code: private void buildLogicalTree()
      {
          if (logicalCombo.getSelectedIndex() != -1)
          {
              LogicalTreeProvider provider = logicalCombo.getItemAt(logicalCombo.getSelectedIndex());
              proc.buildLogicalTree(provider, null); //the parametres should have been set through the GUI
              setLogicalTree(proc.getLogicalAreaTree());
          }
      }
docs: Builds the logical tree the chosen provider and parametres.