[news.eclipse.platform.swt] Re: How to notify View of Editor changes

[andy@xxxxxxxxxxxxxx (Andy D)]

OK - I found this answer for myself, but thought I'd note it here for 
future reference, plus details of some curious behaviour which somebody 
may be able to help me with.

SOLUTION:

I register each editor's viewer with the site, using code of the form:

   getSite().setSelectionProvider(myViewer);

In my view, I have registered a listener to handle events from my 
editor(s), thus:

   getSite().getPage().addSelectionListener(mySelectionListener);

PROBLEM:

The issue I have is that if I specify a typeId as the first parameter for 
the 'addSelectionListener' method, then I *only* seem to get events for 
the most recently created editor instance. However, if I do not give a 
typeId then I get events for all instances (which is what I want).

This would be fine, since I can always filter on the class of the 
IWorkbenchPart that gets passed into my handler. However, this does not 
work for the null case (which I also need to process). In this case I 
can't test the part because it is null. However in the case of the null 
handler the registration process seems to work correctly when I give the 
optional typeId in the call to 'addSelectionListener' (though only for 
null events).

I have therefore had to register two handlers - one with no typeId 
specified to process 'normal' events (doing hand-written filtering), and a 
special null handler which is registered using a typeId and which *only* 
processes null events.

Note: my 'normal' handler implemented the INullHandler interface, since I 
wanted it to process both normal and null events.

As always - any advice most appreciated.

   Andy D


Andy D wrote:

> I have a view defined whose purpose is to show some details for the 
> currently selected item in my editor - both the editor and view are 
> optional (though obviously the view will be empty if the editor does not 
> exist or does not have a current selection).

> What is the recommended way of connecting these two 'things' so that the 
> event get propagated correctly and that the lifetimes etc are also managed 
> correctly?

> My guess is that I need to register the view with some common 'manager' - 
> e.g. the workspace - which can then be notified by the editor(s), but 
> there do not appear to be any built-in mechanisms for me to use (or more 
> likely, I can't find them).

> Any advice would be gratefully received