import java.io.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import utilities.gui.*;

public class DirLister extends Panel
                    implements ActionListener, Runnable {

protected String filePath;
protected Vector fileList;

protected TextField pathTextField;

protected ActionListener fNameListenerChain;

protected static int treeDepth;

//-------------------------------------------------------------------
// DirLister Constructor
//-------------------------------------------------------------------
public DirLister() {

	Label prompt  = new Label("Select Directory:");

	pathTextField = new TextField("", 40);
	pathTextField.addActionListener(this);

	add(prompt);
	add(pathTextField);

	fNameListenerChain = null;
}
//-------------------------------------------------------------------
// DirLister Thread body
//-------------------------------------------------------------------
public void run() {

	fileList = new Vector();

	System.out.println("Scanning directory: "+ filePath);
	scanDir(filePath);

	// transmit all filenames to client bean
	Enumeration fileIterator = fileList.elements();
	while ( fileIterator.hasMoreElements() ) {
		String filename = (String) fileIterator.nextElement();
		fNameListenerChain.actionPerformed( new FilenameActionEvent(this, filename) );
	}

	// finally, terminate list of filenames with a null String
	fNameListenerChain.actionPerformed( new FilenameActionEvent(this, null) );

	// re-enable GUI to allow user input.
	setFrameCursor(this, Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
	pathTextField.setEnabled(true);
}
//-------------------------------------------------------------------
// Recursive directory scanner
//-------------------------------------------------------------------
protected void scanDir (String dir) {

String  dirEntries[];					// list of dir entries (file|dir)
String  filename;
File    path, fpath;

    treeDepth++;						// going down...

    path  = new File(dir);
    dirEntries = path.list();			// create list of files in this dir

    for (int i=0; i < dirEntries.length; i++) {

        filename = dir + File.separator + dirEntries[i];

        fpath = new File(filename);
        if ( fpath.isDirectory() ) {
            scanDir(fpath.getPath());    // recursively descend dir tree
        } else {
			fileList.addElement(fpath.getPath());
        }
    }

    treeDepth--;						// and going up...
}
//-------------------------------------------------------------------
// ActionListener interface method
//-------------------------------------------------------------------
public void actionPerformed(ActionEvent actionEvent) {
Component source;

	// for Self-Test only:
	if ( actionEvent instanceof FilenameActionEvent ) {
		String filename = ((FilenameActionEvent) actionEvent).getFilename();
		System.out.println("File: " + filename );
	} else {
		source = (Component) actionEvent.getSource();
		if ( source instanceof TextField ) {
			filePath = pathTextField.getText();
			startListing(filePath);
		}
	}
}
//-------------------------------------------------------------------
// Start the file listing process as a separate Thread.
//-------------------------------------------------------------------
public boolean startListing(String path) {
File tentative;

	tentative = new File(path);
	if ( tentative.exists()) {
		if (tentative.isDirectory()) {
			// disable GUI to block user input until thread is done.
			setFrameCursor(this, Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR));
			pathTextField.setEnabled(false);

			// start up filename event firing thread.
			new Thread(this).start();
			return true;
		} else {
			DialogKit.ok( "'"+ path +"' Is not a directory.");
		}
	} else {
		DialogKit.ok( "'"+ path +"' Does not exist.");
	}
	return false;
}
//-------------------------------------------------------------------
// ActionListener management methods
//-------------------------------------------------------------------
public void addActionListener(ActionListener listener) {
	fNameListenerChain = AWTEventMulticaster.add(fNameListenerChain, listener);
}
public void removeActionListener(ActionListener listener) {
	fNameListenerChain = AWTEventMulticaster.remove(fNameListenerChain, listener);
}
//-------------------------------------------------------------------
// Set this Component's parent Frame pointer to some Cursor type.
//-------------------------------------------------------------------
public static void setFrameCursor(Component component, Cursor pointerType) {
Component parent;

	parent = component;
	while ( parent != null ) {
		if ( parent instanceof Frame ) {
			parent.setCursor(pointerType);
			break;
		}
		parent = parent.getParent();
	}
}
//-------------------------------------------------------------------
// Self-test
//-------------------------------------------------------------------
public static void main (String[] args) {
Frame window = new Frame("DirLister Self-Test");
DirLister dirLister = new DirLister();

	dirLister.addActionListener(dirLister);	// let DirLister dump own dir list

	window.add("Center", dirLister);
	window.pack();
	window.setVisible(true);
}
} // End of Class DirLister