fix: PolylineLayer throws exception: "The west longitude can't be s…

…maller than the east longitude" (#1879)

lib/src/geo/latlng_bounds.dart

@@ -6,6 +6,18 @@ import 'package:vector_math/vector_math_64.dart';
 /// Data structure representing rectangular bounding box constrained by its
 /// northwest and southeast corners
 class LatLngBounds {
+ /// minimum latitude value, south
+ static const double minLatitude = -90;
+
+ /// maximum latitude value, north
+ static const double maxLatitude = 90;
+
+ /// minimum longitude value, west
+ static const double minLongitude = -180;
+
+ /// maximum longitude value, east
+ static const double maxLongitude = 180;
+
  /// The latitude north edge of the bounds
  double north;
 
@@ -61,26 +73,32 @@ class LatLngBounds {
  required this.south,
  required this.east,
  required this.west,
- }) : assert(
- north <= 90, "The north latitude can't be bigger than 90: $north"),
- assert(north >= -90,
- "The north latitude can't be smaller than -90: $north"),
- assert(
- south <= 90, "The south latitude can't be bigger than 90: $south"),
- assert(south >= -90,
- "The south latitude can't be smaller than -90: $south"),
+ }) : assert(north <= maxLatitude,
+ "The north latitude can't be bigger than $maxLatitude: $north"),
+ assert(north >= minLatitude,
+ "The north latitude can't be smaller than $minLatitude: $north"),
+ assert(south <= maxLatitude,
+ "The south latitude can't be bigger than $maxLatitude: $south"),
+ assert(south >= minLatitude,
+ "The south latitude can't be smaller than $minLatitude: $south"),
+ assert(east <= maxLongitude,
+ "The east longitude can't be bigger than $maxLongitude: $east"),
+ assert(east >= minLongitude,
+ "The east longitude can't be smaller than $minLongitude: $east"),
+ assert(west <= maxLongitude,
+ "The west longitude can't be bigger than $maxLongitude: $west"),
+ assert(west >= minLongitude,
+ "The west longitude can't be smaller than $minLongitude: $west"),
  assert(
- east <= 180, "The east longitude can't be bigger than 180: $east"),
- assert(east >= -180,
- "The east longitude can't be smaller than -180: $east"),
+ north >= south,
+ "The north latitude ($north) can't be smaller than the "
+ 'south latitude ($south)',
+ ),
  assert(
- west <= 180, "The west longitude can't be bigger than 180: $west"),
- assert(west >= -180,
- "The west longitude can't be smaller than -180: $west"),
- assert(north >= south,
- "The north latitude can't be smaller than the south latitude"),
- assert(east >= west,
- "The west longitude can't be smaller than the east longitude");
+ east >= west,
+ "The west longitude ($west) can't be smaller than the "
+ 'east longitude ($east)',
+ );
 
  /// Create a new [LatLngBounds] from a list of [LatLng] points. This
  /// calculates the bounding box of the provided points.
@@ -90,10 +108,10 @@ class LatLngBounds {
  'LatLngBounds cannot be created with an empty List of LatLng',
  );
  // initialize bounds with max values.
- double minX = 180;
- double maxX = -180;
- double minY = 90;
- double maxY = -90;
+ double minX = maxLongitude;
+ double maxX = minLongitude;
+ double minY = maxLatitude;
+ double maxY = minLatitude;
  // find the largest and smallest latitude and longitude
  for (final point in points) {
  if (point.longitude < minX) minX = point.longitude;
@@ -112,20 +130,20 @@ class LatLngBounds {
  /// Expands bounding box by [latLng] coordinate point. This method mutates
  /// the bounds object on which it is called.
  void extend(LatLng latLng) {
- north = min(90, max(north, latLng.latitude));
- south = max(-90, min(south, latLng.latitude));
- east = min(180, max(east, latLng.longitude));
- west = max(-180, min(west, latLng.longitude));
+ north = min(maxLatitude, max(north, latLng.latitude));
+ south = max(minLatitude, min(south, latLng.latitude));
+ east = min(maxLongitude, max(east, latLng.longitude));
+ west = max(minLongitude, min(west, latLng.longitude));
  }
 
  /// Expands bounding box by other [bounds] object. If provided [bounds] object
  /// is smaller than current one, it is not shrunk. This method mutates
  /// the bounds object on which it is called.
  void extendBounds(LatLngBounds bounds) {
- north = min(90, max(north, bounds.north));
- south = max(-90, min(south, bounds.south));
- east = min(180, max(east, bounds.east));
- west = max(-180, min(west, bounds.west));
+ north = min(maxLatitude, max(north, bounds.north));
+ south = max(minLatitude, min(south, bounds.south));
+ east = min(maxLongitude, max(east, bounds.east));
+ west = max(minLongitude, min(west, bounds.west));
  }
 
  /// Obtain coordinates of southwest corner of the bounds.

lib/src/layer/polyline_layer/polyline_layer.dart

@@ -169,10 +169,10 @@ class _PolylineLayerState<R extends Object> extends State<PolylineLayer<R>> {
  // The min(-90), max(180), ... are used to get around the limits of LatLng
  // the value cannot be greater or smaller than that
  final boundsAdjusted = LatLngBounds.unsafe(
- west: math.max(-180, bounds.west - margin),
- east: math.min(90, bounds.east + margin),
- south: math.max(-90, bounds.south - margin),
- north: math.min(180, bounds.north + margin),
+ west: math.max(LatLngBounds.minLongitude, bounds.west - margin),
+ east: math.min(LatLngBounds.maxLongitude, bounds.east + margin),
+ south: math.max(LatLngBounds.minLatitude, bounds.south - margin),
+ north: math.min(LatLngBounds.maxLatitude, bounds.north + margin),
  );
 
  // segment is visible