var Proxy = java.lang.reflect.Proxy;
var Toolkit = java.awt.Toolkit;
var FileFilter = javax.swing.filechooser.FileFilter;
var JFileChooser = javax.swing.JFileChooser;

exports.showDialog = (filter, filterName) => {
    var fileFilter = new FileFilter({
        "getDescription": () => {
            return filterName || 'Default Filter';
        },
        "accept": (f) => {
            return filter(f);
        }
    });
    var chooser = new JFileChooser();
    if (filter != null) {
        chooser.setFileFilter(fileFilter);
    }
    var ret = chooser.showOpenDialog(null);

    if (ret == JFileChooser.APPROVE_OPTION) {
        return chooser.getSelectedFile();
    }
    return null;
};