      setClosedIcon( null );
      setOpenIcon( null );

   }

   public Component getTreeCellRendererComponent(JTree tree,
                                                 Object value,
                                                 boolean sel,
                                                 boolean expanded,
                                                 boolean leaf, int row,
                                                 boolean hasFocus)
   {
      super.getTreeCellRendererComponent( tree,
                                          value,
                                          sel,
                                          expanded,
                                          leaf,
                                          row,
                                          hasFocus );
      pair = (Pair) ((DefaultMutableTreeNode)value).getUserObject();
      setText( pair.second.toString() );
      setIcon( (Icon)pair.first );
      selected = sel;
      return this;
   }

   public String getToolTipText()

   {

      return "";

   }
   private Pair pair;
}


Tad Frysinger (TeamB)