Qt5 has a new function QMetaMethod::fromSignal() for obtaining
the meta-method that corresponds to a particular signal (member
function).
This also avoids calling the virtual metaObject() function to
resolve the meta-method every time the signal is emitted; it is
known at compile-time which class the signals are defined in,
so it's safe to retain the meta-methods across calls.
Change-Id: I47328ec2dfc335c570fb18bcd304a2ee405bfd6e
Reviewed-by: Dmytro Poplavskiy <dmytro.poplavskiy@nokia.com>
71e25920da