Manage bookmarks

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

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

  @override
  State<ManageBookmarks> createState() => _ManageBookmarksState();
}

class _ManageBookmarksState extends State<ManageBookmarks> {
  // Create a controller for the map view.
  final _mapViewController = ArcGISMapView.createController();
  // Declare a list of bookmarks.
  late final List<Bookmark> _bookmarks;
  // A flag for when the map view is ready and controls can be used.
  var _ready = false;
  // A flag for when the bookmarks bottom sheet is visible.
  var _bookmarksVisible = false;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SafeArea(
        top: false,
        left: false,
        right: 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,
                  ),
                ),
                Row(
                  mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                  children: [
                    // A button to add a bookmark at the current Viewpoint.
                    ElevatedButton(
                      onPressed: addBookmark,
                      child: const Text('Add Bookmark'),
                    ),
                    // A button to list the bookmarks.
                    ElevatedButton(
                      onPressed: () => setState(() => _bookmarksVisible = true),
                      child: const Text('Bookmarks'),
                    ),
                  ],
                ),
              ],
            ),
            // Display a progress indicator and prevent interaction until state is ready.
            LoadingIndicator(visible: !_ready),
          ],
        ),
      ),
      // The Bookmarks bottom sheet.
      bottomSheet: _bookmarksVisible ? buildBookmarks(context) : null,
    );
  }

  // The build method for the Bookmarks bottom sheet.
  Widget buildBookmarks(BuildContext context) {
    return Container(
      padding: EdgeInsets.fromLTRB(
        20,
        20,
        20,
        max(
          20,
          View.of(context).viewPadding.bottom /
              View.of(context).devicePixelRatio,
        ),
      ),
      child: Column(
        mainAxisSize: MainAxisSize.min,
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          Row(
            children: [
              Text('Bookmarks', style: Theme.of(context).textTheme.titleLarge),
              const Spacer(),
              IconButton(
                icon: const Icon(Icons.close),
                onPressed: () => setState(() => _bookmarksVisible = false),
              ),
            ],
          ),
          Container(
            constraints: BoxConstraints(
              maxHeight: MediaQuery.sizeOf(context).height * 0.4,
            ),
            child: SingleChildScrollView(
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.stretch,
                children:
                    _bookmarks.map((bookmark) {
                      // When a bookmark is tapped, set the bookmark on the map view.
                      return TextButton(
                        onPressed:
                            () => _mapViewController.setBookmark(bookmark),
                        style: const ButtonStyle(
                          alignment: Alignment.centerLeft,
                        ),
                        child: Text(bookmark.name),
                      );
                    }).toList(),
              ),
            ),
          ),
        ],
      ),
    );
  }

  void onMapViewReady() {
    // Create a map with an imagery basemap style.
    final map = ArcGISMap.withBasemapStyle(BasemapStyle.arcGISImagery);

    // Access the bookmark list from the map.
    _bookmarks = map.bookmarks;

    // Add the predefined bookmarks to the list.
    _bookmarks.addAll([
      Bookmark(
        name: 'Grand Prismatic Spring',
        viewpoint: Viewpoint.withLatLongScale(
          latitude: 44.525,
          longitude: -110.838,
          scale: 6000,
        ),
      ),
      Bookmark(
        name: 'Guitar-Shaped Forest',
        viewpoint: Viewpoint.withLatLongScale(
          latitude: -33.867,
          longitude: -63.985,
          scale: 40000,
        ),
      ),
      Bookmark(
        name: 'Mysterious Desert Pattern',
        viewpoint: Viewpoint.withLatLongScale(
          latitude: 27.380,
          longitude: 33.632,
          scale: 6000,
        ),
      ),
      Bookmark(
        name: 'Strange Symbol',
        viewpoint: Viewpoint.withLatLongScale(
          latitude: 37.401,
          longitude: -116.867,
          scale: 6000,
        ),
      ),
    ]);

    // Set the map on the controller and navigate to the first bookmark.
    _mapViewController.arcGISMap = map;
    _mapViewController.setBookmark(_bookmarks.first);

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

  Future<void> addBookmark() async {
    // Show a dialog to get the name of the bookmark.
    final name = await showDialog<String>(
      context: context,
      builder: (_) => const AddBookmarkDialog(),
    );
    if (name == null || name.isEmpty) return;

    // Create a bookmark with the current viewpoint and add it to the list.
    final bookmark = Bookmark(
      name: name,
      viewpoint: _mapViewController.getCurrentViewpoint(
        ViewpointType.centerAndScale,
      ),
    );
    setState(() => _bookmarks.add(bookmark));
  }
}

// A dialog to get the name for a bookmark.
class AddBookmarkDialog extends StatefulWidget {
  const AddBookmarkDialog({super.key});

  @override
  State<AddBookmarkDialog> createState() => _AddBookmarkDialogState();
}

class _AddBookmarkDialogState extends State<AddBookmarkDialog> {
  final _nameController = TextEditingController();

  @override
  void dispose() {
    _nameController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return AlertDialog(
      content: TextField(
        controller: _nameController,
        autocorrect: false,
        autofocus: true,
        enableSuggestions: false,
        decoration: const InputDecoration(labelText: 'Name'),
        onSubmitted: add,
      ),
      actions: [
        TextButton(onPressed: cancel, child: const Text('Cancel')),
        TextButton(
          onPressed: () => add(_nameController.text),
          child: const Text('Add'),
        ),
      ],
    );
  }

  // Cancel the dialog.
  void cancel() {
    Navigator.of(context).pop();
  }

  // Report the name to be used for the bookmark.
  void add(String name) {
    Navigator.of(context).pop(name);
  }
}