the zoom speed using the mouse wheel can be adjusted (#1289)

* the zoom speed using the mouse wheel can be adjusted * fixed formatting Co-authored-by: Martin Böttcher <martin.boettcher@greenbytes.de>
fleaflet · Jun 28, 2022 · bee620c · bee620c
1 parent 6bca06c
commit bee620c
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Showing 2 changed files with 5 additions and 1 deletion.
diff --git a/lib/flutter_map.dart b/lib/flutter_map.dart
@@ -253,6 +253,7 @@ class MapOptions {
   /// his mouse. This is supported on web and desktop, but might also work well
   /// on Android. A [Listener] is used to capture the onPointerSignal events.
   final bool enableScrollWheel;
+  final double scrollWheelVelocity;
 
   final double? minZoom;
   final double? maxZoom;
@@ -309,6 +310,7 @@ class MapOptions {
     this.pinchMoveWinGestures =
         MultiFingerGesture.pinchZoom | MultiFingerGesture.pinchMove,
     this.enableScrollWheel = true,
+    this.scrollWheelVelocity = 0.005,
     this.minZoom,
     this.maxZoom,
     this.interactiveFlags = InteractiveFlag.all,

diff --git a/lib/src/gestures/gestures.dart b/lib/src/gestures/gestures.dart
@@ -58,7 +58,9 @@ abstract class MapGestureMixin extends State<FlutterMap>
       // Calculate new zoom level
       final minZoom = mapState.options.minZoom ?? 0.0;
       final maxZoom = mapState.options.maxZoom ?? double.infinity;
-      final newZoom = (mapState.zoom + pointerSignal.scrollDelta.dy * -0.005)
+      final newZoom = (mapState.zoom -
+              pointerSignal.scrollDelta.dy *
+                  mapState.options.scrollWheelVelocity)
           .clamp(minZoom, maxZoom);
       // Calculate offset of mouse cursor from viewport center
       final List<dynamic> newCenterZoom = _getNewEventCenterZoomPosition(