I lost the zoom correctness in the mixed code, so now I have something to diagnose with NSLog. The zoom does work correctly with my rebuild on top of Mike's code. I thought I would need a review but I didn't feel hot about trying to write about the column, so the rebuild forced this review.
I noted something serendipitously.
The dock wouldn't drag to to open a file when I built on top of his code. It wouldn't, that is, until I dragged a file to open on the application icon in the finder. Thereafter, dragging onto the dock worked.
Then I observed the code on top of yours had the same sort of enabling of dragging onto dock happen.
So, I got strange intermittently working zooming in build upon Michele's dragging and strange enabling of new drag opening in both "build upon's".
