[google_maps_flutter] Support for Ground Overlay

packages/google_maps_flutter/google_maps_flutter/example/lib/ground_overlay.dart

@@ -0,0 +1,333 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// ignore_for_file: public_member_api_docs
+
+import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart';
+import 'package:google_maps_flutter/google_maps_flutter.dart';
+
+import 'page.dart';
+
+enum _GroundOverlayPlacing { position, bounds }
+
+class GroundOverlayPage extends GoogleMapExampleAppPage {
+  const GroundOverlayPage({Key? key})
+      : super(const Icon(Icons.map), 'Ground overlay', key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return const GroundOverlayBody();
+  }
+}
+
+class GroundOverlayBody extends StatefulWidget {
+  const GroundOverlayBody({super.key});
+
+  @override
+  State<StatefulWidget> createState() => GroundOverlayBodyState();
+}
+
+class GroundOverlayBodyState extends State<GroundOverlayBody> {
+  GroundOverlayBodyState();
+
+  GoogleMapController? controller;
+  GroundOverlay? _groundOverlay;
+
+  final LatLng _mapCenter = const LatLng(37.422026, -122.085329);
+
+  _GroundOverlayPlacing _placingType = _GroundOverlayPlacing.bounds;
+
+  // Positions for demonstranting placing ground overlays with position, and
+  // changing positions.
+  final LatLng _groundOverlayPos1 = const LatLng(37.422026, -122.085329);
+  final LatLng _groundOverlayPos2 = const LatLng(37.42, -122.08);
+  late LatLng _currentGroundOverlayPos;
+
+  // Bounds for demonstranting placing ground overlays with bounds, and
+  // changing bounds.
+  final LatLngBounds _groundOverlayBounds1 = LatLngBounds(
+      southwest: const LatLng(37.42, -122.09),
+      northeast: const LatLng(37.423, -122.084));
+  final LatLngBounds _groundOverlayBounds2 = LatLngBounds(
+      southwest: const LatLng(37.421, -122.091),
+      northeast: const LatLng(37.424, -122.08));
+  late LatLngBounds _currentGroundOverlayBounds;
+
+  Offset _anchor = const Offset(0.5, 0.5);
+
+  Offset _dimensions = const Offset(1000, 1000);
+
+  // Index to be used as identifier for the ground overlay.
+  // If position is changed to bounds and vice versa, the ground overlay will
+  // be removed and added again with the new type. Also anchor can be given only
+  // when the ground overlay is created with position and cannot be changed
+  // after the ground overlay is created.
+  int _groundOverlayIndex = 0;
+
+  @override
+  void initState() {
+    _currentGroundOverlayPos = _groundOverlayPos1;
+    _currentGroundOverlayBounds = _groundOverlayBounds1;
+    super.initState();
+  }
+
+  // ignore: use_setters_to_change_properties
+  void _onMapCreated(GoogleMapController controller) {
+    this.controller = controller;
+  }
+
+  void _removeGroundOverlay() {
+    setState(() {
+      _groundOverlay = null;
+    });
+  }
+
+  Future<void> _addGroundOverlay() async {
+    final AssetMapBitmap assetMapBitmap = await AssetMapBitmap.create(
+      createLocalImageConfiguration(context),
+      'assets/red_square.png',
+      bitmapScaling: MapBitmapScaling.none,
+    );
+
+    _groundOverlayIndex += 1;
+
+    final GroundOverlayId id =
+        GroundOverlayId('ground_overlay_$_groundOverlayIndex');
+
+    final GroundOverlay groundOverlay = switch (_placingType) {
+      _GroundOverlayPlacing.position => GroundOverlay.fromPosition(
+          groundOverlayId: id,
+          image: assetMapBitmap,
+          position: _currentGroundOverlayPos,
+          width: _dimensions.dx, // Android only
+          height: _dimensions.dy, // Android only
+          zoomLevel: 14.0, // iOS only
+          anchor: _anchor,
+          onTap: () {
+            _onGroundOverlayTapped();
+          },
+        ),
+      _GroundOverlayPlacing.bounds => GroundOverlay.fromBounds(
+          groundOverlayId: id,
+          image: assetMapBitmap,
+          bounds: _currentGroundOverlayBounds,
+          anchor: _anchor,
+          onTap: () {
+            _onGroundOverlayTapped();
+          },
+        ),
+    };
+
+    setState(() {
+      _groundOverlay = groundOverlay;
+    });
+  }
+
+  void _onGroundOverlayTapped() {
+    _changePosition();
+  }
+
+  void _setBearing() {
+    assert(_groundOverlay != null);
+    setState(() {
+      _groundOverlay = _groundOverlay!.copyWith(
+          bearingParam: _groundOverlay!.bearing >= 350
+              ? 0
+              : _groundOverlay!.bearing + 10);
+    });
+  }
+
+  void _changeTransparency() {
+    assert(_groundOverlay != null);
+    setState(() {
+      final double transparency =
+          _groundOverlay!.transparency == 0.0 ? 0.5 : 0.0;
+      _groundOverlay =
+          _groundOverlay!.copyWith(transparencyParam: transparency);
+    });
+  }
+
+  Future<void> _changeDimensions() async {
+    assert(_groundOverlay != null);
+    assert(_placingType == _GroundOverlayPlacing.position);
+    setState(() {
+      _dimensions = _dimensions == const Offset(1000, 1000)
+          ? const Offset(1500, 500)
+          : const Offset(1000, 1000);
+    });
+
+    // Re-add the ground overlay to apply the new position, as the position
+    // cannot be changed after the ground overlay is created on all platforms.
+    await _addGroundOverlay();
+  }
+
+  Future<void> _changePosition() async {
+    assert(_groundOverlay != null);
+    assert(_placingType == _GroundOverlayPlacing.position);
+    setState(() {
+      _currentGroundOverlayPos = _currentGroundOverlayPos == _groundOverlayPos1
+          ? _groundOverlayPos2
+          : _groundOverlayPos1;
+    });
+
+    // Re-add the ground overlay to apply the new position, as the position
+    // cannot be changed after the ground overlay is created on all platforms.
+    await _addGroundOverlay();
+  }
+
+  Future<void> _changeBounds() async {
+    assert(_groundOverlay != null);
+    assert(_placingType == _GroundOverlayPlacing.bounds);
+    setState(() {
+      _currentGroundOverlayBounds =
+          _currentGroundOverlayBounds == _groundOverlayBounds1
+              ? _groundOverlayBounds2
+              : _groundOverlayBounds1;
+    });
+
+    // Re-add the ground overlay to apply the new bounds as the bounds cannot be
+    // changed after the ground overlay is created on all platforms.
+    await _addGroundOverlay();
+  }
+
+  void _toggleVisible() {
+    assert(_groundOverlay != null);
+    setState(() {
+      _groundOverlay =
+          _groundOverlay!.copyWith(visibleParam: !_groundOverlay!.visible);
+    });
+  }
+
+  void _changeZIndex() {
+    assert(_groundOverlay != null);
+    final int current = _groundOverlay!.zIndex;
+    final int zIndex = current == 12 ? 0 : current + 1;
+    setState(() {
+      _groundOverlay = _groundOverlay!.copyWith(zIndexParam: zIndex);
+    });
+  }
+
+  Future<void> _changeType() async {
+    setState(() {
+      _placingType = _placingType == _GroundOverlayPlacing.position
+          ? _GroundOverlayPlacing.bounds
+          : _GroundOverlayPlacing.position;
+    });
+
+    // Re-add the ground overlay to change the positioning type.
+    await _addGroundOverlay();
+  }
+
+  Future<void> _changeAnchor() async {
+    assert(_groundOverlay != null);
+    setState(() {
+      _anchor = _groundOverlay!.anchor == const Offset(0.5, 0.5)
+          ? const Offset(1.0, 1.0)
+          : const Offset(0.5, 0.5);
+    });
+
+    // Re-add the ground overlay to apply the new anchor as the anchor cannot be
+    // changed after the ground overlay is created.
+    await _addGroundOverlay();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final Set<GroundOverlay> overlays = <GroundOverlay>{
+      if (_groundOverlay != null) _groundOverlay!,
+    };
+    return Column(
+      mainAxisSize: MainAxisSize.min,
+      mainAxisAlignment: MainAxisAlignment.spaceEvenly,
+      crossAxisAlignment: CrossAxisAlignment.stretch,
+      children: <Widget>[
+        Expanded(
+          child: GoogleMap(
+            initialCameraPosition: CameraPosition(
+              target: _mapCenter,
+              zoom: 14.0,
+            ),
+            groundOverlays: overlays,
+            onMapCreated: _onMapCreated,
+          ),
+        ),
+        Row(
+          mainAxisAlignment: MainAxisAlignment.spaceEvenly,
+          children: <Widget>[
+            TextButton(
+              onPressed: _groundOverlay == null ? _addGroundOverlay : null,
+              child: const Text('Add'),
+            ),
+            TextButton(
+              onPressed: _groundOverlay != null ? _removeGroundOverlay : null,
+              child: const Text('Remove'),
+            ),
+          ],
+        ),
+        Wrap(
+          alignment: WrapAlignment.spaceEvenly,
+          children: <Widget>[
+            TextButton(
+              onPressed:
+                  _groundOverlay == null ? null : () => _changeTransparency(),
+              child: const Text('change transparency'),
+            ),
+            if (!kIsWeb)
+              TextButton(
+                onPressed: _groundOverlay == null ? null : () => _setBearing(),
+                child: const Text('change bearing'),
+              ),
+            TextButton(
+              onPressed: _groundOverlay == null ? null : () => _toggleVisible(),
+              child: const Text('toggle visible'),
+            ),
+            if (!kIsWeb)
+              TextButton(
+                onPressed:
+                    _groundOverlay == null ? null : () => _changeZIndex(),
+                child: const Text('change zIndex'),
+              ),
+            if (!kIsWeb)
+              TextButton(
+                onPressed:
+                    _groundOverlay == null ? null : () => _changeAnchor(),
+                child: const Text('change anchor'),
+              ),
+            if (!kIsWeb)
+              TextButton(
+                onPressed: _groundOverlay == null ? null : () => _changeType(),
+                child: Text(_placingType == _GroundOverlayPlacing.position
+                    ? 'use bounds'
+                    : 'use position'),
+              ),
+            if (!kIsWeb)
+              TextButton(
+                onPressed: _placingType != _GroundOverlayPlacing.position ||
+                        _groundOverlay == null
+                    ? null
+                    : () => _changePosition(),
+                child: const Text('change position'),
+              ),
+            if (defaultTargetPlatform == TargetPlatform.android)
+              TextButton(
+                onPressed: _placingType != _GroundOverlayPlacing.position ||
+                        _groundOverlay == null
+                    ? null
+                    : () => _changeDimensions(),
+                child: const Text('change dimensions'),
+              ),
+            TextButton(
+              onPressed: _placingType != _GroundOverlayPlacing.bounds ||
+                      _groundOverlay == null
+                  ? null
+                  : () => _changeBounds(),
+              child: const Text('change bounds'),
+            ),
+          ],
+        ),
+      ],
+    );
+  }
+}

packages/google_maps_flutter/google_maps_flutter/example/lib/main.dart

@@ -10,6 +10,7 @@ import 'package:google_maps_flutter_platform_interface/google_maps_flutter_platf
 
 import 'animate_camera.dart';
 import 'clustering.dart';
+import 'ground_overlay.dart';
 import 'heatmap.dart';
 import 'lite_mode.dart';
 import 'map_click.dart';
@@ -44,6 +45,7 @@ final List<GoogleMapExampleAppPage> _allPages = <GoogleMapExampleAppPage>[
   const SnapshotPage(),
   const LiteModePage(),
   const TileOverlayPage(),
+  const GroundOverlayPage(),
   const ClusteringPage(),
   const MapIdPage(),
   const HeatmapPage(),

packages/google_maps_flutter/google_maps_flutter/example/pubspec.yaml

@@ -33,3 +33,25 @@ flutter:
   uses-material-design: true
   assets:
     - assets/
+
+# FOR TESTING AND INITIAL REVIEW ONLY. DO NOT MERGE.
+# See https://github.com/flutter/flutter/blob/master/docs/ecosystem/contributing/README.md#changing-federated-plugins
+dependency_overrides:
+  {
+    google_maps_flutter_android:
+      {
+        path: ../../../../packages/google_maps_flutter/google_maps_flutter_android,
+      },
+    google_maps_flutter_ios:
+      {
+        path: ../../../../packages/google_maps_flutter/google_maps_flutter_ios,
+      },
+    google_maps_flutter_platform_interface:
+      {
+        path: ../../../../packages/google_maps_flutter/google_maps_flutter_platform_interface,
+      },
+    google_maps_flutter_web:
+      {
+        path: ../../../../packages/google_maps_flutter/google_maps_flutter_web,
+      },
+  }

packages/google_maps_flutter/google_maps_flutter/lib/google_maps_flutter.dart

@@ -29,6 +29,8 @@ export 'package:google_maps_flutter_platform_interface/google_maps_flutter_platf
         Cluster,
         ClusterManager,
         ClusterManagerId,
+        GroundOverlay,
+        GroundOverlayId,
         Heatmap,
         HeatmapGradient,
         HeatmapGradientColor,