Method stateChanged

src/org/opensourcephysics/tools/Launcher.java:1574–1597

(ChangeEvent e)

		contentPane.add(tabbedPane, BorderLayout.CENTER);
		tabbedPane.addChangeListener(new ChangeListener() {
			@Override
			public void stateChanged(ChangeEvent e) {
				previousNode = selectedNode;
				selectedNode = getSelectedNode();
				newNodeSelected = true;
				refreshSelectedTab();
				if ((previousNode != null) && (selectedNode != null)) {
					// set html properties of newly selected node
					if ((selectedNode.getURL() == null) && !selectedNode.tabData.isEmpty()) {
						int page = Math.max(0, selectedNode.tabNumber);
						LaunchNode.DisplayTab htmlData = selectedNode.tabData.get(page);
						selectedNode.setURL(htmlData.url);
						selectedNode.tabNumber = page;
//            OSPLog.info("set selected node "+selectedNode+" to "+selectedNode.htmlURL //$NON-NLS-1$
//                +"and tabnumber "+selectedNode.tabNumber);  //$NON-NLS-1$
					}
					// post undoable NavEdit
					if (postEdits) {
						UndoableEdit edit = undoManager.new NavEdit(previousNode, selectedNode);
						undoSupport.postEdit(edit);
					}
				}
				refreshGUI();
			}

		});
		tabListener = new MouseAdapter() {