New API suggestion: ListGrid.setCanEditNew() to support editing *new only*

Hi Isomorphic,

I have a ListGrid, where I want the user to be able to add records via ListGrid.startEditingNew(), but not to edit existing records via doubleclick. So I have to set ListGrid.setCanEdit(false).
But these two can't be combined.
Could you introduce a new API ListGrid.setCanEditNew(boolean canEditNew), so that I could set this to true, while still setting ListGrid.setCanEdit(false)?

How could I archive the wanted effect otherwise (e.g. capture the doubleclick and do nothing)? ListGrid.addDoubleClickHandler(...) does not do it.

Thank you & best regards,
Blama