Re: Clipped image when g.

  To: comp.lang.java.gui
Hello Ian,

On Jul 19, 9:16 pm, Ian Shef <inva...@avoiding.spam> wrote:


yes, setClip with negative x and y hasn't worked for me.

I've end up making my component a bit bigger:

class Card extends Component
{
        public static final int WIDTH = 70;
        public static final int HEIGHT = 100;

        // shadow offsets
        public static final int SHDX = 3;
        public static final int SHDY = 4;

        private static Card dragged;
......
        protected Card() {
                // make the card bigger or the shadow will be clipped
                setSize(WIDTH + SHDX, HEIGHT + SHDY);

                enableEvents(AWTEvent.MOUSE_EVENT_MASK |
                    AWTEvent.MOUSE_MOTION_EVENT_MASK);
        }
.....
        public void paint(Graphics g) {
                if (this == dragged)
                        g.drawImage(shadow, SHDX, SHDY, this);
                else
                        g.translate(SHDX, SHDY);
                g.drawImage(opened ? faces[rank][suit] : back, 0, 0,
this);
        }

This has the problem that when the card isn't being dragged,
then it is displaced a bit - it is located at SHDX, SHDY instead
of Component's 0, 0. But I can live with it...

Now I'm struggling with 2 further problems -

1) my Card LW component flickers even though the Deck
    LW Container (represents playing table) to which I add
    it is double-buffered. (Yes I've read few docs about
    flickering LW Components, but still can't fix it)

2) Defining a custom AWT event turned out to be such
    a pain! I wanted my Card to send an event to listeners
    after it has been dragged and released (i.e. the card
   has been played), but have ended up with this hack:

        protected void processMouseEvent(MouseEvent event) {
                if (event.getID() == MouseEvent.MOUSE_PRESSED) {
                        oldX = getLocation().x;
                        oldY = getLocation().y;

                        relX = event.getX();
                        relY = event.getY();

                        dragged = this;
                } else if (event.getID() == MouseEvent.MOUSE_RELEASED)
{
                        // pass the mouse released event to the
listeners,
                        // but only if this card has been dragged
around
                        if (dragged != null) {
                                super.processMouseEvent(event);

                                dragged = null;
                        }
                }
        }

Regards
Alex

PS: And here is my full source code:

// $Id: Card.java,v 1.5 2007/07/19 15:19:46 afarber Exp $

// Card lightweight component which sends a MouseEvent to the
// listeners when it has been dragged around and released

import java.awt.*;
import java.awt.image.*;
import java.awt.event.*;

class Card extends Component
{
    public static final int WIDTH = 70;
    public static final int HEIGHT = 100;

    // shadow offsets
    public static final int SHDX = 3;
    public static final int SHDY = 4;

    public static final int SPADE = 0;
    public static final int CLUB = 1;
    public static final int DIAMOND = 2;
    public static final int HEART = 3;
    public static final int NOTRUMP = 4;

    // which cards may be moved
    public static int allowedOwner;
    public static int allowedSuit = NOTRUMP;

    private static Card dragged;
    private static Image[][] faces;
    private static Image back;
    private static Image shadow;
    private int oldX, oldY;
    // position of the mouse pointer inside the card, when pressed
    private int relX, relY;

    public byte rank, suit;
    public boolean opened;
    // 0, 1, 2 = card belongs to a player; 3 = is on the table
    public int owner;

    public final static String[] SUIT = {
        " spades",
        " clubs",
        " diamonds",
        " hearts"
    };
    public final static String[] RANK4 = {
        "7",
        "8",
        "9",
        "10",
        "J",
        "Q",
        "K",
        "A"
    };

    protected Card() {
        // make the card bigger or the shadow will be clipped
        setSize(WIDTH + SHDX, HEIGHT + SHDY);

        enableEvents(AWTEvent.MOUSE_EVENT_MASK |
            AWTEvent.MOUSE_MOTION_EVENT_MASK);
    }

    public Card(int rank, int suit) {
        this();

        this.rank = (byte) rank;
        this.suit = (byte) suit;
    }

    public Card(char ch) {
        this();

        rank = (byte) (ch >> 8);
        suit = (byte) ch;
    }

    public boolean equals(Card card) {
        return (rank == card.rank && suit == card.suit);
    }

    public char toChar() {
        return (char) ((rank << 8) | suit);
    }

    public void update(Graphics g) {
    }

    public void paint(Graphics g) {
        if (this == dragged)
            g.drawImage(shadow, SHDX, SHDY, this);
        else
            g.translate(SHDX, SHDY);
        g.drawImage(opened ? faces[rank][suit] : back, 0, 0, this);
    }

    public static void prepImages(Image big) {
        ImageProducer source = big.getSource();

        // create 32 card images
        faces = new Image[8][4];
        for (int rank = 0; rank < 8; rank++)
            for (int suit = SPADE; suit <= HEART; suit++) {
                ImageFilter filter =
                    new CropImageFilter(rank * WIDTH,
                    suit * HEIGHT, WIDTH, HEIGHT);
                ImageProducer producer = new
                    FilteredImageSource(source, filter);
                faces[rank][suit] = Toolkit.getDefaultToolkit()
                    .createImage(producer);
            }
        // create the image of a card's back
        ImageFilter filter =
            new CropImageFilter(560, 0, WIDTH, HEIGHT);
        ImageProducer producer =
            new FilteredImageSource(source, filter);
        back = Toolkit.getDefaultToolkit().createImage(producer);
        // use a card shape to create shadow
        int[] pixels = new int[WIDTH * HEIGHT];
        PixelGrabber grabber = new PixelGrabber(big, 0, 0,
            WIDTH, HEIGHT, pixels, 0, WIDTH);
        try {
            grabber.grabPixels();
        } catch (InterruptedException ex) {
            ex.printStackTrace();
        }
        // turn non-transparent pixels to shadow
        for (int i = 0; i < pixels.length; i++)
            if (0 != (pixels[i] & 0xFF000000))
                pixels[i] = 0x60000000;
        shadow = Toolkit.getDefaultToolkit().createImage(
            new MemoryImageSource(WIDTH, HEIGHT, pixels, 0, WIDTH));
    }

    protected void processMouseEvent(MouseEvent event) {
        if (event.getID() == MouseEvent.MOUSE_PRESSED) {
            oldX = getLocation().x;
            oldY = getLocation().y;

            relX = event.getX();
            relY = event.getY();

            dragged = this;
        } else if (event.getID() == MouseEvent.MOUSE_RELEASED) {
            // pass the mouse released event to the listeners,
            // but only if this card has been dragged around
            if (dragged != null) {
                super.processMouseEvent(event);

                dragged = null;
            }
        }
    }

    protected void processMouseMotionEvent(MouseEvent event) {
        if (event.getID() == MouseEvent.MOUSE_DRAGGED) {
            // XXX check allowedOwner + allowedSuit
            // XXX here and display a red glow

            Point loc = getLocation();
            event.translatePoint(loc.x, loc.y);
            setLocation(event.getX() - relX, event.getY() - relY);
        }
    }

    public void putBack() {
        setLocation(oldX, oldY);
    }

    public static int randomRank() {
        return (int) Math.floor(8.0 * Math.random());
    }

    public static int randomSuit() {
        return (int) Math.floor(4.0 * Math.random());
    }

    // FOR TESTING: gmake build/Card.class && java -cp build/ Card
    public static void main(String args[]) {
        Frame frame = new Frame("Card Test");
        frame.setForeground(Color.white);
        frame.setBackground(Color.gray);
        frame.setLayout(null);

        final String PATH = "media/cards.gif";
        Image big = Toolkit.getDefaultToolkit().getImage(PATH);
        MediaTracker tracker = new MediaTracker(frame);
        tracker.addImage(big, 0);
        try {
            tracker.waitForAll();
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        if (tracker.isErrorAny()) {
            System.err.println("Image " + PATH + " not found");
            return;
        }

        Card.prepImages(big);
        Card card = new Card(randomRank(), randomSuit());
        card.opened = true;

        card.addMouseListener(new MouseAdapter() {
            public void mouseReleased(MouseEvent event) {
                //System.out.println("mouseReleased" + event);

                Card card = (Card) event.getSource();

                System.out.println("The card (" +
                     RANK4[card.rank] + ", " +
                     SUIT[card.suit] + ") has been played!");

                card.putBack();
            }
        });

        frame.add(card);
        frame.validate();
        card.setLocation(200, 100);

        frame.setSize(400, 300);
        frame.setVisible(true);
    }
}

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