break up home screen - separate out download dialog

lib/screens/home_screen.dart

@@ -1,16 +1,14 @@
 import 'package:flutter/material.dart';
+import 'package:flutter_map/flutter_map.dart';
 import 'package:provider/provider.dart';
-import 'package:latlong2/latlong.dart';
 
-import 'package:flock_map_app/dev_config.dart';
 import '../app_state.dart';
+import '../dev_config.dart';
 import '../widgets/map_view.dart';
 import '../widgets/tile_provider_with_cache.dart';
-import 'package:flutter_map/flutter_map.dart';
-import '../services/offline_area_service.dart';
 import '../widgets/add_camera_sheet.dart';
 import '../widgets/camera_provider_with_cache.dart';
-import '../services/offline_areas/offline_tile_utils.dart';
+import '../widgets/download_area_dialog.dart';
 
 class HomeScreen extends StatefulWidget {
   const HomeScreen({super.key});
@@ -155,190 +153,3 @@ class _HomeScreenState extends State<HomeScreen> {
   }
 }
 
-// --- Download area dialog ---
-class DownloadAreaDialog extends StatefulWidget {
-  final MapController controller;
-  const DownloadAreaDialog({super.key, required this.controller});
-
-  @override
-  State<DownloadAreaDialog> createState() => _DownloadAreaDialogState();
-}
-
-class _DownloadAreaDialogState extends State<DownloadAreaDialog> {
-  double _zoom = 15;
-  int? _minZoom;
-  int? _tileCount;
-  double? _mbEstimate;
-
-  @override
-  void initState() {
-    super.initState();
-    WidgetsBinding.instance.addPostFrameCallback((_) => _recomputeEstimates());
-  }
-
-  void _recomputeEstimates() {
-    var bounds = widget.controller.camera.visibleBounds;
-    // If the visible area is nearly zero, nudge the bounds for estimation
-    const double epsilon = 0.0002;
-    final latSpan = (bounds.north - bounds.south).abs();
-    final lngSpan = (bounds.east - bounds.west).abs();
-    if (latSpan < epsilon && lngSpan < epsilon) {
-      bounds = LatLngBounds(
-        LatLng(bounds.southWest.latitude - epsilon, bounds.southWest.longitude - epsilon),
-        LatLng(bounds.northEast.latitude + epsilon, bounds.northEast.longitude + epsilon)
-      );
-    } else if (latSpan < epsilon) {
-      bounds = LatLngBounds(
-        LatLng(bounds.southWest.latitude - epsilon, bounds.southWest.longitude),
-        LatLng(bounds.northEast.latitude + epsilon, bounds.northEast.longitude)
-      );
-    } else if (lngSpan < epsilon) {
-      bounds = LatLngBounds(
-        LatLng(bounds.southWest.latitude, bounds.southWest.longitude - epsilon),
-        LatLng(bounds.northEast.latitude, bounds.northEast.longitude + epsilon)
-      );
-    }
-    final minZoom = kWorldMaxZoom + 1; // Use world max zoom + 1 for seamless zoom experience
-    final maxZoom = _zoom.toInt();
-    final nTiles = computeTileList(bounds, minZoom, maxZoom).length;
-    final totalMb = (nTiles * kTileEstimateKb) / 1024.0;
-    setState(() {
-      _minZoom = minZoom;
-      _tileCount = nTiles;
-      _mbEstimate = totalMb;
-    });
-  }
-
-  @override
-  Widget build(BuildContext context) {
-    final bounds = widget.controller.camera.visibleBounds;
-    final maxZoom = _zoom.toInt();
-    double sliderMin;
-    double sliderMax;
-    int sliderDivisions;
-    double sliderValue;
-    // Generate slider min/max/divisions with clarity
-    if (_minZoom != null) {
-      sliderMin = _minZoom!.toDouble();
-    } else {
-      sliderMin = 12.0; //fallback
-    }
-    if (_minZoom != null) {
-      final candidateMax = _minZoom! + kMaxUserDownloadZoomSpan;
-      sliderMax = candidateMax > 19 ? 19.0 : candidateMax.toDouble();
-    } else {
-      sliderMax = 19.0; //fallback
-    }
-    if (_minZoom != null) {
-      final candidateMax = _minZoom! + kMaxUserDownloadZoomSpan;
-      int diff = (candidateMax > 19 ? 19 : candidateMax) - _minZoom!;
-      sliderDivisions = diff > 0 ? diff : 1;
-    } else {
-      sliderDivisions = 7; //fallback
-    }
-    sliderValue = _zoom.clamp(sliderMin, sliderMax);
-    // We recompute estimates when the zoom slider changes
-
-    return AlertDialog(
-      title: Row(
-        children: const [
-          Icon(Icons.download_for_offline),
-          SizedBox(width: 10),
-          Text("Download Map Area"),
-        ],
-      ),
-      content: SizedBox(
-        width: 350,
-        child: Column(
-          mainAxisSize: MainAxisSize.min,
-          children: [
-            Row(
-              mainAxisAlignment: MainAxisAlignment.spaceBetween,
-              children: [
-                const Text('Max zoom level'),
-                Text('Z${_zoom.toStringAsFixed(0)}'),
-              ],
-            ),
-
-            Slider(
-              min: sliderMin,
-              max: sliderMax,
-              divisions: sliderDivisions,
-              label: 'Z${_zoom.toStringAsFixed(0)}',
-              value: sliderValue,
-              onChanged: (v) {
-                setState(() => _zoom = v);
-                WidgetsBinding.instance.addPostFrameCallback((_) => _recomputeEstimates());
-              },
-            ),
-            const SizedBox(height: 8),
-            Row(
-              mainAxisAlignment: MainAxisAlignment.spaceBetween,
-              children: [
-                const Text('Storage estimate:'),
-                Expanded(
-                  child: Text(
-                    _mbEstimate == null
-                        ? '…'
-                        : '${_tileCount} tiles, ${_mbEstimate!.toStringAsFixed(1)} MB',
-                    textAlign: TextAlign.end,
-                    style: const TextStyle(fontSize: 14),
-                  ),
-                ),
-              ],
-            ),
-            if (_minZoom != null)
-              Row(
-                mainAxisAlignment: MainAxisAlignment.spaceBetween,
-                children: [
-                  const Text('Min zoom:'),
-                  Text('Z$_minZoom'),
-                ],
-              )
-          ],
-        ),
-      ),
-      actions: [
-        TextButton(
-          onPressed: () => Navigator.pop(context),
-          child: const Text('Cancel'),
-        ),
-        ElevatedButton(
-          onPressed: () async {
-            try {
-              final id = DateTime.now().toIso8601String().replaceAll(':', '-');
-              final appDocDir = await OfflineAreaService().getOfflineAreaDir();
-              final dir = "${appDocDir.path}/$id";
-              // Fire and forget: don't await download, so dialog closes immediately
-              // ignore: unawaited_futures
-              OfflineAreaService().downloadArea(
-                id: id,
-                bounds: bounds,
-                minZoom: _minZoom ?? 12,
-                maxZoom: maxZoom,
-                directory: dir,
-                onProgress: (progress) {},
-                onComplete: (status) {},
-              );
-              Navigator.pop(context);
-              ScaffoldMessenger.of(context).showSnackBar(
-                const SnackBar(
-                  content: Text('Download started!'),
-                ),
-              );
-            } catch (e) {
-              Navigator.pop(context);
-              ScaffoldMessenger.of(context).showSnackBar(
-                SnackBar(
-                  content: Text('Failed to start download: $e'),
-                ),
-              );
-            }
-          },
-          child: const Text('Download'),
-        ),
-      ],
-    );
-  }
-}
-

lib/widgets/download_area_dialog.dart

@@ -0,0 +1,193 @@
+import 'package:flutter/material.dart';
+import 'package:latlong2/latlong.dart';
+import 'package:flutter_map/flutter_map.dart';
+
+import '../dev_config.dart';
+import '../services/offline_area_service.dart';
+import '../services/offline_areas/offline_tile_utils.dart';
+
+class DownloadAreaDialog extends StatefulWidget {
+  final MapController controller;
+  const DownloadAreaDialog({super.key, required this.controller});
+
+  @override
+  State<DownloadAreaDialog> createState() => _DownloadAreaDialogState();
+}
+
+class _DownloadAreaDialogState extends State<DownloadAreaDialog> {
+  double _zoom = 15;
+  int? _minZoom;
+  int? _tileCount;
+  double? _mbEstimate;
+
+  @override
+  void initState() {
+    super.initState();
+    WidgetsBinding.instance.addPostFrameCallback((_) => _recomputeEstimates());
+  }
+
+  void _recomputeEstimates() {
+    var bounds = widget.controller.camera.visibleBounds;
+    // If the visible area is nearly zero, nudge the bounds for estimation
+    const double epsilon = 0.0002;
+    final latSpan = (bounds.north - bounds.south).abs();
+    final lngSpan = (bounds.east - bounds.west).abs();
+    if (latSpan < epsilon && lngSpan < epsilon) {
+      bounds = LatLngBounds(
+        LatLng(bounds.southWest.latitude - epsilon, bounds.southWest.longitude - epsilon),
+        LatLng(bounds.northEast.latitude + epsilon, bounds.northEast.longitude + epsilon)
+      );
+    } else if (latSpan < epsilon) {
+      bounds = LatLngBounds(
+        LatLng(bounds.southWest.latitude - epsilon, bounds.southWest.longitude),
+        LatLng(bounds.northEast.latitude + epsilon, bounds.northEast.longitude)
+      );
+    } else if (lngSpan < epsilon) {
+      bounds = LatLngBounds(
+        LatLng(bounds.southWest.latitude, bounds.southWest.longitude - epsilon),
+        LatLng(bounds.northEast.latitude, bounds.northEast.longitude + epsilon)
+      );
+    }
+    final minZoom = kWorldMaxZoom + 1; // Use world max zoom + 1 for seamless zoom experience
+    final maxZoom = _zoom.toInt();
+    final nTiles = computeTileList(bounds, minZoom, maxZoom).length;
+    final totalMb = (nTiles * kTileEstimateKb) / 1024.0;
+    setState(() {
+      _minZoom = minZoom;
+      _tileCount = nTiles;
+      _mbEstimate = totalMb;
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final bounds = widget.controller.camera.visibleBounds;
+    final maxZoom = _zoom.toInt();
+    double sliderMin;
+    double sliderMax;
+    int sliderDivisions;
+    double sliderValue;
+    // Generate slider min/max/divisions with clarity
+    if (_minZoom != null) {
+      sliderMin = _minZoom!.toDouble();
+    } else {
+      sliderMin = 12.0; //fallback
+    }
+    if (_minZoom != null) {
+      final candidateMax = _minZoom! + kMaxUserDownloadZoomSpan;
+      sliderMax = candidateMax > 19 ? 19.0 : candidateMax.toDouble();
+    } else {
+      sliderMax = 19.0; //fallback
+    }
+    if (_minZoom != null) {
+      final candidateMax = _minZoom! + kMaxUserDownloadZoomSpan;
+      int diff = (candidateMax > 19 ? 19 : candidateMax) - _minZoom!;
+      sliderDivisions = diff > 0 ? diff : 1;
+    } else {
+      sliderDivisions = 7; //fallback
+    }
+    sliderValue = _zoom.clamp(sliderMin, sliderMax);
+    // We recompute estimates when the zoom slider changes
+
+    return AlertDialog(
+      title: Row(
+        children: const [
+          Icon(Icons.download_for_offline),
+          SizedBox(width: 10),
+          Text("Download Map Area"),
+        ],
+      ),
+      content: SizedBox(
+        width: 350,
+        child: Column(
+          mainAxisSize: MainAxisSize.min,
+          children: [
+            Row(
+              mainAxisAlignment: MainAxisAlignment.spaceBetween,
+              children: [
+                const Text('Max zoom level'),
+                Text('Z${_zoom.toStringAsFixed(0)}'),
+              ],
+            ),
+
+            Slider(
+              min: sliderMin,
+              max: sliderMax,
+              divisions: sliderDivisions,
+              label: 'Z${_zoom.toStringAsFixed(0)}',
+              value: sliderValue,
+              onChanged: (v) {
+                setState(() => _zoom = v);
+                WidgetsBinding.instance.addPostFrameCallback((_) => _recomputeEstimates());
+              },
+            ),
+            const SizedBox(height: 8),
+            Row(
+              mainAxisAlignment: MainAxisAlignment.spaceBetween,
+              children: [
+                const Text('Storage estimate:'),
+                Expanded(
+                  child: Text(
+                    _mbEstimate == null
+                        ? '…'
+                        : '${_tileCount} tiles, ${_mbEstimate!.toStringAsFixed(1)} MB',
+                    textAlign: TextAlign.end,
+                    style: const TextStyle(fontSize: 14),
+                  ),
+                ),
+              ],
+            ),
+            if (_minZoom != null)
+              Row(
+                mainAxisAlignment: MainAxisAlignment.spaceBetween,
+                children: [
+                  const Text('Min zoom:'),
+                  Text('Z$_minZoom'),
+                ],
+              )
+          ],
+        ),
+      ),
+      actions: [
+        TextButton(
+          onPressed: () => Navigator.pop(context),
+          child: const Text('Cancel'),
+        ),
+        ElevatedButton(
+          onPressed: () async {
+            try {
+              final id = DateTime.now().toIso8601String().replaceAll(':', '-');
+              final appDocDir = await OfflineAreaService().getOfflineAreaDir();
+              final dir = "${appDocDir.path}/$id";
+              // Fire and forget: don't await download, so dialog closes immediately
+              // ignore: unawaited_futures
+              OfflineAreaService().downloadArea(
+                id: id,
+                bounds: bounds,
+                minZoom: _minZoom ?? 12,
+                maxZoom: maxZoom,
+                directory: dir,
+                onProgress: (progress) {},
+                onComplete: (status) {},
+              );
+              Navigator.pop(context);
+              ScaffoldMessenger.of(context).showSnackBar(
+                const SnackBar(
+                  content: Text('Download started!'),
+                ),
+              );
+            } catch (e) {
+              Navigator.pop(context);
+              ScaffoldMessenger.of(context).showSnackBar(
+                SnackBar(
+                  content: Text('Failed to start download: $e'),
+                ),
+              );
+            }
+          },
+          child: const Text('Download'),
+        ),
+      ],
+    );
+  }
+}