private void buildTree() {
DefaultMutableTreeNode node = null;
DefaultMutableTreeNode leaf = null;
DefaultMutableTreeNode top = (DefaultMutableTreeNode) getModel()
.getRoot();
libView = new LibView("Bibliothek", gui.getCore());
node = new DropTreeNode(libView);
top.add(node);
gui.setView(libView);
node = new DropTreeNode(new QueueView("Warteschlange", gui.getCore()),