onPointerSignal method

dynamic onPointerSignal(
  1. PointerSignalEvent e
)

Here is for web and desktop, when wheel scrolling of mouse, it will apply or remove zoom

Implementation

onPointerSignal(PointerSignalEvent e) {
  if (e is PointerScrollEvent) {
    final sl = e.scrollDelta.dy;

    if (sl > 0) {
      // to down
      if (ctMap.zoom > 3) {
        ctMap.zoom -= 0.5;
      }
    } else {
      // to up
      if (ctMap.zoom <= 20.5) {
        ctMap.zoom += 0.5;
      }
    }
  }
}