final SwingNode swingNode = new SwingNode();

    SwingUtilities.invokeLater(() -> {
        RSyntaxTextArea ta = new RSyntaxTextArea();

        switch(extension) {
        case "java":
            ta.setSyntaxEditingStyle(SyntaxConstants.SYNTAX_STYLE_JAVA);
            break;
        case "c":
            ta.setSyntaxEditingStyle(SyntaxConstants.SYNTAX_STYLE_C);
            break;
        case "cpp":
            ta.setSyntaxEditingStyle(SyntaxConstants.SYNTAX_STYLE_CPLUSPLUS);
            break;
        case "asm":
            ta.setSyntaxEditingStyle(SyntaxConstants.SYNTAX_STYLE_ASSEMBLER_X86);
            break;
        case "cs":
            ta.setSyntaxEditingStyle(SyntaxConstants.SYNTAX_STYLE_CSHARP);
            break;
        default:
            JTextArea text = new JTextArea(code);
            swingNode.setContent(text);
            return;
        }

        ta.setCodeFoldingEnabled(true);
        ta.setText(code);
        RTextScrollPane rp = new RTextScrollPane(ta);

        swingNode.setContent(rp);
    });