[cap-talk] Drag & "Attenuated" Drop?

[Kevin Reid]

On Dec 12, 2008, at 19:34, James A. Donald wrote:

> Yes, drag, drop, and mysteriously vanish.  It is a big
> problem.
>
> Where should we put access to the undo queue for file
> moves, copies and deletes (delete being a move to the
> trash)?  Any suggestions?


- In Mac OS X, the Finder (system file browser) has a single undo  
stack for all file operations performed using its interface.


- In pondering ideas for novel and capability-based desktop  
interfaces, I have considered the notion of a system-wide _timeline_  
(with multiple filtered views), of previous (and possibly future)  
events/actions. Given this interface, it would be quite natural to  
have "undo" as an operation on such a timeline entry.


This question doesn't have much directly to do with capabilities,  
though.

There's plenty to think about with capabilities and drag-and-drop,  
though; the choice of attenuations, as previously mentioned, for one.  
Given the ease of accidental drops, I think it is important that a  
capability-granting drop should by default create a revokable  
authority (caretaker) if the file is not immutable. Providing UI to  
revoke it is essentially the same sort of problem as providing UI to  
undo file moves, though the former is *more likely* to have un- 
undoable consequences.

-- 
Kevin Reid                                  <http://switchb.org/kpreid/>