/*
 * Proposed solution for CP Lab 1, step 8
 */

import java.awt.*;

class Task extends Thread {
  
    TextField tf;

    public Task(TextField t) {
	tf = t;
    }

    public void run () {
	long delay = (Math.round(Math.random()*12)+4)*1000/tf.getColumns();
	boolean useCPU = true;   // Set true to consume CPU-cycles
	String s = "";

	tf.setText(s);
	while (s.length() < tf.getColumns()) {

	    if (interrupted()) break;  

	    if (useCPU){
		for (int j = 0; j < 100000*delay; j++) {}
	    } else {
		try {
		    Thread.sleep(delay);
		} catch (InterruptedException e) {break;}
	    }

	    s = s + "#";
	    tf.setText(s);
	}
	if (s.length() < tf.getColumns()) {s = s + "|"; tf.setText(s);}
    }
}

public class TaskControl_8 {

    static final int N = 5;   // Number of Textfields

    static int h = 0;         // Number of 'hello'-s

    public static void main(String[] argv) {
	try {

	    // Create window with 'N' TextFields: (d.tf[0], ... , d.tf[N-1])
	    TaskDisplay d = new TaskDisplay("Task Control", N);

	    Task[] task = new Task[N]; 

	    d.println("Type command (x to exit):");

	    W: while (true) {                // Main command interpretation loop

 		char c = d.getKey();
		switch (c) {

		case 'x': break W;

		case 'h': d.println("Hello " + (h++));
	            break;

		case 't': int i = 0;
                    while (i < 5) {
			if (task[i] == null || !task[i].isAlive()) {
			    task[i] = new Task(d.tf[i]);
			    task[i].start();
			    break;
			}
			i++;
                    }
                    if (i==5) 
			d.println("No free text-fields");
                    break;

		case '0':
		case '1':
		case '2':
		case '3':
		case '4': int j = ((int) c) - ((int) '0');
                    if (task[j] != null) task[j].interrupt();
                    break;


		default:  d.println("Don't know '" + c + "'");
		}
	    }

	    d.println("Program terminates");

	    for (int i = 0; i<5; i++) {
		if (task[i] != null) task[i].join();
	    }

	    System.exit(0);

	} catch 
	    (Exception e) {System.out.println("Task Control: " + e); }
    }
}