Adds numpad navigation shortcuts for Linux (#145464)

## Description

This PR adds shortcuts related to numpad keys on Linux.

## Related Issue

Linux side for https://github.com/flutter/flutter/issues/144936

## Tests

Adds 2 tests.

packages/flutter/lib/src/widgets/default_text_editing_shortcuts.dart

@@ -253,8 +253,51 @@ class DefaultTextEditingShortcuts extends StatelessWidget {
 
   static final Map<ShortcutActivator, Intent> _fuchsiaShortcuts = _androidShortcuts;
 
+  static final Map<ShortcutActivator, Intent> _linuxNumpadShortcuts = <ShortcutActivator, Intent>{
+    // When numLock is on, numpad keys shortcuts require shift to be pressed too.
+    const SingleActivator(LogicalKeyboardKey.numpad6, shift: true, numLock: LockState.locked): const ExtendSelectionByCharacterIntent(forward: true, collapseSelection: false),
+    const SingleActivator(LogicalKeyboardKey.numpad4, shift: true, numLock: LockState.locked): const ExtendSelectionByCharacterIntent(forward: false, collapseSelection: false),
+    const SingleActivator(LogicalKeyboardKey.numpad8, shift: true, numLock: LockState.locked): const ExtendSelectionVerticallyToAdjacentLineIntent(forward: false, collapseSelection: false),
+    const SingleActivator(LogicalKeyboardKey.numpad2, shift: true, numLock: LockState.locked): const ExtendSelectionVerticallyToAdjacentLineIntent(forward: true, collapseSelection: false),
+
+    const SingleActivator(LogicalKeyboardKey.numpad6, shift: true, control: true, numLock: LockState.locked): const ExtendSelectionToNextWordBoundaryIntent(forward: true, collapseSelection: false),
+    const SingleActivator(LogicalKeyboardKey.numpad4, shift: true, control: true, numLock: LockState.locked): const ExtendSelectionToNextWordBoundaryIntent(forward: false, collapseSelection: false),
+    const SingleActivator(LogicalKeyboardKey.numpad8, shift: true, control: true, numLock: LockState.locked): const ExtendSelectionToNextParagraphBoundaryIntent(forward: false, collapseSelection: false),
+    const SingleActivator(LogicalKeyboardKey.numpad2, shift: true, control: true, numLock: LockState.locked): const ExtendSelectionToNextParagraphBoundaryIntent(forward: true, collapseSelection: false),
+
+    const SingleActivator(LogicalKeyboardKey.numpad9, shift: true, numLock: LockState.locked): const ExtendSelectionVerticallyToAdjacentPageIntent(forward: false, collapseSelection: false),
+    const SingleActivator(LogicalKeyboardKey.numpad3, shift: true, numLock: LockState.locked): const ExtendSelectionVerticallyToAdjacentPageIntent(forward: true, collapseSelection: false),
+
+    const SingleActivator(LogicalKeyboardKey.numpad7, shift: true, numLock: LockState.locked): const ExtendSelectionVerticallyToAdjacentLineIntent(forward: false, collapseSelection: false),
+    const SingleActivator(LogicalKeyboardKey.numpad1, shift: true, numLock: LockState.locked): const ExtendSelectionVerticallyToAdjacentLineIntent(forward: true, collapseSelection: false),
+
+    const SingleActivator(LogicalKeyboardKey.numpadDecimal, shift: true, numLock: LockState.locked): const DeleteCharacterIntent(forward: true),
+    const SingleActivator(LogicalKeyboardKey.numpadDecimal, shift: true, control: true, numLock: LockState.locked): const DeleteToNextWordBoundaryIntent(forward: true),
+
+    // When numLock is off, numpad keys shortcuts require shift not to be pressed.
+    const SingleActivator(LogicalKeyboardKey.numpad6, numLock: LockState.unlocked): const ExtendSelectionByCharacterIntent(forward: true, collapseSelection: true),
+    const SingleActivator(LogicalKeyboardKey.numpad4, numLock: LockState.unlocked): const ExtendSelectionByCharacterIntent(forward: false, collapseSelection: true),
+    const SingleActivator(LogicalKeyboardKey.numpad8, numLock: LockState.unlocked): const ExtendSelectionVerticallyToAdjacentLineIntent(forward: false, collapseSelection: true),
+    const SingleActivator(LogicalKeyboardKey.numpad2, numLock: LockState.unlocked): const ExtendSelectionVerticallyToAdjacentLineIntent(forward: true, collapseSelection: true),
+
+    const SingleActivator(LogicalKeyboardKey.numpad6, control: true, numLock: LockState.unlocked): const ExtendSelectionToNextWordBoundaryIntent(forward: true, collapseSelection: true),
+    const SingleActivator(LogicalKeyboardKey.numpad4, control: true, numLock: LockState.unlocked): const ExtendSelectionToNextWordBoundaryIntent(forward: false, collapseSelection: true),
+    const SingleActivator(LogicalKeyboardKey.numpad8, control: true, numLock: LockState.unlocked): const ExtendSelectionToNextParagraphBoundaryIntent(forward: false, collapseSelection: true),
+    const SingleActivator(LogicalKeyboardKey.numpad2, control: true, numLock: LockState.unlocked): const ExtendSelectionToNextParagraphBoundaryIntent(forward: true, collapseSelection: true),
+
+    const SingleActivator(LogicalKeyboardKey.numpad9, numLock: LockState.unlocked): const ExtendSelectionVerticallyToAdjacentPageIntent(forward: false, collapseSelection: true),
+    const SingleActivator(LogicalKeyboardKey.numpad3, numLock: LockState.unlocked): const ExtendSelectionVerticallyToAdjacentPageIntent(forward: true, collapseSelection: true),
+
+    const SingleActivator(LogicalKeyboardKey.numpad7, numLock: LockState.unlocked): const ExtendSelectionVerticallyToAdjacentLineIntent(forward: false, collapseSelection: true),
+    const SingleActivator(LogicalKeyboardKey.numpad1, numLock: LockState.unlocked): const ExtendSelectionVerticallyToAdjacentLineIntent(forward: true, collapseSelection: true),
+
+    const SingleActivator(LogicalKeyboardKey.numpadDecimal, numLock: LockState.unlocked): const DeleteCharacterIntent(forward: true),
+    const SingleActivator(LogicalKeyboardKey.numpadDecimal, control: true, numLock: LockState.unlocked): const DeleteToNextWordBoundaryIntent(forward: true),
+  };
+
   static final Map<ShortcutActivator, Intent> _linuxShortcuts = <ShortcutActivator, Intent>{
     ..._commonShortcuts,
+    ..._linuxNumpadShortcuts,
     const SingleActivator(LogicalKeyboardKey.home): const ExtendSelectionToLineBreakIntent(forward: false, collapseSelection: true),
     const SingleActivator(LogicalKeyboardKey.end): const ExtendSelectionToLineBreakIntent(forward: true, collapseSelection: true),
     const SingleActivator(LogicalKeyboardKey.home, shift: true): const ExtendSelectionToLineBreakIntent(forward: false, collapseSelection: false),

packages/flutter/test/widgets/default_text_editing_shortcuts_test.dart

@@ -486,6 +486,185 @@ void main() {
       expect(state.lastIntent, isA<ExtendSelectionToLineBreakIntent>());
     }, variant: macOSOnly);
   }, skip: kIsWeb); // [intended] specific tests target non-web.
+
+  group('Linux does accept numpad shortcuts', () {
+    testWidgets('when numlock is locked', (WidgetTester tester) async {
+      final FocusNode editable = FocusNode();
+      addTearDown(editable.dispose);
+      final FocusNode spy = FocusNode();
+      addTearDown(spy.dispose);
+
+      await tester.pumpWidget(
+        buildSpyAboveEditableText(
+          editableFocusNode: editable,
+          spyFocusNode: spy,
+        ),
+      );
+      spy.requestFocus();
+      await tester.pump();
+      final ActionSpyState state = tester.state<ActionSpyState>(find.byType(ActionSpy));
+
+      // Lock NumLock.
+      await tester.sendKeyEvent(LogicalKeyboardKey.numLock);
+      expect(HardwareKeyboard.instance.lockModesEnabled.contains(KeyboardLockMode.numLock), isTrue);
+
+      await sendKeyCombination(tester, const SingleActivator(LogicalKeyboardKey.numpad6, shift: true));
+      expect(state.lastIntent, isA<ExtendSelectionByCharacterIntent>());
+      expect((state.lastIntent! as ExtendSelectionByCharacterIntent).forward, true);
+      expect((state.lastIntent! as ExtendSelectionByCharacterIntent).collapseSelection, false);
+
+      await sendKeyCombination(tester, const SingleActivator(LogicalKeyboardKey.numpad4, shift: true));
+      expect(state.lastIntent, isA<ExtendSelectionByCharacterIntent>());
+      expect((state.lastIntent! as ExtendSelectionByCharacterIntent).forward, false);
+      expect((state.lastIntent! as ExtendSelectionByCharacterIntent).collapseSelection, false);
+
+      await sendKeyCombination(tester, const SingleActivator(LogicalKeyboardKey.numpad8, shift: true));
+      expect(state.lastIntent, isA<ExtendSelectionVerticallyToAdjacentLineIntent>());
+      expect((state.lastIntent! as ExtendSelectionVerticallyToAdjacentLineIntent).forward, false);
+      expect((state.lastIntent! as ExtendSelectionVerticallyToAdjacentLineIntent).collapseSelection, false);
+
+      await sendKeyCombination(tester, const SingleActivator(LogicalKeyboardKey.numpad2, shift: true));
+      expect(state.lastIntent, isA<ExtendSelectionVerticallyToAdjacentLineIntent>());
+      expect((state.lastIntent! as ExtendSelectionVerticallyToAdjacentLineIntent).forward, true);
+      expect((state.lastIntent! as ExtendSelectionVerticallyToAdjacentLineIntent).collapseSelection, false);
+
+      await sendKeyCombination(tester, const SingleActivator(LogicalKeyboardKey.numpad9, shift: true));
+      expect(state.lastIntent, isA<ExtendSelectionVerticallyToAdjacentPageIntent>());
+      expect((state.lastIntent! as ExtendSelectionVerticallyToAdjacentPageIntent).forward, false);
+      expect((state.lastIntent! as ExtendSelectionVerticallyToAdjacentPageIntent).collapseSelection, false);
+
+      await sendKeyCombination(tester, const SingleActivator(LogicalKeyboardKey.numpad3, shift: true));
+      expect(state.lastIntent, isA<ExtendSelectionVerticallyToAdjacentPageIntent>());
+      expect((state.lastIntent! as ExtendSelectionVerticallyToAdjacentPageIntent).forward, true);
+      expect((state.lastIntent! as ExtendSelectionVerticallyToAdjacentPageIntent).collapseSelection, false);
+
+      await sendKeyCombination(tester, const SingleActivator(LogicalKeyboardKey.numpad7, shift: true));
+      expect(state.lastIntent, isA<ExtendSelectionVerticallyToAdjacentLineIntent>());
+      expect((state.lastIntent! as ExtendSelectionVerticallyToAdjacentLineIntent).forward, false);
+      expect((state.lastIntent! as ExtendSelectionVerticallyToAdjacentLineIntent).collapseSelection, false);
+
+      await sendKeyCombination(tester, const SingleActivator(LogicalKeyboardKey.numpad1, shift: true));
+      expect(state.lastIntent, isA<ExtendSelectionVerticallyToAdjacentLineIntent>());
+      expect((state.lastIntent! as ExtendSelectionVerticallyToAdjacentLineIntent).forward, true);
+      expect((state.lastIntent! as ExtendSelectionVerticallyToAdjacentLineIntent).collapseSelection, false);
+
+      await sendKeyCombination(tester, const SingleActivator(LogicalKeyboardKey.numpadDecimal, shift: true));
+      expect(state.lastIntent, isA<DeleteCharacterIntent>());
+      expect((state.lastIntent! as DeleteCharacterIntent).forward, true);
+
+      await sendKeyCombination(tester, const SingleActivator(LogicalKeyboardKey.numpad6, shift: true, control: true));
+      expect(state.lastIntent, isA<ExtendSelectionToNextWordBoundaryIntent>());
+      expect((state.lastIntent! as ExtendSelectionToNextWordBoundaryIntent).forward, true);
+      expect((state.lastIntent! as ExtendSelectionToNextWordBoundaryIntent).collapseSelection, false);
+
+      await sendKeyCombination(tester, const SingleActivator(LogicalKeyboardKey.numpad4, shift: true, control: true));
+      expect(state.lastIntent, isA<ExtendSelectionToNextWordBoundaryIntent>());
+      expect((state.lastIntent! as ExtendSelectionToNextWordBoundaryIntent).forward, false);
+      expect((state.lastIntent! as ExtendSelectionToNextWordBoundaryIntent).collapseSelection, false);
+
+      await sendKeyCombination(tester, const SingleActivator(LogicalKeyboardKey.numpad8, shift: true, control: true));
+      expect(state.lastIntent, isA<ExtendSelectionToNextParagraphBoundaryIntent>());
+      expect((state.lastIntent! as ExtendSelectionToNextParagraphBoundaryIntent).forward, false);
+      expect((state.lastIntent! as ExtendSelectionToNextParagraphBoundaryIntent).collapseSelection, false);
+
+      await sendKeyCombination(tester, const SingleActivator(LogicalKeyboardKey.numpad2, shift: true, control: true));
+      expect(state.lastIntent, isA<ExtendSelectionToNextParagraphBoundaryIntent>());
+      expect((state.lastIntent! as ExtendSelectionToNextParagraphBoundaryIntent).forward, true);
+      expect((state.lastIntent! as ExtendSelectionToNextParagraphBoundaryIntent).collapseSelection, false);
+
+      await sendKeyCombination(tester, const SingleActivator(LogicalKeyboardKey.numpadDecimal, shift: true, control: true));
+      expect(state.lastIntent, isA<DeleteToNextWordBoundaryIntent>());
+      expect((state.lastIntent! as DeleteToNextWordBoundaryIntent).forward, true);
+    }, variant: TargetPlatformVariant.only(TargetPlatform.linux));
+
+    testWidgets('when numlock is unlocked', (WidgetTester tester) async {
+      final FocusNode editable = FocusNode();
+      addTearDown(editable.dispose);
+      final FocusNode spy = FocusNode();
+      addTearDown(spy.dispose);
+
+      await tester.pumpWidget(
+        buildSpyAboveEditableText(
+          editableFocusNode: editable,
+          spyFocusNode: spy,
+        ),
+      );
+      spy.requestFocus();
+      await tester.pump();
+      final ActionSpyState state = tester.state<ActionSpyState>(find.byType(ActionSpy));
+
+      // Verify that NumLock is unlocked.
+      expect(HardwareKeyboard.instance.lockModesEnabled.contains(KeyboardLockMode.numLock), isFalse);
+
+      await sendKeyCombination(tester, const SingleActivator(LogicalKeyboardKey.numpad6));
+      expect(state.lastIntent, isA<ExtendSelectionByCharacterIntent>());
+      expect((state.lastIntent! as ExtendSelectionByCharacterIntent).forward, true);
+      expect((state.lastIntent! as ExtendSelectionByCharacterIntent).collapseSelection, true);
+
+      await sendKeyCombination(tester, const SingleActivator(LogicalKeyboardKey.numpad4));
+      expect(state.lastIntent, isA<ExtendSelectionByCharacterIntent>());
+      expect((state.lastIntent! as ExtendSelectionByCharacterIntent).forward, false);
+      expect((state.lastIntent! as ExtendSelectionByCharacterIntent).collapseSelection, true);
+
+      await sendKeyCombination(tester, const SingleActivator(LogicalKeyboardKey.numpad8));
+      expect(state.lastIntent, isA<ExtendSelectionVerticallyToAdjacentLineIntent>());
+      expect((state.lastIntent! as ExtendSelectionVerticallyToAdjacentLineIntent).forward, false);
+      expect((state.lastIntent! as ExtendSelectionVerticallyToAdjacentLineIntent).collapseSelection, true);
+
+      await sendKeyCombination(tester, const SingleActivator(LogicalKeyboardKey.numpad2));
+      expect(state.lastIntent, isA<ExtendSelectionVerticallyToAdjacentLineIntent>());
+      expect((state.lastIntent! as ExtendSelectionVerticallyToAdjacentLineIntent).forward, true);
+      expect((state.lastIntent! as ExtendSelectionVerticallyToAdjacentLineIntent).collapseSelection, true);
+
+      await sendKeyCombination(tester, const SingleActivator(LogicalKeyboardKey.numpad9));
+      expect(state.lastIntent, isA<ExtendSelectionVerticallyToAdjacentPageIntent>());
+      expect((state.lastIntent! as ExtendSelectionVerticallyToAdjacentPageIntent).forward, false);
+      expect((state.lastIntent! as ExtendSelectionVerticallyToAdjacentPageIntent).collapseSelection, true);
+
+      await sendKeyCombination(tester, const SingleActivator(LogicalKeyboardKey.numpad3));
+      expect(state.lastIntent, isA<ExtendSelectionVerticallyToAdjacentPageIntent>());
+      expect((state.lastIntent! as ExtendSelectionVerticallyToAdjacentPageIntent).forward, true);
+      expect((state.lastIntent! as ExtendSelectionVerticallyToAdjacentPageIntent).collapseSelection, true);
+
+      await sendKeyCombination(tester, const SingleActivator(LogicalKeyboardKey.numpad7));
+      expect(state.lastIntent, isA<ExtendSelectionVerticallyToAdjacentLineIntent>());
+      expect((state.lastIntent! as ExtendSelectionVerticallyToAdjacentLineIntent).forward, false);
+      expect((state.lastIntent! as ExtendSelectionVerticallyToAdjacentLineIntent).collapseSelection, true);
+
+      await sendKeyCombination(tester, const SingleActivator(LogicalKeyboardKey.numpad1));
+      expect(state.lastIntent, isA<ExtendSelectionVerticallyToAdjacentLineIntent>());
+      expect((state.lastIntent! as ExtendSelectionVerticallyToAdjacentLineIntent).forward, true);
+      expect((state.lastIntent! as ExtendSelectionVerticallyToAdjacentLineIntent).collapseSelection, true);
+
+      await sendKeyCombination(tester, const SingleActivator(LogicalKeyboardKey.numpadDecimal));
+      expect(state.lastIntent, isA<DeleteCharacterIntent>());
+      expect((state.lastIntent! as DeleteCharacterIntent).forward, true);
+
+      await sendKeyCombination(tester, const SingleActivator(LogicalKeyboardKey.numpad6, control: true));
+      expect(state.lastIntent, isA<ExtendSelectionToNextWordBoundaryIntent>());
+      expect((state.lastIntent! as ExtendSelectionToNextWordBoundaryIntent).forward, true);
+      expect((state.lastIntent! as ExtendSelectionToNextWordBoundaryIntent).collapseSelection, true);
+
+      await sendKeyCombination(tester, const SingleActivator(LogicalKeyboardKey.numpad4, control: true));
+      expect(state.lastIntent, isA<ExtendSelectionToNextWordBoundaryIntent>());
+      expect((state.lastIntent! as ExtendSelectionToNextWordBoundaryIntent).forward, false);
+      expect((state.lastIntent! as ExtendSelectionToNextWordBoundaryIntent).collapseSelection, true);
+
+      await sendKeyCombination(tester, const SingleActivator(LogicalKeyboardKey.numpad8, control: true));
+      expect(state.lastIntent, isA<ExtendSelectionToNextParagraphBoundaryIntent>());
+      expect((state.lastIntent! as ExtendSelectionToNextParagraphBoundaryIntent).forward, false);
+      expect((state.lastIntent! as ExtendSelectionToNextParagraphBoundaryIntent).collapseSelection, true);
+
+      await sendKeyCombination(tester, const SingleActivator(LogicalKeyboardKey.numpad2, control: true));
+      expect(state.lastIntent, isA<ExtendSelectionToNextParagraphBoundaryIntent>());
+      expect((state.lastIntent! as ExtendSelectionToNextParagraphBoundaryIntent).forward, true);
+      expect((state.lastIntent! as ExtendSelectionToNextParagraphBoundaryIntent).collapseSelection, true);
+
+      await sendKeyCombination(tester, const SingleActivator(LogicalKeyboardKey.numpadDecimal, control: true));
+      expect(state.lastIntent, isA<DeleteToNextWordBoundaryIntent>());
+      expect((state.lastIntent! as DeleteToNextWordBoundaryIntent).forward, true);
+    }, variant: TargetPlatformVariant.only(TargetPlatform.linux));
+  }, skip: kIsWeb); // [intended] specific tests target non-web.
 }
 
 class ActionSpy extends StatefulWidget {
@@ -508,6 +687,8 @@ class ActionSpyState extends State<ActionSpy> {
     ExtendSelectionVerticallyToAdjacentLineIntent: CallbackAction<ExtendSelectionVerticallyToAdjacentLineIntent>(onInvoke: _captureIntent),
     ExtendSelectionToDocumentBoundaryIntent: CallbackAction<ExtendSelectionToDocumentBoundaryIntent>(onInvoke: _captureIntent),
     ExtendSelectionToNextWordBoundaryOrCaretLocationIntent: CallbackAction<ExtendSelectionToNextWordBoundaryOrCaretLocationIntent>(onInvoke: _captureIntent),
+    ExtendSelectionToNextParagraphBoundaryIntent: CallbackAction<ExtendSelectionToNextParagraphBoundaryIntent>(onInvoke: _captureIntent),
+    ExtendSelectionVerticallyToAdjacentPageIntent: CallbackAction<ExtendSelectionVerticallyToAdjacentPageIntent>(onInvoke: _captureIntent),
 
     DeleteToLineBreakIntent: CallbackAction<DeleteToLineBreakIntent>(onInvoke: _captureIntent),
     DeleteToNextWordBoundaryIntent: CallbackAction<DeleteToNextWordBoundaryIntent>(onInvoke: _captureIntent),