I'm developing a drag-and-drop reordering interface for books on shelves. (You can try it live if you're on the latest WebKit.) When you drag a book over a shelf, it accommodates space for it by ...
I have a problem with a column in a table in which the cells may receive data in multiple ways: You may write a number, say 1.0. If you write you can only write numbers. Place an object in the cell, ...