If a floating QWidget has a parent on a different screen, its DPI was
still inherited from the parent instead of taken from the screen.
The only reason we did was in case there is a customDpi set.
(customDpi is a private thing that is only used in designer to change
the appearance of the previewed widget)
So instead of recursing into QWidget::metric for each ancestor, just
use a for loop to find if one parent has a customDpi. If no customDpi
is found, then return the DPI of the right screen.
Task-number: QTBUG-58959
Task-number: QTBUG-48242
Change-Id: Ie6e9e48cdd10234994c0919ba3aea9b0cdb52494
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>
1d9270ee42