import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
import java.util.LinkedList;
import java.text.NumberFormat;
public class ComputerPad extends Frame implements ActionListener 
{
   NumberButton numberButton[];                  
   OperationButton oprationButton[];             
   Button 小數(shù)點(diǎn)按鈕,正負(fù)號(hào)按鈕,退格按鈕,
          求倒數(shù)按鈕,等號(hào)按鈕,清零按鈕;
   Panel panel;                                 
   JTextField resultShow;                        
   String 運(yùn)算符號(hào)[]={"+","-","*","/"};
   LinkedList 鏈表;                              
   boolean  是否按下等號(hào)=false;                  
  
 public ComputerPad()
   {
     super("計(jì)算器");
     鏈表=new LinkedList();
     numberButton=new NumberButton[10];          
     for(int i=0;i<=9;i++)
        {
          numberButton[i]=new NumberButton(i);
          numberButton[i].addActionListener(this);
        }
     oprationButton=new OperationButton[4];    
     for(int i=0;i<4;i++)
        {
          oprationButton[i]=new OperationButton(運(yùn)算符號(hào)[i]);
          oprationButton[i].addActionListener(this);
        }
     小數(shù)點(diǎn)按鈕=new Button(".");
     正負(fù)號(hào)按鈕  =new Button("+/-"); 
     等號(hào)按鈕=new Button("=");
     求倒數(shù)按鈕=new Button("1/x");
     退格按鈕=new Button("退格");
     清零按鈕=new Button("C");
     清零按鈕.setForeground(Color.red);
     退格按鈕.setForeground(Color.red);
     等號(hào)按鈕.setForeground(Color.red);
     求倒數(shù)按鈕.setForeground(Color.blue);
     正負(fù)號(hào)按鈕.setForeground(Color.blue);
     小數(shù)點(diǎn)按鈕.setForeground(Color.blue);
     退格按鈕.addActionListener(this);
     清零按鈕.addActionListener(this);
     等號(hào)按鈕.addActionListener(this);
     小數(shù)點(diǎn)按鈕.addActionListener(this);
     正負(fù)號(hào)按鈕.addActionListener(this);
     求倒數(shù)按鈕.addActionListener(this);
     resultShow=new JTextField(10);
     resultShow.setHorizontalAlignment(JTextField.RIGHT);
     resultShow.setForeground(Color.blue);
     resultShow.setFont(new Font("TimesRoman",Font.PLAIN,14));
     resultShow.setBorder(new SoftBevelBorder(BevelBorder.LOWERED));
     resultShow.setBackground(Color.white); 
     resultShow.setEditable(false);
     panel=new Panel();                                             
     panel.setLayout(new GridLayout(4,5)); 
     
     panel.add(numberButton[1]);
     panel.add(numberButton[2]);
     panel.add(numberButton[3]);
     panel.add(oprationButton[0]);
     panel.add(清零按鈕);
     
     panel.add(numberButton[4]);
     panel.add(numberButton[5]);
     panel.add(numberButton[6]);
     panel.add(oprationButton[1]);
     panel.add(退格按鈕);
     
     panel.add(numberButton[7]);
     panel.add(numberButton[8]);
     panel.add(numberButton[9]);
     panel.add(oprationButton[2]);
     panel.add(求倒數(shù)按鈕);
     
     panel.add(numberButton[0]);
     panel.add(正負(fù)號(hào)按鈕);
     panel.add(小數(shù)點(diǎn)按鈕);
     panel.add(oprationButton[3]);
     panel.add(等號(hào)按鈕);
     add(panel,BorderLayout.CENTER);
     add(resultShow,BorderLayout.NORTH);
    
     addWindowListener(new WindowAdapter()
                    { public void windowClosing(WindowEvent e)
                       {
                         System.exit(0);
                       }
                    });
    setVisible(true);
    setBounds(100,50,240,180);
    setResizable(false);
    validate();
   }
 public void actionPerformed(ActionEvent e)
   {
   
    if(e.getSource() instanceof NumberButton)   
     {
       NumberButton b=(NumberButton)e.getSource();
        if(鏈表.size()==0) 
         {
           int number=b.getNumber();          
           鏈表.add(""+number);               
           resultShow.setText(""+number);
           是否按下等號(hào)=false;
         }
        
        else if(鏈表.size()==1&&是否按下等號(hào)==false)
         {
           int number=b.getNumber();
           String num=(String)鏈表.getFirst();
           String s=num.concat(""+number);     
           鏈表.set(0,s);
           resultShow.setText(s);
         }
        else if(鏈表.size()==1&&是否按下等號(hào)==true)
         {
           int number=b.getNumber();
            鏈表.removeFirst();
           鏈表.add(""+number);                 
           是否按下等號(hào)=false;
           resultShow.setText(""+number);
         }
        else if(鏈表.size()==2)                
         {
           int number=b.getNumber();           
           鏈表.add(""+number);               
                                              
           resultShow.setText(""+number);
         }
        else if(鏈表.size()==3)                
         {
           int number=b.getNumber();
           String num=(String)鏈表.getLast();
           String s=num.concat(""+number);     
           鏈表.set(2,s);
           resultShow.setText(s);
         }
     }
   else if(e.getSource() instanceof OperationButton) 
     {
       OperationButton b=(OperationButton)e.getSource();
       if(鏈表.size()==1)
         {
           String fuhao=b.get運(yùn)算符號(hào)();
           
           鏈表.add(fuhao);                
         }
       else if(鏈表.size()==2)
         {
           String fuhao=b.get運(yùn)算符號(hào)();
           鏈表.set(1,fuhao);             
         }
       else if(鏈表.size()==3)
         {
           String fuhao=b.get運(yùn)算符號(hào)();
           String number1=(String)鏈表.getFirst();
           String number2=(String)鏈表.getLast();
           String 運(yùn)算符號(hào)=(String)鏈表.get(1);
           try
            {
               double n1=Double.parseDouble(number1);
               double n2=Double.parseDouble(number2);
               double n=0;
               if(運(yùn)算符號(hào).equals("+"))
                 {
                   n=n1+n2;
                 }
               else if(運(yùn)算符號(hào).equals("-"))
                 {
                   n=n1-n2;
                 }
               else if(運(yùn)算符號(hào).equals("*"))
                 {
                   n=n1*n2;
                 }
               else if(運(yùn)算符號(hào).equals("/"))
                 {
                   n=n1/n2;
                 }
               鏈表.clear();
               鏈表.add(""+n);                   
               鏈表.add(fuhao);                  
               resultShow.setText(""+n);
            }
          catch(Exception ee)
            {
            }
         }
     }
   else if(e.getSource()==等號(hào)按鈕) 
     {
        是否按下等號(hào)=true;
        if(鏈表.size()==1||鏈表.size()==2)                       
         {
           String num=(String)鏈表.getFirst();
           resultShow.setText(""+num);
         }
        else if(鏈表.size()==3)
         {
           String number1=(String)鏈表.getFirst();
           String number2=(String)鏈表.getLast();
           String 運(yùn)算符號(hào)=(String)鏈表.get(1);
           try
            {
               double n1=Double.parseDouble(number1);
               double n2=Double.parseDouble(number2);
               double n=0;
               if(運(yùn)算符號(hào).equals("+"))
                 {
                   n=n1+n2;
                 }
               else if(運(yùn)算符號(hào).equals("-"))
                 {
                   n=n1-n2;
                 }
               else if(運(yùn)算符號(hào).equals("*"))
                 {
                   n=n1*n2;
                 }
               else if(運(yùn)算符號(hào).equals("/"))
                 {
                   n=n1/n2;
                 }
               resultShow.setText(""+n);
               鏈表.set(0,""+n);
               鏈表.removeLast();  
               鏈表.removeLast();  
            
            }
          catch(Exception ee)
            {
            }
         }
     }
   else if(e.getSource()==小數(shù)點(diǎn)按鈕)
     {
        if(鏈表.size()==0) 
         {
            是否按下等號(hào)=false;
         }
       else if(鏈表.size()==1)                               
        {
           String dot=小數(shù)點(diǎn)按鈕.getLabel();             
           String num=(String)鏈表.getFirst();
           String s=null;
           if(num.indexOf(dot)==-1)                     
               {
                 s=num.concat(dot); 
                 鏈表.set(0,s);                  
               }
           else
               {
                 s=num;  
               }
           鏈表.set(0,s);
           resultShow.setText(s);
        }
       
       else if(鏈表.size()==3)
        {
           String dot=小數(shù)點(diǎn)按鈕.getLabel();             
           String num=(String)鏈表.getLast();
           String s=null;
           if(num.indexOf(dot)==-1)
              {
                s=num.concat(dot); 
                鏈表.set(2,s);
              }
           else
              {
                s=num;
              }
           resultShow.setText(s); 
        } 
     }
     else if(e.getSource()==退格按鈕)
     {
       if(鏈表.size()==1)                               
        {
           String num=(String)鏈表.getFirst();
           if(num.length()>=1)
            {
             num=num.substring(0,num.length()-1);
             鏈表.set(0,num);                  
             resultShow.setText(num);
            }
          else
            {
              鏈表.removeLast();                  
              resultShow.setText("0");
            }
        }
      else if(鏈表.size()==3)
        {
           String num=(String)鏈表.getLast();
           if(num.length()>=1)
            { num=num.substring(0,num.length()-1);
              鏈表.set(2,num);                  
              resultShow.setText(num);
            }
           else
            {
              鏈表.removeLast();                  
              resultShow.setText("0");
            }
        }   
     }
   else if(e.getSource()==正負(fù)號(hào)按鈕)
     {
       if(鏈表.size()==1)
        {
          String number1=(String)鏈表.getFirst();
           try
              {
                double d=Double.parseDouble(number1);
                d=-1*d;
                String str=String.valueOf(d);
                鏈表.set(0,str);
                resultShow.setText(str); 
              }
           catch(Exception ee)
              {
              }
        } 
      else if(鏈表.size()==3)
        {
          String number2=(String)鏈表.getLast();
           try
              {
                double d=Double.parseDouble(number2);
                d=-1*d;
                String str=String.valueOf(d);
                鏈表.set(2,str);
                resultShow.setText(str);
              }
           catch(Exception ee)
              {
              }
        } 
     }
   else if(e.getSource()==求倒數(shù)按鈕)
     {
       if(鏈表.size()==1||鏈表.size()==2)
        {
          String number1=(String)鏈表.getFirst();
           try
              {
                double d=Double.parseDouble(number1);
                d=1.0/d;
                String str=String.valueOf(d);
                鏈表.set(0,str);
                resultShow.setText(str); 
              }
           catch(Exception ee)
              {
              }
        } 
       else if(鏈表.size()==3)
        {
          String number2=(String)鏈表.getLast();
           try
              {
                double d=Double.parseDouble(number2);
                d=1.0/d;
                String str=String.valueOf(d);
                鏈表.set(0,str);
                resultShow.setText(str); 
              }
           catch(Exception ee)
              {
              }
        }
     } 
   else if(e.getSource()==清零按鈕)
     { 
        是否按下等號(hào)=false;
        resultShow.setText("0");
        鏈表.clear();
     } 
    }
 public  static void main(String args[])
   {
      new ComputerPad();
   }  
}