package src.calculadora;
import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Stack;
import javax.swing.JFrame;
import javax.swing.JButton;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class Main extends JFrame implements ActionListener {
private JTextField t;
Stack<String> stack;
char operator;
boolean finished;
public static void main(String[] args) { new Main();
}
/*
Inicializamos variables varias e invocamos al configurador del formulario
*/
public Main() { super("Calculadora Básica - Versión 1.1"); finished = false;
stack = new Stack<String>();
this.initFrame();
}
/*
* Configurador del formulario
* Setea los controles en pantalla y enlaza a eventos
* Muestra el frame
*/
private void initFrame() { String labelButtons[] = {"7", "8", "9", "/", "4", "5", "6", "*", "1", "2", "3", "-", "0", ".", "=", "+", "C"}; JPanel cp = (JPanel) this.getContentPane();
cp.setLayout(new BorderLayout());
JPanel p = new JPanel();
p.setLayout(new GridLayout(0, 4));
for (int i = 0; i < labelButtons.length; ++i) { JButton button = new JButton(labelButtons[i]);
button.addActionListener(this);
p.add(button);
}
t = new JTextField();
t.setHorizontalAlignment(JTextField.RIGHT);
t.setEditable(false);
cp.add(t, BorderLayout.PAGE_START);
cp.add(p, BorderLayout.CENTER);
this.setSize(300, 300);
this.setLocationRelativeTo(null);
this.setVisible(true);
this.setDefaultCloseOperation(Main.EXIT_ON_CLOSE);
}
/*
* Interpreta la pulsación de botones y aplica el algoritmo correspondiente
*/
public void actionPerformed(ActionEvent e) { char c = ((JButton) e.getSource()).getText().charAt(0);
if (finished) { t.setText(""); finished = false;
}
if (c >= '0' && c <= '9') { t.setText(t.getText() + c);
} else if (c == '.') { if (!t.getText().contains(".") && !t.getText().equals("")) { t.setText(t.getText() + ".");
}
} else if (c == 'C') { t.setText(""); stack.removeAllElements();
} else if (c == '=') { calc();
} else { operator = c;
if (!t.getText().equals("")) { stack.push(t.getText());
}
t.setText(""); }
}
/*
* Efectua la operación en si
*/
private void calc() { if (!t.getText().equals("") && !stack.isEmpty()) { double a = Double.parseDouble(stack.pop());
double b = Double.parseDouble(t.getText());
double r = 0;
if (operator == '+') { r = a + b;
} else if (operator == '-') { r = a - b;
} else if (operator == '*') { r = a * b;
} else if (operator == '/') { r = a / (b != 0 ? b : 1);
}
t.setText(Double.toString(r));
}
finished = true;
}
}
muchas muchas gracias