[e4-dev] Some random thoughts after browsing the e4 code base

[Philipp Kursawe <phil.kursawe@xxxxxxxxx>]

Hello all,

I hope its ok for non-contributors to post on this list?

I thought I might get some more information about how e4 is supposed to
work (I have no idea what all this modeling is doing though) and checked
out the newest HEAD. Some random thoughts I would like to share with you:

1. Why is e4 still using an (empty) Activator in almost every project?
Shouldn't it be a good OSGi citizen and use the
FramworkUtil.getBundle(Class) whenever the current Bundle/BundleContext
is needed? Also the Activator.ID is error prone to refactoring, thats
why I never use it in my own projects.
A similar problem has the NLS feature of Eclipse PDE, when it creates 
the Messages class and puts the BUNDLE into a string rather to have
NLS.initialize(Messages.class.getPackage().getName() + ".messages",
Messages.class)

2. Why are you still using Require-Bundle in almost every bundle when a
I-P would do just fine? And then the CSS core bundle is requiring the
batik bundle which it does not use one class from, does it?

3. The CSS bundles are too tightly coupled with each other. As far as I
understand the concept, there are handlers for CSS elements. Couldn't
those handlers and other components that make up a CSS engine
implementation be contributed by extensions?

4. What is the use of OSGi services in e4? So far I have seen there is
an IEclipseContext which allows you to fetch services like the old
IServiceLocator in 3.x does. What about putting more services directly
into OSGi (that are not local to any part of the workbench)? I would put
my declarative services to more use depending on the workbench services
available. For instance, now in 3.5 I export the IWorkbench as a service
myself and have my other services consume it. Similar to the
ISelectionService, IProgressService and others.

5. I actually like the idea of being able to define the layout of RCP
applications. Currently I have gone through great pain to have a custom
view on top of each perspective that you can not close/move or whatever.
It provides a kind of "startbar" with custom gradient background. See here:

Please understand my points not as criticism purely, I am sure for a lot
of things there are good reasons just unknown to me.

Said that, I am more than willing to contribute to e4 if possible after
I got more insight on the processes going on.

Keep up the good work!

Cheers,
Phil