entry: split change notifier, address fallback

lib/model/image_collection.dart

@@ -120,7 +120,7 @@ class ImageCollection with ChangeNotifier {
 
   catalogEntries() async {
     final start = DateTime.now();
-    final uncataloguedEntries = _rawEntries.where((entry) => !entry.isCatalogued);
+    final uncataloguedEntries = _rawEntries.where((entry) => !entry.isCatalogued).toList();
     final newMetadata = List<CatalogMetadata>();
     await Future.forEach<ImageEntry>(uncataloguedEntries, (entry) async {
       await entry.catalog();
@@ -133,7 +133,7 @@ class ImageCollection with ChangeNotifier {
 
   locateEntries() async {
     final start = DateTime.now();
-    final unlocatedEntries = _rawEntries.where((entry) => entry.hasGps && !entry.isLocated);
+    final unlocatedEntries = _rawEntries.where((entry) => entry.hasGps && !entry.isLocated).toList();
     final newAddresses = List<AddressDetails>();
     await Future.forEach<ImageEntry>(unlocatedEntries, (entry) async {
       await entry.locate();

lib/model/image_entry.dart

@@ -3,6 +3,7 @@ import 'dart:collection';
 import 'package:aves/model/image_file_service.dart';
 import 'package:aves/model/image_metadata.dart';
 import 'package:aves/model/metadata_service.dart';
+import 'package:aves/utils/change_notifier.dart';
 import 'package:flutter/foundation.dart';
 import 'package:geocoder/geocoder.dart';
 import 'package:path/path.dart';
@@ -10,7 +11,7 @@ import 'package:tuple/tuple.dart';
 
 import 'mime_types.dart';
 
-class ImageEntry with ChangeNotifier {
+class ImageEntry {
   String uri;
   String path;
   String directory;
@@ -28,6 +29,8 @@ class ImageEntry with ChangeNotifier {
   CatalogMetadata catalogMetadata;
   AddressDetails addressDetails;
 
+  AChangeNotifier imageChangeNotifier = new AChangeNotifier(), metadataChangeNotifier = new AChangeNotifier(), addressChangeNotifier = new AChangeNotifier();
+
   ImageEntry({
     this.uri,
     this.path,
@@ -80,6 +83,12 @@ class ImageEntry with ChangeNotifier {
     };
   }
 
+  dispose() {
+    imageChangeNotifier.dispose();
+    metadataChangeNotifier.dispose();
+    addressChangeNotifier.dispose();
+  }
+
   @override
   String toString() {
     return 'ImageEntry{uri=$uri, path=$path}';
@@ -143,7 +152,7 @@ class ImageEntry with ChangeNotifier {
   catalog() async {
     if (isCatalogued) return;
     catalogMetadata = await MetadataService.getCatalogMetadata(this);
-    notifyListeners();
+    metadataChangeNotifier.notifyListeners();
   }
 
   locate() async {
@@ -166,10 +175,10 @@ class ImageEntry with ChangeNotifier {
           adminArea: address.adminArea,
           locality: address.locality,
         );
-        notifyListeners();
+        addressChangeNotifier.notifyListeners();
       }
-    } catch (e) {
-      debugPrint('$runtimeType addAddressToMetadata failed with exception=${e.message}');
+    } catch (exception) {
+      debugPrint('$runtimeType addAddressToMetadata failed with exception=$exception');
     }
   }
 
@@ -204,7 +213,7 @@ class ImageEntry with ChangeNotifier {
     if (contentId != null) this.contentId = contentId;
     final title = newFields['title'];
     if (title != null) this.title = title;
-    notifyListeners();
+    metadataChangeNotifier.notifyListeners();
     return true;
   }
 
@@ -220,7 +229,7 @@ class ImageEntry with ChangeNotifier {
     if (height != null) this.height = height;
     final orientationDegrees = newFields['orientationDegrees'];
     if (orientationDegrees != null) this.orientationDegrees = orientationDegrees;
-    notifyListeners();
+    imageChangeNotifier.notifyListeners();
     return true;
   }
 }

lib/utils/android_file_utils.dart

@@ -5,16 +5,16 @@ final AndroidFileUtils androidFileUtils = AndroidFileUtils._private();
 typedef void AndroidFileUtilsCallback(String key, dynamic oldValue, dynamic newValue);
 
 class AndroidFileUtils {
-  String dcimPath, downloadPath, picturesPath;
+  String externalStorage, dcimPath, downloadPath, picturesPath;
 
   AndroidFileUtils._private();
 
   init() async {
     // path_provider getExternalStorageDirectory() gives '/storage/emulated/0/Android/data/deckers.thibault.aves/files'
-    final ext = '/storage/emulated/0';
-    dcimPath = join(ext, 'DCIM');
-    downloadPath = join(ext, 'Download');
-    picturesPath = join(ext, 'Pictures');
+    externalStorage = '/storage/emulated/0';
+    dcimPath = join(externalStorage, 'DCIM');
+    downloadPath = join(externalStorage, 'Download');
+    picturesPath = join(externalStorage, 'Pictures');
   }
 
   bool isCameraPath(String path) => path != null && path.startsWith(dcimPath) && (path.endsWith('Camera') || path.endsWith('100ANDRO'));

lib/utils/change_notifier.dart

@@ -0,0 +1,27 @@
+import 'package:flutter/foundation.dart';
+
+// reimplemented ChangeNotifier so that it can be used anywhere, not just as a mixin
+class AChangeNotifier implements Listenable {
+  ObserverList<VoidCallback> _listeners = ObserverList<VoidCallback>();
+
+  @override
+  void addListener(VoidCallback listener) => _listeners.add(listener);
+
+  @override
+  void removeListener(VoidCallback listener) => _listeners.remove(listener);
+
+  void dispose() => _listeners = null;
+
+  @protected
+  void notifyListeners() {
+    if (_listeners == null) return;
+    final localListeners = List<VoidCallback>.from(_listeners);
+    for (final listener in localListeners) {
+      try {
+        if (_listeners.contains(listener)) listener();
+      } catch (exception, stack) {
+        debugPrint('$runtimeType failed to notify listeners with exception=$exception\n$stack');
+      }
+    }
+  }
+}

lib/utils/geo_utils.dart

@@ -0,0 +1,38 @@
+import 'dart:math' as math;
+
+import 'package:intl/intl.dart';
+import 'package:tuple/tuple.dart';
+
+// adapted from Mike Mitterer's dart-latlong library
+String _decimal2sexagesimal(final double dec) {
+  double _round(final double value, {final int decimals: 6}) => (value * math.pow(10, decimals)).round() / math.pow(10, decimals);
+
+  List<int> _split(final double value) {
+    // NumberFormat is necessary to create digit after comma if the value
+    // has no decimal point (only necessary for browser)
+    final List<String> tmp = new NumberFormat('0.0#####').format(_round(value, decimals: 10)).split('.');
+    return <int>[int.parse(tmp[0]).abs(), int.parse(tmp[1])];
+  }
+
+  final List<int> parts = _split(dec);
+  final int integerPart = parts[0];
+  final int fractionalPart = parts[1];
+
+  final int deg = integerPart;
+  final double min = double.parse('0.$fractionalPart') * 60;
+
+  final List<int> minParts = _split(min);
+  final int minFractionalPart = minParts[1];
+
+  final double sec = (double.parse('0.$minFractionalPart') * 60);
+
+  return '$deg° ${min.floor()}′ ${_round(sec, decimals: 2).toStringAsFixed(2)}″';
+}
+
+// return coordinates formatted as DMS, e.g. ['41°24′12.2″ N', '2°10′26.5″E']
+List<String> toDMS(Tuple2<double, double> latLng) {
+  if (latLng == null) return [];
+  final lat = latLng.item1;
+  final lng = latLng.item2;
+  return ['${_decimal2sexagesimal(lat)} ${lat < 0 ? 'S' : 'N'}', '${_decimal2sexagesimal(lng)} ${lng < 0 ? 'W' : 'E'}'];
+}

lib/widgets/album/thumbnail.dart

@@ -25,6 +25,7 @@ class Thumbnail extends StatefulWidget {
 
 class ThumbnailState extends State<Thumbnail> {
   Future<Uint8List> _byteLoader;
+  Listenable _entryChangeNotifier;
 
   ImageEntry get entry => widget.entry;
 
@@ -33,7 +34,8 @@ class ThumbnailState extends State<Thumbnail> {
   @override
   void initState() {
     super.initState();
-    entry.addListener(onEntryChange);
+    _entryChangeNotifier = Listenable.merge([entry.imageChangeNotifier, entry.metadataChangeNotifier]);
+    _entryChangeNotifier.addListener(onEntryChange);
     initByteLoader();
   }
 
@@ -53,7 +55,7 @@ class ThumbnailState extends State<Thumbnail> {
 
   @override
   void dispose() {
-    entry.removeListener(onEntryChange);
+    _entryChangeNotifier.removeListener(onEntryChange);
     super.dispose();
   }
 

lib/widgets/common/icons.dart

@@ -99,7 +99,7 @@ class IconUtils {
     if (androidFileUtils.isDownloadPath(albumDirectory)) return Icon(Icons.file_download);
 
     final parts = albumDirectory.split(separator);
-    if (albumDirectory.startsWith(androidFileUtils.picturesPath) && appNameMap.keys.contains(parts.last)) {
+    if (albumDirectory.startsWith(androidFileUtils.externalStorage) && appNameMap.keys.contains(parts.last)) {
       final packageName = appNameMap[parts.last];
       return AppIcon(
         packageName: packageName,

lib/widgets/fullscreen/info/location_section.dart

@@ -9,11 +9,11 @@ class LocationSection extends AnimatedWidget {
   final ImageEntry entry;
   final showTitle;
 
-  const LocationSection({
+  LocationSection({
     Key key,
     @required this.entry,
     @required this.showTitle,
-  }) : super(key: key, listenable: entry);
+  }) : super(key: key, listenable: Listenable.merge([entry.metadataChangeNotifier, entry.addressChangeNotifier]));
 
   @override
   Widget build(BuildContext context) {

lib/widgets/fullscreen/info/xmp_section.dart

@@ -8,11 +8,11 @@ class XmpTagSection extends AnimatedWidget {
   final ImageCollection collection;
   final ImageEntry entry;
 
-  const XmpTagSection({
+  XmpTagSection({
     Key key,
     @required this.collection,
     @required this.entry,
-  }) : super(key: key, listenable: entry);
+  }) : super(key: key, listenable: entry.metadataChangeNotifier);
 
   @override
   Widget build(BuildContext context) {

lib/widgets/fullscreen/overlay_bottom.dart

@@ -4,6 +4,7 @@ import 'dart:ui';
 import 'package:aves/model/image_entry.dart';
 import 'package:aves/model/image_metadata.dart';
 import 'package:aves/model/metadata_service.dart';
+import 'package:aves/utils/geo_utils.dart';
 import 'package:aves/widgets/common/blurred.dart';
 import 'package:flutter/material.dart';
 import 'package:intl/intl.dart';
@@ -123,7 +124,7 @@ class _FullscreenBottomOverlayContent extends StatelessWidget {
             width: maxWidth,
             child: Text('$position – ${entry.title}', overflow: TextOverflow.ellipsis),
           ),
-          if (entry.isLocated)
+          if (entry.hasGps)
             Container(
               padding: EdgeInsets.only(top: interRowPadding),
               width: subRowWidth,
@@ -158,11 +159,17 @@ class _FullscreenBottomOverlayContent extends StatelessWidget {
   }
 
   Widget _buildLocationRow() {
+    String text;
+    if (entry.isLocated) {
+      text = entry.shortAddress;
+    } else if (entry.hasGps) {
+      text = toDMS(entry.latLng).join(', ');
+    }
     return Row(
       children: [
         Icon(Icons.place, size: iconSize),
         SizedBox(width: iconPadding),
-        Expanded(child: Text(entry.shortAddress, overflow: TextOverflow.ellipsis)),
+        Expanded(child: Text(text, overflow: TextOverflow.ellipsis)),
       ],
     );
   }

lib/widgets/fullscreen/overlay_top.dart

@@ -45,6 +45,15 @@ class FullscreenTopOverlay extends StatelessWidget {
               ),
             ),
             SizedBox(width: 8),
+            OverlayButton(
+              scale: scale,
+              child: IconButton(
+                icon: Icon(Icons.delete_outline),
+                onPressed: () => onActionSelected?.call(FullscreenAction.delete),
+                tooltip: 'Delete',
+              ),
+            ),
+            SizedBox(width: 8),
             OverlayButton(
               scale: scale,
               child: PopupMenuButton<FullscreenAction>(
@@ -53,10 +62,6 @@ class FullscreenTopOverlay extends StatelessWidget {
                     value: FullscreenAction.info,
                     child: MenuRow(text: 'Info', icon: Icons.info_outline),
                   ),
-                  PopupMenuItem(
-                    value: FullscreenAction.delete,
-                    child: MenuRow(text: 'Delete', icon: Icons.delete_outline),
-                  ),
                   PopupMenuItem(
                     value: FullscreenAction.rename,
                     child: MenuRow(text: 'Rename', icon: Icons.title),