Add raster from service

// Copyright 2025 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 'package:arcgis_maps/arcgis_maps.dart';
import 'package:arcgis_maps_sdk_flutter_samples/common/busy_indicator.dart';
import 'package:arcgis_maps_sdk_flutter_samples/common/common.dart';
import 'package:flutter/material.dart';

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

  @override
  State<AddRasterFromService> createState() => _AddRasterFromServiceState();
}

class _AddRasterFromServiceState extends State<AddRasterFromService>
    with SampleStateSupport {
  // Create a controller for the map view.
  final _mapViewController = ArcGISMapView.createController();
  // A flag indicating the map is currently drawing layers.
  var _drawing = false;
  // A flag for when the map view is ready and controls can be used.
  var _ready = false;
  // A subscription to listen for MapViewController draw status state changes.
  late final StreamSubscription _drawStatusChangedSubscription;
  // A subscription to listen for layer view state changes.
  late final StreamSubscription _layerViewChangedSubscription;

  @override
  void dispose() {
    _drawStatusChangedSubscription.cancel();
    _layerViewChangedSubscription.cancel();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Stack(
        children: [
          ArcGISMapView(
            controllerProvider: () => _mapViewController,
            onMapViewReady: onMapViewReady,
          ),
          LoadingIndicator(visible: !_ready),
          BusyIndicator(labelText: 'Drawing...', visible: _drawing),
        ],
      ),
    );
  }

  void onMapViewReady() {
    _drawStatusChangedSubscription = _mapViewController.onDrawStatusChanged
        .listen((status) {
          if (status == DrawStatus.inProgress) {
            setState(() => _drawing = true);
          } else {
            setState(() => _drawing = false);
          }
        });

    // Create a map with the ArcGIS DarkGrayBase basemap style and set to the map view.
    final map = ArcGISMap.withBasemapStyle(BasemapStyle.arcGISDarkGrayBase);

    // Set the map to the map view.
    _mapViewController.arcGISMap = map;

    // Creates an initial viewpoint with a coordinate point centered on
    // San Francisco's Golden Gate Bridge.
    _mapViewController.setViewpoint(
      Viewpoint.fromCenter(
        ArcGISPoint(
          x: -13637000,
          y: 4550000,
          spatialReference: SpatialReference.webMercator,
        ),
        scale: 100000,
      ),
    );

    // Creates a raster from an image service.
    final imageServiceRaster = ImageServiceRaster(
      uri: Uri.parse(
        'https://gis.ngdc.noaa.gov/arcgis/rest/services/bag_hillshades_subsets/ImageServer',
      ),
    );

    // Create a raster layer from the raster.
    final rasterLayer = RasterLayer.withRaster(imageServiceRaster);

    // Add Raster layer to the map.
    map.operationalLayers.add(rasterLayer);
    // Listen for layer view state changes.
    _layerViewChangedSubscription = _mapViewController.onLayerViewStateChanged
        .listen((layerViewState) {
          if (layerViewState.layer == rasterLayer &&
              layerViewState.layerViewState.status.contains(
                LayerViewStatus.active,
              )) {
            setState(() => _ready = true);
          }
        });
  }
}