pyramid/lib/layout/panel_layout.dart

import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:pyramid/features/rooms/rooms_page.dart';

final sidebarWidthProvider = StateProvider<double>((ref) => 280);

class PanelLayout extends ConsumerWidget {
  final Widget mainContent;
  const PanelLayout({super.key, required this.mainContent});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final sidebarWidth = ref.watch(sidebarWidthProvider);

    return Row(
      children: [
        SizedBox(
          width: sidebarWidth,
          child: const RoomsPage(),
        ),
        _ResizeDivider(
          onDrag: (delta) {
            final notifier = ref.read(sidebarWidthProvider.notifier);
            notifier.state =
                (notifier.state + delta).clamp(180.0, 480.0);
          },
        ),
        Expanded(child: mainContent),
      ],
    );
  }
}

class _ResizeDivider extends StatelessWidget {
  final ValueChanged<double> onDrag;
  const _ResizeDivider({required this.onDrag});

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      behavior: HitTestBehavior.translucent,
      onHorizontalDragUpdate: (d) => onDrag(d.delta.dx),
      child: MouseRegion(
        cursor: SystemMouseCursors.resizeColumn,
        child: Container(
          width: 6,
          color: Theme.of(context).dividerColor,
        ),
      ),
    );
  }
}