/// ============================================================
/// 闲言APP — 延迟渲染包装组件
/// 创建时间: 2026-06-02
/// 更新时间: 2026-06-02
/// 作用: 将子组件(如syncfusion chart)延迟到postFrameCallback渲染
///       避免chart在build阶段触发markNeedsLayout导致卡死
/// 上次更新: 初始创建
/// ============================================================

import 'package:flutter/widgets.dart';

class DeferredBuilder extends StatefulWidget {
  const DeferredBuilder({super.key, required this.builder});

  final WidgetBuilder builder;

  @override
  State<DeferredBuilder> createState() => _DeferredBuilderState();
}

class _DeferredBuilderState extends State<DeferredBuilder> {
  bool _ready = false;

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (mounted) setState(() => _ready = true);
    });
  }

  @override
  Widget build(BuildContext context) {
    if (!_ready) {
      return const SizedBox.expand();
    }
    return widget.builder(context);
  }
}