c# tooltip draw function bounding rectangle issue

I am trying to create a custom tool tip which consists of 3 lines, due to the content I have switched the font in the _Draw event to "Courier New", size 8. However its clear from the results that the bounding rectangle needs to be recomputed, but I cannot see how. Looking at the many samples online none of these show how to adjust the bounding rectangle.

I also tried implementing the _Popup event handler with odd results where the event handler is just not being called.

Labels: c#, tooltips, bounding rectangle