safer metadata retrieval

android/app/src/main/java/deckers/thibault/aves/channelhandlers/MetadataHandler.java

@@ -176,7 +176,7 @@ public class MetadataHandler implements MethodChannel.MethodCallHandler {
                             XMPProperty item = xmpMeta.getArrayItem(XMP_DC_SCHEMA_NS, XMP_SUBJECT_PROP_NAME, i);
                             sb.append(" ").append(item.getValue());
                         }
-                        metadataMap.put("keywords", sb.toString());
+                        metadataMap.put("xmpSubjects", sb.toString());
                     }
                 } catch (XMPException e) {
                     e.printStackTrace();

lib/model/image_entry.dart

@@ -106,20 +106,20 @@ class ImageEntry {
 
 class CatalogMetadata {
   final int contentId, dateMillis;
-  final String keywords;
+  final String xmpSubjects;
   final double latitude, longitude;
   Address address;
 
-  CatalogMetadata({this.contentId, this.dateMillis, this.keywords, double latitude, double longitude})
+  CatalogMetadata({this.contentId, this.dateMillis, this.xmpSubjects, double latitude, double longitude})
       // Geocoder throws an IllegalArgumentException when a coordinate has a funky values like 1.7056881853375E7
-      : this.latitude = latitude < -90.0 || latitude > 90.0 ? null : latitude,
+      : this.latitude = latitude == null || latitude < -90.0 || latitude > 90.0 ? null : latitude,
-        this.longitude = longitude < -180.0 || longitude > 180.0 ? null : longitude;
+        this.longitude = longitude == null || longitude < -180.0 || longitude > 180.0 ? null : longitude;
 
   factory CatalogMetadata.fromMap(Map map) {
     return CatalogMetadata(
       contentId: map['contentId'],
       dateMillis: map['dateMillis'],
-      keywords: map['keywords'],
+      xmpSubjects: map['xmpSubjects'],
       latitude: map['latitude'],
       longitude: map['longitude'],
     );
@@ -128,13 +128,13 @@ class CatalogMetadata {
   Map<String, dynamic> toMap() => {
         'contentId': contentId,
         'dateMillis': dateMillis,
-        'keywords': keywords,
+        'xmpSubjects': xmpSubjects,
         'latitude': latitude,
         'longitude': longitude,
       };
 
   @override
   String toString() {
-    return 'CatalogMetadata{contentId: $contentId, dateMillis: $dateMillis, latitude: $latitude, longitude: $longitude, keywords=$keywords}';
+    return 'CatalogMetadata{contentId: $contentId, dateMillis: $dateMillis, latitude: $latitude, longitude: $longitude, xmpSubjects=$xmpSubjects}';
   }
 }

lib/model/metadata_service.dart

@@ -26,7 +26,7 @@ class MetadataService {
       // 'dateMillis': date taken in milliseconds since Epoch (long)
       // 'latitude': latitude (double)
       // 'longitude': longitude (double)
-      // 'keywords': space separated XMP subjects (string)
+      // 'xmpSubjects': space separated XMP subjects (string)
       final result = await platform.invokeMethod('getCatalogMetadata', <String, dynamic>{
         'path': path,
       }) as Map;

lib/model/metadata_storage_service.dart

@@ -20,7 +20,7 @@ class MetadataDb {
       await path,
       onCreate: (db, version) {
         return db.execute(
-          'CREATE TABLE $table(contentId INTEGER PRIMARY KEY, dateMillis INTEGER, keywords TEXT, latitude REAL, longitude REAL)',
+          'CREATE TABLE $table(contentId INTEGER PRIMARY KEY, dateMillis INTEGER, xmpSubjects TEXT, latitude REAL, longitude REAL)',
         );
       },
       version: 1,

lib/widgets/fullscreen/info_page.dart

@@ -37,19 +37,26 @@ class InfoPageState extends State<InfoPage> {
   }
 
   initMetadataLoader() {
-    _catalogLoader = MetadataService.getCatalogMetadata(entry.contentId, entry.path).then((metadata) async {
+    _catalogLoader = MetadataService.getCatalogMetadata(entry.contentId, entry.path);//.then(addAddressToMetadata);
-      final latitude = metadata.latitude;
+    _metadataLoader = MetadataService.getAllMetadata(entry.path);
-      final longitude = metadata.longitude;
+  }
-      if (latitude != null && longitude != null) {
+
-        final coordinates = Coordinates(latitude, longitude);
+  Future<CatalogMetadata> addAddressToMetadata(metadata) async {
+    if (metadata == null) return null;
+    final latitude = metadata.latitude;
+    final longitude = metadata.longitude;
+    if (latitude != null && longitude != null) {
+      final coordinates = Coordinates(latitude, longitude);
+      try {
         final addresses = await Geocoder.local.findAddressesFromCoordinates(coordinates);
         if (addresses != null && addresses.length > 0) {
           metadata.address = addresses.first;
         }
+      } catch (e) {
+        debugPrint('$runtimeType addAddressToMetadata failed with exception=${e.message}');
       }
-      return metadata;
+    }
-    });
+    return metadata;
-    _metadataLoader = MetadataService.getAllMetadata(entry.path);
   }
 
   @override
@@ -104,8 +111,8 @@ class InfoPageState extends State<InfoPage> {
                 return Column(
                   crossAxisAlignment: CrossAxisAlignment.start,
                   children: [
-                    ..._buildLocationSection(metadata.latitude, metadata.longitude, metadata.address),
+                    ..._buildLocationSection(metadata?.latitude, metadata?.longitude, metadata?.address),
-                    ..._buildTagSection(metadata.keywords),
+                    ..._buildTagSection(metadata?.xmpSubjects),
                   ],
                 );
               },
@@ -180,12 +187,12 @@ class InfoPageState extends State<InfoPage> {
     ];
   }
 
-  List<Widget> _buildTagSection(String keywords) {
+  List<Widget> _buildTagSection(String xmpSubjects) {
-    if (keywords == null) return [];
+    if (xmpSubjects == null) return [];
     return [
       SectionRow('XMP Tags'),
       Wrap(
-        children: keywords
+        children: xmpSubjects
             .split(' ')
             .where((word) => word.isNotEmpty)
             .map((word) => Padding(