1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/java/CaesarovaŠifra/src/cz/frantovo/příklady/Caesar.java	Sat Jun 22 16:00:39 2013 +0200
     1.3 @@ -0,0 +1,108 @@
     1.4 +package cz.frantovo.příklady;
     1.5 +
     1.6 +/**
     1.7 + * This program is free software: you can redistribute it and/or modify
     1.8 + * it under the terms of the GNU General Public License as published by
     1.9 + * the Free Software Foundation, either version 3 of the License, or
    1.10 + * (at your option) any later version.
    1.11 + *
    1.12 + * This program is distributed in the hope that it will be useful,
    1.13 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
    1.14 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    1.15 + * GNU General Public License for more details.
    1.16 + *
    1.17 + * You should have received a copy of the GNU General Public License
    1.18 + * along with this program. If not, see <http://www.gnu.org/licenses/>.
    1.19 + */
    1.20 +import java.awt.GridLayout;
    1.21 +import java.awt.HeadlessException;
    1.22 +import java.awt.event.ActionEvent;
    1.23 +import java.awt.event.ActionListener;
    1.24 +import java.util.ArrayList;
    1.25 +import java.util.Collections;
    1.26 +import java.util.List;
    1.27 +import javax.swing.JButton;
    1.28 +import javax.swing.JFrame;
    1.29 +import javax.swing.JLabel;
    1.30 +import javax.swing.JTextField;
    1.31 +
    1.32 +/**
    1.33 + * @author Ing. František Kučera (frantovo.cz)
    1.34 + */
    1.35 +public class Caesar extends JFrame {
    1.36 +
    1.37 +	private JTextField prostýText = new JTextField();
    1.38 +	private JTextField šifrovanýText = new JTextField();
    1.39 +	private JButton šifruj = new JButton("Šifruj");
    1.40 +	private JButton dešifruj = new JButton("Dešifruj");
    1.41 +	private static final char[] ABECEDA_ZNAKY = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789".toCharArray();
    1.42 +	private static final List<Character> ABECEDA;
    1.43 +	private static final int SKOK = 3;
    1.44 +
    1.45 +	static {
    1.46 +		List<Character> abeceda = new ArrayList<>();
    1.47 +		for (char z : ABECEDA_ZNAKY) {
    1.48 +			abeceda.add(z);
    1.49 +		}
    1.50 +		ABECEDA = Collections.unmodifiableList(abeceda);
    1.51 +	}
    1.52 +
    1.53 +	public static void main(String[] args) {
    1.54 +		Caesar c = new Caesar();
    1.55 +		c.setVisible(true);
    1.56 +	}
    1.57 +
    1.58 +	public Caesar() throws HeadlessException {
    1.59 +		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    1.60 +		setTitle("Caesarova šifra");
    1.61 +		setLocationRelativeTo(null);
    1.62 +		setLayout(new GridLayout(3, 2));
    1.63 +		
    1.64 +		add(new JLabel("Prostý text"));
    1.65 +		add(prostýText);
    1.66 +
    1.67 +		add(new JLabel("Šifrovaný text"));
    1.68 +		add(šifrovanýText);
    1.69 +
    1.70 +		add(šifruj);
    1.71 +		add(dešifruj);
    1.72 +
    1.73 +		šifruj.addActionListener(new ActionListener() {
    1.74 +			@Override
    1.75 +			public void actionPerformed(ActionEvent e) {
    1.76 +				šifrovanýText.setText(posuň(prostýText.getText(), SKOK));
    1.77 +			}
    1.78 +		});
    1.79 +
    1.80 +		dešifruj.addActionListener(new ActionListener() {
    1.81 +			@Override
    1.82 +			public void actionPerformed(ActionEvent e) {
    1.83 +				prostýText.setText(posuň(šifrovanýText.getText(), -SKOK));
    1.84 +			}
    1.85 +		});
    1.86 +
    1.87 +		pack();
    1.88 +	}
    1.89 +
    1.90 +	private static String posuň(String text, int oKolik) {
    1.91 +		StringBuilder posunutý = new StringBuilder(text.length());
    1.92 +
    1.93 +		for (char z : text.toCharArray()) {
    1.94 +			posunutý.append(posuň(z, oKolik));
    1.95 +		}
    1.96 +
    1.97 +		return posunutý.toString();
    1.98 +	}
    1.99 +
   1.100 +	private static char posuň(char znak, int oKolik) {
   1.101 +		int původníPozice = ABECEDA.indexOf(znak);
   1.102 +
   1.103 +		if (původníPozice < 0) {
   1.104 +			return znak;
   1.105 +		} else {
   1.106 +			int nováPozice = (původníPozice + oKolik) % ABECEDA_ZNAKY.length;
   1.107 +			nováPozice = nováPozice < 0 ? ABECEDA_ZNAKY.length + nováPozice : nováPozice;
   1.108 +			return ABECEDA.get(nováPozice);
   1.109 +		}
   1.110 +	}
   1.111 +}