refactor(ui): redesign and modernize poll creator components

packages/stream_chat_flutter/lib/src/poll/creator/poll_config_option.dart

@@ -0,0 +1,180 @@
+import 'package:flutter/material.dart';
+import 'package:stream_chat_flutter/stream_chat_flutter.dart';
+
+/// {@template pollConfigOption}
+/// A card-style toggle for poll configuration options.
+///
+/// Renders a rounded card with a title, description, and toggle switch.
+/// When the switch is enabled and [child] is provided, it is revealed
+/// below the header with an animated size transition.
+///
+/// Can be nested — since the header is a simple [Row] rather than a tappable
+/// list tile, padding from an outer [PollConfigOption] does not interfere
+/// with an inner one.
+/// {@endtemplate}
+class PollConfigOption extends StatelessWidget {
+  /// {@macro pollConfigOption}
+  const PollConfigOption({
+    super.key,
+    this.value = false,
+    required this.title,
+    this.description,
+    this.child,
+    this.backgroundColor,
+    this.contentPadding,
+    this.childSpacing,
+    this.onChanged,
+  });
+
+  /// Whether the toggle switch is on.
+  final bool value;
+
+  /// The primary label of the card.
+  final String title;
+
+  /// An optional short description displayed below [title].
+  final String? description;
+
+  /// Optional widget displayed below the header when [value] is true.
+  final Widget? child;
+
+  /// The background color of the card.
+  ///
+  /// Defaults to [StreamColorScheme.backgroundSurfaceCard].
+  final Color? backgroundColor;
+
+  /// The padding inside the card around the content.
+  ///
+  /// Defaults to `EdgeInsets.all(spacing.md)`. Pass [EdgeInsets.zero] for
+  /// nested cards that sit inside a parent card's content padding.
+  final EdgeInsetsGeometry? contentPadding;
+
+  /// The vertical spacing between the header and [child].
+  ///
+  /// Defaults to `spacing.md`.
+  final double? childSpacing;
+
+  /// Called when the user toggles the switch on or off.
+  ///
+  /// The card passes the new value to the callback but does not actually
+  /// change state until the parent widget rebuilds with the new [value].
+  final ValueChanged<bool>? onChanged;
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = StreamPollCreatorTheme.of(context);
+    final defaults = _PollConfigOptionDefaults(context);
+
+    final configOptionStyle = theme.configOptionStyle;
+
+    final radius = context.streamRadius;
+
+    final effectiveBackgroundColor = backgroundColor ?? configOptionStyle?.backgroundColor ?? defaults.backgroundColor;
+    final effectiveContentPadding = contentPadding ?? configOptionStyle?.contentPadding ?? defaults.contentPadding;
+    final effectiveChildSpacing = childSpacing ?? configOptionStyle?.childSpacing ?? defaults.childSpacing;
+
+    return AnimatedSize(
+      duration: kThemeAnimationDuration,
+      alignment: Alignment.topCenter,
+      child: DecoratedBox(
+        decoration: BoxDecoration(
+          color: effectiveBackgroundColor,
+          borderRadius: BorderRadius.all(radius.xl),
+        ),
+        child: Padding(
+          padding: effectiveContentPadding,
+          child: Column(
+            mainAxisSize: MainAxisSize.min,
+            crossAxisAlignment: CrossAxisAlignment.start,
+            spacing: effectiveChildSpacing,
+            children: [
+              _PollConfigOptionHeader(
+                title: title,
+                description: description,
+                value: value,
+                onChanged: onChanged,
+              ),
+              if (child case final child? when value) child,
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+}
+
+// The header row: title/description on the left, toggle switch on the right.
+class _PollConfigOptionHeader extends StatelessWidget {
+  const _PollConfigOptionHeader({
+    required this.value,
+    required this.title,
+    this.description,
+    this.onChanged,
+  });
+
+  final String title;
+  final String? description;
+  final bool value;
+  final ValueChanged<bool>? onChanged;
+
+  @override
+  Widget build(BuildContext context) {
+    final spacing = context.streamSpacing;
+
+    final theme = StreamPollCreatorTheme.of(context);
+    final defaults = _PollConfigOptionDefaults(context);
+    final configOptionStyle = theme.configOptionStyle;
+
+    final effectiveTitleStyle = configOptionStyle?.titleTextStyle ?? defaults.titleTextStyle;
+    final effectiveDescriptionStyle = configOptionStyle?.descriptionTextStyle ?? defaults.descriptionTextStyle;
+    final effectiveSwitchStyle = configOptionStyle?.switchStyle ?? defaults.switchStyle;
+
+    return Row(
+      spacing: spacing.md,
+      crossAxisAlignment: CrossAxisAlignment.center,
+      children: [
+        Expanded(
+          child: Column(
+            spacing: spacing.xxs,
+            mainAxisSize: MainAxisSize.min,
+            crossAxisAlignment: CrossAxisAlignment.start,
+            children: [
+              Text(title, style: effectiveTitleStyle),
+              if (description case final description?) Text(description, style: effectiveDescriptionStyle),
+            ],
+          ),
+        ),
+        StreamSwitch(
+          value: value,
+          onChanged: onChanged,
+          style: effectiveSwitchStyle,
+        ),
+      ],
+    );
+  }
+}
+
+class _PollConfigOptionDefaults extends StreamPollConfigOptionStyle {
+  _PollConfigOptionDefaults(this._context);
+
+  final BuildContext _context;
+
+  late final _colorScheme = _context.streamColorScheme;
+  late final _textTheme = _context.streamTextTheme;
+  late final _spacing = _context.streamSpacing;
+
+  @override
+  double get childSpacing => _spacing.md;
+
+  @override
+  Color get backgroundColor => _colorScheme.backgroundSurfaceCard;
+
+  @override
+  EdgeInsetsGeometry get contentPadding => EdgeInsets.all(_spacing.md);
+
+  @override
+  TextStyle get titleTextStyle => _textTheme.headingSm.copyWith(color: _colorScheme.textPrimary);
+
+  @override
+  TextStyle get descriptionTextStyle => _textTheme.captionDefault.copyWith(color: _colorScheme.textTertiary);
+}