I tried to add it to the outline

    public void expandAll() {
        ExplorerManager em = ExplorerManager.find(this);
        if (em != null) {
            Node node = em.getRootContext();
            expandAll(node);
        }
    }

    private void expandAll(Node node) {
        if (node == null) {
            return;
        }

        expandNode(node);

        for (Node child : node.getChildren().getNodes()) {
            expandAll(child);
        }

    }

I have also add the setRootVisible method
    public void setRootVisible(boolean vis){
        getOutline().setRootVisible(vis);
    }

(In reply to comment #2)
> I have also add the setRootVisible method
>     public void setRootVisible(boolean vis){
>         getOutline().setRootVisible(vis);
>     }

Where did you add this? I does not appear in the daily build yet...

In my RCP I create a class that extended OutlineView. I cannot commit to NetBeans sources. the code I posted is just a suggested implementation.