Style graphics with symbols

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

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

  @override
  State<StyleGraphicsWithSymbols> createState() =>
      _StyleGraphicsWithSymbolsState();
}

class _StyleGraphicsWithSymbolsState extends State<StyleGraphicsWithSymbols>
    with SampleStateSupport {
  // Create a controller for the map view.
  final _mapViewController = ArcGISMapView.createController();

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

  final _graphicsOverlay = GraphicsOverlay();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Stack(
        children: [
          ArcGISMapView(
            controllerProvider: () => _mapViewController,
            onMapViewReady: onMapViewReady,
          ),
          // Display a progress indicator and prevent interaction until state is ready.
          Visibility(
            visible: !_ready,
            child: const SizedBox.expand(
              child: ColoredBox(
                color: Colors.white30,
                child: Center(child: CircularProgressIndicator()),
              ),
            ),
          ),
        ],
      ),
    );
  }

  void onMapViewReady() {
    // Create the map.
    final map = ArcGISMap.withBasemapStyle(BasemapStyle.arcGISOceans);

    // Create a point using x and y coordinates.
    final point = ArcGISPoint(
      x: 56.075844,
      y: -2.681572,
      spatialReference: SpatialReference.wgs84,
    );

    // Set the initial viewpoint of the map to the point and provide a scale.
    map.initialViewpoint = Viewpoint.fromCenter(point, scale: 2000);

    // Set the map to the mapview controller.
    _mapViewController.arcGISMap = map;

    // Add graphics overlay to the mapview controller.
    _mapViewController.graphicsOverlays.add(_graphicsOverlay);

    // Call functions to create the graphics.
    _createPoints();
    _createPolyline();
    _createPolygon();
    _createText();

    // Update the extent to encompass all of the symbols.
    _setExtent();

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

  void _createPoints() {
    // Create a red circle simple marker symbol.
    final redCircleSymbol = SimpleMarkerSymbol(
      style: SimpleMarkerSymbolStyle.circle,
      color: Colors.red,
      size: 10,
    );

    // Create graphics and add them to graphics overlay.
    var graphic = Graphic(
      geometry: ArcGISPoint(
        x: -2.72,
        y: 56.065,
        spatialReference: SpatialReference.wgs84,
      ),
      symbol: redCircleSymbol,
    );
    _graphicsOverlay.graphics.add(graphic);

    graphic = Graphic(
      geometry: ArcGISPoint(
        x: -2.69,
        y: 56.065,
        spatialReference: SpatialReference.wgs84,
      ),
      symbol: redCircleSymbol,
    );
    _graphicsOverlay.graphics.add(graphic);

    graphic = Graphic(
      geometry: ArcGISPoint(
        x: -2.66,
        y: 56.065,
        spatialReference: SpatialReference.wgs84,
      ),
      symbol: redCircleSymbol,
    );
    _graphicsOverlay.graphics.add(graphic);

    graphic = Graphic(
      geometry: ArcGISPoint(
        x: -2.63,
        y: 56.065,
        spatialReference: SpatialReference.wgs84,
      ),
      symbol: redCircleSymbol,
    );
    _graphicsOverlay.graphics.add(graphic);
  }

  void _createPolyline() {
    // Create a purple simple line symbol.
    final lineSymbol = SimpleLineSymbol(
      style: SimpleLineSymbolStyle.dash,
      color: Colors.purple,
      width: 10,
    );

    // Build a polyline.
    final polylineBuilder =
        PolylineBuilder(spatialReference: SpatialReference.wgs84);
    polylineBuilder.addPointXY(x: -2.715, y: 56.061);
    polylineBuilder.addPointXY(x: -2.6438, y: 56.079);
    polylineBuilder.addPointXY(x: -2.638, y: 56.079);
    polylineBuilder.addPointXY(x: -2.636, y: 56.078);
    polylineBuilder.addPointXY(x: -2.636, y: 56.077);
    polylineBuilder.addPointXY(x: -2.637, y: 56.076);
    polylineBuilder.addPointXY(x: -2.715, y: 56.061);

    final polyline = polylineBuilder.toGeometry();

    // Create the graphic with polyline and symbol.
    final graphic = Graphic(geometry: polyline, symbol: lineSymbol);

    // Add graphic to the graphics overlay.
    _graphicsOverlay.graphics.add(graphic);
  }

  void _createPolygon() {
    // Create a green dash line symbol.
    final outlineSymbol = SimpleLineSymbol(
      style: SimpleLineSymbolStyle.dash,
      color: Colors.green,
      width: 1,
    );

    // Create a green mesh simple fill symbol.
    final fillSymbol = SimpleFillSymbol(
      style: SimpleFillSymbolStyle.diagonalCross,
      color: Colors.green,
      outline: outlineSymbol,
    );

    // Create a new point collection for polygon.
    final polygonBuilder =
        PolygonBuilder(spatialReference: SpatialReference.wgs84);

    polygonBuilder.addPointXY(x: -2.6425, y: 56.0784);
    polygonBuilder.addPointXY(x: -2.6430, y: 56.0763);
    polygonBuilder.addPointXY(x: -2.6410, y: 56.0759);
    polygonBuilder.addPointXY(x: -2.6380, y: 56.0765);
    polygonBuilder.addPointXY(x: -2.6380, y: 56.0784);
    polygonBuilder.addPointXY(x: -2.6410, y: 56.0786);

    final polygon = polygonBuilder.toGeometry();

    // Create the graphic with polygon and symbol.
    final graphic = Graphic(geometry: polygon, symbol: fillSymbol);

    // Add graphic to the graphics overlay.
    _graphicsOverlay.graphics.add(graphic);
  }

  void _createText() {
    // Create two text symbols.
    final bassRockTextSymbol = TextSymbol(
      text: 'Black Rock',
      color: Colors.blue,
      size: 10,
      horizontalAlignment: HorizontalAlignment.left,
      verticalAlignment: VerticalAlignment.bottom,
    );

    final craigleithTextSymbol = TextSymbol(
      text: 'Craigleith',
      color: Colors.blue,
      size: 10,
      horizontalAlignment: HorizontalAlignment.right,
      verticalAlignment: VerticalAlignment.top,
    );

    // Create two points.
    final bassPoint = ArcGISPoint(
      x: -2.64,
      y: 56.079,
      spatialReference: SpatialReference.wgs84,
    );
    final craigleithPoint = ArcGISPoint(
      x: -2.72,
      y: 56.076,
      spatialReference: SpatialReference.wgs84,
    );

    // Create two graphics from the points and symbols.
    final bassRockGraphic =
        Graphic(geometry: bassPoint, symbol: bassRockTextSymbol);
    final craigleithGraphic =
        Graphic(geometry: craigleithPoint, symbol: craigleithTextSymbol);

    // Add graphics to the graphics overlay.
    _graphicsOverlay.graphics.addAll([bassRockGraphic, craigleithGraphic]);
  }

  void _setExtent() async {
    // Create a new envelope builder using the same spatial reference as the graphics.
    final myEnvelopeBuilder =
        EnvelopeBuilder(spatialReference: SpatialReference.wgs84);

    // Loop through each graphic in the graphic collection.
    for (final graphic in _graphicsOverlay.graphics) {
      // Union the extent of each graphic in the envelope builder.
      myEnvelopeBuilder.unionWithEnvelope(graphic.geometry!.extent);
    }

    // Expand the envelope builder by 30%.
    myEnvelopeBuilder.expandBy(1.3);

    // Adjust the viewable area of the map to encompass all of the graphics in the
    // graphics overlay plus an extra 30% margin for better viewing.
    _mapViewController.setViewpointAnimated(
      Viewpoint.fromTargetExtent(myEnvelopeBuilder.extent),
    );
  }
}