Mega Code Archive
A tree model using the SortTreeModel with a File hierarchy as input
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/*
Java Swing, 2nd Edition
By Marc Loy, Robert Eckstein, Dave Wood, James Elliott, Brian Cole
ISBN: 0-596-00408-7
Publisher: O'Reilly
*/
// SortTreeDemo.java
//This class creates a tree model using the SortTreeModel with
//a File hierarchy as input.
//
import java.io.File;
import java.util.Comparator;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.MutableTreeNode;
import javax.swing.tree.TreeNode;
public class SortTreeDemo extends JFrame {
public SortTreeDemo(String startDir) {
super("SortTreeModel Demonstration");
setSize(300, 400);
setDefaultCloseOperation(EXIT_ON_CLOSE);
PrettyFile f = new PrettyFile(startDir);
DefaultMutableTreeNode root = new DefaultMutableTreeNode(f);
SortTreeModel model = new SortTreeModel(root,
new TreeStringComparator());
fillModel(model, root);
JTree tree = new JTree(model);
getContentPane().add(new JScrollPane(tree));
}
protected void fillModel(SortTreeModel model, DefaultMutableTreeNode current) {
PrettyFile pf = (PrettyFile) current.getUserObject();
File f = pf.getFile();
if (f.isDirectory()) {
String files[] = f.list();
// ignore "." files
for (int i = 0; i < files.length; i++) {
if (files[i].startsWith("."))
continue;
PrettyFile tmp = new PrettyFile(pf, files[i]);
DefaultMutableTreeNode node = new DefaultMutableTreeNode(tmp);
model.insertNodeInto(node, current);
if (tmp.getFile().isDirectory()) {
fillModel(model, node);
}
}
}
}
public class PrettyFile {
File f;
public PrettyFile(String s) {
f = new File(s);
}
public PrettyFile(PrettyFile pf, String s) {
f = new File(pf.f, s);
}
public File getFile() {
return f;
}
public String toString() {
return f.getName();
}
}
public static void main(String args[]) {
SortTreeDemo demo = new SortTreeDemo(args.length == 1 ? args[0] : ".");
demo.setVisible(true);
}
}
//SortTreeModel.java
//This class is similar to the DefaultTreeModel, but it keeps
//a node's children in alphabetical order.
//
class SortTreeModel extends DefaultTreeModel {
private Comparator comparator;
public SortTreeModel(TreeNode node, Comparator c) {
super(node);
comparator = c;
}
public SortTreeModel(TreeNode node, boolean asksAllowsChildren, Comparator c) {
super(node, asksAllowsChildren);
comparator = c;
}
public void insertNodeInto(MutableTreeNode child, MutableTreeNode parent) {
int index = findIndexFor(child, parent);
super.insertNodeInto(child, parent, index);
}
public void insertNodeInto(MutableTreeNode child, MutableTreeNode par, int i) {
// The index is useless in this model, so just ignore it.
insertNodeInto(child, par);
}
// Perform a recursive binary search on the children to find the right
// insertion point for the next node.
private int findIndexFor(MutableTreeNode child, MutableTreeNode parent) {
int cc = parent.getChildCount();
if (cc == 0) {
return 0;
}
if (cc == 1) {
return comparator.compare(child, parent.getChildAt(0)) <= 0 ? 0 : 1;
}
return findIndexFor(child, parent, 0, cc - 1); // First & last index
}
private int findIndexFor(MutableTreeNode child, MutableTreeNode parent,
int i1, int i2) {
if (i1 == i2) {
return comparator.compare(child, parent.getChildAt(i1)) <= 0 ? i1
: i1 + 1;
}
int half = (i1 + i2) / 2;
if (comparator.compare(child, parent.getChildAt(half)) <= 0) {
return findIndexFor(child, parent, i1, half);
}
return findIndexFor(child, parent, half + 1, i2);
}
}
//TreeStringComparator.java
//This class compares the contents of the userObject as strings.
//It's case-insensitive.
//
class TreeStringComparator implements Comparator {
public int compare(Object o1, Object o2) {
if (!(o1 instanceof DefaultMutableTreeNode && o2 instanceof DefaultMutableTreeNode)) {
throw new IllegalArgumentException(
"Can only compare DefaultMutableTreeNode objects");
}
String s1 = ((DefaultMutableTreeNode) o1).getUserObject().toString();
String s2 = ((DefaultMutableTreeNode) o2).getUserObject().toString();
return s1.compareToIgnoreCase(s2);
}
}
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