QWidgetWindow dispatched only tablet presses to the toplevel widget if
no child was found at the position; other events, such as hover events,
were discarded. The tabletTracking test case even documented that
shortcoming in a comment.
Fix that by falling back to the toplevel widget for any event. As
before, only press events initialize the tablet grabbing target widget.
Remove the now unneeded parent widget from the test case, and move the
test class into the only test function that uses it.
Amends ea615b421b and
8fd6cef372.
Pick-to: 6.4
Fixes: QTBUG-108747
Change-Id: I79050f1e063931e439945f64b50712dcc1ecb18c
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>
7956d9e060