Fix exception when loadind metadata for png/webp

lib/entity/file_util.dart

@@ -10,6 +10,9 @@ bool isSupportedImageFormat(File file) =>
 bool isSupportedVideoFormat(File file) =>
     isSupportedFormat(file) && file.contentType?.startsWith("video/") == true;
 
+bool isMetadataSupportedFormat(File file) =>
+    _metadataSupportedFormatMimes.contains(file.contentType);
+
 const _supportedFormatMimes = [
   "image/jpeg",
   "image/png",
@@ -18,3 +21,8 @@ const _supportedFormatMimes = [
   // video player currently doesn't work on web
   if (!platform_k.isWeb) "video/mp4",
 ];
+
+const _metadataSupportedFormatMimes = [
+  "image/jpeg",
+  "image/heic",
+];

lib/mobile/metadata_loader.dart

@@ -23,7 +23,7 @@ class MetadataLoader implements itf.MetadataLoader {
       Future.delayed(Duration(seconds: 10)),
     ]);
     if (_getFileTask.isGood && result is FileInfo) {
-      return _onGetFile(result);
+      return _onGetFile(file, result);
     } else {
       // timeout
       _getFileTask.cancel();
@@ -42,6 +42,7 @@ class MetadataLoader implements itf.MetadataLoader {
           message: "Failed communicating with server: ${response.statusCode}");
     }
     return itf.MetadataLoader.loadMetadata(
+      file: file,
       exifdartReaderBuilder: () => MemoryBlobReader(response.body),
       imageSizeGetterInputBuilder: () => AsyncMemoryInput(response.body),
     );
@@ -55,7 +56,7 @@ class MetadataLoader implements itf.MetadataLoader {
       // no cache
       return loadNewFile(account, file);
     } else {
-      return _onGetFile(info);
+      return _onGetFile(file, info);
     }
   }
 
@@ -64,10 +65,11 @@ class MetadataLoader implements itf.MetadataLoader {
     _getFileTask.cancel();
   }
 
-  Future<Map<String, dynamic>> _onGetFile(FileInfo f) {
+  Future<Map<String, dynamic>> _onGetFile(File file, FileInfo info) {
     return itf.MetadataLoader.loadMetadata(
-      exifdartReaderBuilder: () => FileReader(f.file),
+      file: file,
-      imageSizeGetterInputBuilder: () => AsyncFileInput(f.file),
+      exifdartReaderBuilder: () => FileReader(info.file),
+      imageSizeGetterInputBuilder: () => AsyncFileInput(info.file),
     );
   }
 

lib/platform/metadata_loader.dart

@@ -1,8 +1,9 @@
-import 'package:exifdart/exifdart.dart';
+import 'package:exifdart/exifdart.dart' as exifdart;
 import 'package:flutter/foundation.dart';
 import 'package:image_size_getter/image_size_getter.dart';
 import 'package:nc_photos/account.dart';
 import 'package:nc_photos/entity/file.dart';
+import 'package:nc_photos/entity/file_util.dart' as file_util;
 
 abstract class MetadataLoader {
   /// Load metadata for [file] from cache
@@ -24,10 +25,16 @@ abstract class MetadataLoader {
 
   @protected
   static Future<Map<String, dynamic>> loadMetadata({
-    AbstractBlobReader Function() exifdartReaderBuilder,
+    @required File file,
+    exifdart.AbstractBlobReader Function() exifdartReaderBuilder,
     AsyncImageInput Function() imageSizeGetterInputBuilder,
   }) async {
-    final metadata = await readMetadata(exifdartReaderBuilder());
+    exifdart.Metadata metadata;
+    if (file_util.isMetadataSupportedFormat(file)) {
+      metadata = await exifdart.readMetadata(exifdartReaderBuilder());
+    } else {
+      metadata = exifdart.Metadata();
+    }
     int imageWidth, imageHeight;
     if (metadata.imageWidth == null || metadata.imageHeight == null) {
       final resolution =

lib/web/metadata_loader.dart

@@ -27,6 +27,7 @@ class MetadataLoader implements itf.MetadataLoader {
           message: "Failed communicating with server: ${response.statusCode}");
     }
     return itf.MetadataLoader.loadMetadata(
+      file: file,
       exifdartReaderBuilder: () => MemoryBlobReader(response.body),
       imageSizeGetterInputBuilder: () => AsyncMemoryInput(response.body),
     );