Show device location

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
//
// Copyright 2024 Esri
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//   https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//

import 'dart:async';
import 'dart:math';

import 'package:arcgis_maps/arcgis_maps.dart';
import 'package:flutter/material.dart';

import '../../utils/sample_state_support.dart';

class ShowDeviceLocation extends StatefulWidget {
  const ShowDeviceLocation({super.key});

  @override
  State<ShowDeviceLocation> createState() => _ShowDeviceLocationState();
}

class _ShowDeviceLocationState extends State<ShowDeviceLocation>
    with SampleStateSupport {
  // Create a controller for the map view.
  final _mapViewController = ArcGISMapView.createController();
  // A flag for when the settings bottom sheet is visible.
  var _settingsVisible = false;
  // Create the system location data source.
  final _locationDataSource = SystemLocationDataSource();
  // A subscription to receive status changes of the location data source.
  StreamSubscription? _statusSubscription;
  var _status = LocationDataSourceStatus.stopped;
  // A subscription to receive changes to the auto-pan mode.
  StreamSubscription? _autoPanModeSubscription;
  var _autoPanMode = LocationDisplayAutoPanMode.recenter;
  // A flag for when the map view is ready and controls can be used.
  var _ready = false;

  @override
  void dispose() {
    // When exiting, stop the location data source and cancel subscriptions.
    _locationDataSource.stop();
    _statusSubscription?.cancel();
    _autoPanModeSubscription?.cancel();

    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SafeArea(
        top: false,
        child: Stack(
          children: [
            Column(
              children: [
                Expanded(
                  // Add a map view to the widget tree and set a controller.
                  child: ArcGISMapView(
                    controllerProvider: () => _mapViewController,
                    onMapViewReady: onMapViewReady,
                  ),
                ),
                Center(
                  child: ElevatedButton(
                    onPressed: _status == LocationDataSourceStatus.failedToStart
                        ? null
                        : () => setState(() => _settingsVisible = true),
                    child: const Text('Location Settings'),
                  ),
                ),
              ],
            ),
            // Display a progress indicator and prevent interaction until state is ready.
            Visibility(
              visible: !_ready,
              child: SizedBox.expand(
                child: Container(
                  color: Colors.white30,
                  child: const Center(child: CircularProgressIndicator()),
                ),
              ),
            ),
          ],
        ),
      ),
      // The Settings bottom sheet.
      bottomSheet: _settingsVisible ? buildSettings(context) : null,
    );
  }

  // The build method for the Geometry Settings bottom sheet.
  Widget buildSettings(BuildContext context) {
    return Container(
      padding: EdgeInsets.fromLTRB(
        20.0,
        20.0,
        20.0,
        max(
          20.0,
          View.of(context).viewPadding.bottom /
              View.of(context).devicePixelRatio,
        ),
      ),
      child: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          Row(
            children: [
              Text(
                'Location Settings',
                style: Theme.of(context).textTheme.titleLarge,
              ),
              const Spacer(),
              IconButton(
                icon: const Icon(Icons.close),
                onPressed: () => setState(() => _settingsVisible = false),
              ),
            ],
          ),
          Row(
            children: [
              const Text('Show Location'),
              const Spacer(),
              // A switch to start and stop the location data source.
              Switch(
                value: _status == LocationDataSourceStatus.started,
                onChanged: (_) {
                  if (_status == LocationDataSourceStatus.started) {
                    _mapViewController.locationDisplay.stop();
                  } else {
                    _mapViewController.locationDisplay.start();
                  }
                },
              ),
            ],
          ),
          Row(
            children: [
              const Text('Auto-Pan Mode'),
              const Spacer(),
              // A dropdown button to select the auto-pan mode.
              DropdownButton(
                value: _autoPanMode,
                onChanged: (value) {
                  _mapViewController.locationDisplay.autoPanMode = value!;
                },
                items: const [
                  DropdownMenuItem(
                    value: LocationDisplayAutoPanMode.off,
                    child: Text('Off'),
                  ),
                  DropdownMenuItem(
                    value: LocationDisplayAutoPanMode.recenter,
                    child: Text('Recenter'),
                  ),
                  DropdownMenuItem(
                    value: LocationDisplayAutoPanMode.navigation,
                    child: Text('Navigation'),
                  ),
                  DropdownMenuItem(
                    value: LocationDisplayAutoPanMode.compassNavigation,
                    child: Text('Compass'),
                  ),
                ],
              ),
            ],
          ),
        ],
      ),
    );
  }

  void onMapViewReady() async {
    // Create a map with the Navigation Night basemap style.
    _mapViewController.arcGISMap =
        ArcGISMap.withBasemapStyle(BasemapStyle.arcGISNavigationNight);

    // Set the initial system location data source and auto-pan mode.
    _mapViewController.locationDisplay.dataSource = _locationDataSource;
    _mapViewController.locationDisplay.autoPanMode =
        LocationDisplayAutoPanMode.recenter;

    // Subscribe to status changes and changes to the auto-pan mode.
    _statusSubscription = _locationDataSource.onStatusChanged.listen((status) {
      setState(() => _status = status);
    });
    setState(() => _status = _locationDataSource.status);
    _autoPanModeSubscription =
        _mapViewController.locationDisplay.onAutoPanModeChanged.listen((mode) {
      setState(() => _autoPanMode = mode);
    });
    setState(
      () => _autoPanMode = _mapViewController.locationDisplay.autoPanMode,
    );

    // Attempt to start the location data source (this will prompt the user for permission).
    try {
      await _locationDataSource.start();
    } on ArcGISException catch (e) {
      if (mounted) {
        showDialog(
          context: context,
          builder: (_) => AlertDialog(content: Text(e.message)),
        );
      }
    }

    // Set the ready state variable to true to enable the UI.
    setState(() => _ready = true);
  }
}