Add raster from file

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// 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:io';

import 'package:arcgis_maps/arcgis_maps.dart';
import 'package:arcgis_maps_sdk_flutter_samples/common/common.dart';
import 'package:flutter/material.dart';
import 'package:path_provider/path_provider.dart';

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

  @override
  State<AddRasterFromFile> createState() => _AddRasterFromFileState();
}

class _AddRasterFromFileState extends State<AddRasterFromFile>
    with SampleStateSupport {
  // Create a controller for the map view.
  final _mapViewController = ArcGISMapView.createController();
  // download message
  var _downloadMessage = '';

  // A flag for when the map view is ready and controls can be used.
  var _ready = false;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Stack(
        children: [
          // Add a map view to the widget tree and set a controller.
          ArcGISMapView(
            controllerProvider: () => _mapViewController,
            onMapViewReady: onMapViewReady,
          ),
          // Display a progress indicator and prevent interaction until state is ready.
          LoadingIndicator(visible: !_ready, text: _downloadMessage),
        ],
      ),
    );
  }

  Future<void> onMapViewReady() async {
    // Create a map with the ArcGIS ImageryStandard basemap style and set to the map view.
    final map = ArcGISMap.withBasemapStyle(BasemapStyle.arcGISImageryStandard);

    // Set the map on the map view controller.
    _mapViewController.arcGISMap = map;

    // Load the raster layer.
    final rasterLayer = await loadRasterLayerFromFile();

    if (rasterLayer != null) {
      // Add the raster layer to the map's operational layers.
      map.operationalLayers.add(rasterLayer);

      // Set the viewpoint to the center of the raster layer's full extent.
      final fullExtent = rasterLayer.fullExtent;
      if (fullExtent != null) {
        final viewpoint = Viewpoint.fromCenter(fullExtent.center, scale: 80000);

        // Set the viewpoint to the raster layer.
        _mapViewController.setViewpoint(viewpoint);
      }
    }
    // Set the ready state variable to true to enable the sample UI.
    setState(() => _ready = true);
  }

  Future<RasterLayer?> loadRasterLayerFromFile() async {
    const downloadFileName = 'raster-file';
    final appDir = await getApplicationDocumentsDirectory();
    final zipFile = File('${appDir.absolute.path}/$downloadFileName.zip');
    final shastaTifFile = File(
      '${appDir.absolute.path}/$downloadFileName/$downloadFileName/Shasta.tif',
    );

    // Download the sample data if it does not exist.
    if (!zipFile.existsSync()) {
      await downloadSampleDataWithProgress(
        itemIds: ['7c4c679ab06a4df19dc497f577f111bd'],
        destinationFiles: [zipFile],
        onProgress: (progress) {
          setState(
            () =>
                _downloadMessage =
                    'Downloading raster file... ${progress * 100}%',
          );
        },
      );
    }

    // Create a raster from the file URI.
    final raster = Raster.withFileUri(shastaTifFile.uri);
    // Load the raster object.
    await raster.load();

    // Create a raster layer using the raster object.
    final rasterLayer = RasterLayer.withRaster(raster);
    return rasterLayer;
  }
}