Alexandre Bergel wrote:

  | view rawView el1 el2 edge line |
  rawView := ROView new.
  el1 := ROElement new.
  el1 extent: 50@50.
  el1 + ROBox red  +  ROCircle yellow  + ROLabel  @  RODraggable.
  rawView add: el1.
  rawView open


neat isn't it?

...except that it would be nice if the ROLabel could be centred.


Yes, I will work on this.

In addition, being able to place the ROLabel in various "offset" locations,


Right, top, center, bottom? Is this what you mean?

I think that would satisfy a lot of my composition requirements - for example building a transformer compound symbol with two overlapping circles and two labels for "equipment tag" and "power size".  To that effect it would be great if ROLabel or similar could have a callback mechanism to get different attributes from the model.  Alternatively I guess I could make a new subclass of ROShape that draws such that directly.


I do not understand what you mean by these attributes from the model?
You can do things like (using the last version):

-=-=-=-=-=-=-=-=-=-=-=-=
 | view rawView el1 el2 edge line |
  rawView := ROView new.
  el1 := ROElement on: 1.
  el1 extent: 50@50.
  el1 + (ROLabel new color: [ :model | model odd ifTrue: [ Color red ] ifFalse: [ Color blue ]]). 
  el1 on: ROMouseLeftClick do: [ :ann | ann element model: (ann element model + 1). el1 shapesDo: #resetCache. rawView signalUpdate ].
  el1 @ RODraggable.

  rawView add: el1.
  rawView open
-=-=-=-=-=-=-=-=-=-=-=-=

Cheers,
Alexandre

That is truely inspiring - I see a LOT of potential. By 'attributes' I meant any selector of the model's data. For example (using a fake model), I was actually thinking along the lines of...

| view rawView el1 el2 edge line mymodel |
rawView := ROView new.
mymodel := Dictionary new.
mymodel add: (#name -> 'Ben').
mymodel add: (#country -> ' Australia').
el1 := ROElement on: mymodel.
el1 extent: 50@50.
el1 + ( ROLabel new text: [ :element | element model at: #name ifAbsent: [ ] ]) .
el1 + ( ROLabel new text: [ :element | element model at: #country ifAbsent: [ ] ]) .

el1 @ RODraggable.
rawView add: el1.
rawView open

The second ROLabel should be able to have an offset to place it on the next line.
Here I faked it with spaces in #country so that the labels don't clash.

-ben