详解Java图形化编程中的鼠标事件设计

import java.applet.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
class MyPanel extends JPanel{
  public void print(int r){
    Graphics g = getGraphics();
    g.clearRect(0,0,this.getWidth(),this.getHeight());
    g.setColor(Color.red);
    g.fillOval(10,10,r,r);
  }
}
class MyWindow extends JFrame implements MouseListener{
  JTextArea text;
  MyPanel panel;
  int x,y,r =10;
  int mouseFlg=0;
  static String mouseStates[]={"鼠标键按下","鼠标松开","鼠标进来","鼠标走开","鼠标双击"};
  MyWindow(String s){
    super(s);
    Container con = this.getContentPane();
    con.setLayout(new GridLayout(2,1));
    this.setSize(200,300);
    this.setLocation(100,100);
    panel = new MyPanel();
    con.add(panel);
    text = new JTextArea(10,20);
    text.setBackground(Color.blue);
    con.add(text);
    addMouseListener(this);
    this.setVisible(true);
    this.pack();
  }
  public void paint(Graphics g){
    r = r+4;
    if(r>80){
      r=10;
    }
    text.append(mouseStates[mouseFlg]+"了，位置是：" +x+","+y+"\n");
    panel.print(r);
  }
  public void mousePressed(MouseEvent e){
    x = e.getX();
    y = e.getY();
    mouseFlg = 0;
    repaint();
  }
  public void mouseRelease(MouseEvent e){
    x = e.getX();
    y = e.getY();
    mouseFlg = 1;
    repaint();
  }
  public void mouseEntered(MouseEvent e){
    x = e.getX();
    y = e.getY();
    mouseFlg = 2;
    repaint();
  }
  public void mouseExited(MouseEvent e){
    x = e.getX();
    y = e.getY();
    mouseFlg = 3;
    repaint();
  }
  public void mouseClicked(MouseEvent e){
    if(e.getClickCount()==2){
      x = e.getX();
      y = e.getY();
      mouseFlg = 4;
      repaint();
    }
    else{}
  }
}
public class Example6_8 extends Applet{
  public void init(){
    MyWindow myWnd = new MyWindow("鼠标事件示意程序");
  }
}

JButton button;
public void init(){
  button = new JButton(“按钮也能发生鼠标事件”);
  r = 10;
  text = new JTextArea(15,20);
  add(button);
  add(text);
  button.addMouseListener(this);
}

  e.getModifiers()==InputEvent. BUTTON3_MASK

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
class MyWindow extends JFrame{
  public MyWindow(String s){
    super(s);
    Container con = this.getContentPane();
    con.setLayout(new BorderLayout());
    this.setLocation(100,100);
    JScrollBar xAxis = new JScrollBar(JScrollBar.HORIZONTAL,50,1,0,100);
    jScrollBar yAxis = new jScrollBar(JScrollBar.VERTICAL,50,1,0,100);
    MyListener listener = new MyListener(xAxis,yAxis,238,118);
    Jpanel scrolledCanvas = new JPanel();
    scrolledCanvas.setLayout(new BorderLayout());
    scrolledCanvas.add(listener,BorderLayout.CENTER);
    scrolledCanvas.add(xAix,BorderLayout.SOUTH);
    scrolledCanvas.add(yAix,BorderLayout.EAST);
    con.add(scrolledCanvas,BorderLayout.NORTH);
    this.setVisible(true);
    this.pack();
  }
  public Dimension getPreferredSize(){
    return new Dimension(500,300);
  }
}
class MyListener extends JComponent implements MouseListener, MouseMotionListener,AdjustmentListener{
  private int x,y;
  private JScrollBar xScrollBar;
  private JScrollBar yScrollBar;
  private void updateScrollBars(int x,int y){
    int d;
    d = (int)(((float)x/(float)getSize().width)*100.0);
    xScrollBar.setValue(d);
    d = (int)(((float)y/(float)getSize().height)*100.0);
    yScrollBar.setValue(d);
  }
  public MyListener(JScrollBar xaxis,JScrollBar yaxis,int x0,int y0){
    xScrollBar =xaxis;
    yScrollBar =yaxis;
    x = x0;
    y=y0;
    xScrollBar.addAdjustmentListener(this);
    yScrollBar.addAdjustmentListener(this);
    this.addMouseListener(this);
    this.addMouseMotionListener(this);
  }
  public void paint(Graphics g){
    g.setColor(getBackground());
    Dimension size = getSize();
    g.fillRect(0,0,size.width,size.height);
    g.setColor(Color.blue);
    g.fillRect(x,y,50,50);
  }
  public void mouseEntered(MouseEvent e){}
  public void mouseExited(MouseEvent e){}
  public void mouseClicked(MouseEvent e){}
  public void mouseRelease(MouseEvent e){}
  public void mouseMoved(MouseEvent e){}
  public void mousePressed(MouseEvent e){
    x = e.getX();
    y = e.getY();
    updateScrollBars(x,y);
    repaint();
  }
  public void mouseDragged(MouseEvent e){
    x = e.getX();
    y = e.getY();
    updateScrollBars(x,y);
    repaint();
  }
  public void adjustmentValueChanged(AdjustmentEvent e){
    if(e.getSource()==xScrollBar)
      x=(int)((float)(xScrollBar.getValue()/100.0)*getSize().width);
    else if(e.getSource()==yScrollBar)
      y = (int)((float)(yScrollBar.getValue()/100.0)*getSize().height);
    repaint();
  }
}
public class Example6_9{
  public static void main(){
    MyWindow myWindow = new MyWindow("滚动条示意程序");
  }
}

class MyWindow extends JFrame{
  public MyWindow(String s){
    super(s);
    Container con = this.getContentPane();
    con.setLayout(new BorderLayout());
    this.setLocaltion(100,100);
    MyListener listener = new MyListener();
    listener.setPreferredSize(new Dimension(700,700));
    JScrollPane scrolledCanvas = new JScrollPane(listener);
    this.add(scrolledCanvas,BorderLayout.CENTER);
    this.setVisible(true);
    this.pack();
  }
  public Dimension getPreferredSize(){
    return new Dimension(400,400);
  }
}