Mega Code Archive
TreeExpansionListener, TreeWillExpandListener
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/*
* 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.
*/
/*
* TreeExpandEventDemo2.java requires no other files.
*/
import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import javax.swing.BorderFactory;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTree;
import javax.swing.event.TreeExpansionEvent;
import javax.swing.event.TreeExpansionListener;
import javax.swing.event.TreeWillExpandListener;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.ExpandVetoException;
import javax.swing.tree.TreeNode;
public class TreeExpandEventDemo2 extends JPanel {
DemoArea demoArea;
JTextArea textArea;
final static String newline = "\n";
public TreeExpandEventDemo2() {
super(new GridBagLayout());
GridBagLayout gridbag = (GridBagLayout) getLayout();
GridBagConstraints c = new GridBagConstraints();
c.fill = GridBagConstraints.BOTH;
c.gridwidth = GridBagConstraints.REMAINDER;
c.weightx = 1.0;
c.weighty = 1.0;
c.insets = new Insets(1, 1, 1, 1);
demoArea = new DemoArea();
gridbag.setConstraints(demoArea, c);
add(demoArea);
c.insets = new Insets(0, 0, 0, 0);
textArea = new JTextArea();
textArea.setEditable(false);
JScrollPane scrollPane = new JScrollPane(textArea);
scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
scrollPane.setPreferredSize(new Dimension(200, 75));
gridbag.setConstraints(scrollPane, c);
add(scrollPane);
setPreferredSize(new Dimension(450, 450));
setBorder(BorderFactory.createEmptyBorder(20, 20, 20, 20));
}
void saySomething(String eventDescription, TreeExpansionEvent e) {
textArea
.append(eventDescription + "; " + "path = " + e.getPath() + newline);
}
class DemoArea extends JScrollPane implements TreeExpansionListener,
TreeWillExpandListener {
Dimension minSize = new Dimension(100, 100);
JTree tree;
Object[] willExpandOptions = { "Cancel Expansion", "Expand" };
String willExpandText = "A branch node is about to be expanded.\n"
+ "Click \"Cancel Expansion\" to prevent it.";
String willExpandTitle = "Tree Will Expand";
public DemoArea() {
TreeNode rootNode = createNodes();
tree = new JTree(rootNode);
tree.addTreeExpansionListener(this);
tree.addTreeWillExpandListener(this);
setViewportView(tree);
}
private TreeNode createNodes() {
DefaultMutableTreeNode root;
DefaultMutableTreeNode grandparent;
DefaultMutableTreeNode parent;
DefaultMutableTreeNode child;
root = new DefaultMutableTreeNode("San Francisco");
grandparent = new DefaultMutableTreeNode("Potrero Hill");
root.add(grandparent);
//
parent = new DefaultMutableTreeNode("Restaurants");
grandparent.add(parent);
child = new DefaultMutableTreeNode("Thai Barbeque");
parent.add(child);
child = new DefaultMutableTreeNode("Goat Hill Pizza");
parent.add(child);
//
parent = new DefaultMutableTreeNode("Grocery Stores");
grandparent.add(parent);
child = new DefaultMutableTreeNode("Good Life Grocery");
parent.add(child);
child = new DefaultMutableTreeNode("Safeway");
parent.add(child);
grandparent = new DefaultMutableTreeNode("Noe Valley");
root.add(grandparent);
//
parent = new DefaultMutableTreeNode("Restaurants");
grandparent.add(parent);
child = new DefaultMutableTreeNode("Hamano Sushi");
parent.add(child);
child = new DefaultMutableTreeNode("Hahn's Hibachi");
parent.add(child);
//
parent = new DefaultMutableTreeNode("Grocery Stores");
grandparent.add(parent);
child = new DefaultMutableTreeNode("Real Foods");
parent.add(child);
child = new DefaultMutableTreeNode("Bell Market");
parent.add(child);
return root;
}
public Dimension getMinimumSize() {
return minSize;
}
public Dimension getPreferredSize() {
return minSize;
}
// Required by TreeWillExpandListener interface.
public void treeWillExpand(TreeExpansionEvent e) throws ExpandVetoException {
saySomething("Tree-will-expand event detected", e);
int n = JOptionPane.showOptionDialog(this, willExpandText,
willExpandTitle, JOptionPane.YES_NO_OPTION,
JOptionPane.QUESTION_MESSAGE, null, willExpandOptions,
willExpandOptions[1]);
if (n == 0) {
// User said cancel expansion.
saySomething("Tree expansion cancelled", e);
throw new ExpandVetoException(e);
}
}
// Required by TreeWillExpandListener interface.
public void treeWillCollapse(TreeExpansionEvent e) {
saySomething("Tree-will-collapse event detected", e);
}
// Required by TreeExpansionListener interface.
public void treeExpanded(TreeExpansionEvent e) {
saySomething("Tree-expanded event detected", e);
}
// Required by TreeExpansionListener interface.
public void treeCollapsed(TreeExpansionEvent e) {
saySomething("Tree-collapsed event detected", e);
}
}
/**
* 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("TreeExpandEventDemo2");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// Create and set up the content pane.
JComponent newContentPane = new TreeExpandEventDemo2();
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();
}
});
}
}
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