trackCameraPosition is inferred from GoogleMap.onCameraMove (#1314)

* trackCameraPosition is inferred from GoogleMap.onCameraMove

* Update changelog

* update test

* format

Author: iskakaushik

packages/google_maps_flutter/CHANGELOG.md

@@ -2,6 +2,7 @@
 
 * Change events are call backs on GoogleMap widget.
 * GoogleMapController no longer handles change events.
+* trackCameraPosition is inferred from GoogleMap.onCameraMove being set.
 
 ## 0.3.0+3
 

packages/google_maps_flutter/example/lib/map_ui.dart

@@ -175,7 +175,6 @@ class MapUiBodyState extends State<MapUiBody> {
     final GoogleMap googleMap = GoogleMap(
       onMapCreated: onMapCreated,
       initialCameraPosition: _kInitialPosition,
-      trackCameraPosition: true,
       compassEnabled: _compassEnabled,
       cameraTargetBounds: _cameraTargetBounds,
       minMaxZoomPreference: _minMaxZoomPreference,

packages/google_maps_flutter/lib/src/google_map.dart

@@ -9,10 +9,9 @@ typedef void MapCreatedCallback(GoogleMapController controller);
 /// Callback that receives updates to the camera position.
 ///
 /// This callback is triggered when the platform Google Map
-/// registers a camera movement. This will be called with null if
-/// [GoogleMap.trackCameraPosition] is false.
+/// registers a camera movement.
 ///
-/// This is used in [GoogleMap.onCameraMove] and [GoogleMap.onMapOptionsUpdate].
+/// This is used in [GoogleMap.onCameraMove].
 typedef void CameraPositionCallback(CameraPosition position);
 
 class GoogleMap extends StatefulWidget {
@@ -28,7 +27,6 @@ class GoogleMap extends StatefulWidget {
     this.scrollGesturesEnabled = true,
     this.zoomGesturesEnabled = true,
     this.tiltGesturesEnabled = true,
-    this.trackCameraPosition = false,
     this.myLocationEnabled = false,
     this.markers,
     this.onCameraMoveStarted,
@@ -67,9 +65,6 @@ class GoogleMap extends StatefulWidget {
   /// True if the map view should respond to tilt gestures.
   final bool tiltGesturesEnabled;
 
-  /// True if the map view should relay camera move events to Flutter.
-  final bool trackCameraPosition;
-
   /// Markers to be placed on the map.
   final Set<Marker> markers;
 
@@ -81,17 +76,13 @@ class GoogleMap extends StatefulWidget {
   /// 2. Programmatically initiated animation.
   /// 3. Camera motion initiated in response to user gestures on the map.
   ///    For example: pan, tilt, pinch to zoom, or rotate.
-  ///
-  /// Note: This is callback is called even if [trackCameraPosition] is false.
   final VoidCallback onCameraMoveStarted;
 
   /// Called repeatedly as the camera continues to move after an
   /// onCameraMoveStarted call.
   ///
   /// This may be called as often as once every frame and should
   /// not perform expensive operations.
-  ///
-  /// This is only called if [trackCameraPosition] is true.
   final CameraPositionCallback onCameraMove;
 
   /// Called when camera movement has ended, there are no pending
@@ -259,7 +250,7 @@ class _GoogleMapOptions {
       rotateGesturesEnabled: map.rotateGesturesEnabled,
       scrollGesturesEnabled: map.scrollGesturesEnabled,
       tiltGesturesEnabled: map.tiltGesturesEnabled,
-      trackCameraPosition: map.trackCameraPosition,
+      trackCameraPosition: map.onCameraMove != null,
       zoomGesturesEnabled: map.zoomGesturesEnabled,
       myLocationEnabled: map.myLocationEnabled,
     );

packages/google_maps_flutter/test/google_map_test.dart

@@ -303,7 +303,6 @@ void main() {
         textDirection: TextDirection.ltr,
         child: GoogleMap(
           initialCameraPosition: CameraPosition(target: LatLng(10.0, 15.0)),
-          trackCameraPosition: false,
         ),
       ),
     );
@@ -314,11 +313,12 @@ void main() {
     expect(platformGoogleMap.trackCameraPosition, false);
 
     await tester.pumpWidget(
-      const Directionality(
+      Directionality(
         textDirection: TextDirection.ltr,
         child: GoogleMap(
-          initialCameraPosition: CameraPosition(target: LatLng(10.0, 15.0)),
-          trackCameraPosition: true,
+          initialCameraPosition:
+              const CameraPosition(target: LatLng(10.0, 15.0)),
+          onCameraMove: (CameraPosition position) {},
         ),
       ),
     );