/*****************************************
展示JTextArea
*************************************************/
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class ui24 extends JFrame implements ActionListener
{
    Container c;
    JButton bot1,bot2,bot0;
    ImageIcon icon1,icon2;
    JTextField txt1,txt2;
    JPasswordField pwd1;
    JTextArea tea;
    JLabel lab;
    String[] show=new String[3];
    public ui24()
    {
        super("多行文字區展示");
        int i;
        c=getContentPane();
        icon1 = new ImageIcon("bridge/01.GIF");
        icon2 = new ImageIcon("bridge/52.GIF");
        c.setLayout(new FlowLayout(FlowLayout.CENTER));
        bot1=new JButton("加",icon1);
        bot2=new JButton("減",icon2);
        tea=new JTextArea(20,20);
        bot1.setFont(new Font("Serif",Font.PLAIN,20));//可以設定文字
        tea.setFont(new Font("Serif",Font.PLAIN,10));//設定文字
        bot1.setPressedIcon(icon1);//繼承自AbstractButton，設定壓下去的icon
        bot0=new JButton("結束");
        txt1=new JTextField("0",5);//內定文字與長度
        txt2=new JTextField("答案",5);//內定文字與長度
        pwd1=new JPasswordField(5);
        pwd1.setEchoChar('圈');//可以設定按下去的顯示文字 
        show[0]=new String("這是招牌一");
        show[1]=new String("這是招牌二");
        show[2]=new String("這是招牌三");
        c.add(bot0);
        c.add(bot1);
        c.add(bot2);
        c.add(txt1);
        c.add(pwd1);
        c.add(txt2);
        c.add(tea);
        bot0.addActionListener(this);
        bot1.addActionListener(this);
        bot2.addActionListener(this);
        txt1.addActionListener(this);
        pwd1.addActionListener(this);
        setSize(400,500);
        setVisible(true);
    }
    public void paint(Graphics g)
    {
        super.paint(g);
    }
    /***按鈕事件的傾聽方法****/
    public void actionPerformed(ActionEvent e) //按鈕事件的處理方法
    { 
        double a,b,c;
        if (e.getSource()==bot1)
        {
            a=Double.parseDouble(txt1.getText());
            b=Double.parseDouble(new String(pwd1.getPassword()));
            c=a+b;
            txt2.setText(Double.toString(c));
            tea.append(a+"+"+b+"="+c+"\n");
        }
        else if (e.getSource()==bot2)
        {
            a=Double.parseDouble(txt1.getText());
            b=Double.parseDouble(new String(pwd1.getPassword()));
            c=a-b;
            txt2.setText(Double.toString(c));
            tea.append(a+"-"+b+"="+c+"\n");
        }
        else if (e.getSource()==txt1)
        {
            txt2.setText(txt1.getText());
        }
        else if (e.getSource()==pwd1)
        {
            txt2.setText(new String(pwd1.getPassword()));
        }
        else if (e.getSource()==bot0)
        {
            System.exit(0);
        }
        a=Double.parseDouble(txt2.getText());
        if (a==3) txt2.setEditable(false);//設定成不能修改
        repaint();
    }
    
    public static void main(String args[]) //程式起點
    {
        ui24 app=new ui24(); //畫圖
        //處理視窗關閉要求
        app.addWindowListener(
         new WindowAdapter()
         {
            public void windowClosing(WindowEvent e)
            {  System.exit(0);}
         });
    }
}