static void inputDirPath(fS msg, fO action) {
  inputDirPath(msg, userDir(), action);
}

// action: voidfunc(File)
static void inputDirPath(fS msg, final File defaultDir, fO action) {
  awt {
    final JTextField tfPath = jtextfield(f2s(or(defaultDir, userDir())));
    S title = joinStrings(" | ", msg, programName());
    final Runnable ok = r {
      callF(action, new File(getTextTrim(tfPath)))
    };
    JComponent form = showFormTitled(title,
      unnull(msg), centerAndEast(tfPath, jbutton("Browse...", r {
        JFileChooser fileChooser = new JFileChooser(getTextTrim(tfPath));
        fileChooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
        fileChooser.setAcceptAllFileFilterUsed(false);

        if (fileChooser.showOpenDialog(tfPath) == JFileChooser.APPROVE_OPTION) {
          tfPath.setText(fileChooser.getSelectedFile().getAbsolutePath());
          //tfPath.requestFocus();
          callF(ok);
          disposePossiblyInternalFrame(tfPath);
        }
      })), ok);
    renameSubmitButton(form, "OK");
  }
}

Began life as a copy of #1006692