キーボードショートカットとそのフォーカス管理のためのスニペット/ライブラリ(まだ正しい挙動はしない)

keyboardShortcutLib.dart

import 'package:flutter/services.dart';
import 'package:flutter/widgets.dart';

class ShortcutPrefer{
  LogicalKeyboardKey key;
  void Function(Event) asNew;
  static void Function(BuildContext) defaultHandler = (BuildContext context){};
  ShortcutPrefer(this.key, this.asNew);
}
class ShortcutPreferAfresh extends ShortcutPrefer{
  ShortcutPreferAfresh(LogicalKeyboardKey key, void Function(Event) asNew): super(key, asNew);
}
class ShortcutPreferRemove extends ShortcutPrefer{
  ShortcutPreferRemove(LogicalKeyboardKey key): super(key, ShortcutPrefer.defaultHandler);
}
class ShortcutPreferChange extends ShortcutPrefer{
  ShortcutPreferChange(LogicalKeyboardKey key, void Function(Event) asNew): super(key, asNew);
}
extension ShortcutListManager on List<ShortcutPrefer>{
  List<ShortcutPrefer> onKind(List<Type> tps){
    Type typrOfShortcuts = tps.where((Type tp)=>tp == ShortcutPreferAfresh || tp == ShortcutPreferRemove || tp == ShortcutPreferChange).toList();
    return this;
  }
  Map<LogicalKeySet, Intent> get toDisable{
    List<ShortcutPrefer> list = this.onKind([ShortcutPreferRemove, ShortcutPreferChange]);
    return list.asMap().map((int ind, ShortcutPrefer pf)=>MapEntry(LogicalKeySet(key),Intent.doNothing));
  }
  void toHandle(LogicalKeyboardKey actKey, BuildContext context){
    this.forEach((ShortcutPrefer pf)=>pf.key == actKey ? pf.asNew(context) : (){}());
  }
}
Widget Function(BuildContext) shortcutBuilder(FocusNode focusNode, List<ShortcutPrefer> preferences){
  return (BuildContext context){
    return Shortcuts(
      shortcuts: preferences.toDisable,
      child: RawKeyboardListener(
        focusNode: focusNode,
        onKey: (event) {
          if (event is  RawKeyDownEvent) {
            final LogicalKeyboardKey logicalKey = event.logicalKey;
            preferences.toHandle(logicalKey, context);
          }
        }
  };
}

cf.

• https://twitter.com/_mono/status/1188751366501457920
• https://github.com/mono0926/flutter_mono_kit/blob/ecade799af32e141914b112d6c24c72c0e85b32c/lib/widgets/scroll_keyboard_shortcut.dart#L41