El programa no accede al método paintComponent() de la clase JPanel extendida

Resuelto Jisan Mahmud asked hace 12 años • 1 respuestas

Este es elJFrame

package client.connection;

import java.awt.Dimension;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import javax.swing.JFrame;


class DrawFrameRemoteControl extends JFrame
{
    private DrawPanelRemoteControl imagePanel;
    private ClientRemoteControlConnection clientRemoteControlConnection;
    private ObjectInputStream clientInputStream;
    private ObjectOutputStream clientOutputStream;
    private Dimension imageDimension;
    private Dimension serverDimension;

    public DrawFrameRemoteControl(Dimension imageDimension,ClientRemoteControlConnection clientRemoteControlConnection,ObjectInputStream clientInputStream,ObjectOutputStream clientOutputStream,Dimension serverDimension)
    {
        super("Remote Desktop Control");

        this.clientRemoteControlConnection=clientRemoteControlConnection;
        this.clientInputStream=clientInputStream;
        this.clientOutputStream=clientOutputStream;
        this.imageDimension=imageDimension;
        this.serverDimension=serverDimension;

        imagePanel=new DrawPanelRemoteControl(imageDimension);
        add(imagePanel);


        setSize(imageDimension.width,imageDimension.height);
        setResizable(false);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setVisible(true);
        setLocationRelativeTo(null);
    }

    void drawNewImageGrayscale(byte[] array)
    {
        imagePanel.setNewImageGrayscale(array);
        imagePanel.repaint();
    }
}

Y esta es la clase JPanel extendida.

package client.connection;

import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Toolkit;
import java.awt.Transparency;
import java.awt.color.ColorSpace;
import java.awt.image.BufferedImage;
import java.awt.image.ColorModel;
import java.awt.image.ComponentColorModel;
import java.awt.image.DataBuffer;
import java.awt.image.DataBufferByte;
import java.awt.image.MemoryImageSource;
import java.awt.image.Raster;
import java.awt.image.SampleModel;
import java.awt.image.WritableRaster;
import javax.swing.ImageIcon;
import javax.swing.JLabel;
import javax.swing.JPanel;

class DrawPanelRemoteControl extends JPanel
{
    private byte[] byteArray=null;
    private Image image;
    private JLabel imageLabel=new JLabel();
    private Dimension imageDimension;

    public DrawPanelRemoteControl(Dimension imageDimension)
    {
        this.imageDimension=imageDimension;
        add(imageLabel);
    }

    @Override
    protected void paintComponent(Graphics g)
    {
        super.paintComponent(g);
        System.out.println(".");
        if(byteArray!=null)
        {
            image=getGrayscaleImageFromArray(byteArray,imageDimension.width,imageDimension.height);
            imageLabel.setIcon(new ImageIcon(image));
        }
    }

    private Image getGrayscaleImageFromArray(byte[] buffer, int width, int height)
    {
        ColorSpace cs = ColorSpace.getInstance(ColorSpace.CS_GRAY);
        int[] nBits = { 8 };
        ColorModel cm = new ComponentColorModel(cs, nBits, false, true,Transparency.OPAQUE, DataBuffer.TYPE_BYTE);
        SampleModel sm = cm.createCompatibleSampleModel(width, height);
        DataBufferByte db = new DataBufferByte(buffer, width * height);
        WritableRaster raster = Raster.createWritableRaster(sm, db, null);
        BufferedImage result = new BufferedImage(cm, raster, false, null);
        return result;
    }

    void setNewImageGrayscale(byte[] array)
    {
        this.byteArray=array;
        this.intArray=null;
    }
}

Intenté depurar el código, aunque imagePanel.repaint()se ejecuta muchas veces, el programa nunca llega al paintComponent()método de DrawPanelRemoteControlla clase.

¿Alguien puede darme alguna idea de por qué podría estar sucediendo esto? ¿Tiene algo que ver con el imageDimensionobjeto?

Información adicional: en el main()método, DrawFrameRemoteControlse crea un objeto y su drawNewImageGrayscale(byte[] arr)método se actualiza main()cada segundo.

Jisan Mahmud avatar Sep 01 '12 15:09 Jisan Mahmud
Aceptado

No está claro por qué está pasando byte[], pero parece que desea actualizar un componente Iconcon una miniatura gris. El siguiente ejemplo crea íconos en escala de grises a partir de íconos de muestra existentes y los utiliza setIcon()para realizar la actualización. Un enfoque similar funciona con cualquier Image. Vea también este ejemplo que sugiere ColorConvertOpy este ejemplo que actualiza componentes completos en lugar de íconos.

Iconos grises Aqua

Iconos grises Nimbus

import java.awt.Color;
import java.awt.EventQueue;
import java.awt.Graphics2D;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.awt.image.ColorConvertOp;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JToggleButton;
import javax.swing.Timer;
import javax.swing.UIManager;

/**
 * @see https://stackoverflow.com/a/12228640/230513
 * @see https://stackoverflow.com/a/7935040/230513
 */
public class GrayIcons extends JPanel {

    private List<Icon> list = new ArrayList<Icon>();
    private List<JToggleButton> buttons = new ArrayList<JToggleButton>();
    private Timer timer = new Timer(1000, new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent e) {
            update();
        }
    });

    public GrayIcons() {
        this.setLayout(new GridLayout(1, 0));
        list.add(getGray(UIManager.getIcon("OptionPane.errorIcon")));
        list.add(getGray(UIManager.getIcon("OptionPane.informationIcon")));
        list.add(getGray(UIManager.getIcon("OptionPane.warningIcon")));
        list.add(getGray(UIManager.getIcon("OptionPane.questionIcon")));
        for (Icon icon : list) {
            JToggleButton jtb = new JToggleButton(icon);
            buttons.add(jtb);
            this.add(jtb);
        }
        timer.start();
    }

    private void update() {
        Collections.shuffle(list);
        int index = 0;
        for (JToggleButton b : buttons) {
            b.setIcon(list.get(index++));
        }
    }

    /**
     * @see https://stackoverflow.com/q/5830533/230513
     * @see https://stackoverflow.com/a/3106550/230513
     */
    private Icon getGray(Icon icon) {
        final int w = icon.getIconWidth();
        final int h = icon.getIconHeight();
        GraphicsEnvironment ge =
            GraphicsEnvironment.getLocalGraphicsEnvironment();
        GraphicsDevice gd = ge.getDefaultScreenDevice();
        GraphicsConfiguration gc = gd.getDefaultConfiguration();
        BufferedImage image = gc.createCompatibleImage(w, h);
        Graphics2D g2d = image.createGraphics();
        g2d.setPaint(new Color(0x00f0f0f0));
        g2d.fillRect(0, 0, w, h);
        icon.paintIcon(null, g2d, 0, 0);
        BufferedImage gray = new BufferedImage(w, h, BufferedImage.TYPE_BYTE_GRAY);
        ColorConvertOp op = new ColorConvertOp(
            image.getColorModel().getColorSpace(),
            gray.getColorModel().getColorSpace(), null);
        op.filter(image, gray);
        return new ImageIcon(gray);
    }

    private void display() {
        JFrame f = new JFrame("GrayIcons");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(this);
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                new GrayIcons().display();
            }
        });
    }
}
trashgod avatar Sep 01 '2012 14:09 trashgod