[Springframework-rcp-dev] Am I getting the idea?

[Andy D. <an...@ma...>]

With Spring RCP being so new, it appears the only documentation is the 
source. :-)  So, after reading the source, let me see if I'm getting the idea 
(btw, I don't have any experience with Eclipse, so any concepts spring-rcp 
borrows from Eclipse I've learned only through spring-rcp source).  If I'm 
getting this wrong, please let me know.

An Application consists of one or more windows (ApplicationWindow), managed by 
WindowManager.  An application has at least one window (a main window).  A 
Window displays a single page (ApplicationPage) at a time.  A page contains a 
View registry.  This means a Page can contain multiple Views.  So, if my 
application's main window consists of a single Page (which is really the only 
option, right?), then I can swap out the contents of the main window by 
swapping pages?  I'm guessing an example of this would be "workbenches" in 
the IDE world?  For example, if I am in Edit mode, then I have several views 
open on my page: maybe a folder view, an edit view, and an output view.  In 
Debug mode, I have a "watches" view, breakpoint view, source code view, stack 
view, etc.  With this understanding, I'm having trouble figuring out where 
the Perspective class fits in, as it seems to be a one-to-one 
relationshipship with a View (though it is by the view's ID and not a 
reference to a View itself).
OK.  On to Actions.  In rcp, you have VisualActions and ActionHandlers.  A 
VisualAction defines only the visual representation and keyboard access (menu 
item, toolbar item, icon, text, mnemonic, accelerator, etc).  The actual 
functionality of the action is provided separately in an ActionHandler.  
Actions are registered in a global ActionRegistry, and ActionHandlers are 
registered with views (via the ViewContext).  Well, I guess it is also 
possible to associate an ActionHandler directly with an Action (for those 
actions that are not view dependent).  So, when a View becomes active, 
spring-rcp will query the view against every registered global Action to see 
if that View provides an ActionHandler for the Action.  This means that the 
functionality of a particular Action can be dynamically implemented per-view 
(kinda cool, actually).  It looks like for this to work, your Actions must 
also implement TargetableVisualAction (which is implemented by 
DefaultVisualAction).
The org.springframework.rcp.action.contribution package seems to be all about 
building menus and toolbars.  I'm not sure I have this right, since I haven't 
played around with it.  Since an Application can present the user with 
multiple ways to do actions (menus, toolbars, pop up menus. etc), spring-rcp 
provides an abstraction that allows you to group such actions logically and 
automatically represent that group as any of these more concrete 
implementations.  So, a ContributionItem is an abstraction on top of a menu 
item, toolbar button, etc and a ContributionItemManager is an abstraction on 
top of a menu bar, toolbar set, etc.  ContributionItemManager allows you to 
group ContributionItems (via group id) - each group becoming a different menu 
along a menubar, or a different toolbar in a toolbar set(?)  I'm not too sure 
about this actually. ContributionItem seems similar in many ways to an 
Action... but I guess it needs to be different because some menu items (such 
as seperators) are not actions?  In fact, ActionContributionItem seems to be 
no more than a wrapper (adapter) that makes an Action look like a 
ContributionItem.  A ContributionItem can create menu items and toolbar 
controls just like an Action can.
Some questions on my exploration of the source so far:
What is the preferred way for creating/configuring controls from spring-rcp?
I don't see a common Page interface... it looks like dialogs get their own 
idea of what a page is and windows get another.  Is this intentional?

Well, that's about all the further I've gotten so far.
BTW, if anyone has any example configuration files used with spring-rcp, I'd 
love to see them.

Thanks,
  Andy