import 'package:flutter/material.dart';

/// 统一页面切换：300ms 淡入淡出（12 号组装稿 §7 流程约束）。
///
/// [settings] 从 M2 起必传路由名（page_viewed 取数来源，03 号评估 §2.1），
/// 名字用 `AnalyticsPageName` 枚举的 pageName 值。
Route<T> fadePageRoute<T>(Widget page, {RouteSettings? settings}) {
  return PageRouteBuilder<T>(
    settings: settings,
    transitionDuration: const Duration(milliseconds: 300),
    reverseTransitionDuration: const Duration(milliseconds: 300),
    pageBuilder: (context, animation, secondaryAnimation) => page,
    transitionsBuilder: (context, animation, secondaryAnimation, child) {
      return FadeTransition(opacity: animation, child: child);
    },
  );
}