ComponentRenderer setup and basics steps

Hi all,

i’m fairly new to vaadin and right now i’m trying to use this addon:!addon/componentrenderer

which i found to be perfect for what i want to achieve in my application.
However, i have some trouble to make it work properly:
Basically, based on what i’ve found on the demo, i did setup a classic vaadin Grid

Grid gridExemple = new Grid();
FocusPreserveExtension focusPreserveExtension = FocusPreserveExtension.extend(gridExemple);

and a container with generated properties:
GeneratedPropertyContainer gpc = new GeneratedPropertyContainer(container);

then i specified also a generated column for the grid
gpc.addGeneratedProperty(“TEST”, new PropertyValueGenerator() {

        public Component getValue(Item item, Object itemId, Object propertyId) {

            HorizontalLayout mainLayout = new HorizontalLayout();
            Button b = new Button("test");
            b.setWidth(30, Unit.PIXELS);
            b.setHeight(20, Unit.PIXELS);

            return mainLayout;

        public Class<Component> getType() {
            return Component.class;

and, finally, i setup the ComponentRenderer renderer for that column
gridExemple.getColumn(“TEST”).setRenderer(new ComponentRenderer());

Now, the problem is that the renderer does not work, because the TEST column disappears from the grid. Without the .setRenderer method, however, the column appears and renders the java Object in the cell of each element of the container. (Each other column of the container shows fine)

So, i wonder how to use properly this addon. Am i doing the setup in the wrong way?
Also, Is it necessary to compile the widgetset inside the componentrenderer jar in my application Vaadin folder?

Thank you very much