private void setUpTypeComboBox(TypeConstraint[] typeConstraints) {
    final EditorComboBoxEditor comboEditor = new EditorComboBoxEditor(myProject, GroovyFileType.GROOVY_FILE_TYPE);

    final Document document = createDocument("");
    LOG.assertTrue(document != null);

    comboEditor.setItem(document);

    myTypeComboBox.setEditor(comboEditor);
    myTypeComboBox.setEditable(true);
    myTypeComboBox.grabFocus();

    PsiType type = typeConstraints.length == 1 ? typeConstraints[0].getDefaultType() : TypesUtil.getJavaLangObject(myContext);
    myTypeComboBox.getEditor().setItem(createDocument(type.getCanonicalText()));
  }
private void setUpTypeComboBox(TypeConstraint[] typeConstraints)