/**
 * <applet code="CalcApplet.class" width="300" height="300">
 * </applet>
 *
 * $RCSfile: CalcApplet.java,v $
 * $Date: 2007/01/28 23:15:22 $
 * $Revision: 1.6 $
 * $State: Exp $
 *
 * 高度情報処理基礎II 授業用プログラム
 *
 */

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class CalcApplet extends JApplet implements ActionListener {
    CalcEngine engine;
    String digits;
    Display display;
    JPanel kp;			// key panel
    JButton plus, minus, mul, div, mod, enter, point;
    JButton clear, allclear, pi, e, E, BS, sqrt, sin, cos, tan, plmi;
    JButton[] tenkey;

    public static void main(String[] args) {
	JFrame frame = new JFrame("Calulator");
	frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	JApplet applet = new CalcApplet();
	applet.init();
	frame.add(applet);
	frame.setSize(300, 300);
        frame.setVisible(true);
      //frame.show();
	applet.start();
    }

    public void init() {
	engine = new CalcEngine();
	digits = "";
	display = new Display();
	kp = new JPanel();

	//Container pane = getContentPane();
	//pane.setLayout(new BorderLayout());
	//pane.add(display, BorderLayout.NORTH);
	//pane.add(kp, BorderLayout.CENTER);
	this.setLayout(new BorderLayout());
	this.add(display, BorderLayout.NORTH);
	this.add(kp, BorderLayout.CENTER);

	tenkey = new JButton[10];
	for (int i = 0; i < 10; i++) {
	    tenkey[i] = new JButton("" + i);
	    tenkey[i].addActionListener(this);
	}
	plus  = new JButton("+");      plus.addActionListener(this);
	minus = new JButton("-");     minus.addActionListener(this);
	mul   = new JButton("*");       mul.addActionListener(this);
	div   = new JButton("/");       div.addActionListener(this);
	mod   = new JButton("(mod)");   mod.addActionListener(this);
	enter = new JButton("=");     enter.addActionListener(this);
	point = new JButton(".");     point.addActionListener(this);
	pi    = new JButton("π(PI)");   pi.addActionListener(this);
	clear = new JButton("C");     clear.addActionListener(this);
	allclear = new JButton("AC"); allclear.addActionListener(this);
	e     = new JButton("e");         e.addActionListener(this);
	E     = new JButton("E");         E.addActionListener(this);
	BS    = new JButton("BS");       BS.addActionListener(this);
	sqrt  = new JButton("√");     sqrt.addActionListener(this);
	sin   = new JButton("sin°");   sin.addActionListener(this);
	cos   = new JButton("cos°");   cos.addActionListener(this);
	tan   = new JButton("tan°");   tan.addActionListener(this);
	plmi  = new JButton("±");     plmi.addActionListener(this);

	kp.setLayout(new GridLayout(8, 4));
	kp.add(allclear);  kp.add(clear)    ; kp.add(plmi);      kp.add(BS);
	kp.add(pi);        kp.add(e);         kp.add(sqrt); 	 kp.add(mod);
	kp.add(sin);       kp.add(cos);       kp.add(tan);       kp.add(div);
	kp.add(new JButton("")); kp.add(new JButton("")); kp.add(new JButton("")); kp.add(new JButton(""));
	kp.add(tenkey[7]); kp.add(tenkey[8]); kp.add(tenkey[9]); kp.add(mul); 
	kp.add(tenkey[4]); kp.add(tenkey[5]); kp.add(tenkey[6]); kp.add(minus);
	kp.add(tenkey[1]); kp.add(tenkey[2]); kp.add(tenkey[3]); kp.add(plus);
	kp.add(tenkey[0]); kp.add(point);     kp.add(E);         kp.add(enter);
    }

  public void actionPerformed(ActionEvent evt) {
    // まず、数字と小数点の場合の処理
    for (int i = 0; i < 10; i++) {
      if (evt.getSource() == tenkey[i]) {
        digits += i;	// 文字列 digits の後ろに追加
        display.setText(digits);
        return;
      }
    }
    if (evt.getSource() == point) {
      digits += ".";
      display.setText(digits);
      return;
    }
    else if (evt.getSource() == pi) {
      // 円周率の入力
      digits = "" +Math.PI;
      display.setText(digits);
      return;
    }
    else if (evt.getSource() == e) {
      // 自然対数の入力
      digits = "" + Math.E;
      display.setText(digits);
      return;
    }
    else if (evt.getSource() == clear) {
      digits = "";
      display.setText(digits);
      return;
    }
    else if (evt.getSource() == allclear) {
      engine.reset();
      digits = "";
      display.setText(digits);
      return;
    }
    else if (evt.getSource() == E) {
      digits += "E";
      display.setText(digits);
      return;
    }
    else if (evt.getSource() == BS){
      if(digits.length() == 0){
        return;
      }
      digits = digits.substring(0,digits.length() -1);
      display.setText(digits);
      return;
    }
    else if (evt.getSource() == plmi){
      if(digits.length() == 0){
        return;
      }
      if(digits.charAt(digits.length() -1) == 'E') {
        digits = digits + "-";
      }
      else if(digits.charAt(0) == '-'){
        digits = digits.substring(1);
      }
      else {
        digits = "-" + digits;
      }
      display.setText(digits);
      return;
    }
    
    
    // そうでなければ、演算ボタンか "="    
    // その演算処理をする前に、数が入力されていたら、レジスタに登録
    if (! digits.equals("")) {
      try {
        engine.register(Double.parseDouble(digits));
        digits = "";
        }
      catch (NumberFormatException e) {
        display.setText("?");
        digits = "";
        return;
      }
    }
    
    double ans = 0.0;
    if (evt.getSource() == enter) {
      ans = engine.getAnswer();
    }
    else if (evt.getSource() == plus) {
      ans = engine.operate(CalcEngine.ADD);
    }
    else if (evt.getSource() == minus) {
      ans = engine.operate(CalcEngine.SUB);
    }
    else if (evt.getSource() == mul) {
      ans = engine.operate(CalcEngine.MUL);
    }
    else if (evt.getSource() == div) {
      ans = engine.operate(CalcEngine.DIV);
    }
    else if (evt.getSource() == mod) {
      ans = engine.operate(CalcEngine.MOD);
    }
    else if (evt.getSource() == sqrt) {
      ans = engine.function(CalcEngine.sqrt);
    }
    else if (evt.getSource() == sin) {
      ans = engine.function(CalcEngine.sin);
    }
    else if (evt.getSource() == cos) {
      ans = engine.function(CalcEngine.cos);
    }
    else if (evt.getSource() == tan) {
      ans = engine.function(CalcEngine.tan);
    }
    
    display.setText("" + ans);
  }
}

class Display extends JLabel {
    Display() {
	super("0", RIGHT);
	setFont(new Font("Monospaced", Font.PLAIN, 24));
    }

    public void setText(String text) {
	if (text.equals("")) {
	    super.setText("0");
	}
	else {
	    super.setText(text);
	}
    }
}