opt.

lib/view/widget/picker.dart

@@ -1,42 +1,52 @@
 import 'package:flutter/material.dart';
 
-Widget buildPicker(
-  List<Widget> items,
-  Function(int idx) onSelected, {
-  double height = 157,
-}) {
-  final pad = (height - 37) / 2;
-  return SizedBox(
-    height: height,
-    child: Stack(
-      children: [
-        Positioned(
-          top: pad,
-          bottom: pad,
-          left: 0,
-          right: 0,
-          child: Container(
-            height: 37,
-            decoration: const BoxDecoration(
-              borderRadius: BorderRadius.all(Radius.circular(7)),
-              color: Colors.black12,
+class Picker extends StatelessWidget {
+  final List<Widget> items;
+  final Function(int idx) onSelected;
+  final double height;
+
+  const Picker({
+    super.key,
+    required this.items,
+    required this.onSelected,
+    this.height = 157,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final pad = (height - 37) / 2;
+    return SizedBox(
+      height: height,
+      child: Stack(
+        children: [
+          Positioned(
+            top: pad,
+            bottom: pad,
+            left: 0,
+            right: 0,
+            child: Container(
+              height: 37,
+              decoration: const BoxDecoration(
+                borderRadius: BorderRadius.all(Radius.circular(7)),
+                color: Colors.black12,
+              ),
             ),
           ),
-        ),
-        ListWheelScrollView.useDelegate(
-          itemExtent: 37,
-          diameterRatio: 2.7,
-          controller: FixedExtentScrollController(initialItem: 0),
-          onSelectedItemChanged: (idx) => onSelected(idx),
-          physics: const FixedExtentScrollPhysics(),
-          childDelegate: ListWheelChildBuilderDelegate(
-            builder: (context, index) => Center(
-              child: items[index],
+          ListWheelScrollView.useDelegate(
+            itemExtent: 37,
+            diameterRatio: 2.7,
+            controller: FixedExtentScrollController(initialItem: 0),
+            onSelectedItemChanged: (idx) => onSelected(idx),
+            physics: const FixedExtentScrollPhysics(),
+            childDelegate: ListWheelChildBuilderDelegate(
+              builder: (context, index) => Center(
+                child: items[index],
+              ),
+              childCount: items.length,
             ),
-            childCount: items.length,
-          ),
-        )
-      ],
-    ),
-  );
+          )
+        ],
+      ),
+    );
+  }
 }