[news.eclipse.tools.emf] Re: Use of Copy, Paste Command

[Frank Budinsky <frankb@xxxxxxxxxx>]

Balaji,

It sounds kind of kludgy to enforce this kind of restriction by passing some
information from a copy command to a paste command (where would you store the
original's eContainer? In a wrapper object for the copy which you put on the
clipboard?). What if the same thing is done using a copy and add command instead
of via the clipboard?

I think that ideally the model should be designed in such a way that the copied
model object itself has all the necessary state information (maybe it's a
specific subclass) that controls its suitability for adding at one place or
another.

Frank.


Balaji wrote:

> All,
> I use my own copy and paste command to copy / paste objects using EMF
> commands. I had to validate the owner on which the object is pasted.
> for e.g. A contains a list of B objects.
> If B's parent is a (instance of A), then B can be pasted only to a.
>
> To accomplish this, I need to know the eContainer of B. But the
> PasteFromClipboardCommand does not provide me with the eContainer of the
> object copied.
>
> command.append
>
> (new CommandWrapper()
>
> {
>
> protected Command createCommand()
>
> {
>
> // Command copyCommand = CopyCommand.create(domain, domain.getClipboard());
>
> CompoundCommand compoundCommand = new CompoundCommand();
>
> Collection objectsToBePasted = copyCommand.getResult();
>
> ...
>
> }
>
> The objectsToBePasted has information regarding the object but not the
> container. What is the recommended approach in this case. Should I store the
> eContainer of the owner when it is copied and use it when it is pasted ?.
>
> Thanks
>
> Balaji