java 动态树型菜单实现

import javax.swing.*; import javax.swing.event.*; import java.awt.BorderLayout; import java.awt.Color; import java.awt.Dimension; import java.awt.FlowLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; import java.util.*; import javax.swing.tree.*; public class SampleTree { /** Window for showing Tree. */ protected JFrame frame; /** Tree used for the example. */ protected JTree tree; /** Tree model. */ protected DefaultTreeModel treeModel; /** * Constructs a new instance of SampleTree. */ public SampleTree() { // Force SampleTree to come up in the Cross Platform L&F try { UIManager.setLookAndFeel(UIManager.getCrossPlatformLookAndFeelClassName()); // If you want the System L&F instead, comment out the above line and // uncomment the following: // UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); } catch (Exception exc) { System.err.println("Error loading L&F: " + exc); } JMenuBar menuBar = constructMenuBar(); JPanel panel = new JPanel(true); frame = new JFrame("SampleTree"); frame.getContentPane().add("Center", panel); frame.setJMenuBar(menuBar); frame.setBackground(Color.lightGray); /* Create the JTreeModel. */ DefaultMutableTreeNode root = createNewNode("Root"); treeModel = new SampleTreeModel(root); /* Create the tree. */ tree = new JTree(treeModel); /* Enable tool tips for the tree, without this tool tips will not be picked up. */ ToolTipManager.sharedInstance().registerComponent(tree); /* Make the tree use an instance of SampleTreeCellRenderer for drawing. */ tree.setCellRenderer(new SampleTreeCellRenderer()); /* Make tree ask for the height of each row. */ tree.setRowHeight(-1); /* Put the Tree in a scroller. */ JScrollPane sp = new JScrollPane(); sp.setPreferredSize(new Dimension(300, 300)); sp.getViewport().add(tree); /* And show it. */ panel.setLayout(new BorderLayout()); panel.add("Center", sp); panel.add("South", constructOptionsPanel()); frame.addWindowListener( new WindowAdapter() { public void windowClosing(WindowEvent e) {System.exit(0);}}); frame.pack(); frame.show(); } /** Constructs a JPanel containing check boxes for the different * options that tree supports. */ private JPanel constructOptionsPanel() { JCheckBox aCheckbox; JPanel retPanel = new JPanel(false); JPanel borderPane = new JPanel(false); borderPane.setLayout(new BorderLayout()); retPanel.setLayout(new FlowLayout()); aCheckbox = new JCheckBox("show handles"); aCheckbox.setSelected(tree.getShowsRootHandles()); aCheckbox.addChangeListener(new ShowHandlesChangeListener()); retPanel.add(aCheckbox); aCheckbox = new JCheckBox("show root"); aCheckbox.setSelected(tree.isRootVisible()); aCheckbox.addChangeListener(new ShowRootChangeListener()); retPanel.add(aCheckbox); aCheckbox = new JCheckBox("editable"); aCheckbox.setSelected(tree.isEditable()); aCheckbox.addChangeListener(new TreeEditableChangeListener()); aCheckbox.setToolTipText("Triple click to edit"); retPanel.add(aCheckbox); borderPane.add(retPanel, BorderLayout.CENTER); /* Create a set of radio buttons that dictate what selection should be allowed in the tree. */ ButtonGroup group = new ButtonGroup(); JPanel buttonPane = new JPanel(false); JRadioButton button; buttonPane.setLayout(new FlowLayout()); button = new JRadioButton("Single"); button.addActionListener(new AbstractAction() { public boolean isEnabled() { return true; } public void actionPerformed(ActionEvent e) { tree.getSelectionModel().setSelectionMode (TreeSelectionModel.SINGLE_TREE_SELECTION); } }); group.add(button); buttonPane.add(button); button = new JRadioButton("Contiguous"); button.addActionListener(new AbstractAction() { public boolean isEnabled() { return true; } public void actionPerformed(ActionEvent e) { tree.getSelectionModel().setSelectionMode (TreeSelectionModel.CONTIGUOUS_TREE_SELECTION); } }); group.add(button); buttonPane.add(button); button = new JRadioButton("Discontiguous"); button.addActionListener(new AbstractAction() { public boolean isEnabled() { return true; } public void actionPerformed(ActionEvent e) { tree.getSelectionModel().setSelectionMode (TreeSelectionModel.DISCONTIGUOUS_TREE_SELECTION); } }); button.setSelected(true); group.add(button); buttonPane.add(button); borderPane.add(buttonPane, BorderLayout.SOUTH); // NOTE: This will be enabled in a future release. // Create a label and combobox to determine how many clicks are // needed to expand. /* JPanel clickPanel = new JPanel(); Object[] values = { "Never", new Integer(1), new Integer(2), new Integer(3) }; final JComboBox clickCBox = new JComboBox(values); clickPanel.setLayout(new FlowLayout()); clickPanel.add(new JLabel("Click count to expand:")); clickCBox.setSelectedIndex(2); clickCBox.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent ae) { Object selItem = clickCBox.getSelectedItem(); if(selItem instanceof Integer) tree.setToggleClickCount(((Integer)selItem).intValue()); else // Don't toggle tree.setToggleClickCount(0); } }); clickPanel.add(clickCBox); borderPane.add(clickPanel, BorderLayout.NORTH); */ return borderPane; } /** Construct a menu. */ private JMenuBar constructMenuBar() { JMenu menu; JMenuBar menuBar = new JMenuBar(); JMenuItem menuItem; /* Good ol exit. */ menu = new JMenu("File"); menuBar.add(menu); menuItem = menu.add(new JMenuItem("Exit")); menuItem.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { System.exit(0); }}); /* Tree related stuff. */ menu = new JMenu("Tree"); menuBar.add(menu); menuItem = menu.add(new JMenuItem("Add")); menuItem.addActionListener(new AddAction()); menuItem = menu.add(new JMenuItem("Insert")); menuItem.addActionListener(new InsertAction()); menuItem = menu.add(new JMenuItem("Reload")); menuItem.addActionListener(new ReloadAction()); menuItem = menu.add(new JMenuItem("Remove")); menuItem.addActionListener(new RemoveAction()); return menuBar; } /** * Returns the TreeNode instance that is selected in the tree. * If nothing is selected, null is returned. */ protected DefaultMutableTreeNode getSelectedNode() { TreePath selPath = tree.getSelectionPath(); if(selPath != null) return (DefaultMutableTreeNode)selPath.getLastPathComponent(); return null; } /** * Returns the selected TreePaths in the tree, may return null if * nothing is selected. */ protected TreePath[] getSelectedPaths() { return tree.getSelectionPaths(); } protected DefaultMutableTreeNode createNewNode(String name) { return new DynamicTreeNode(new SampleData(null, Color.black, name)); } /** * AddAction is used to add a new item after the selected item. */ class AddAction extends Object implements ActionListener { /** Number of nodes that have been added. */ public int addCount; /** * Messaged when the user clicks on the Add menu item. * Determines the selection from the Tree and adds an item * after that. If nothing is selected, an item is added to * the root. */ public void actionPerformed(ActionEvent e) { DefaultMutableTreeNode lastItem = getSelectedNode(); DefaultMutableTreeNode parent; /* Determine where to create the new node. */ if(lastItem != null) { parent = (DefaultMutableTreeNode)lastItem.getParent(); if(parent == null) { parent = (DefaultMuta