[google_maps_flutter] Add pointForMeters to plugin in iOS

packages/google_maps_flutter/CHANGELOG.md

@@ -1,3 +1,8 @@
+## 0.5.22+2
+
+* Support projection method pointForMeters to get the distance in meters to content size
+  from the specified LatLng in the map.
+
 ## 0.5.22+1
 
 * Fix for toggling traffic layer on Android not working

packages/google_maps_flutter/example/test_driver/google_maps_e2e.dart

@@ -718,6 +718,35 @@ void main() {
     expect(topLeft, const ScreenCoordinate(x: 0, y: 0));
   });
 
+  testWidgets('testGetDistance', (WidgetTester tester) async {
+    final Key key = GlobalKey();
+    final Completer<GoogleMapController> controllerCompleter =
+        Completer<GoogleMapController>();
+
+    await tester.pumpWidget(Directionality(
+      textDirection: TextDirection.ltr,
+      child: GoogleMap(
+        key: key,
+        initialCameraPosition: _kInitialCameraPosition,
+        onMapCreated: (GoogleMapController controller) {
+          controllerCompleter.complete(controller);
+        },
+      ),
+    ));
+    final GoogleMapController controller = await controllerCompleter.future;
+
+    // We suspected a bug in the iOS Google Maps SDK caused the camera is not properly positioned at
+    // initialization. https://github.com/flutter/flutter/issues/24806
+    // This temporary workaround fix is provided while the actual fix in the Google Maps SDK is
+    // still being investigated.
+    // TODO(cyanglaz): Remove this temporary fix once the Maps SDK issue is resolved.
+    // https://github.com/flutter/flutter/issues/27550
+    await tester.pumpAndSettle(const Duration(seconds: 3));
+
+    final double distance = await controller.getDistance(1, _kInitialMapCenter);
+    expect(distance, 0.00020464534463826567);
+  });
+
   testWidgets('testResizeWidget', (WidgetTester tester) async {
     final Completer<GoogleMapController> controllerCompleter =
         Completer<GoogleMapController>();

packages/google_maps_flutter/ios/Classes/GoogleMapController.m

@@ -169,6 +169,18 @@ - (void)onMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
                                  message:@"getLatLng called prior to map initialization"
                                  details:nil]);
     }
+  } else if ([call.method isEqualToString:@"map#getDistance"]) {
+    if (_mapView != nil) {
+      CLLocationDistance meter = ToDouble(call.arguments[@"meter"]);
+      CLLocationCoordinate2D location =
+          [FLTGoogleMapJsonConversions toLocation:call.arguments[@"location"]];
+      CGFloat distance = [_mapView.projection pointsForMeters:meter atCoordinate:location];
+      result(@(distance));
+    } else {
+      result([FlutterError errorWithCode:@"GoogleMap uninitialized"
+                                 message:@"getPoints called prior to map initialization"
+                                 details:nil]);
+    }
   } else if ([call.method isEqualToString:@"map#waitForMap"]) {
     result(nil);
   } else if ([call.method isEqualToString:@"markers#update"]) {

packages/google_maps_flutter/lib/src/controller.dart

@@ -236,4 +236,15 @@ class GoogleMapController {
         'map#getLatLng', screenCoordinate._toJson());
     return LatLng(latLng[0], latLng[1]);
   }
+
+  /// Returns [double] corresponding to the distance in meters of the [LatLng] in the current map view.
+  ///
+  /// Return NaN (Not-a-Number) if unable to get distance in meters.
+  /// This is only accurate for small Earth distances.
+  Future<double> getDistance(double meters, LatLng latLng) async {
+    final double distance = await channel.invokeMethod<double>(
+        'map#getDistance',
+        <String, dynamic>{"meter": meters, "location": latLng._toJson()});
+    return distance;
+  }
 }

packages/google_maps_flutter/pubspec.yaml

@@ -1,7 +1,7 @@
 name: google_maps_flutter
 description: A Flutter plugin for integrating Google Maps in iOS and Android applications.
 homepage: https://github.com/flutter/plugins/tree/master/packages/google_maps_flutter
-version: 0.5.22+1
+version: 0.5.22+2
 
 dependencies:
   flutter: