onPanning method

void onPanning(MapPanDetails details)

Called whenever panning is happening.

Subclasses can override this method to do any custom operations based on the details provided in the MapPanDetails. When super.onPanning(details) is not called, panning will not happen.

MapPanDetails contains following properties.

• MapPanDetails.previousVisibleBounds - provides the visible bounds before the current panning operation completes i.e. current visible bounds.
• MapPanDetails.newVisibleBounds - provides the new visible bounds when the current pan completes. Hence, if the super.onPanning(details) is not called, there will be no changes in the UI.
• MapPanDetails.zoomLevel - provides the current zoom level.
• MapPanDetails.delta - The difference in pixels between touch start and current touch position.
• MapPanDetails.globalFocalPoint - The global focal point of the pointers in contact with the screen.
• MapPanDetails.localFocalPoint - The local focal point of the pointers in contact with the screen.

Implementation

void onPanning(MapPanDetails details) {
  if (_controller != null) {
    _latLngBounds = details.newVisibleBounds;
    if (_controller!.layerType == LayerType.shape) {
      _controller!.notifyPanningListeners(details);
      _controller!.notifyListeners();
    } else {
      _controller!
        ..isInInteractive = true
        ..gesture = Gesture.pan
        ..localScale = 1.0
        ..panDistance += details.delta!;
      focalLatLng = details.focalLatLng;
      _controller!.notifyListeners();
    }
  }
}