refactor: navigation/offline handling

and other improvments

lib/focus/dpad_navigator.dart

@@ -1,54 +1,55 @@
 import 'package:flutter/services.dart';
 
+/// Shared sets for keyboard key categories.
+final _dpadDirectionKeys = {
+  LogicalKeyboardKey.arrowUp,
+  LogicalKeyboardKey.arrowDown,
+  LogicalKeyboardKey.arrowLeft,
+  LogicalKeyboardKey.arrowRight,
+};
+
+final _selectKeys = {
+  LogicalKeyboardKey.select,
+  LogicalKeyboardKey.enter,
+  LogicalKeyboardKey.numpadEnter,
+  LogicalKeyboardKey.gameButtonA,
+};
+
+final _backKeys = {
+  LogicalKeyboardKey.escape,
+  LogicalKeyboardKey.goBack,
+  LogicalKeyboardKey.browserBack,
+  LogicalKeyboardKey.gameButtonB,
+};
+
+final _contextMenuKeys = {
+  LogicalKeyboardKey.contextMenu,
+  LogicalKeyboardKey.gameButtonX,
+};
+
 /// Extension methods for checking D-pad related keys.
 extension DpadKeyExtension on LogicalKeyboardKey {
   /// Whether this key is a D-pad directional key.
-  bool get isDpadDirection {
-    return this == LogicalKeyboardKey.arrowUp ||
-        this == LogicalKeyboardKey.arrowDown ||
-        this == LogicalKeyboardKey.arrowLeft ||
-        this == LogicalKeyboardKey.arrowRight;
-  }
+  bool get isDpadDirection => _dpadDirectionKeys.contains(this);
 
   /// Whether this key is a select/activate key.
-  bool get isSelectKey {
-    return this == LogicalKeyboardKey.select ||
-        this == LogicalKeyboardKey.enter ||
-        this == LogicalKeyboardKey.numpadEnter ||
-        this == LogicalKeyboardKey.gameButtonA;
-  }
+  bool get isSelectKey => _selectKeys.contains(this);
 
   /// Whether this key is a back/cancel key.
-  bool get isBackKey {
-    return this == LogicalKeyboardKey.escape ||
-        this == LogicalKeyboardKey.goBack ||
-        this == LogicalKeyboardKey.browserBack ||
-        this == LogicalKeyboardKey.gameButtonB;
-  }
+  bool get isBackKey => _backKeys.contains(this);
 
   /// Whether this key is a context menu key.
-  bool get isContextMenuKey {
-    return this == LogicalKeyboardKey.contextMenu ||
-        this == LogicalKeyboardKey.gameButtonX;
-  }
+  bool get isContextMenuKey => _contextMenuKeys.contains(this);
 
   /// Whether this key moves focus left.
-  bool get isLeftKey {
-    return this == LogicalKeyboardKey.arrowLeft;
-  }
+  bool get isLeftKey => this == LogicalKeyboardKey.arrowLeft;
 
   /// Whether this key moves focus right.
-  bool get isRightKey {
-    return this == LogicalKeyboardKey.arrowRight;
-  }
+  bool get isRightKey => this == LogicalKeyboardKey.arrowRight;
 
   /// Whether this key moves focus up.
-  bool get isUpKey {
-    return this == LogicalKeyboardKey.arrowUp;
-  }
+  bool get isUpKey => this == LogicalKeyboardKey.arrowUp;
 
   /// Whether this key moves focus down.
-  bool get isDownKey {
-    return this == LogicalKeyboardKey.arrowDown;
-  }
+  bool get isDownKey => this == LogicalKeyboardKey.arrowDown;
 }