sm-emby-share/lib/features/detail/widgets/detail_immersive_scaffold.dart

import 'dart:io' show Platform;
import 'dart:ui' show ImageFilter;

import 'package:flutter/material.dart';

import 'detail_backdrop.dart';


class DetailImmersiveScaffold extends StatelessWidget {
  final ScrollController scrollController;
  final ValueNotifier<double> scrollProgress;
  final String? backdropUrl;
  final List<String> fallbackUrls;
  final String embyBaseUrl;
  final Map<String, String>? imageHeaders;
  final Widget child;
  final bool compact;
  final double horizontalPadding;

  const DetailImmersiveScaffold({
    super.key,
    required this.scrollController,
    required this.scrollProgress,
    required this.child,
    this.backdropUrl,
    this.fallbackUrls = const <String>[],
    this.embyBaseUrl = '',
    this.imageHeaders,
    this.compact = false,
    this.horizontalPadding = 32,
  });

  @override
  Widget build(BuildContext context) {
    final screenSize = MediaQuery.sizeOf(context);
    final screenHeight = screenSize.height;
    final screenWidth = screenSize.width;
    final bannerHeight = compact
        ? screenHeight * 0.30
        : (screenWidth * 9.0 / 16.0).clamp(280.0, screenHeight * 0.6);
    final backdrop = backdropUrl;

    return Stack(
      children: [
        if (backdrop != null)
          DetailBackdrop(
            scrollProgress: scrollProgress,
            backdropUrl: backdrop,
            fallbackUrls: fallbackUrls,
            embyBaseUrl: embyBaseUrl,
            imageHeaders: imageHeaders,
          ),
        SingleChildScrollView(
          controller: scrollController,
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              SizedBox(height: bannerHeight - 80),
              Stack(
                children: [
                  Positioned.fill(child: _FrostedPanelVeil()),
                  Padding(
                    padding: EdgeInsets.fromLTRB(
                      horizontalPadding,
                      64,
                      horizontalPadding,
                      48,
                    ),
                    child: Align(
                      alignment: Alignment.topCenter,
                      child: ConstrainedBox(
                        constraints: const BoxConstraints(maxWidth: 1200),
                        child: child,
                      ),
                    ),
                  ),
                ],
              ),
            ],
          ),
        ),
      ],
    );
  }
}

class _FrostedPanelVeil extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    if (Platform.isAndroid) {
      return IgnorePointer(
        child: ShaderMask(
          shaderCallback: (rect) {
            final ratio = (140.0 / rect.height).clamp(0.02, 0.5);
            return LinearGradient(
              begin: Alignment.topCenter,
              end: Alignment.bottomCenter,
              colors: const [Colors.transparent, Colors.black],
              stops: [0.0, ratio],
            ).createShader(rect);
          },
          blendMode: BlendMode.dstIn,
          child: DecoratedBox(
            decoration: BoxDecoration(
              gradient: LinearGradient(
                begin: Alignment.topCenter,
                end: Alignment.bottomCenter,
                stops: const [0.0, 0.12, 1.0],
                colors: [
                  const Color(0xFF0a0c10).withValues(alpha: 0.0),
                  const Color(0xFF0a0c10).withValues(alpha: 0.88),
                  const Color(0xFF0a0c10).withValues(alpha: 0.96),
                ],
              ),
            ),
          ),
        ),
      );
    }

    return IgnorePointer(
      child: ShaderMask(
        shaderCallback: (rect) {
          final ratio = (140.0 / rect.height).clamp(0.02, 0.5);
          return LinearGradient(
            begin: Alignment.topCenter,
            end: Alignment.bottomCenter,
            colors: const [Colors.transparent, Colors.black],
            stops: [0.0, ratio],
          ).createShader(rect);
        },
        blendMode: BlendMode.dstIn,
        child: BackdropFilter(
          filter: ImageFilter.blur(sigmaX: 40, sigmaY: 40),
          child: DecoratedBox(
            decoration: BoxDecoration(
              gradient: LinearGradient(
                begin: Alignment.topCenter,
                end: Alignment.bottomCenter,
                stops: const [0.0, 0.20, 1.0],
                colors: [
                  const Color(0xFF0a0c10).withValues(alpha: 0.0),
                  const Color(0xFF0a0c10).withValues(alpha: 0.12),
                  const Color(0xFF0a0c10).withValues(alpha: 0.20),
                ],
              ),
            ),
          ),
        ),
      ),
    );
  }
}