conditional_parent_widget.dart

import 'package:flutter/widgets.dart';

// From https://gist.github.com/ltOgt/3771c824fc1c8811f5ec1a81a9a4937b

/// Conditionally wrap a subtree with a parent widget without breaking the code tree.
///
/// [condition]: the condition depending on which the subtree [child] is wrapped with the parent.
/// [child]: The subtree that should always be build.
/// [parentBuilder]: builds the parent with the subtree [child].
///
/// ___________
/// Usage:
/// ```dart
/// return ConditionalParentWidget(
///   condition: shouldIncludeParent,
///   child: Widget1(
///     child: Widget2(
///       child: Widget3(),
///     ),
///   ),
///   parentBuilder: (Widget child) => SomeParentWidget(child: child),
///);
/// ```
///
/// ___________
/// Instead of:
/// ```dart
/// Widget child = Widget1(
///   child: Widget2(
///     child: Widget3(),
///   ),
/// );
///
/// return shouldIncludeParent ? SomeParentWidget(child: child) : child;
/// ```
///
class ConditionalParentWidget extends StatelessWidget {
  const ConditionalParentWidget({
    super.key,
    required this.condition,
    required this.child,
    required this.parentBuilder,
  });

  final Widget child;
  final bool condition;
  final Widget Function(Widget child) parentBuilder;

  @override
  Widget build(BuildContext context) {
    // Using indexed stack to avoid building the widget tree twice.
    // This will help to prevent rebuilding the widget tree when the condition changes.
    // Which is helpfull to preserve states of both parent and child.
    // More at: https://stackoverflow.com/questions/59516450
    return IndexedStack(
      index: condition ? 0 : 1,
      children: [
        parentBuilder(child),
        child,
      ],
    );

    // Or if you want to rebuild everytime the condition changes:
    // return condition ? parentBuilder(child) : child;
  }
}