⚡ Improve post detail page first time loading

lib/router.dart

@@ -2,6 +2,7 @@ import 'package:animations/animations.dart';
 import 'package:flutter/material.dart';
 import 'package:go_router/go_router.dart';
 import 'package:solian/bootstrapper.dart';
+import 'package:solian/models/post.dart';
 import 'package:solian/models/realm.dart';
 import 'package:solian/screens/about.dart';
 import 'package:solian/screens/account.dart';
@@ -108,6 +109,7 @@ abstract class AppRouter {
           state: state,
           child: PostDetailScreen(
             id: state.pathParameters['id']!,
+            post: state.extra as Post?,
           ),
         ),
       ),

lib/screens/chat.dart

@@ -19,6 +19,7 @@ import 'package:solian/widgets/app_bar_title.dart';
 import 'package:solian/widgets/channel/channel_list.dart';
 import 'package:solian/widgets/chat/call/chat_call_indicator.dart';
 import 'package:solian/widgets/current_state_action.dart';
+import 'package:solian/widgets/loading_indicator.dart';
 import 'package:solian/widgets/root_container.dart';
 import 'package:solian/widgets/sidebar/empty_placeholder.dart';
 
@@ -280,26 +281,7 @@ class _ChatListState extends State<ChatList> {
               return Column(
                 children: [
                   const ChatCallCurrentIndicator(),
-                  if (_isBusy)
-                    Container(
-                      color: Theme.of(context)
-                          .colorScheme
-                          .surfaceContainerLow
-                          .withOpacity(0.8),
-                      child: Row(
-                        mainAxisAlignment: MainAxisAlignment.center,
-                        crossAxisAlignment: CrossAxisAlignment.center,
-                        children: [
-                          const SizedBox(
-                            height: 16,
-                            width: 16,
-                            child: CircularProgressIndicator(strokeWidth: 2.5),
-                          ),
-                          const Gap(8),
-                          Text('loading'.tr)
-                        ],
-                      ).paddingSymmetric(vertical: 8),
-                    ),
+                  if (_isBusy) const LoadingIndicator(),
                   Expanded(
                     child: TabBarView(
                       children: [

lib/screens/posts/post_detail.dart

@@ -5,6 +5,7 @@ import 'package:solian/models/post.dart';
 import 'package:solian/providers/content/posts.dart';
 import 'package:solian/providers/last_read.dart';
 import 'package:solian/theme.dart';
+import 'package:solian/widgets/loading_indicator.dart';
 import 'package:solian/widgets/posts/post_item.dart';
 import 'package:solian/widgets/posts/post_replies.dart';
 
@@ -23,35 +24,37 @@ class PostDetailScreen extends StatefulWidget {
 }
 
 class _PostDetailScreenState extends State<PostDetailScreen> {
-  Post? item;
+  bool _isBusy = true;
 
-  Future<Post?> _getDetail() async {
-    if (widget.post != null) {
-      setState(() {
-        item = widget.post;
-      });
-    }
+  Post? _item;
 
-    final PostProvider provider = Get.find();
+  Future<void> _getDetail() async {
+    final PostProvider posts = Get.find();
 
     try {
-      final resp = await provider.getPost(widget.id);
-      item = Post.fromJson(resp.body);
+      final resp = await posts.getPost(widget.id);
+      _item = Post.fromJson(resp.body);
     } catch (e) {
       context.showErrorDialog(e).then((_) => Navigator.pop(context));
     }
 
-    Get.find<LastReadProvider>().feedLastReadAt = item?.id;
+    Get.find<LastReadProvider>().feedLastReadAt = _item?.id;
 
-    return item;
+    setState(() => _isBusy = false);
+  }
+
+  @override
+  void initState() {
+    super.initState();
+    if (widget.post != null) {
+      _item = widget.post;
+    }
+    _getDetail();
   }
 
   @override
   Widget build(BuildContext context) {
-    return FutureBuilder(
-      future: _getDetail(),
-      builder: (context, snapshot) {
-        if (!snapshot.hasData || snapshot.data == null) {
+    if (_isBusy && _item == null) {
       return const Center(
         child: CircularProgressIndicator(),
       );
@@ -59,9 +62,13 @@ class _PostDetailScreenState extends State<PostDetailScreen> {
 
     return CustomScrollView(
       slivers: [
+        if (_isBusy)
+          SliverToBoxAdapter(
+            child: LoadingIndicator(),
+          ),
         SliverToBoxAdapter(
           child: PostItem(
-                item: item!,
+            item: _item!,
             isClickable: false,
             isOverrideEmbedClickable: true,
             isFullDate: true,
@@ -90,7 +97,7 @@ class _PostDetailScreenState extends State<PostDetailScreen> {
           ),
         ),
         PostReplyList(
-              item: item!,
+          item: _item!,
           padding: AppTheme.isLargeScreen(context)
               ? EdgeInsets.symmetric(
                   horizontal: 4,
@@ -103,7 +110,5 @@ class _PostDetailScreenState extends State<PostDetailScreen> {
         ),
       ],
     );
-      },
-    );
   }
 }

lib/widgets/loading_indicator.dart

@@ -0,0 +1,28 @@
+import 'package:flutter/material.dart';
+import 'package:gap/gap.dart';
+import 'package:get/get.dart';
+
+class LoadingIndicator extends StatelessWidget {
+  const LoadingIndicator({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return Container(
+      padding: const EdgeInsets.symmetric(vertical: 16, horizontal: 24),
+      color: Theme.of(context).colorScheme.surfaceContainerLow.withOpacity(0.8),
+      child: Row(
+        mainAxisAlignment: MainAxisAlignment.center,
+        crossAxisAlignment: CrossAxisAlignment.center,
+        children: [
+          const SizedBox(
+            height: 16,
+            width: 16,
+            child: CircularProgressIndicator(strokeWidth: 2.5),
+          ),
+          const Gap(8),
+          Text('loading'.tr)
+        ],
+      ),
+    );
+  }
+}

lib/widgets/posts/post_item.dart

@@ -250,6 +250,7 @@ class _PostItemState extends State<PostItem> {
           AppRouter.instance.pushNamed(
             'postDetail',
             pathParameters: {'id': item.id.toString()},
+            extra: item,
           );
         }
       },