package test;

import java.awt.Color;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class Calculator {

    public Calculator() {

    }

    //创建五个面板
    JPanel panel3=new JPanel();  //上半部分
    JPanel buttonPane=new JPanel();  //存按钮
    JLabel expLabel,resultLabel;

    String exp="",result="";



    String[] buttons= {
        "1","2","3","+","Del","4","5","6","-","C","7","8","9","*","01",".","0","=","/","02" 
    };


    public void initButton() {
        buttonPane.setLayout(new GridLayout(4,5));
        for(String s:buttons) {
            JButton button=new JButton(s);
            buttonPane.add(button);
            button.setFont(new Font("宋体",Font.BOLD,18));
            button.setForeground(Color.GREEN);
            button.addActionListener(new MyActionListener());
        }
    }

    private class MyActionListener implements ActionListener{
        @Override
        public void actionPerformed(ActionEvent e) {
            // TODO Auto-generated method stub
            String c=e.getActionCommand();
            for(int i=0;i<10;i++)
            {
                if(c.equals(i+"")) {
                    exp+=c;
                    expLabel.setText(exp);
                    return;
                }
            }
            switch(c) {
            case "+":
                exp +="+";
                break;
            case "-":
                exp +="-";
                break;
            case "*":
                exp +="*";
                break;
            case "/":
                exp +="/";
                break;
            case "Del":
                exp=exp.substring(0,exp.length()-1);
                break;
            case "c":
                clear();
                break;
            case "=":

                default:
                    break;

            }
            expLabel.setText(exp);
            if(!result.equals("")) {
                resultLabel.setText(result);
            }
        }

}
    public void clear() {
        exp="";
        result="";
        resultLabel.setText(result);
    }

    public void compute() {
        String[] arr=exp.split(" ");
        Double num1=Double.parseDouble(arr[0]);
    }


    public void initLabel() {
        expLabel=new JLabel();
        resultLabel=new JLabel();

    }

    public void showUI() {
        JFrame window=new JFrame("计算器");
        window.setSize(400,500);
        window.setLayout(new GridLayout(2,1));
        window.setLocationRelativeTo(null);
        window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);


        initButton();
        initLabel();

        panel3.setLayout(new GridLayout(2,1));
        panel3.add(expLabel);
        panel3.add(resultLabel);

        window.add(panel3);
        window.add(buttonPane);

        window.setVisible(true);

    }
    public static void main(String[] args) {
        Calculator Cal=new Calculator();
        Cal.showUI();
    }

}