imagepanel.java~11~

1． 消息即时通信 2． 消息发送实现一对一、一对多等多种发送模式 3． 发送的消息实现多彩文本编辑

package chat;

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
/* the class is for painting background image to a panel */
public class ImagePanel extends JPanel {
  private String imageFilename = null;
  private Image image = null;
  private Toolkit toolkit = null;
  public ImagePanel() {
    super();
    toolkit = Toolkit.getDefaultToolkit();
  }

  public ImagePanel(String filename) {
    super();
    toolkit = Toolkit.getDefaultToolkit();
    setImageFilename(filename);
  }

  public void setImageFilename(String filename) {
    imageFilename = filename;
    try {
      image = toolkit.createImage(imageFilename);
      setPreferredSize(new Dimension(image.getWidth(this), image.getHeight(this)));
      repaint();
    }
    catch (Exception e) {
      e.printStackTrace();
      imageFilename = null;
      image = null;
    }
  }

  public void setImage(Image image) {
    this.image = image;
    try {
      setPreferredSize(new Dimension(this.image.getWidth(this),
                                     this.image.getHeight(this)));
      repaint();
      System.out.println(image.getHeight(this));
    }
    catch (Exception e) {
      e.printStackTrace();
      this.image = null;
    }
  }

  public void clearImage() {
    image = null;
    repaint();
  }

  public Dimension getPreferredSize() {
    if (image == null)
      return new Dimension(0, 0);
    else
      return new Dimension(image.getWidth(this), image.getHeight(this));
  }

  protected void paintComponent(Graphics g) {
    Insets insets = getInsets();
    g.setColor(Color.white);
    g.fillRect(0, 0, insets.left + getWidth(), insets.top + getHeight());
    super.paintComponent(g);
    if (image != null) {
      g.drawImage(image, insets.top, insets.left, this);
    }
  }

  public void reloadImage() {
    if (imageFilename != null) {
      try {
        image = toolkit.createImage(imageFilename);
        repaint();
      }
      catch (Exception e) {
        imageFilename = null;
        image = null;
      }
    }
  }
  public static void main(String[] args){
    JFrame frame=new JFrame();
    ImagePanel imagePanel=new ImagePanel();
      Image image = Toolkit.getDefaultToolkit().getImage("one.jpg");
      imagePanel.setImage(image);
      JButton button=new JButton("ooooooooooooookkkkkkkkkkk");
    imagePanel.add(button);
    frame.getContentPane().add(imagePanel);
    frame.setVisible(true);
  }
}