initial

lib/utils/placeholders.dart

@@ -0,0 +1,58 @@
+import 'package:flutter/material.dart';
+import 'package:gap/gap.dart';
+import 'package:hooks_riverpod/hooks_riverpod.dart';
+
+// TODO: improve
+class SliverBodyPlaceholder extends HookConsumerWidget {
+  const SliverBodyPlaceholder(this.children, {super.key});
+
+  final List<Widget> children;
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    return SliverFillRemaining(
+      hasScrollBody: false,
+      child: Column(
+        mainAxisAlignment: MainAxisAlignment.center,
+        children: children,
+      ),
+    );
+  }
+}
+
+class SliverLoadingBodyPlaceholder extends HookConsumerWidget {
+  const SliverLoadingBodyPlaceholder({super.key});
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    return const SliverFillRemaining(
+      hasScrollBody: false,
+      child: Column(
+        mainAxisAlignment: MainAxisAlignment.center,
+        children: [CircularProgressIndicator()],
+      ),
+    );
+  }
+}
+
+class SliverErrorBodyPlaceholder extends HookConsumerWidget {
+  const SliverErrorBodyPlaceholder(this.msg, {super.key, this.icon});
+
+  final String msg;
+  final IconData? icon;
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    return SliverFillRemaining(
+      hasScrollBody: false,
+      child: Column(
+        mainAxisAlignment: MainAxisAlignment.center,
+        children: [
+          Icon(icon ?? Icons.error),
+          const Gap(16),
+          Text(msg),
+        ],
+      ),
+    );
+  }
+}