QObject::timer/thread problem in PlaybackBoxHelper

[Jeff Lu <jll544@…>]

While a PlaybackBox? is active on an FE, the console prints "QObject::startTimer: timers cannot be started from another thread" and "QObject::killTimer: timers cannot be stopped from another thread". More precisely, for me start/killTimer prints an error in Windows but fails silently in Linux (verified by watching for free space queries with "-v network").

Error is caused by PlaybackBoxHelper::UpdateFreeSpace? attempting to manipulate timers while called from PBHEventHandler::event. The helper was created in a different thread than the event handler, so PBHEventHandler cannot start/kill timers belonging to PlaybackBoxHelper?.

Attached patch is one way to fix this problem: move the free space timer from PlaybackBoxHelper? to PBHEventHandler.

[Jeff Lu <jll544@…>]

took too many letters out of the variable name

[danielk]

(In [23522]) Fixes #8053. Applies Qt timer fix for the update free space time. I broke this when introducing the PBBhelper class (after spending so much time fixing these issues for #5318, doh!)