I saw your camera mirror example and fixed the some mistakes I spotted in the code.
- Using QTextStream to construct a QString is not required. It slows things down. QString, in contrast to i.e. Java's string class, does efficient concatenation.
- The way you were using QApplication::translate() would not have worked. I don't really see why one would want to translate the style sheet in this particular situation anyway.
I couldn't find the source code, but it would be nice if you could incorporate those fixes.
Some other things I saw:
- Using symbian native code is not supported by the Nokia Qt SDK (I know it's needed, but if it works, it only works by chance). Instead, QApplication::desktopWidget() emits the resized(int) signal.
- Do not ever use setGeometry() to position an item. use QLayout.
- Even more than annoying users, calling sleep() will block the event loop.