Calculator 실습 완성

여러가지 기능사용, 구현에 급급해서 MVC패턴과 같은 기법을 적용시키지 않고, class도 구분하지 않아 많이 복잡한 코드로 보인다.

이후로는 독서를 통해 다시 Java에 대한 지식을 명확하게 잡아야겠다.

 

Main.java

package calculator;

public class Main {
	public static void main(String[] args) {
		CalculatorFrame mainFrame = new CalculatorFrame();
	}
}

CalculatorFrame.java

package calculator;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.util.StringTokenizer;

public class CalculatorFrame extends JFrame { 
	JTextArea textarea = new JTextArea();
	JButton button_number[] = new JButton[12];
	JButton button_oper[] = new JButton[4];
	GridBagLayout grid = new GridBagLayout();
	GridBagConstraints grid2 = new GridBagConstraints();	
	
	private void addGrid(GridBagLayout gbl, GridBagConstraints gbc, Component c, 
            int gridx, int gridy, int gridwidth, int gridheight, int weightx, int weighty) {
      gbc.gridx = gridx;
      gbc.gridy = gridy;
      gbc.gridwidth = gridwidth;
      gbc.gridheight = gridheight;
      gbc.weightx = weightx;
      gbc.weighty = weighty;
      gbl.setConstraints(c, gbc);
      add(c);
    }
	
	public CalculatorFrame() {
		super("Calculator");
		
		for (int i = 7; i > 0; i -= 3) {
			for (int j = 0; j < 3; j++) {
				button_number[i+j] = new JButton(Integer.toString(i+j));
			}
		}
		button_number[0] = new JButton(Integer.toString(0));
		button_number[10] = new JButton(".");
		button_number[11] = new JButton("=");
		
		button_oper[0] = new JButton("+");
		button_oper[1] = new JButton("-");
		button_oper[2] = new JButton("*");
		button_oper[3] = new JButton("/");
		
		ActionListener numberEventHandler = new ActionListener() {
			
			public void actionPerformed(ActionEvent e) {
				if(textarea.getText().indexOf('+') == -1 && textarea.getText().indexOf('-') == -1 && textarea.getText().indexOf('*') == -1 && textarea.getText().indexOf('/') == -1)
					textarea.append(e.getActionCommand());
			}
		};
		
		ActionListener operEventHandler = new ActionListener() {
			
			public void actionPerformed(ActionEvent e) {
				if(textarea.getText().indexOf('=') == -1)
					textarea.append(e.getActionCommand());
			}
		};

		
		ActionListener resultEventHandler = new ActionListener() {
			
			public void actionPerformed(ActionEvent e) {
					String data = textarea.getText();
					StringTokenizer token = new StringTokenizer(data,"+-*/",true);
					double a = Double.parseDouble(token.nextToken());
					String buffer = token.nextToken();
					double b = Double.parseDouble(token.nextToken());
					textarea.append(e.getActionCommand());
					if(buffer.equals("+")) {
						textarea.append(Double.toString(a+b));
					}
					
					else if (buffer.equals("-")) {
						textarea.append(Double.toString(a-b));
					}
					
					else if (buffer.equals("*")) {
						textarea.append(Double.toString(a*b));
					}
					
					else if (buffer.equals("/")) {
						textarea.append(Double.toString(a/b));
					}
			}
		};
		
		for (int i = 0; i < 4; i++) {
			button_oper[i].addActionListener(numberEventHandler);
		}
		
		for (int i = 0; i < 11; i++) {
			button_number[i].addActionListener(operEventHandler);
		}
		
		button_number[11].addActionListener(resultEventHandler);
		
		grid2.fill=GridBagConstraints.BOTH;
		addGrid(grid, grid2, textarea, 0,0,4,1,1,1);
		
		int k = 0;
		for (int i = 7; i > 0; i -= 3) {
			for (int j = 0; j < 3; j++) {
				addGrid(grid, grid2, button_number[i+j], j, k+1, 1,1,1,1);
			}
			k++;
		}

		for (int i = 0; i < 4; i++)
		{		
			addGrid(grid, grid2, button_oper[i], 3,i+1,1,1,1,1);
		}
		
		addGrid(grid, grid2, button_number[10], 0,4,1,1,1,1);
		addGrid(grid, grid2, button_number[0], 1,4,1,1,1,1);
		addGrid(grid, grid2, button_number[11], 2,4,1,1,1,1);
		setLayout(grid);
		
		setSize(300,400);
		setVisible(true);
		setResizable(false);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		
	}
}

Calculator