At Xamarin we have historically been a GTK+ shop but with our new multi-platform focus, we have recently developed Xwt, a cross-desktop UI library which allows us to write our UI code once and run it natively on GTK+, Cocoa and WPF. Come to learn how the API works, how it's built and, why not, help us improve it.

1. Xwt
A cross-desktop UI toolkit
Jérémie Laval
@jeremie_laval

2. Quickie about me
A Xamarin-ista
Mono Contributor (classlib, Pfx, PLinq, …)
MonoDevelop team (these days)

3. Xwt: WAT?
X-platform Widget Toolkit
One UI toolkit to rule them all

4. Why Xwt?
Pushing native UI feature with minimal cost
Goals:
Long-term → Xwt-based MonoDevelop
Short-term → share UI features between VS and MD
Create a nicer (hopefully!) API in the process

5. Xwt all the things
Xamarin Android Designer

6. Where we stand
2 main approaches: WxWidgets and Qt
WxWidgets → native widgets, limited to common denominator
Qt → fully emulated, look&feel through theming
*
: Xwt strikes a balance of both
*
( = Lluis Sanchez, Xwt creator, as Dogbert)

7. Design goals
Not general purpose, solving a problem at hand
Architecture:
MVC
Gtk box model
Cairo-like drawing API
Can be easily integrated with existing UI code

8. Relationship with Gtk
NIH, we borrow heavily from Gtk+ API
: We love Gtk but…
Simpler widget hierarchy
No (Gtk,Gdk)Window dichotomy
No container class

9. Where we differ
Miguel on WPF (2004): “The implementation details transpire everywhere”

10. General architecture

11. What it looks like?

12. Demo
Let's make a new widget: awesometacular arrow

13. Demo
Let's integrate Xwt with Gtk

14. Demo
Let's spicy up Xwt.Gtk with Xwt.Mac

15. The Future
Sort out the WPF backend (layout, drawing, …)
Animation support (CoreAnimation, Clutter, …)
More widgets

16. The Good Stuff
https://github.com/mono/xwt
https://github.com/mono/xwt/wiki/Coding-Guidelines
http://group.google.com/group/xwt-list

17. The End
Questions?