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/**
* @version 1.00 1999-07-17
* @author Cay Horstmann
*/
import java.awt.Component;
import java.awt.Container;
import java.awt.Font;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.lang.reflect.Modifier;
import java.util.Enumeration;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextField;
import javax.swing.JTree;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.TreePath;
public class ClassTree {
public static void main(String[] args) {
JFrame frame = new ClassTreeFrame();
frame.show();
}
}
class ClassTreeFrame extends JFrame implements ActionListener {
public ClassTreeFrame() {
setTitle("ClassTree");
setSize(300, 200);
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
// the root of the class tree is Object
root = new DefaultMutableTreeNode(java.lang.Object.class);
model = new DefaultTreeModel(root);
tree = new JTree(model);
// add this class to populate the tree with some data
addClass(getClass());
// set up node icons
ClassNameTreeCellRenderer renderer = new ClassNameTreeCellRenderer();
// renderer.setClosedIcon(new ImageIcon("red-ball.gif"));
// renderer.setOpenIcon(new ImageIcon("yellow-ball.gif"));
// renderer.setLeafIcon(new ImageIcon("blue-ball.gif"));
tree.setCellRenderer(renderer);
Container contentPane = getContentPane();
contentPane.add(new JScrollPane(tree), "Center");
// new class names are typed into this text field
textField = new JTextField();
textField.addActionListener(this);
contentPane.add(textField, "South");
}
public void actionPerformed(ActionEvent event) { // add the class whose name
// is in the text field
try {
String text = textField.getText();
addClass(Class.forName(text));
// clear text field to indicate success
textField.setText("");
} catch (ClassNotFoundException e) {
Toolkit.getDefaultToolkit().beep();
}
}
public DefaultMutableTreeNode findUserObject(Object obj) { // find the node
// containing a
// user object
Enumeration e = root.breadthFirstEnumeration();
while (e.hasMoreElements()) {
DefaultMutableTreeNode node = (DefaultMutableTreeNode) e
.nextElement();
if (node.getUserObject().equals(obj))
return node;
}
return null;
}
public DefaultMutableTreeNode addClass(Class c) { // add a new class to the
// tree
// skip non-class types
if (c.isInterface() || c.isPrimitive())
return null;
// if the class is already in the tree, return its node
DefaultMutableTreeNode node = findUserObject(c);
if (node != null)
return node;
// class isn't present--first add class parent recursively
Class s = c.getSuperclass();
DefaultMutableTreeNode parent;
if (s == null)
parent = root;
else
parent = addClass(s);
// add the class as a child to the parent
DefaultMutableTreeNode newNode = new DefaultMutableTreeNode(c);
model.insertNodeInto(newNode, parent, parent.getChildCount());
// make node visible
TreePath path = new TreePath(model.getPathToRoot(newNode));
tree.makeVisible(path);
return newNode;
}
private DefaultMutableTreeNode root;
private DefaultTreeModel model;
private JTree tree;
private JTextField textField;
}
class ClassNameTreeCellRenderer extends DefaultTreeCellRenderer {
public Component getTreeCellRendererComponent(JTree tree, Object value,
boolean selected, boolean expanded, boolean leaf, int row,
boolean hasFocus) {
super.getTreeCellRendererComponent(tree, value, selected, expanded,
leaf, row, hasFocus);
// get the user object
DefaultMutableTreeNode node = (DefaultMutableTreeNode) value;
Class c = (Class) node.getUserObject();
// the first time, derive italic font from plain font
if (plainFont == null) {
plainFont = getFont();
/*
* the tree cell renderer is sometimes called with a label that has
* a null font
*/
if (plainFont != null)
italicFont = plainFont.deriveFont(Font.ITALIC);
}
// set font to italic if the class is abstract
if ((c.getModifiers() & Modifier.ABSTRACT) == 0)
setFont(plainFont);
else
setFont(italicFont);
return this;
}
private Font plainFont = null;
private Font italicFont = null;
};
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