package thinkInjava.c14;

//: Counter5.java
//Adjusting the priorities of threads
import java.applet.Applet;
import java.awt.BorderLayout;
import java.awt.Button;
import java.awt.Container;
import java.awt.Frame;
import java.awt.Label;
import java.awt.Panel;
import java.awt.TextField;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

class Ticker2 extends Thread {
	private Button b = new Button("Toggle"), incPriority = new Button("up"), decPriority = new Button("down");
	private TextField t = new TextField(10), pr = new TextField(3); // Display priority
	private int count = 0;
	private boolean runFlag = true;

	public Ticker2(Container c) {
		b.addActionListener(new ToggleL());
		incPriority.addActionListener(new UpL());
		decPriority.addActionListener(new DownL());
		Panel p = new Panel();
		p.add(t);
		p.add(pr);
		p.add(b);
		p.add(incPriority);
		p.add(decPriority);
		c.add(p);
	}

	class ToggleL implements ActionListener {
		@Override
		public void actionPerformed(ActionEvent e) {
			runFlag = !runFlag;
		}
	}

	class UpL implements ActionListener {
		@Override
		public void actionPerformed(ActionEvent e) {
			int newPriority = getPriority() + 1;
			if (newPriority > Thread.MAX_PRIORITY) {
				newPriority = Thread.MAX_PRIORITY;
			}
			setPriority(newPriority);
		}
	}

	class DownL implements ActionListener {
		@Override
		public void actionPerformed(ActionEvent e) {
			int newPriority = getPriority() - 1;
			if (newPriority < Thread.MIN_PRIORITY) {
				newPriority = Thread.MIN_PRIORITY;
			}
			setPriority(newPriority);
		}
	}

	@Override
	public void run() {
		while (true) {
			if (runFlag) {
				t.setText(Integer.toString(count++));
				pr.setText(Integer.toString(getPriority()));
			}
			yield();
		}
	}
}

public class Counter5 extends Applet {
	private Button start = new Button("Start"), upMax = new Button("Inc Max Priority"), downMax = new Button(
			"Dec Max Priority");
	private boolean started = false;
	private static final int SIZE = 10;
	private Ticker2[] s = new Ticker2[SIZE];
	private TextField mp = new TextField(3);

	@Override
	public void init() {
		for (int i = 0; i < s.length; i++) {
			s[i] = new Ticker2(this);
		}
		add(new Label("MAX_PRIORITY = " + Thread.MAX_PRIORITY));
		add(new Label("MIN_PRIORITY = " + Thread.MIN_PRIORITY));
		add(new Label("Group Max Priority = "));
		add(mp);
		add(start);
		add(upMax);
		add(downMax);
		start.addActionListener(new StartL());
		upMax.addActionListener(new UpMaxL());
		downMax.addActionListener(new DownMaxL());
		showMaxPriority();
		// Recursively display parent thread groups:
		ThreadGroup parent = s[0].getThreadGroup().getParent();
		while (parent != null) {
			add(new Label("Parent threadgroup max priority = " + parent.getMaxPriority()));
			parent = parent.getParent();
		}
	}

	public void showMaxPriority() {
		mp.setText(Integer.toString(s[0].getThreadGroup().getMaxPriority()));
	}

	class StartL implements ActionListener {
		@Override
		public void actionPerformed(ActionEvent e) {
			if (!started) {
				started = true;
				for (Ticker2 element : s) {
					element.start();
				}
			}
		}
	}

	class UpMaxL implements ActionListener {
		@Override
		public void actionPerformed(ActionEvent e) {
			int maxp = s[0].getThreadGroup().getMaxPriority();
			if (++maxp > Thread.MAX_PRIORITY) {
				maxp = Thread.MAX_PRIORITY;
			}
			s[0].getThreadGroup().setMaxPriority(maxp);
			showMaxPriority();
		}
	}

	class DownMaxL implements ActionListener {
		@Override
		public void actionPerformed(ActionEvent e) {
			int maxp = s[0].getThreadGroup().getMaxPriority();
			if (--maxp < Thread.MIN_PRIORITY) {
				maxp = Thread.MIN_PRIORITY;
			}
			s[0].getThreadGroup().setMaxPriority(maxp);
			showMaxPriority();
		}
	}

	public static void main(String[] args) {
		Counter5 applet = new Counter5();
		Frame aFrame = new Frame("Counter5");
		aFrame.addWindowListener(new WindowAdapter() {
			@Override
			public void windowClosing(WindowEvent e) {
				System.exit(0);
			}
		});
		aFrame.add(applet, BorderLayout.CENTER);
		aFrame.setSize(300, 600);
		applet.init();
		applet.start();
		aFrame.setVisible(true);
	}
} // /:~


add Counter5.java