Comment 17 for bug 62949

Pasting an email from TrollTech here:

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Qt can only provide an API to 5 mouse buttons, as other windowing
systems, i.e. Win32, do not support anything beyond L, R, M, X1 and X1
at this point.

http://doc.trolltech.com/4.0/qt.html#MouseButton-enum

KDE, and specifically KDE's window manager, could implement handling for
more mouse buttons by reimplementing QWidget::x11Event() in a platform
specific fashion.
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