public static void main(String[] args) {
   Display display = new Display();
   Shell shell = new Shell(display);
   shell.setLayout(new RowLayout());
   Text text = new Text(shell, SWT.MULTI | SWT.BORDER);
   String modifier = SWT.MOD1 == SWT.CTRL ? "Ctrl" : "Command";
   text.setText("Hit " + modifier + "+Return\nto see\nthe default button\nrun");
   text.addTraverseListener(
       e -> {
         switch (e.detail) {
           case SWT.TRAVERSE_RETURN:
             if ((e.stateMask & SWT.MOD1) != 0) e.doit = true;
         }
       });
   Button button = new Button(shell, SWT.PUSH);
   button.pack();
   button.setText("OK");
   button.addSelectionListener(
       new SelectionAdapter() {
         @Override
         public void widgetSelected(SelectionEvent e) {
           System.out.println("OK selected");
         }
       });
   shell.setDefaultButton(button);
   shell.pack();
   shell.open();
   while (!shell.isDisposed()) {
     if (!display.readAndDispatch()) display.sleep();
   }
   display.dispose();
 }
    protected authDialog(
        AESemaphore _sem,
        Display display,
        String realm,
        boolean is_tracker,
        String target,
        String details) {
      sem = _sem;

      if (display.isDisposed()) {

        sem.releaseForever();

        return;
      }

      final String ignore_key = "IgnoreAuth:" + realm + ":" + target + ":" + details;

      if (RememberedDecisionsManager.getRememberedDecision(ignore_key) == 1) {

        Debug.out(
            "Authentication for "
                + realm
                + "/"
                + target
                + "/"
                + details
                + " ignored as told not to ask again");

        sem.releaseForever();

        return;
      }

      shell = ShellFactory.createMainShell(SWT.DIALOG_TRIM | SWT.APPLICATION_MODAL);

      Utils.setShellIcon(shell);
      Messages.setLanguageText(shell, "authenticator.title");

      GridLayout layout = new GridLayout();
      layout.numColumns = 3;

      shell.setLayout(layout);

      GridData gridData;

      // realm

      Label realm_label = new Label(shell, SWT.NULL);
      Messages.setLanguageText(realm_label, "authenticator.realm");
      gridData = new GridData(GridData.FILL_BOTH);
      gridData.horizontalSpan = 1;
      realm_label.setLayoutData(gridData);

      Label realm_value = new Label(shell, SWT.NULL);
      realm_value.setText(realm.replaceAll("&", "&&"));
      gridData = new GridData(GridData.FILL_BOTH);
      gridData.horizontalSpan = 2;
      realm_value.setLayoutData(gridData);

      // target

      Label target_label = new Label(shell, SWT.NULL);
      Messages.setLanguageText(
          target_label, is_tracker ? "authenticator.tracker" : "authenticator.location");
      gridData = new GridData(GridData.FILL_BOTH);
      gridData.horizontalSpan = 1;
      target_label.setLayoutData(gridData);

      Label target_value = new Label(shell, SWT.NULL);
      target_value.setText(target.replaceAll("&", "&&"));
      gridData = new GridData(GridData.FILL_BOTH);
      gridData.horizontalSpan = 2;
      target_value.setLayoutData(gridData);

      if (details != null) {

        Label details_label = new Label(shell, SWT.NULL);
        Messages.setLanguageText(
            details_label, is_tracker ? "authenticator.torrent" : "authenticator.details");
        gridData = new GridData(GridData.FILL_BOTH);
        gridData.horizontalSpan = 1;
        details_label.setLayoutData(gridData);

        Label details_value = new Label(shell, SWT.NULL);
        details_value.setText(details.replaceAll("&", "&&"));
        gridData = new GridData(GridData.FILL_BOTH);
        gridData.horizontalSpan = 2;
        details_value.setLayoutData(gridData);
      }
      // user

      Label user_label = new Label(shell, SWT.NULL);
      Messages.setLanguageText(user_label, "authenticator.user");
      gridData = new GridData(GridData.FILL_BOTH);
      gridData.horizontalSpan = 1;
      user_label.setLayoutData(gridData);

      final Text user_value = new Text(shell, SWT.BORDER);
      user_value.setText("");
      gridData = new GridData(GridData.FILL_BOTH);
      gridData.horizontalSpan = 2;
      user_value.setLayoutData(gridData);

      user_value.addListener(
          SWT.Modify,
          new Listener() {
            public void handleEvent(Event event) {
              username = user_value.getText();
            }
          });

      // password

      Label password_label = new Label(shell, SWT.NULL);
      Messages.setLanguageText(password_label, "authenticator.password");
      gridData = new GridData(GridData.FILL_BOTH);
      gridData.horizontalSpan = 1;
      password_label.setLayoutData(gridData);

      final Text password_value = new Text(shell, SWT.BORDER);
      password_value.setEchoChar('*');
      password_value.setText("");
      gridData = new GridData(GridData.FILL_BOTH);
      gridData.horizontalSpan = 2;
      password_value.setLayoutData(gridData);

      password_value.addListener(
          SWT.Modify,
          new Listener() {
            public void handleEvent(Event event) {
              password = password_value.getText();
            }
          });

      // persist

      Label blank_label = new Label(shell, SWT.NULL);
      gridData = new GridData(GridData.FILL_BOTH);
      gridData.horizontalSpan = 1;
      blank_label.setLayoutData(gridData);

      final Button checkBox = new Button(shell, SWT.CHECK);
      checkBox.setText(MessageText.getString("authenticator.savepassword"));
      gridData = new GridData(GridData.FILL_BOTH);
      gridData.horizontalSpan = 1;
      checkBox.setLayoutData(gridData);
      checkBox.addListener(
          SWT.Selection,
          new Listener() {
            public void handleEvent(Event e) {
              persist = checkBox.getSelection();
            }
          });

      final Button dontAsk = new Button(shell, SWT.CHECK);
      dontAsk.setText(MessageText.getString("general.dont.ask.again"));
      gridData = new GridData(GridData.FILL_BOTH);
      gridData.horizontalSpan = 1;
      dontAsk.setLayoutData(gridData);
      dontAsk.addListener(
          SWT.Selection,
          new Listener() {
            public void handleEvent(Event e) {
              RememberedDecisionsManager.setRemembered(ignore_key, dontAsk.getSelection() ? 1 : 0);
            }
          });

      // line

      Label labelSeparator = new Label(shell, SWT.SEPARATOR | SWT.HORIZONTAL);
      gridData = new GridData(GridData.FILL_HORIZONTAL);
      gridData.horizontalSpan = 3;
      labelSeparator.setLayoutData(gridData);

      // buttons

      new Label(shell, SWT.NULL);

      Button bOk = new Button(shell, SWT.PUSH);
      Messages.setLanguageText(bOk, "Button.ok");
      gridData =
          new GridData(
              GridData.FILL_HORIZONTAL
                  | GridData.HORIZONTAL_ALIGN_END
                  | GridData.HORIZONTAL_ALIGN_FILL);
      gridData.grabExcessHorizontalSpace = true;
      gridData.widthHint = 70;
      bOk.setLayoutData(gridData);
      bOk.addListener(
          SWT.Selection,
          new Listener() {
            public void handleEvent(Event e) {
              close(true);
            }
          });

      Button bCancel = new Button(shell, SWT.PUSH);
      Messages.setLanguageText(bCancel, "Button.cancel");
      gridData = new GridData(GridData.HORIZONTAL_ALIGN_END);
      gridData.grabExcessHorizontalSpace = false;
      gridData.widthHint = 70;
      bCancel.setLayoutData(gridData);
      bCancel.addListener(
          SWT.Selection,
          new Listener() {
            public void handleEvent(Event e) {
              close(false);
            }
          });

      shell.setDefaultButton(bOk);

      shell.addListener(
          SWT.Traverse,
          new Listener() {
            public void handleEvent(Event e) {
              if (e.character == SWT.ESC) {
                close(false);
              }
            }
          });

      shell.pack();

      Utils.centreWindow(shell);

      shell.open();
    }
    protected authDialog(
        AESemaphore _sem, Display display, String realm, String tracker, String torrent_name) {
      sem = _sem;

      if (display.isDisposed()) {

        sem.release();

        return;
      }

      shell = new Shell(display, SWT.DIALOG_TRIM | SWT.APPLICATION_MODAL);

      Utils.setShellIcon(shell);
      Messages.setLanguageText(shell, "authenticator.title");

      GridLayout layout = new GridLayout();
      layout.numColumns = 3;

      shell.setLayout(layout);

      GridData gridData;

      // realm

      Label realm_label = new Label(shell, SWT.NULL);
      Messages.setLanguageText(realm_label, "authenticator.realm");
      gridData = new GridData(GridData.FILL_BOTH);
      gridData.horizontalSpan = 1;
      realm_label.setLayoutData(gridData);

      Label realm_value = new Label(shell, SWT.NULL);
      realm_value.setText(realm.replaceAll("&", "&&"));
      gridData = new GridData(GridData.FILL_BOTH);
      gridData.horizontalSpan = 2;
      realm_value.setLayoutData(gridData);

      // tracker

      Label tracker_label = new Label(shell, SWT.NULL);
      Messages.setLanguageText(tracker_label, "authenticator.tracker");
      gridData = new GridData(GridData.FILL_BOTH);
      gridData.horizontalSpan = 1;
      tracker_label.setLayoutData(gridData);

      Label tracker_value = new Label(shell, SWT.NULL);
      tracker_value.setText(tracker.replaceAll("&", "&&"));
      gridData = new GridData(GridData.FILL_BOTH);
      gridData.horizontalSpan = 2;
      tracker_value.setLayoutData(gridData);

      if (torrent_name != null) {

        Label torrent_label = new Label(shell, SWT.NULL);
        Messages.setLanguageText(torrent_label, "authenticator.torrent");
        gridData = new GridData(GridData.FILL_BOTH);
        gridData.horizontalSpan = 1;
        torrent_label.setLayoutData(gridData);

        Label torrent_value = new Label(shell, SWT.NULL);
        torrent_value.setText(torrent_name.replaceAll("&", "&&"));
        gridData = new GridData(GridData.FILL_BOTH);
        gridData.horizontalSpan = 2;
        torrent_value.setLayoutData(gridData);
      }
      // user

      Label user_label = new Label(shell, SWT.NULL);
      Messages.setLanguageText(user_label, "authenticator.user");
      gridData = new GridData(GridData.FILL_BOTH);
      gridData.horizontalSpan = 1;
      user_label.setLayoutData(gridData);

      final Text user_value = new Text(shell, SWT.BORDER);
      user_value.setText("");
      gridData = new GridData(GridData.FILL_BOTH);
      gridData.horizontalSpan = 2;
      user_value.setLayoutData(gridData);

      user_value.addListener(
          SWT.Modify,
          new Listener() {
            public void handleEvent(Event event) {
              username = user_value.getText();
            }
          });

      // password

      Label password_label = new Label(shell, SWT.NULL);
      Messages.setLanguageText(password_label, "authenticator.password");
      gridData = new GridData(GridData.FILL_BOTH);
      gridData.horizontalSpan = 1;
      password_label.setLayoutData(gridData);

      final Text password_value = new Text(shell, SWT.BORDER);
      password_value.setEchoChar('*');
      password_value.setText("");
      gridData = new GridData(GridData.FILL_BOTH);
      gridData.horizontalSpan = 2;
      password_value.setLayoutData(gridData);

      password_value.addListener(
          SWT.Modify,
          new Listener() {
            public void handleEvent(Event event) {
              password = password_value.getText();
            }
          });

      // persist

      Label blank_label = new Label(shell, SWT.NULL);
      gridData = new GridData(GridData.FILL_BOTH);
      gridData.horizontalSpan = 1;
      blank_label.setLayoutData(gridData);

      final Button checkBox = new Button(shell, SWT.CHECK);
      checkBox.setText(MessageText.getString("authenticator.savepassword"));
      gridData = new GridData(GridData.FILL_BOTH);
      gridData.horizontalSpan = 2;
      checkBox.setLayoutData(gridData);
      checkBox.addListener(
          SWT.Selection,
          new Listener() {
            public void handleEvent(Event e) {
              persist = checkBox.getSelection();
            }
          });

      // line

      Label labelSeparator = new Label(shell, SWT.SEPARATOR | SWT.HORIZONTAL);
      gridData = new GridData(GridData.FILL_HORIZONTAL);
      gridData.horizontalSpan = 3;
      labelSeparator.setLayoutData(gridData);

      // buttons

      new Label(shell, SWT.NULL);

      Button bOk = new Button(shell, SWT.PUSH);
      Messages.setLanguageText(bOk, "Button.ok");
      gridData =
          new GridData(
              GridData.FILL_HORIZONTAL
                  | GridData.HORIZONTAL_ALIGN_END
                  | GridData.HORIZONTAL_ALIGN_FILL);
      gridData.grabExcessHorizontalSpace = true;
      gridData.widthHint = 70;
      bOk.setLayoutData(gridData);
      bOk.addListener(
          SWT.Selection,
          new Listener() {
            public void handleEvent(Event e) {
              close(true);
            }
          });

      Button bCancel = new Button(shell, SWT.PUSH);
      Messages.setLanguageText(bCancel, "Button.cancel");
      gridData = new GridData(GridData.HORIZONTAL_ALIGN_END);
      gridData.grabExcessHorizontalSpace = false;
      gridData.widthHint = 70;
      bCancel.setLayoutData(gridData);
      bCancel.addListener(
          SWT.Selection,
          new Listener() {
            public void handleEvent(Event e) {
              close(false);
            }
          });

      shell.setDefaultButton(bOk);

      shell.addListener(
          SWT.Traverse,
          new Listener() {
            public void handleEvent(Event e) {
              if (e.character == SWT.ESC) {
                close(false);
              }
            }
          });

      shell.pack();

      Utils.centreWindow(shell);

      shell.open();

      shell.forceActive();
    }