Hell everybody!
I'm makeing my own calculator (as homework). It uses reversed polish notation (http://en.wikipedia.org/wiki/Reverse_Polish_notation).
Quick explanation of RPN:
You first have to type both numbers, then you can type mathematical operation.
Example:
5
ENTER
16
ENTER
+
(this will write 21 in label)
My program works well if you use buttons. However, I can't make my program to recognize numbers I press using keyboard. I have made new KeyListener (k), but don't know where to add it.
I tried
addKeyListener(k);
and
this.getContentPane.addKeyListener(k);
and
(Label) kutija.addKeyListener(k);
and
(Panel) panel.addKeyListener(k);
but none works.
Here's code. I really appreciate your help!
Simple explanation of the code:
I use BorderLayout.
I have label where I write numbers user presses (BorderLayout.PAGE_START) and panel (GridLayout (4, 5)) for buttons (BorderLayout.CENTER).
CODE
package vjezba;
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.util.Stack;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingConstants;
import javax.swing.WindowConstants;
public class Calculator extends JFrame
{
/**
*
*/
private static final long serialVersionUID = 1L;
private Stack<Double> stog;
private JLabel kutija;
private boolean moze;
private boolean tocka;
private boolean cos1;
private boolean cos2;
private boolean sin1;
private boolean sin2;
public Calculator ()
{
super();
stog = new Stack<Double>();
initGUI();
}
protected void initGUI()
{
cos1 = cos2 = sin1 = sin2 = false;
moze = true;
tocka = false;
setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
setSize(400, 250);
setLocation(40, 40);
setTitle("Digic");
this.getContentPane().setLayout(new BorderLayout());
kutija = new JLabel("0");
kutija.setHorizontalAlignment(SwingConstants.RIGHT);
kutija.setVerticalAlignment(SwingConstants.CENTER);
kutija.setPreferredSize(new Dimension(50, 50));
this.getContentPane().add(kutija, BorderLayout.PAGE_START);
KeyListener k = new KeyListener()
{
public void keyTyped(KeyEvent arg0)
{}
public void keyReleased(KeyEvent arg0)
{}
public void keyPressed(KeyEvent arg0)
{
char c = arg0.getKeyChar();
if (Character.isDigit(c))
System.out.println("slovo");
else if (c == '+' || c == '-' || c == '*' || c == '/')
{
operacija(c);
}
else if (c == 'c')
cos1 = true;
else if (c == 'o')
{
if (cos1)
cos2 = true;
}
else if (c == 's')
{
if (cos1 && cos2)
{
cos1 = false;
cos2 = false;
operacijaTwo("cos");
}
else
sin1 = true;
}
else if (c == 'i')
{
if (sin1)
sin2 = true;
}
else if (c == 'n')
{
if (sin1 && sin2)
operacijaTwo("sin");
}
}
};
JPanel panel = new JPanel(new GridLayout(4, 5));
JButton gumb = new JButton("7");
panel.add(gumb);
gumb.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent arg0)
{
akcija(7);
}
});
gumb = new JButton("8");
panel.add(gumb);
gumb.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent arg0)
{
akcija(8);
}
});
gumb = new JButton("9");
panel.add(gumb);
gumb.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent arg0)
{
akcija(9);
}
});
gumb = new JButton("DEL");
panel.add(gumb);
gumb.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
if (kutija.getText().equals("Niste unijeli dovoljno brojeva!")
|| kutija.getText().length() == 1 || moze)
{
kutija.setText("0");
moze = true;
}
else if (kutija.getText().length() > 1)
kutija.setText(new String(kutija.getText().substring(0,
kutija.getText().length() - 1)));
}
});
gumb = new JButton("/");
panel.add(gumb);
gumb.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent arg0)
{
operacija('/');
}
});
gumb = new JButton("4");
panel.add(gumb);
gumb.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent arg0)
{
akcija(4);
}
});
gumb = new JButton("5");
panel.add(gumb);
gumb.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent arg0)
{
akcija(5);
}
});
gumb = new JButton("6");
panel.add(gumb);
gumb.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent arg0)
{
akcija(6);
}
});
gumb = new JButton("RESET");
panel.add(gumb);
gumb.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
stog.clear();
kutija.setText("0");
moze = true;
tocka = false;
}
});
gumb = new JButton("*");
panel.add(gumb);
gumb.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent arg0)
{
operacija('*');
}
});
gumb = new JButton("1");
panel.add(gumb);
gumb.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent arg0)
{
akcija(1);
}
});
gumb = new JButton("2");
panel.add(gumb);
gumb.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent arg0)
{
akcija(2);
}
});
gumb = new JButton("3");
panel.add(gumb);
gumb.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent arg0)
{
akcija(3);
}
});
gumb = new JButton("sin");
panel.add(gumb);
gumb.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent arg0)
{
operacijaTwo("sin");
}
});
gumb = new JButton("-");
panel.add(gumb);
gumb.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent arg0)
{
operacija('-');
}
});
gumb = new JButton("0");
panel.add(gumb);
gumb.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent arg0)
{
akcija(0);
}
});
gumb = new JButton(".");
panel.add(gumb);
gumb.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
if (!tocka)
{
tocka = true;
if (!moze)
kutija.setText(kutija.getText() + ".");
else
{
kutija.setText("0.");
moze = false;
}
}
}
});
gumb = new JButton("ENTER");
panel.add(gumb);
gumb.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent arg0)
{
if (!moze)
{
stog.push(Double.parseDouble(kutija.getText()));
moze = true;
tocka = false;
}
}
});
gumb = new JButton("cos");
panel.add(gumb);
gumb.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent arg0)
{
operacijaTwo("cos");
}
});
gumb = new JButton("+");
panel.add(gumb);
gumb.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent arg0)
{
operacija('+');
}
});
this.getContentPane().add(panel, BorderLayout.CENTER);
setVisible(true);
}
private void operacija(char c)
{
if (stog.size() > 1)
{
double broj = stog.pop();
double broj2 = stog.pop();
double rez;
if (c == '*')
rez = broj2 * broj;
else if (c == '+')
rez = broj2 + broj;
else if (c == '-')
rez = broj2 + broj;
else
rez = broj2 / broj;
stog.push(rez);
kutija.setText(((Double)rez).toString());
}
else
{
kutija.setText("Niste unijeli dovoljno brojeva!");
moze = true;
tocka = false;
}
}
private void operacijaTwo(String str)
{
if (!stog.empty())
{
moze = true;
if (str.equals("cos"))
stog.push(Math.cos(stog.pop()));
else
stog.push(Math.sin(stog.pop()));
kutija.setText(stog.peek().toString());
}
else
{
kutija.setText("Niste unijeli dovoljno brojeva!");
moze = true;
tocka = false;
}
}
protected void akcija(int i)
{
if (moze)
kutija.setText(((Integer)i).toString());
else if (!tocka)
kutija.setText(kutija.getText() + i);
else
kutija.setText(kutija.getText() + i);
if (!kutija.getText().equals("0"))
moze = false;
}
}
Main class with main method:
CODE
package hr.fer.zemris.java.tecaj_6.vjezba;
import java.lang.reflect.InvocationTargetException;
import javax.swing.SwingUtilities;
public class Main
{
/**
* @param args
*/
public static void main(String[] args)
{
try
{
SwingUtilities.invokeAndWait(new Runnable()
{
public void run()
{
new Calculator();
}
});
} catch (InvocationTargetException e)
{} catch (InterruptedException e)
{}
}
}
Thank you!
7 May, 2008 - 03:44 PM
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