refactor(mobile): cleanup image providers (#31824)

* refactor(mobile): remove redundant cancellation checks in image providers

* refactor(mobile): extract request helpers in full image providers

(cherry picked from commit 795507cfec262f8a6a9bd3ddd6f5647781e605ca)

mobile/lib/presentation/widgets/images/local_image_provider.dart

@@ -152,13 +152,8 @@ class LocalFullImageProvider extends ImageProvider<LocalFullImageProvider> {
     }
 
     final loadOriginal = SettingsRepository.instance.appConfig.image.loadOriginal;
-    final devicePixelRatio = PlatformDispatcher.instance.views.first.devicePixelRatio;
-    var request = loader.request = LocalImageRequest(
-      localId: key.id,
-      size: _previewTarget(devicePixelRatio, !loadOriginal),
-      assetType: key.assetType,
-    );
-    yield* loader.loadRequest(request, decode, isFinal: !loadOriginal);
+    final previewRequest = loader.request = _previewRequest(key, isFinal: !loadOriginal);
+    yield* loader.loadRequest(previewRequest, decode, isFinal: !loadOriginal);
 
     if (!loadOriginal) {
       return;
@@ -168,9 +163,8 @@ class LocalFullImageProvider extends ImageProvider<LocalFullImageProvider> {
       return;
     }
 
-    request = loader.request = LocalImageRequest(localId: key.id, assetType: key.assetType, size: Size.zero);
-
-    yield* loader.loadRequest(request, decode, isFinal: true);
+    final originalRequest = loader.request = _originalRequest(key);
+    yield* loader.loadRequest(originalRequest, decode, isFinal: true);
   }
 
   Stream<Object> _animatedCodec(ImageLoader loader, LocalFullImageProvider key, ImageDecoderCallback decode) async* {
@@ -180,12 +174,7 @@ class LocalFullImageProvider extends ImageProvider<LocalFullImageProvider> {
       return;
     }
 
-    final devicePixelRatio = PlatformDispatcher.instance.views.first.devicePixelRatio;
-    final previewRequest = loader.request = LocalImageRequest(
-      localId: key.id,
-      size: _previewTarget(devicePixelRatio, false),
-      assetType: key.assetType,
-    );
+    final previewRequest = loader.request = _previewRequest(key, isFinal: false);
     yield* loader.loadRequest(previewRequest, decode, isFinal: false);
 
     if (loader.isCancelled) {
@@ -193,11 +182,7 @@ class LocalFullImageProvider extends ImageProvider<LocalFullImageProvider> {
     }
 
     // always try original for animated, since previews don't support animation
-    final originalRequest = loader.request = LocalImageRequest(
-      localId: key.id,
-      size: Size.zero,
-      assetType: key.assetType,
-    );
+    final originalRequest = loader.request = _originalRequest(key);
     final codec = await loader.loadCodecRequest(originalRequest, isFinal: true);
     if (codec == null) {
       if (loader.isCancelled) {
@@ -208,6 +193,15 @@ class LocalFullImageProvider extends ImageProvider<LocalFullImageProvider> {
     yield codec;
   }
 
+  LocalImageRequest _previewRequest(LocalFullImageProvider key, {required bool isFinal}) => LocalImageRequest(
+    localId: key.id,
+    size: _previewTarget(PlatformDispatcher.instance.views.first.devicePixelRatio, isFinal),
+    assetType: key.assetType,
+  );
+
+  LocalImageRequest _originalRequest(LocalFullImageProvider key) =>
+      LocalImageRequest(localId: key.id, size: Size.zero, assetType: key.assetType);
+
   @override
   bool operator ==(Object other) {
     if (identical(this, other)) {

mobile/lib/presentation/widgets/images/remote_image_provider.dart

@@ -132,14 +132,7 @@ class RemoteFullImageProvider extends ImageProvider<RemoteFullImageProvider> {
       return;
     }
 
-    final previewRequest = loader.request = RemoteImageRequest(
-      uri: getThumbnailUrlForRemoteId(
-        key.assetId,
-        type: AssetMediaSize.preview,
-        thumbhash: key.thumbhash,
-        edited: key.edited,
-      ),
-    );
+    final previewRequest = loader.request = _previewRequest(key);
     final loadOriginal = assetType == AssetType.image && SettingsRepository.instance.appConfig.image.loadOriginal;
     yield* loader.loadRequest(previewRequest, decode, isFinal: !loadOriginal);
 
@@ -151,9 +144,7 @@ class RemoteFullImageProvider extends ImageProvider<RemoteFullImageProvider> {
       return;
     }
 
-    final originalRequest = loader.request = RemoteImageRequest(
-      uri: getOriginalUrlForRemoteId(key.assetId, edited: key.edited),
-    );
+    final originalRequest = loader.request = _originalRequest(key);
     yield* loader.loadRequest(originalRequest, decode, isFinal: true);
   }
 
@@ -164,14 +155,7 @@ class RemoteFullImageProvider extends ImageProvider<RemoteFullImageProvider> {
       return;
     }
 
-    final previewRequest = loader.request = RemoteImageRequest(
-      uri: getThumbnailUrlForRemoteId(
-        key.assetId,
-        type: AssetMediaSize.preview,
-        thumbhash: key.thumbhash,
-        edited: key.edited,
-      ),
-    );
+    final previewRequest = loader.request = _previewRequest(key);
     yield* loader.loadRequest(previewRequest, decode, isFinal: false);
 
     if (loader.isCancelled) {
@@ -179,9 +163,7 @@ class RemoteFullImageProvider extends ImageProvider<RemoteFullImageProvider> {
     }
 
     // always try original for animated, since previews don't support animation
-    final originalRequest = loader.request = RemoteImageRequest(
-      uri: getOriginalUrlForRemoteId(key.assetId, edited: key.edited),
-    );
+    final originalRequest = loader.request = _originalRequest(key);
     final codec = await loader.loadCodecRequest(originalRequest, isFinal: true);
     if (codec == null) {
       if (loader.isCancelled) {
@@ -192,6 +174,18 @@ class RemoteFullImageProvider extends ImageProvider<RemoteFullImageProvider> {
     yield codec;
   }
 
+  RemoteImageRequest _previewRequest(RemoteFullImageProvider key) => RemoteImageRequest(
+    uri: getThumbnailUrlForRemoteId(
+      key.assetId,
+      type: AssetMediaSize.preview,
+      thumbhash: key.thumbhash,
+      edited: key.edited,
+    ),
+  );
+
+  RemoteImageRequest _originalRequest(RemoteFullImageProvider key) =>
+      RemoteImageRequest(uri: getOriginalUrlForRemoteId(key.assetId, edited: key.edited));
+
   @override
   bool operator ==(Object other) {
     if (identical(this, other)) {