Hi,
I am currently working on upgrading Qt from version 5.4.2 to version 5.5.1 in my application. It's all working fine, except for a problem I am having with QwtPlotDirectPainter on OS X. That problem is the one I described here and here, i.e. that sometimes part of or all of the plotting area becomes black.
Now, unlike in the first link where I tried to solve my problem by setting QwtPlotDirectPainter::FullRepaint to true, this time I decided to find out at what point, in the Qwt code, things go 'wrong'. Wrong in quotes because the problem might indeed be with Qt 5.5.1 and not Qwt as such, but the fact is that it's much easier and quicker to find out what goes 'wrong' in Qwt than in Qt.
Anyway, the bottom line is that the 'problem' lies in QwtPlotDirectPainter::drawSeries(). Now, the fix that seems to be working consists of commenting out the installation/removal of an event filter (see here). I must confess that I don't quite understand the reason for that filter since such an event filter will always return false in the case of a canvas, or am I missing something? (Actually, I might since having that event filter does make things go 'wrong'!)
Whatever the case, I am wondering my 'fix' is 'valid', 'acceptable'?
Cheers, Alan.
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