The Missing Grouping Pattern For Flutter Selectable

Flutter’s new RadioGroup gets praise for grouped radio buttons, but a critical gap remains: no native widget group system for arbitrary selectable items - TV menus, keyboard drawers, or desktop selectors all suffer from fragmented focus and selection logic. Developers still patch together manual focus tracking and WidgetState.selected toggling, wasting time and risking bugs. Flutter’s RadioGroup pattern works because it ties selection tightly to a registry, but arbitrary widgets fall through. Enter SelectionGroup - a lightweight, zero-configuration widget that brings the same focus-aware grouping to any UI element.

SelectionGroup acts like a RadioGroup for your buttons, selects, or inputs - but it manages both selection and focus automatically. Key benefits include:

• Tracks which item is selected across a group
• Restores focus to the chosen item when re-entering the group
• Hides the selected state when the group has focus, avoiding visual glitches
• Triggers on focused item changes with seamless notifications

What makes this unique? It uses a mixin-driven approach, so developers just wrap their widget with SelectionGroupItemMixin and get instant access to selection logic - no RadioClient, no unregisterClient, no boilerplate. Think of it as Flutter’s RadioGroup, but for any widget. Real-world examples show how a navigation drawer or game menu can instantly restore intuitive focus without custom wiring.

Behind the scenes, SelectionGroup solves a psychological friction: users expect consistency. When you select a choice, you want to be guided back to it - especially after losing focus. Yet current tools force trade-offs between usability and complexity. The real elephant in the room? Most teams reimplement focus logic from scratch, duplicating effort and increasing technical debt.

Safety first: SelectionGroup suppresses WidgetState.selected when the group is active, preventing conflicting states. This keeps UI predictable, even in complex, nested layouts. For teams building accessible, responsive interfaces, this isn’t just a convenience - it’s a cornerstone of reliable design.