Using JFace ProjectionViewer in Standalone App

I've been trying to use the JFace ProjectionViewer to implement folding in a standalone Java app. I got the idea from this article: http://www.eclipse.org/articles/Article-Folding-in-Eclipse-Text-Editors/folding.html However the source code provided with the article is for an Eclipse plug-in, not for a standalone.

The particular problem I'm having is that I can't get the VerticalRuler to respond and cause folding/unfolding.

Since I get the expected results, i.e. line numbers in the ruler, when I change from using a VerticalRuler to a LineNumberRuler while leaving everything else the same, I think my problem is specific to the implementation of the relationship among the ProjectionViewer, the VerticalRuler, and the Annotations.

My exact question is whether anyone has gotten this to work i开发者_C百科n a stand-alone code and, if so, how?