Adding custom views to NSCells
How do you add a view (spinner, text field, button etc.) into the cells of NSTableView or NSOutlineView?
Simple:
1. Keep a reference to the view in your NSCell.
2. In drawInteriorWithFrame:inView: you should create the view if needed and add to the controlView if needed. controlView is provided as a second argument to this method.
3. Position the view according to the cellFrame (first argument to the drawing method).
4. Do not forget to retain or nullify the view in copyWithZone method. Remember that copy and copyWithZone copy instance variables as-is without retaining object pointers when you might need that.
Correction on January 6th, 2011:
There is no point in keeping a reference to a view in the cell. After the cell is drawn it is often deallocated immediately, so the view will stay visible forever. You need to keep the reference to the view in some external non-volatile object: a view, a view controller, or a model.