digital_electricity limit pan area
limit zoom area to have 2 levels of zoom in and 2 levels of zoom out limit pan area accordingly
(cherry picked from commit 26dca81473d3a3b6c61618e7d014575f69f3b611)
it's better to use the real types in qml (int, real, double, string...)
no need of the 0 here and below
cleaned those, thanks