Used QGesture for this as per the gesture example.
Moved the help and info text to separate lines.
Enabled word wrap to prevent text going off screen.
As a drive-by, the code to center the window at a size that's a fraction
of the screen is replaced with a simple sizeHint() override. The user
should have control over placement, particularly now that it should be
placed manually onto a touchscreen if the user has one.
Done-with: Shawn Rutledge
Fixes: QTBUG-96702
Pick-to: 6.4
Change-Id: I8dba8b09bed474f585341e9a7a8c71fb60293eee
Reviewed-by: Rami Potinkara <rami.potinkara@qt.io>
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>