Projectors and Xrandr
Like kees mentioned, Kees and I tested his laptops on the Hitachi projector that Elmo lent me from work.
The background here is pretty simple: We want Linux to work with projectors, or at *least* for Ubuntu to work with Canonical's specific projectors. It's embarrassing enough as a presenter to walk into a Linux conference providing some random projector and not be able to connect; imagine how frustrating it is to go to a Ubuntu conference with an up to date Ubuntu laptop, and plug into Canonical's own projector and not be able to get it to work!
Historically, getting a laptop to work with a projector has been a Dark Art, requiring major xorg.conf tweakage. Things have gotten better with the introduction of Xrandr, though.
Intel graphics was the first to get good Xrandr support. Both my (working) laptops are Intel based, and sadly I could find no bugs with the projector. Hotplugging, resolution switching, rotation... it all just worked.
Kees had described some rather nasty issues he'd found with his ATI graphics laptop, so I knew there were resolution issues, I just had to find them!
So a couple weeks ago I ordered several popular (but cheap) nVidia 7000-series and ATI cards, and tested 9 different hardware configurations.
I did find some bugs - rotation on -ati is **horribly** busted, for example - but was surprised to see that by and large, resolution changing worked amazingly well. Hotplugging not so much. But I never had to fiddle with xorg.conf. Most of the issues I did find were oddball corner cases, or were easily fixed by doing a vt switch, or switching to another resolution and back, or etc.
So today I had Kees bring his laptops over, including the aforementioned broken ATI one, which he also upgraded to Hardy today. The other projector is a Dell with a recent 8000-series nVidia graphics chipset.
Amazingly, he was able to boot the projector on both laptops to just about every resolution supported. There were a handful of various little glitches and issues, but mostly known bug - I mentioned to him that I felt like he was demoing everything currently in Launchpad for Xorg. Even rotation sort of worked for him on -ati: We could invert the screen without problems, but Left/Right didn't work and required restarting X.
Of course, we did nearly all of this testing with the new Xrandr GUI, which aside from a couple issues fulfilled its role admirably. I was particularly gratified seeing the Revert Dialog (which I'd only just uploaded last night) came up and worked exactly as expected.
Unfortunately, while we were pleased with X and the Xrandr GUI at letting us experiment with all these resolutions on the fly, it's clear that things beyond X need work. GNOME's panels were quite easy to get confused. The desktop background can get strangely stretched in some configs. Full screen apps (games and movie players) also seem to get easily confused; they tend to want to display on the laptop, when of course you want them to go up on the projector!
I guess my hope is that providing an easier way for people to experiment with their Xrandr settings, it will better expose these WM-level and app-level issues and make it simpler to test them, and maybe we'll start seeing improvements in Intrepid and later. I'll look forward to seeing games and movies display properly on the expected output.