import java.awt.event.*;			// for KeyListener, KeyEvent
import java.util.*;					// for Date
import java.io.*;					// for PrintStream
import utilities.beans.*;

public class KeyLogger extends VisibleCanvas implements KeyListener {

protected PrintStream log;			// the log to record events in
protected int maxInterKeyWait;		// event compression time window
protected long lastKeyTime;

//-------------------------------------------------------------------
// KeyLogger Constructors
//-------------------------------------------------------------------
public KeyLogger() {
	// default log stream is STDOUT, default inter-key wait: 1 sec
	this(System.out, 1000);
}
public KeyLogger(PrintStream logStream, int maxInterKeyWait) {

	this.log			 = logStream;
	this.maxInterKeyWait = maxInterKeyWait;

	this.lastKeyTime	 = 0;		// guarantee 1st key with full t-stamp
}
//-------------------------------------------------------------------
// Implemented KeyListener methods
//-------------------------------------------------------------------
public void keyTyped(KeyEvent keyEvent) {
	log("Key typed", keyEvent);
}
public void keyPressed(KeyEvent keyEvent) {
	log("Key pressed", keyEvent);
}
public void keyReleased(KeyEvent keyEvent) {
	log("Key released", keyEvent);
}
//-------------------------------------------------------------------
// Log a date/time-stamped key event.
// Compress key events arriving within N milliseconds of each other
// into words or sentences with a single timestamp
//-------------------------------------------------------------------
protected void log(String entry, KeyEvent keyEvent) {
long now = System.currentTimeMillis();
char key = keyEvent.getKeyChar();

	if ( now - lastKeyTime > maxInterKeyWait ) {
		log.print("\n" + entry + " on " + new Date() +": ");
		log.print(key);
	} else {
		log.print(key);
	}
	log.flush();

	// start new interKeyWait "timer"
	lastKeyTime = now;
}
} // End of Bean KeyLogger