Mega Code Archive
JTree Displaying the File System Hierarchy Using the Custom Tree Model
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import java.io.File;
import java.util.Enumeration;
import java.util.Vector;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.event.TreeModelEvent;
import javax.swing.event.TreeModelListener;
import javax.swing.tree.TreeModel;
import javax.swing.tree.TreePath;
public class CreatingTreeModel {
public static void main(String[] a) {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
FileSystemModel fileSystemDataModel = new FileSystemModel();
JTree tree = new JTree(fileSystemDataModel);
JScrollPane scrollPane = new JScrollPane(tree);
frame.add(scrollPane);
frame.setSize(300, 200);
frame.setVisible(true);
}
}
class FileSystemModel implements TreeModel {
private String root; // The root identifier
private Vector listeners; // Declare the listeners vector
public FileSystemModel() {
root = System.getProperty("user.home");
File tempFile = new File(root);
root = tempFile.getParent();
listeners = new Vector();
}
public Object getRoot() {
return (new File(root));
}
public Object getChild(Object parent, int index) {
File directory = (File) parent;
String[] directoryMembers = directory.list();
return (new File(directory, directoryMembers[index]));
}
public int getChildCount(Object parent) {
File fileSystemMember = (File) parent;
if (fileSystemMember.isDirectory()) {
String[] directoryMembers = fileSystemMember.list();
return directoryMembers.length;
}
else {
return 0;
}
}
public int getIndexOfChild(Object parent, Object child) {
File directory = (File) parent;
File directoryMember = (File) child;
String[] directoryMemberNames = directory.list();
int result = -1;
for (int i = 0; i < directoryMemberNames.length; ++i) {
if (directoryMember.getName().equals(directoryMemberNames[i])) {
result = i;
break;
}
}
return result;
}
public boolean isLeaf(Object node) {
return ((File) node).isFile();
}
public void addTreeModelListener(TreeModelListener l) {
if (l != null && !listeners.contains(l)) {
listeners.addElement(l);
}
}
public void removeTreeModelListener(TreeModelListener l) {
if (l != null) {
listeners.removeElement(l);
}
}
public void valueForPathChanged(TreePath path, Object newValue) {
// Does Nothing!
}
public void fireTreeNodesInserted(TreeModelEvent e) {
Enumeration listenerCount = listeners.elements();
while (listenerCount.hasMoreElements()) {
TreeModelListener listener = (TreeModelListener) listenerCount.nextElement();
listener.treeNodesInserted(e);
}
}
public void fireTreeNodesRemoved(TreeModelEvent e) {
Enumeration listenerCount = listeners.elements();
while (listenerCount.hasMoreElements()) {
TreeModelListener listener = (TreeModelListener) listenerCount.nextElement();
listener.treeNodesRemoved(e);
}
}
public void fireTreeNodesChanged(TreeModelEvent e) {
Enumeration listenerCount = listeners.elements();
while (listenerCount.hasMoreElements()) {
TreeModelListener listener = (TreeModelListener) listenerCount.nextElement();
listener.treeNodesChanged(e);
}
}
public void fireTreeStructureChanged(TreeModelEvent e) {
Enumeration listenerCount = listeners.elements();
while (listenerCount.hasMoreElements()) {
TreeModelListener listener = (TreeModelListener) listenerCount.nextElement();
listener.treeStructureChanged(e);
}
}
}
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