As a javascript coder of TestComplete I would love the ability to collapse custom objects. I have very large objects that take up a large amount of space. But there is no support for collap...
Have you looked into the outlining feature of TestComplete? You can mark blocks an "outline" them which allows you to collapse anything you want.
Essentially, automatic outlining recognizes only certain keywords for adding a block to outlining. However, you can manually outline any selection you want. Just highlight the selection, right click, select "Outlining - Hide Selection" and it will collapse whatever you have selected.