Fladder/lib/screens/shared/media/expanding_overview.dart

import 'package:flutter/material.dart';

import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:flutter_widget_from_html/flutter_widget_from_html.dart';
import 'package:iconsax_plus/iconsax_plus.dart';

import 'package:fladder/util/localization_helper.dart';
import 'package:fladder/util/sticky_header_text.dart';

class ExpandingOverview extends ConsumerStatefulWidget {
  final String text;
  const ExpandingOverview({required this.text, super.key});

  @override
  ConsumerState<ConsumerStatefulWidget> createState() => _ExpandingOverviewState();
}

class _ExpandingOverviewState extends ConsumerState<ExpandingOverview> {
  bool expanded = false;

  void toggleState() {
    setState(() {
      expanded = !expanded;
    });
  }

  @override
  Widget build(BuildContext context) {
    final color = Theme.of(context).colorScheme.onSurface;
    const int maxLength = 200;
    final bool canExpand = widget.text.length > maxLength;
    return AnimatedSize(
      duration: const Duration(milliseconds: 250),
      alignment: Alignment.topCenter,
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        mainAxisSize: MainAxisSize.min,
        children: [
          StickyHeaderText(
            label: context.localized.overview,
          ),
          ShaderMask(
            shaderCallback: (bounds) => LinearGradient(
              begin: Alignment.topCenter,
              end: Alignment.bottomCenter,
              stops: const [0, 1],
              colors: [
                color,
                color.withValues(
                    alpha: !canExpand
                        ? 1
                        : expanded
                            ? 1
                            : 0),
              ],
            ).createShader(bounds),
            child: HtmlWidget(
              widget.text.substring(0, !expanded ? maxLength.clamp(0, widget.text.length) : widget.text.length - 1),
              textStyle: Theme.of(context).textTheme.bodyLarge,
            ),
          ),
          if (canExpand) ...{
            const SizedBox(height: 16),
            Align(
              alignment: Alignment.center,
              child: Transform.translate(
                offset: Offset(0, expanded ? 0 : -15),
                child: AnimatedSwitcher(
                  duration: const Duration(milliseconds: 250),
                  child: expanded
                      ? IconButton.filledTonal(
                          onPressed: toggleState,
                          icon: const Icon(IconsaxPlusLinear.arrow_up_1),
                        )
                      : IconButton.filledTonal(
                          onPressed: toggleState,
                          icon: const Icon(IconsaxPlusLinear.arrow_down),
                        ),
                ),
              ),
            ),
          },
        ],
      ),
    );
  }
}