Interesting, I wasn't aware this was a pain-point. I may have some similar (Qt) work coming up soon and was wondering if you could elaborate with some examples, i.e. situations where you encounter the X11 APIs when working with Qt.
I'm working on an application launcher so what I've seen might be different from what you'll see.
I don't directly have to call many X11 apis (only some hotkey grabber thing). It is more a matter of occasionally going through Qt code to find out why X doesn't work or workers strangely.
The most annoying continuing thing from my viewpoint is how every top-level QT window appears on any task-list under Gnome. I don't even know if this a Gnome or an X11 artifact. I suppose what I should say is the annoyance is having a multitude of lower levels apis to page through when you find a problem and are looking for the culprit.
On a break this week, otherwise I'd go back and give more specific example.
I'm working on an application launcher so what I've seen might be different from what you'll see.
Probably. We use Qt for an application [1], and we didn't encounter any serious problems on Linux/X11. We never had to dig deeper than any of the Qt classes. Qt itself has some weak spots (e.g. if you have a table view in a tab with very many items, switching between tabs can become very slow). But the most serious problems we encountered on OS X, mostly because Qt doesn't naturally map to how OS X applications work (e.g. Document-based interfaces, OS X-specific features) and Qt on OS X seems to be less well-tested (e.g. between Qt 4.7 and 4.8 the default renderer was changed, but the new renderer had a bug, which broke painting in our application).
I'm working on a GUI app in Qt where we use X11 in several places. The main usage is to open multiple connections to the X server for GL widgets, so that we can refresh their time-sensitive contents even when the main Qt event loop is blocked. Another is to query the current X11 virtual desktop as soon as possible after app startup, so we can display subsequent Qt windows there by default even if you switch away to browse the web while our levianthanic app loads. There are a number of less interesting examples, like setting X11-specific attributes on windows, and papering over minutiae that varies between e.g. X11 and OSX. Despite these few things, Qt has served us fantastically well.
