Focus problems

801176

Hy everyone!

I have some focusing problems. (I hope it's focusing...)

I have 3 java files:

package testproject;

import java.applet.Applet;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;

/**
 *
 * @author Laxika
 */
public class Main extends Applet implements MouseMotionListener, KeyListener {
//Added these variables just to test the DoubleBuffering.

    public static int posX = 0;
    public static int posY = 0;

    @Override
    public void init() {
        setSize(300, 300);
        this.add(new DoubleBufferTest());
        addMouseMotionListener(this);
        addKeyListener(this);
    }

    public void mouseDragged(MouseEvent e) {
    }

    public void mouseMoved(MouseEvent e) {
        posX = e.getX();
        posY = e.getY();
        this.getComponent(0).repaint();
    }

    public void keyTyped(KeyEvent e) {
        System.out.println("Typed");
    }

    public void keyPressed(KeyEvent e) {
        System.out.println("Pressed");
    }

    public void keyReleased(KeyEvent e) {
         System.out.println("Released");
    }
}

package testproject;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Rectangle;

/**
 *
 * @author Rendszergazda
 */
public class DoubleBufferTest extends DoubleBufferedCanvas {

    public DoubleBufferTest() {
        super.setBounds(new Rectangle(300, 300));
    }

    @Override
    public void paint(Graphics g) {
        g.clearRect(0, 0, 300, 300);
        try {
            g.setColor(Color.red);
            g.fillRect(Main.posX, Main.posY, 40, 40);
        } finally {
            //Best to dispose graphics object after finish.
            g.dispose();
        }
    }
}

package testproject;

import java.awt.Canvas;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Rectangle;
import java.awt.Toolkit;
import java.awt.image.BufferStrategy;

/**
 *
 * @author Laxika
 * @version 1.0
 */
public abstract class DoubleBufferedCanvas extends Canvas {

    private int width;
    private int height;

    /**
     * Set the width and the height of the canvas.
     *
     * @param width The width of the canvas.
     * @param height The height of the canvas.
     */
    @Override
    public void setBounds(Rectangle r) {
        this.width = (int) r.getWidth();
        this.height = (int) r.getHeight();
    }

    @Override
    public void addNotify() {
        super.addNotify();
        this.createBufferStrategy(2);
        //The main Applet will handle every event.
        this.setEnabled(false);
    }

    @Override
    public void repaint() {
        BufferStrategy bf = this.getBufferStrategy();

        paint(bf.getDrawGraphics());

        bf.show();
        Toolkit.getDefaultToolkit().sync();
    }

    @Override
    public abstract void paint(Graphics g);

    @Override
    public Dimension getMinimumSize() {
        return new Dimension(width, height);
    }

    @Override
    public Dimension getPreferredSize() {
        return new Dimension(width, height);
    }

    @Override
    public Dimension getMaximumSize() {
        return new Dimension(width, height);
    }
}

My problem is that I can't get the Key events on main.java after I add the DoubleBufferTest class to the applet. ( this.add(new DoubleBufferTest()); )

If I try hasFocus test after added the Canvas, I get false.

Someone can helm me with this?

darrylburke

Moderator action: Moved from Java Programming.

db

darrylburke

You add the <tt>KeyListener</tt> to the <tt>Applet</tt>, so why do you expect to get <tt>KeyEvent</tt>s in the <tt>Canvas</tt>?

Do you have a reason for using an <tt>Applet</tt> (AWT) and not a <tt>JApplet</tt> (Swing)? With a Swing <tt>JApplet</tt> and a <tt>JPanel</tt>, you get double buffering for free and you can use Key Bindings.

db

801176

Uhh thanks!

I want they Key event s in the Applet. But I don't get them.:S

EDIT:

I found the solution, if someone have the same problem:

KeyboardFocusManager.getCurrentKeyboardFocusManager().addKeyEventDispatcher(new KeyEventDispatcher() {

            public boolean dispatchKeyEvent(KeyEvent e) { // This example converts all typed keys to upper case
                if (e.getID() == KeyEvent.KEY_TYPED) {
                    e.setKeyChar(Character.toUpperCase(e.getKeyChar()));
                } // If the key should not be dispatched to the
                // focused component, set discardEvent to true
                System.out.println(e.getKeyChar());
                boolean discardEvent = false;
                return discardEvent;
            }
        });

Edited by: Teh Heavenly on 2010.10.05. 12:43

801176

Took me 3 hours googling, but finally...