twodemo.java

来自「java课程的资料以及实验的代码」· Java 代码 · 共 75 行

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

 class TwoListener implements MouseMotionListener,
                                    MouseListener {
    private Frame f;
    private TextField tf;

    public TwoListener() {
      f = new Frame("Two listeners example");
      tf = new TextField(30);
    }

    public void launchFrame() {
      Label label = new Label("Click and drag the mouse");
      // Add components to the frame
      f.add(label, BorderLayout.NORTH);
      f.add(tf, BorderLayout.SOUTH);
      // Add this object as a listener
      f.addMouseMotionListener(this);
      f.addMouseListener(this);
      f.addWindowListener( new MyWindowAdapter() );
      // Size the frame and make it visible
      f.setSize(300, 200);
      f.setVisible(true);
    }

    private class MyWindowAdapter extends WindowAdapter{
      public void windowClosing(WindowEvent wevent) {
        if (false)
          f.dispose();
        else
          System.exit(0);
      }
    }

    // These are MouseMotionListener events
    public void mouseDragged(MouseEvent e) {
      String s = "Mouse dragging: X = " + e.getX()
          + " Y = " + e.getY();
      tf.setText(s);
    }

    public void mouseEntered(MouseEvent e) {
      String s = "The mouse entered";
      tf.setText(s);
    }

    public void mouseExited(MouseEvent e) {
      String s = "The mouse has left the building";
      tf.setText(s);
    }

  // Unused MouseMotionListener method.
  // All methods of a listener must be present in the
  // class even if they are not used.
    public void mouseMoved(MouseEvent e) {}
  // Unused MouseListener methods.
    public void mousePressed(MouseEvent e) {}
    public void mouseClicked(MouseEvent e) {}
    public void mouseReleased(MouseEvent e) {}

}


public class TwoDemo {
  public TwoDemo() {
  }

  public static void main(String[] args){
    TwoListener two = new TwoListener();
    two.launchFrame();
  }
}