Java tutorial
/* * Copyright (c) 1995 - 2008 Sun Microsystems, Inc. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * - Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * - Neither the name of Sun Microsystems nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ //package components; /* * This code is based on an example provided by Richard Stanford, * a tutorial reader. */ import java.awt.BorderLayout; import java.awt.Dimension; import java.awt.GridLayout; import java.awt.Toolkit; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JScrollPane; import javax.swing.JTree; import javax.swing.event.TreeModelEvent; import javax.swing.event.TreeModelListener; import javax.swing.tree.DefaultMutableTreeNode; import javax.swing.tree.DefaultTreeModel; import javax.swing.tree.MutableTreeNode; import javax.swing.tree.TreePath; import javax.swing.tree.TreeSelectionModel; public class DynamicTreeDemo extends JPanel implements ActionListener { private int newNodeSuffix = 1; private static String ADD_COMMAND = "add"; private static String REMOVE_COMMAND = "remove"; private static String CLEAR_COMMAND = "clear"; private DynamicTree treePanel; public DynamicTreeDemo() { super(new BorderLayout()); // Create the components. treePanel = new DynamicTree(); populateTree(treePanel); JButton addButton = new JButton("Add"); addButton.setActionCommand(ADD_COMMAND); addButton.addActionListener(this); JButton removeButton = new JButton("Remove"); removeButton.setActionCommand(REMOVE_COMMAND); removeButton.addActionListener(this); JButton clearButton = new JButton("Clear"); clearButton.setActionCommand(CLEAR_COMMAND); clearButton.addActionListener(this); // Lay everything out. treePanel.setPreferredSize(new Dimension(300, 150)); add(treePanel, BorderLayout.CENTER); JPanel panel = new JPanel(new GridLayout(0, 3)); panel.add(addButton); panel.add(removeButton); panel.add(clearButton); add(panel, BorderLayout.SOUTH); } public void populateTree(DynamicTree treePanel) { String p1Name = new String("Parent 1"); String p2Name = new String("Parent 2"); String c1Name = new String("Child 1"); String c2Name = new String("Child 2"); DefaultMutableTreeNode p1, p2; p1 = treePanel.addObject(null, p1Name); p2 = treePanel.addObject(null, p2Name); treePanel.addObject(p1, c1Name); treePanel.addObject(p1, c2Name); treePanel.addObject(p2, c1Name); treePanel.addObject(p2, c2Name); } public void actionPerformed(ActionEvent e) { String command = e.getActionCommand(); if (ADD_COMMAND.equals(command)) { // Add button clicked treePanel.addObject("New Node " + newNodeSuffix++); } else if (REMOVE_COMMAND.equals(command)) { // Remove button clicked treePanel.removeCurrentNode(); } else if (CLEAR_COMMAND.equals(command)) { // Clear button clicked. treePanel.clear(); } } /** * Create the GUI and show it. For thread safety, this method should be * invoked from the event-dispatching thread. */ private static void createAndShowGUI() { // Create and set up the window. JFrame frame = new JFrame("DynamicTreeDemo"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // Create and set up the content pane. DynamicTreeDemo newContentPane = new DynamicTreeDemo(); newContentPane.setOpaque(true); // content panes must be opaque frame.setContentPane(newContentPane); // Display the window. frame.pack(); frame.setVisible(true); } public static void main(String[] args) { // Schedule a job for the event-dispatching thread: // creating and showing this application's GUI. javax.swing.SwingUtilities.invokeLater(new Runnable() { public void run() { createAndShowGUI(); } }); } } /* * Copyright (c) 1995 - 2008 Sun Microsystems, Inc. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: - * Redistributions of source code must retain the above copyright notice, this * list of conditions and the following disclaimer. - Redistributions in binary * form must reproduce the above copyright notice, this list of conditions and * the following disclaimer in the documentation and/or other materials provided * with the distribution. - Neither the name of Sun Microsystems nor the names * of its contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ // package components; /* * This code is based on an example provided by Richard Stanford, a tutorial * reader. */ class DynamicTree extends JPanel { protected DefaultMutableTreeNode rootNode; protected DefaultTreeModel treeModel; protected JTree tree; private Toolkit toolkit = Toolkit.getDefaultToolkit(); public DynamicTree() { super(new GridLayout(1, 0)); rootNode = new DefaultMutableTreeNode("Root Node"); treeModel = new DefaultTreeModel(rootNode); tree = new JTree(treeModel); tree.setEditable(true); tree.getSelectionModel().setSelectionMode(TreeSelectionModel.SINGLE_TREE_SELECTION); tree.setShowsRootHandles(true); JScrollPane scrollPane = new JScrollPane(tree); add(scrollPane); } /** Remove all nodes except the root node. */ public void clear() { rootNode.removeAllChildren(); treeModel.reload(); } /** Remove the currently selected node. */ public void removeCurrentNode() { TreePath currentSelection = tree.getSelectionPath(); if (currentSelection != null) { DefaultMutableTreeNode currentNode = (DefaultMutableTreeNode) (currentSelection.getLastPathComponent()); MutableTreeNode parent = (MutableTreeNode) (currentNode.getParent()); if (parent != null) { treeModel.removeNodeFromParent(currentNode); return; } } // Either there was no selection, or the root was selected. toolkit.beep(); } /** Add child to the currently selected node. */ public DefaultMutableTreeNode addObject(Object child) { DefaultMutableTreeNode parentNode = null; TreePath parentPath = tree.getSelectionPath(); if (parentPath == null) { parentNode = rootNode; } else { parentNode = (DefaultMutableTreeNode) (parentPath.getLastPathComponent()); } return addObject(parentNode, child, true); } public DefaultMutableTreeNode addObject(DefaultMutableTreeNode parent, Object child) { return addObject(parent, child, false); } public DefaultMutableTreeNode addObject(DefaultMutableTreeNode parent, Object child, boolean shouldBeVisible) { DefaultMutableTreeNode childNode = new DefaultMutableTreeNode(child); if (parent == null) { parent = rootNode; } // It is key to invoke this on the TreeModel, and NOT DefaultMutableTreeNode treeModel.insertNodeInto(childNode, parent, parent.getChildCount()); // Make sure the user can see the lovely new node. if (shouldBeVisible) { tree.scrollPathToVisible(new TreePath(childNode.getPath())); } return childNode; } class MyTreeModelListener implements TreeModelListener { public void treeNodesChanged(TreeModelEvent e) { DefaultMutableTreeNode node; node = (DefaultMutableTreeNode) (e.getTreePath().getLastPathComponent()); /* * If the event lists children, then the changed node is the child of the * node we've already gotten. Otherwise, the changed node and the * specified node are the same. */ int index = e.getChildIndices()[0]; node = (DefaultMutableTreeNode) (node.getChildAt(index)); System.out.println("The user has finished editing the node."); System.out.println("New value: " + node.getUserObject()); } public void treeNodesInserted(TreeModelEvent e) { } public void treeNodesRemoved(TreeModelEvent e) { } public void treeStructureChanged(TreeModelEvent e) { } } }