DataGrid With PopUp Editor

Some folks seem to be in need of an itemEditor in the DataGrid that can popup or float over the DataGrid. The DataGrid currently limits the editor to fit within its size and if you need more space than that, you’ll need to popup an editor.
It is tricky to do so because of a bug in DataGrid plus the complexities of focus handlng and how it is normally used to end the edit session.
Here’s a workaround for the bug and my take on how to create popup editors. Usual caveats apply.
Download Source
Run Example