⚡️ Improve image provider's constructor and decode (#124)

Author: AlexV525

example/lib/pages/multi_assets_page.dart

@@ -216,11 +216,7 @@ class _MultiAssetsPageState extends State<MultiAssetsPage>
 
   Widget _imageAssetWidget(AssetEntity asset) {
     return Image(
-      image: AssetEntityImageProvider(
-        asset,
-        isOriginal: false,
-        thumbSize: <int>[100, 100],
-      ),
+      image: AssetEntityImageProvider(asset, isOriginal: false),
       fit: BoxFit.cover,
     );
   }

example/lib/pages/single_assets_page.dart

@@ -186,11 +186,7 @@ class _SingleAssetPageState extends State<SingleAssetPage>
 
   Widget _imageAssetWidget(AssetEntity asset) {
     return Image(
-      image: AssetEntityImageProvider(
-        asset,
-        isOriginal: false,
-        thumbSize: <int>[100, 100],
-      ),
+      image: AssetEntityImageProvider(asset, isOriginal: false),
       fit: BoxFit.cover,
     );
   }

lib/src/delegates/asset_picker_viewer_builder_delegate.dart

@@ -367,11 +367,7 @@ class DefaultAssetPickerViewerBuilderDelegate
     return Positioned.fill(
       child: RepaintBoundary(
         child: ExtendedImage(
-          image: AssetEntityImageProvider(
-            asset,
-            isOriginal: previewThumbSize == null,
-            thumbSize: previewThumbSize,
-          ),
+          image: AssetEntityImageProvider(asset, isOriginal: false),
           fit: BoxFit.cover,
         ),
       ),
@@ -388,7 +384,7 @@ class DefaultAssetPickerViewerBuilderDelegate
           Center(
             child: Icon(
               Icons.video_library,
-              color: themeData.colorScheme.surface.withOpacity(0.54),
+              color: themeData.iconTheme.color?.withOpacity(0.54),
             ),
           ),
         ],

lib/src/provider/asset_entity_image_provider.dart

@@ -14,7 +14,10 @@ class AssetEntityImageProvider extends ImageProvider<AssetEntityImageProvider> {
   const AssetEntityImageProvider(
     this.entity, {
     this.scale = 1.0,
-    this.thumbSize,
+    this.thumbSize = const <int>[
+      Constants.defaultGridThumbSize,
+      Constants.defaultGridThumbSize,
+    ],
     this.isOriginal = true,
   }) : assert(
           isOriginal || thumbSize?.length == 2,
@@ -68,7 +71,18 @@ class AssetEntityImageProvider extends ImageProvider<AssetEntityImageProvider> {
     assert(key == this);
     Uint8List? data;
     if (isOriginal) {
-      if (imageFileType == ImageFileType.heic) {
+      if (key.entity.type == AssetType.audio ||
+          key.entity.type == AssetType.other) {
+        throw UnsupportedError(
+          'Image data for the ${key.entity.type} is not supported.',
+        );
+      }
+      if (key.entity.type == AssetType.video) {
+        data = await key.entity.thumbDataWithSize(
+          Constants.defaultGridThumbSize,
+          Constants.defaultGridThumbSize,
+        );
+      } else if (imageFileType == ImageFileType.heic) {
         data = await (await key.entity.file)?.readAsBytes();
       } else {
         data = await key.entity.originBytes;