tree.addPropertyChangeListener(selectionModelPropertyChangeListener);
selectionModelPropertyChangeListener = createSelectionModelPropertyChangeListener(); if (treeSelectionModel != null && selectionModelPropertyChangeListener != null) { treeSelectionModel.addPropertyChangeListener (selectionModelPropertyChangeListener); }  componentListener = createComponentListener();
  protected void installListeners()  {    tree.addPropertyChangeListener(propertyChangeListener);    tree.addFocusListener(focusListener);    tree.addTreeSelectionListener(treeSelectionListener);    tree.addMouseListener(mouseListener);    tree.addKeyListener(keyListener);    tree.addPropertyChangeListener(selectionModelPropertyChangeListener);    tree.addComponentListener(componentListener);    tree.addTreeExpansionListener(treeExpansionListener);    if (treeModel != null)      treeModel.addTreeModelListener(treeModelListener);  }