better password generator

src/main/java/cz/kamma/jkeepass/KeepassApp.java

@@ -80,6 +80,7 @@ public class KeepassApp extends JFrame {
     private static final String PREF_WINDOW_HEIGHT = "window_height";
     private static final String PREF_MAIN_DIVIDER = "main_divider_location";
     private static final String PREF_RIGHT_DIVIDER = "right_divider_location";
+    private static final String PREF_SPECIAL_CHARS = "password_generator_special_chars";
     private static final int MAX_RECENT_FILES = 5;
     private File currentFile;
     private String currentPassword;
@@ -737,6 +738,108 @@ public class KeepassApp extends JFrame {
         }
     }
 
+    /**
+     * Dialog for generating passwords
+     */
+    private static class PasswordGeneratorDialog extends JDialog {
+        private final JCheckBox upperCheck = new JCheckBox("A-Z", true);
+        private final JCheckBox lowerCheck = new JCheckBox("a-z", true);
+        private final JCheckBox digitCheck = new JCheckBox("0-9", true);
+        private final JTextField specialField;
+        private final JPanel listPanel = new JPanel();
+        private String selectedPassword = null;
+        private final Preferences prefs = Preferences.userNodeForPackage(KeepassApp.class);
+
+        public PasswordGeneratorDialog(JDialog owner) {
+            super(owner, "Password Generator", true);
+            setLayout(new BorderLayout());
+
+            String savedSpecial = prefs.get(PREF_SPECIAL_CHARS, "!@#$%^&*()-_=+[]{}|;:,.<>?");
+            specialField = new JTextField(savedSpecial, 15);
+
+            JPanel optionsPanel = new JPanel(new FlowLayout());
+            optionsPanel.add(upperCheck);
+            optionsPanel.add(lowerCheck);
+            optionsPanel.add(digitCheck);
+            optionsPanel.add(new JLabel("Special:"));
+            optionsPanel.add(specialField);
+
+            add(optionsPanel, BorderLayout.NORTH);
+
+            listPanel.setLayout(new GridBagLayout());
+            JScrollPane scrollPane = new JScrollPane(listPanel);
+            add(scrollPane, BorderLayout.CENTER);
+
+            JButton regenBtn = new JButton("Regenerate");
+            regenBtn.addActionListener(e -> {
+                prefs.put(PREF_SPECIAL_CHARS, specialField.getText());
+                generateList();
+            });
+            JButton closeBtn = new JButton("Close");
+            closeBtn.addActionListener(e -> {
+                prefs.put(PREF_SPECIAL_CHARS, specialField.getText());
+                setVisible(false);
+            });
+
+            JPanel btnPanel = new JPanel();
+            btnPanel.add(regenBtn);
+            btnPanel.add(closeBtn);
+            add(btnPanel, BorderLayout.SOUTH);
+
+            generateList();
+
+            setSize(450, 450);
+            setLocationRelativeTo(owner);
+        }
+
+        private void generateList() {
+            listPanel.removeAll();
+            GridBagConstraints gbc = new GridBagConstraints();
+            gbc.insets = new Insets(2, 5, 2, 5);
+            gbc.fill = GridBagConstraints.HORIZONTAL;
+            gbc.weightx = 1.0;
+            gbc.gridx = 0;
+
+            String upper = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+            String lower = "abcdefghijklmnopqrstuvwxyz";
+            String digits = "0123456789";
+            String special = specialField.getText();
+
+            StringBuilder chars = new StringBuilder();
+            if (upperCheck.isSelected()) chars.append(upper);
+            if (lowerCheck.isSelected()) chars.append(lower);
+            if (digitCheck.isSelected()) chars.append(digits);
+            chars.append(special);
+
+            if (chars.length() == 0) {
+                listPanel.add(new JLabel("Select at least one option or enter special chars"), gbc);
+            } else {
+                SecureRandom random = new SecureRandom();
+                for (int i = 0; i < 10; i++) {
+                    StringBuilder sb = new StringBuilder();
+                    for (int j = 0; j < 16; j++) {
+                        sb.append(chars.charAt(random.nextInt(chars.length())));
+                    }
+                    String pass = sb.toString();
+                    JButton passBtn = new JButton(pass);
+                    passBtn.setHorizontalAlignment(JButton.LEFT);
+                    passBtn.addActionListener(e -> {
+                        selectedPassword = pass;
+                        setVisible(false);
+                    });
+                    gbc.gridy = i;
+                    listPanel.add(passBtn, gbc);
+                }
+            }
+            listPanel.revalidate();
+            listPanel.repaint();
+        }
+
+        public String getSelectedPassword() {
+            return selectedPassword;
+        }
+    }
+
     /**
      * Dialog for adding/editing entries
      */
@@ -786,12 +889,21 @@ public class KeepassApp extends JFrame {
             showPassCheck.addActionListener(e -> {
                 if (showPassCheck.isSelected()) {
                     passField.setEchoChar((char) 0);
+                    passField.putClientProperty("JPasswordField.cutCopyAllowed", Boolean.TRUE);
                 } else {
                     passField.setEchoChar('•');
+                    passField.putClientProperty("JPasswordField.cutCopyAllowed", Boolean.FALSE);
                 }
             });
             JButton genBtn = new JButton("Generate");
-            genBtn.addActionListener(e -> passField.setText(generateRandomPassword(16)));
+            genBtn.addActionListener(e -> {
+                PasswordGeneratorDialog pgd = new PasswordGeneratorDialog(this);
+                pgd.setVisible(true);
+                String pass = pgd.getSelectedPassword();
+                if (pass != null) {
+                    passField.setText(pass);
+                }
+            });
             passBtnOptionPanel.add(showPassCheck);
             passBtnOptionPanel.add(genBtn);
             gbc.gridx = 2;