Re: [ecf-dev] Menu Contribution Conflicts...

[Scott Lewis <slewis@xxxxxxxxxxxxx>]

Remy Chi Jian Suen wrote:
> Hi everyone,
>
> On this week's call, Scott talked briefly about how one would
> contribute directly to a view via its ID without having to set a
> Require-Bundle on said view's ID. In the context at hand, it would
> allow us to add a 'Send File' action to the MultiRosterView's context
> menu via writing the code in a provider's ui.
>
> This looks great on paper but actually presents a flaw in the design
> once you "scale up" in the number of supported protocols.
>
> The idea here is that you would subclass CompoundContributionItem,
> check the workbench's current selection, and pop it up.
>
> In a scenario in which one protocol supports file transfer and the
> other doesn't (like the current scenario of XMPP and MSN, yes, MSN
> does support file transfers, I just haven't written the implementation
> code), the popup menu will appear in either case even though MSN does
> not support this. Thus, the standard sanity check of IRosterEntry
> would not work, you would instead have to check its
> implementation.This currently would still fail since XMPP actually
> just uses the convenient implementation of RosterEntry, so if future
> implementors uses it too, that will fail. Worse, if all protocols
> supported file transfers, you would get an n number of menu items that
> stated 'Send File'!

Here's what I do as a sanity check with the Skype ui contribution (in 
SkypeActionContributionItems)...I'm not saying this is the best/only 
approach, but it does work.

       if (selectedModel != null && selectedModel instanceof 
IRosterEntry) {
           IRosterEntry rosterEntry = (IRosterEntry) selectedModel;
           IContainer container = (IContainer) rosterEntry.getRoster()
                   
.getPresenceContainerAdapter().getAdapter(IContainer.class);
           IAction[] actions = new IAction[1];
           // Here's what limits it to adding menu entries only for Skype
           // this is kind of ugly though...admittedly
           if (container instanceof SkypeContainer) {
               actions[0] = new SkypeCallAction(
               ....fill out action

The tricky bits here are the 'if (container instanceof 
SkypeContainer)'.  Although this works fine, it would be better to have 
alternatives.

Scott