Fix some issues

lib/db/db_helper.dart

@@ -95,12 +95,14 @@ class DatabaseHelper {
         .update(table, row, where: '$columnHash = ?', whereArgs: [hash]);
   }
 
-  Future<bool> containsPath(String path) async {
+  Future<Photo> getPhotoByUrl(String url) async {
     Database db = await instance.database;
-    return (await db
-                .query(table, where: '$columnLocalPath =?', whereArgs: [path]))
-            .length >
-        0;
+    var rows = await db.query(table, where: '$columnUrl =?', whereArgs: [url]);
+    if (rows.length > 0) {
+      return Photo.fromRow(rows[0]);
+    } else {
+      throw ("No cached photo");
+    }
   }
 
   Future<bool> containsPhotoHash(String hash) async {

lib/main.dart

@@ -20,10 +20,13 @@ void main() async {
   runApp(MyApp());
   await provider.refreshGalleryList();
 
-  provider.list[0].assetList.then((assets) {
-    var photoSyncManager = PhotoSyncManager(assets);
-    photoSyncManager.init();
-  });
+  if (provider.list.length > 0) {
+    provider.list[0].assetList.then((assets) {
+      init(assets);
+    });
+  } else {
+    init(List<AssetEntity>());
+  }
 }
 
 Future<void> init(List<AssetEntity> assets) async {

lib/models/photo.dart

@@ -34,10 +34,10 @@ class Photo {
     var file = (await asset.originFile);
     photo.localPath = file.path;
     photo.hash = getHash(file);
-    return setThumbnail(photo).then((value) => photo);
+    return setThumbnail(photo);
   }
 
-  static Future<void> setThumbnail(Photo photo) async {
+  static Future<Photo> setThumbnail(Photo photo) async {
     var externalPath = (await getApplicationDocumentsDirectory()).path;
     var thumbnailPath =
         externalPath + "/photos/thumbnails/" + photo.hash + ".thumbnail";

lib/photo_sync_manager.dart

@@ -115,7 +115,7 @@ class PhotoSyncManager {
             .download(Constants.ENDPOINT + photo.url, localPath)
             .catchError(_onError);
         photo.localPath = localPath;
-        Photo.setThumbnail(photo);
+        await Photo.setThumbnail(photo);
         await DatabaseHelper.instance.insertPhoto(photo);
         PhotoLoader.instance.reloadPhotos();
       }

lib/ui/detail_page.dart

@@ -5,17 +5,11 @@ import 'package:myapp/core/lru_map.dart';
 import 'package:myapp/models/photo.dart';
 import 'package:share_extend/share_extend.dart';
 
-class DetailPage extends StatefulWidget {
+class DetailPage extends StatelessWidget {
   final Photo photo;
-  final String url;
 
-  const DetailPage({Key key, this.photo, this.url}) : super(key: key);
+  const DetailPage(this.photo, {Key key}) : super(key: key);
 
-  @override
-  _DetailPageState createState() => _DetailPageState();
-}
-
-class _DetailPageState extends State<DetailPage> {
   @override
   Widget build(BuildContext context) {
     return Scaffold(
@@ -25,7 +19,7 @@ class _DetailPageState extends State<DetailPage> {
           IconButton(
             icon: Icon(Icons.share),
             onPressed: () {
-              ShareExtend.share(widget.photo.localPath, "image");
+              ShareExtend.share(photo.localPath, "image");
             },
           )
         ],
@@ -43,12 +37,12 @@ class _DetailPageState extends State<DetailPage> {
       onVerticalDragUpdate: (details) {
         Navigator.pop(context);
       },
-      child: ImageLruCache.getData(widget.photo.localPath) == null
+      child: ImageLruCache.getData(photo.localPath) == null
           ? Image.file(
-              File(widget.photo.localPath),
+              File(photo.localPath),
               filterQuality: FilterQuality.low,
             )
-          : ImageLruCache.getData(widget.photo.localPath),
+          : ImageLruCache.getData(photo.localPath),
     );
   }
 }

lib/ui/face_search_results_page.dart

@@ -2,9 +2,11 @@ import 'package:flutter/material.dart';
 import 'package:myapp/db/db_helper.dart';
 import 'package:myapp/face_search_manager.dart';
 import 'package:myapp/models/face.dart';
+import 'package:myapp/models/photo.dart';
 import 'package:myapp/models/search_result.dart';
 import 'package:myapp/ui/circular_network_image_widget.dart';
 import 'package:myapp/core/constants.dart' as Constants;
+import 'package:myapp/ui/image_widget.dart';
 import 'package:myapp/ui/network_image_detail_page.dart';
 
 import 'detail_page.dart';
@@ -42,8 +44,8 @@ class FaceSearchResultsPage extends StatelessWidget {
       builder: (context, snapshot) {
         if (snapshot.hasData) {
           return GridView.builder(
-              itemBuilder: (_, index) => _buildItem(
-                  context, Constants.ENDPOINT + snapshot.data[index].url),
+              itemBuilder: (_, index) =>
+                  _buildItem(context, snapshot.data[index].url),
               itemCount: snapshot.data.length,
               gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
                 crossAxisCount: 4,
@@ -57,18 +59,38 @@ class FaceSearchResultsPage extends StatelessWidget {
 
   Widget _buildItem(BuildContext context, String url) {
     return GestureDetector(
-      onTap: () {
+      onTap: () async {
         _routeToDetailPage(url, context);
       },
-      child: Container(
-        margin: EdgeInsets.all(2),
-        child: Image.network(url, height: 124, width: 124, fit: BoxFit.cover),
-      ),
+      child: _getImage(url),
     );
   }
 
-  void _routeToDetailPage(String url, BuildContext context) {
-    final page = NetworkImageDetailPage(url);
+  Widget _getImage(String url) {
+    return FutureBuilder<Photo>(
+      future: DatabaseHelper.instance.getPhotoByUrl(url),
+      builder: (_, snapshot) {
+        if (snapshot.hasData) {
+          return ImageWidget(path: snapshot.data.thumbnailPath);
+        } else if (snapshot.hasError) {
+          return Container(
+            margin: EdgeInsets.all(2),
+            child: Image.network(Constants.ENDPOINT + url,
+                height: 124, width: 124, fit: BoxFit.cover),
+          );
+        } else {
+          return Text("Loading...");
+        }
+      },
+    );
+  }
+
+  void _routeToDetailPage(String url, BuildContext context) async {
+    Widget page = NetworkImageDetailPage(url);
+    var photo = await DatabaseHelper.instance.getPhotoByUrl(url);
+    if (photo != null) {
+      page = DetailPage(photo);
+    }
     Navigator.of(context).push(
       MaterialPageRoute(
         builder: (BuildContext context) {

lib/ui/gallery.dart

@@ -74,9 +74,7 @@ class _GalleryState extends State<Gallery> {
   }
 
   void routeToDetailPage(Photo photo, BuildContext context) {
-    final page = DetailPage(
-      photo: photo,
-    );
+    final page = DetailPage(photo);
     Navigator.of(context).push(
       MaterialPageRoute(
         builder: (BuildContext context) {