Mega Code Archive
Displaying Hierarchical Data within a JTree
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import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.event.TreeSelectionEvent;
import javax.swing.event.TreeSelectionListener;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.TreeCellRenderer;
import javax.swing.tree.TreePath;
public class TreeIt {
class MyCellRenderer extends JLabel implements TreeCellRenderer {
MyCellRenderer() {
setOpaque(true);
}
public Component getTreeCellRendererComponent(JTree tree, Object value,
boolean selected, boolean expanded, boolean leaf, int row,
boolean hasFocus) {
StringBuffer text = new StringBuffer();
if (expanded)
text.append("E:");
if (leaf)
text.append("L:");
if (hasFocus)
text.append("H:");
text.append(row + "->");
text.append(value.toString());
setBackground(selected ? Color.BLUE : Color.YELLOW);
setForeground(selected ? Color.YELLOW : Color.BLUE);
setText(text.toString());
return this;
}
}
public TreeIt() {
JFrame f = new JFrame();
DefaultMutableTreeNode root = new DefaultMutableTreeNode("Calendar");
DefaultMutableTreeNode months = new DefaultMutableTreeNode("Months");
root.add(months);
String monthLabels[] = { "January", "February", "March", "April",
"May", "June", "July", "August", "September", "October",
"November", "December" };
for (int i = 0, n = monthLabels.length; i < n; i++)
months.add(new DefaultMutableTreeNode(monthLabels[i]));
DefaultMutableTreeNode weeks = new DefaultMutableTreeNode("Weeks");
root.add(weeks);
String weekLabels[] = { "Monday", "Tuesday", "Wednesday", "Thursday",
"Friday", "Saturday", "Sunday" };
for (int i = 0, n = weekLabels.length; i < n; i++)
weeks.add(new DefaultMutableTreeNode(weekLabels[i]));
JTree jt = new JTree(root);
jt.addTreeSelectionListener(new TreeSelectionListener() {
public void valueChanged(TreeSelectionEvent e) {
TreePath path = e.getPath();
System.out.println("Picked: " + path.getLastPathComponent());
Object elements[] = path.getPath();
for (int i = 0, n = elements.length; i < n; i++) {
System.out.print("->" + elements[i]);
}
System.out.println();
}
});
DefaultMutableTreeNode lastLeaf = root.getLastLeaf();
TreePath path = new TreePath(lastLeaf.getPath());
jt.setSelectionPath(path);
jt.setCellRenderer(new MyCellRenderer());
JScrollPane jsp = new JScrollPane(jt);
Container c = f.getContentPane();
c.add(jsp, BorderLayout.CENTER);
f.setSize(250, 250);
f.show();
}
public static void main(String args[]) {
new TreeIt();
}
}
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