What are Composite objects good for?
 

I'm just looking at the new persona window and seeing the use of composite objects therein. I admit I have no idea what those are good for. From they behaviour the appear identical to a page? Anyone know what's up with them?

From the user perspective they don't make any difference. From the designer perspective they arrange the children objects automatically. I prefer more exact control so I didn't use them in my persona window stats tab.

From the UIBuilder doc:
Composite
Parent : Page
Page that automatically spaces visible widgets

Orientation
Horizontal/Vertical

Spacing - gap size
integer

SpacingType
Fill - make the widgets take up all the space
Spread - spread the widgets equally
Constant - fixed spacing

Alignment
Front - left/top
Center - center
Back - right/bottom

Padding -
Internal - spacing between items
External - spacing on the outside
Both - spacing both between and on the outside

What Othesus said plus allot of the overhead that a page has is not there. I use them to hold my user effect or any thing I want evenly spaced out.

One nice advantage you get with a Composite is that the spacing dynamically updates as objects are show/hidden. For example SOE has been using them with a nested page and auto-hiding scrollbar. When the scrollbar hides, the page expands to fill the empty space.

Back in the day, composites didn't work right so I didn't implement them on a wide scale, but have been slowly adding them where useful.

Note to self: RTFM. :) Thanks you all.

I had only looked at them in UIbuilder and no automatic spacing happens therein. Sounds like an interesting control then, basically like a volume page in just one direction.

Would be interesting to hear from Rothgar what is most efficient, automatic placement via PackLocation, via a Composite or via a VolumePage.

As far as performance goes, I'm not sure if there is a noticeable difference between the three methods to really worry about it. I really do like Composite objects though, because I'm a stickler for things being lined up properly and looking nice when pages are resized. And like Zonx mentioned, it works great for when a page hides a vertical scrollbar.

Thanks Rothgar. I agree they are nice. I'm using two vertical composites on my persona window as well now, in addition to the volume pages I always used there (I like correct spacing as well ;)).

And the scrollbar idea is good, I know a couple of windows I will update with that, getting rid of the OnShow code I currently have doing the same thing.