Imagem no JPanel

Assuntos Gerais
#1

Gostaria de colocar uma imagem no fundo do JPanel…

Alguem sabe como posso fazer isso :?:

vkw

#2

Do nosso amigo de fórum ViniGodoy:

import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Paint;
import java.awt.TexturePaint;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

import javax.imageio.ImageIO;
import javax.swing.JPanel;

/**
 * A panel that contains a background image. The background image is
 * automatically sized to fit in the panel.
 */
public class JImagePanel extends JPanel
{
    private BufferedImage image = null;
    private FillType fillType = FillType.RESIZE;

    /**
     * Creates a new panel with the given background image.
     * 
     * @param img The background image.
     */
    public JImagePanel(BufferedImage img)
    {
        setImage(img);
    }

    /**
     * Creates a new panel with the given background image.
     * 
     * @param img The background image.
     * @throws IOException, if the image file is not found.
     */
    public JImagePanel(File imgSrc) throws IOException
    {
        this(ImageIO.read(imgSrc));
    }

    /**
     * Creates a new panel with the given background image.
     * 
     * @param img The background image.
     * @throws IOException, if the image file is not found.
     */
    public JImagePanel(String fileName) throws IOException
    {
        this(new File(fileName));
    }

    /**
     * Changes the image panel image.
     * 
     * @param img The new image to set.
     */
    public final void setImage(BufferedImage img)
    {
        if (img == null)
            throw new NullPointerException("Buffered image cannot be null!");

        this.image = img;
        invalidate();
    }

    /**
     * Changes the image panel image.
     * 
     * @param img The new image to set.
     * @throws IOException If the file does not exist or is invalid.
     */
    public void setImage(File img) throws IOException
    {
        setImage(ImageIO.read(img));
    }

    /**
     * Changes the image panel image.
     * 
     * @param img The new image to set.
     * @throws IOException If the file does not exist or is invalid.
     */
    public void setImage(String fileName) throws IOException
    {
        setImage(new File(fileName));
    }

    /**
     * Returns the image associated with this image panel.
     * 
     * @return The associated image.
     */
    public BufferedImage getImage()
    {
        return image;
    }

    @Override
    protected void paintComponent(Graphics g)
    {
        super.paintComponent(g);
        Graphics2D g2d = (Graphics2D) g.create();
        fillType.drawImage(this, g2d, image);        
        g2d.dispose();
    }

    /**
     * Returns the way this image fills itself.
     * 
     * @return The fill type.
     */
    public FillType getFillType()
    {
        return fillType;
    }

    /**
     * Changes the fill type.
     * 
     * @param fillType The new fill type
     * @throws IllegalArgumentException If the fill type is null.
     */
    public void setFillType(FillType fillType)
    {
        if (fillType == null)
            throw new IllegalArgumentException("Invalid fill type!");

        this.fillType = fillType;
        invalidate();
    }

    public static enum FillType
    {
        /**
         * Make the image size equal to the panel size, by resizing it.
         */
        RESIZE
        {
            @Override
            public void drawImage(JPanel panel, Graphics2D g2d,
                    BufferedImage image)
            {
                g2d.drawImage(image, 0, 0, panel.getWidth(), panel.getHeight(),
                        null);
            }
        },

        /**
         * Centers the image on the panel.
         */
        CENTER
        {
            @Override
            public void drawImage(JPanel panel, Graphics2D g2d,
                    BufferedImage image)
            {
                int left = (panel.getHeight() - image.getHeight()) / 2;
                int top = (panel.getWidth() - image.getWidth()) / 2;
                g2d.drawImage(image, top, left, null);
            }

        },
        /**
         * Makes several copies of the image in the panel, putting them side by
         * side.
         */
        SIDE_BY_SIDE
        {
            @Override
            public void drawImage(JPanel panel, Graphics2D g2d,
                    BufferedImage image)
            {
                Paint p = new TexturePaint(image, new Rectangle2D.Float(0, 0,
                        image.getWidth(), image.getHeight()));
                g2d.setPaint(p);
                g2d.fillRect(0, 0, panel.getWidth(), panel.getHeight());
            }
        };

        public abstract void drawImage(JPanel panel, Graphics2D g2d,
                BufferedImage image);
    }
}
#3

Post original da dica: http://www.guj.com.br/posts/list/56248.java#295271

Da próxima vez… use a busca do fórum antes de perguntar, ok? :wink:
Pra coisas assim, a resposta geralmente já está por aqui.

#4