[jbosstools-dev] Fwd: Quick SWT Question

[Ian Stewart-Binks]

Holy cow. Thanks for the help, all. Zimbra's presented me with quite the sea of... quotation-al soup.

Not sure if I'm doing the jbosstools-dev mailing list right. Here goes...:

> Date: Wed, 15 Jul 2015 16:19:56 +0100
> From: phantomjinx <p.g.richardson at phantomjinx.co.uk>

> In addition to Display.asyncExec, you make want to put your code inside a runnable, launched from
> its own thread.

> My reasoning:
> The workbench can be started after some plugins have already been activated as such
> getWorkbench().getActiveWorkbenchWindow() can be null even on the UI thread. Consequently, I find
> it prudent to create a polling thread that listens on getWorkbench().isStarting().

Thanks for your suggestion, Paul.

At what point am I guaranteed that there is an active workbench window?
Is it necessary to poll the workbench to see when it's active? Is it likely that plugins crash otherwise?

> Returns true then delay
> Returns false then the workbench window should exist as well as the Display thread and so
> Display.asyncExec(addSelectionServiceRunnable) should be good to go.

> Once control has been passed to the Display thread, the original polling thread will finish and
> disappear.

> HTH

> PGR

> From: Denis Golovin <dgolovin at exadel.com>

Thanks for your response, Denis.

> Ian,

> Bundle.start() is always none UI thread.

I'm not entirely certain that Bundle is an ancestor of the class I'm referring to.
The listener appears to be registered successfully when the plugin is run,
and it only has this problem in the context of SWTBot testing.

> If the tool is targeting Eclipse 4
> and up, you can try to use injection see details here
> https://wiki.eclipse.org/Eclipse4/RCP/EAS/Workbench_Services.

Thanks for the link. The plugin also targets Eclipse 3 platforms, but I'll take a look at this nevertheless

> I can be more
> specific if you could share your source code.

This is the PR that adds in the listener, and everything listener like:
https://github.com/eclipse/buildship/pull/120

> Denis

> From: "Max Rydahl Andersen" <manderse at redhat.com>

Thanks for your response, Max.

> I think you need to look *when* you actually need the selection listener 
> registered.

This is indeed something I'm doing right now. However, the UiPlugin seems to have a pattern of
registering/unregistering listeners/services on start/stop. I'm hesitant to break that pattern.

> Normally it is not something to do at startup, but more when your gfx 
> part (editor/view etc.) gets created you need to start to listen.

I'll need to do a bit more reading on this one in order to see if it's a feasible solution.
The selection listener seems to be fairly general. I'm still taking the time to understand its purpose
and what the best solution is. For reference, this shows the earlier state of the code: https://github.com/eclipse/buildship/pull/120/files

> /max

From: Alexey Kazakov <alkazako at redhat.com>
Subject: Re: [jbosstools-dev] Quick SWT Question
To: jbosstools-dev at lists.jboss.org
Message-ID: <55A6948C.1000906 at redhat.com>
Content-Type: text/plain; charset=utf-8; format=flowed

> Agree with Max. But if you really need something general to listen to 
> everything you can use the early start up mechanism (see 
> org.eclipse.ui.IStartup). Your code will be invoked when the workbench 
> is initialized.
> For example we use it in our usage to register a wizard listener to be 
> able to track all wizards in Eclipse.

I'm looking at this solution now. Is there any chance that the 'BundleActivator.stop()' method (the method that unregisters the listener, if it hasn't already been unregistered) could be invoked before the 'earlyStartup' method?