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Undo/Redo support for non EMF based domain objects [message #556346]

Tue, 31 August 2010 21:41

Shenxue Zhou

Messages: 60
Registered: July 2009

Member

It seems that if my domain objects are not EMF based, then we don't get the undo/redo support (whether it's a move feature or add feature). After some digging, I noticed that Graphiti uses GFCommandStack class which seems to replace GEF's command stack with emf's command stack.

How do I get undo/redo support if my domain objects are not EMF based? Thank you for your suggestions!

Shenxue

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Re: Undo/Redo support for non EMF based domain objects [message #557283 is a reply to message #556346]

Mon, 06 September 2010 12:32

Michael Wenz

Messages: 1931
Registered: July 2009
Location: Walldorf, Germany

Senior Member

Yes, you are right. The advantage of doing it that way is that we can
completely handle undo/redo on EMF level by simply using the
RecordingCommand of EMF.

Also in a scenario with non-EMF domain objects, the part concerning the
graphical objects are handled automatically by Graphiti. Only the undo/redo
of the non-EMF domain object changes need to be implemented by you. In order
to do that you can use a GEF CommandStackEventListener that you register at
the CommandStack by
getEditDomain().getCommandStack().addCommandStackEventListen er(listener)
after the initiallization (e.g. by overriding setInput in DiagramEditor and
after calling super.setInput). There you can react to events POST_REDO and
POST_UNDO.

Hope that helps.

-Michael

"Shenxue Zhou" <shenxue.zhou@oracle.com> wrote in message
news:i5jsv9$74t$1@build.eclipse.org...
> It seems that if my domain objects are not EMF based, then we don't get
> the undo/redo support (whether it's a move feature or add feature). After
> some digging, I noticed that Graphiti uses GFCommandStack class which
> seems to replace GEF's command stack with emf's command stack.
> How do I get undo/redo support if my domain objects are not EMF based?
> Thank you for your suggestions!
>
> Shenxue

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Re: Undo/Redo support for non EMF based domain objects [message #557499 is a reply to message #557283]

Tue, 07 September 2010 19:47

Shenxue Zhou

Messages: 60
Registered: July 2009

Member

Michael,

Thanks for your reply. I did some experiment based on your suggestion. In my editor, I overrode the setInput() method. My setInput() method looks like this:

@Override
protected void setInput(IEditorInput input)
{
super.setInput(input);
getEditDomain().getCommandStack().addCommandStackEventListen er(this);
}

But I'm registering a command stack event listener to GFCommandStack() since the default domain's GEF command stack has been replaced by GFCommandStack after super.setInput() is called. GFCommandStack doesn't seem to notify listeners about POST_REDO/POST_UNDO events.

Thoughts?

Shenxue

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Re: Undo/Redo support for non EMF based domain objects [message #557655 is a reply to message #557499]

Wed, 08 September 2010 12:35

Michael Wenz

Messages: 1931
Registered: July 2009
Location: Walldorf, Germany

Senior Member

Shenxue,

I just had a closer look and saw that you are right. This is a gap in our
command stack implementation. After a short team discussion we also saw that
there is currently no other hook to actually undo/redo non-EMF changes.

Could you please open an enhancement request Bugzilla (Under modeling,
product GMP, component Graphiti) for this? We have a rough idea how to
implement the feature, but this needs to be detailed out.

Thanks,
Michael

"Shenxue Zhou" <shenxue.zhou@oracle.com> wrote in message
news:i664t9$44g$1@build.eclipse.org...
> Michael,
>
> Thanks for your reply. I did some experiment based on your suggestion. In
> my editor, I overrode the setInput() method. My setInput() method looks
> like this:
>
> @Override
> protected void setInput(IEditorInput input) {
> super.setInput(input);
> getEditDomain().getCommandStack().addCommandStackEventListen er(this); }
>
> But I'm registering a command stack event listener to GFCommandStack()
> since the default domain's GEF command stack has been replaced by
> GFCommandStack after super.setInput() is called. GFCommandStack doesn't
> seem to notify listeners about POST_REDO/POST_UNDO events.
>
> Thoughts?
>
> Shenxue

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