Mac cmd + shift + left/right (#95948)

packages/flutter/lib/src/services/text_editing.dart

@@ -238,8 +238,8 @@ class TextSelection extends TextRange {
   /// [TextSelection.extentOffset] to the given [TextPosition].
   ///
   /// In some cases, the [TextSelection.baseOffset] and
-  /// [TextSelection.extentOffset] may flip during this operation, or the size
-  /// of the selection may shrink.
+  /// [TextSelection.extentOffset] may flip during this operation, and/or the
+  /// size of the selection may shrink.
   ///
   /// ## Difference with [expandTo]
   /// In contrast with this method, [expandTo] is strictly growth; the

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

@@ -307,8 +307,8 @@ class DefaultTextEditingShortcuts extends Shortcuts {
     const SingleActivator(LogicalKeyboardKey.arrowUp, meta: true): const ExtendSelectionToDocumentBoundaryIntent(forward: false, collapseSelection: true),
     const SingleActivator(LogicalKeyboardKey.arrowDown, meta: true): const ExtendSelectionToDocumentBoundaryIntent(forward: true, collapseSelection: true),
 
-    const SingleActivator(LogicalKeyboardKey.arrowLeft, shift: true, meta: true): const ExtendSelectionToLineBreakIntent(forward: false, collapseSelection: false),
-    const SingleActivator(LogicalKeyboardKey.arrowRight, shift: true, meta: true): const ExtendSelectionToLineBreakIntent(forward: true, collapseSelection: false),
+    const SingleActivator(LogicalKeyboardKey.arrowLeft, shift: true, meta: true): const ExpandSelectionToLineBreakIntent(forward: false),
+    const SingleActivator(LogicalKeyboardKey.arrowRight, shift: true, meta: true): const ExpandSelectionToLineBreakIntent(forward: true),
     const SingleActivator(LogicalKeyboardKey.arrowUp, shift: true, meta: true): const ExtendSelectionToDocumentBoundaryIntent(forward: false, collapseSelection: false),
     const SingleActivator(LogicalKeyboardKey.arrowDown, shift: true, meta: true): const ExtendSelectionToDocumentBoundaryIntent(forward: true, collapseSelection: false),
 

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

@@ -2931,6 +2931,30 @@ class EditableTextState extends State<EditableText> with AutomaticKeepAliveClien
 
   late final _UpdateTextSelectionToAdjacentLineAction<ExtendSelectionVerticallyToAdjacentLineIntent> _adjacentLineAction = _UpdateTextSelectionToAdjacentLineAction<ExtendSelectionVerticallyToAdjacentLineIntent>(this);
 
+  void _expandSelection(ExpandSelectionToLineBreakIntent intent) {
+    final _TextBoundary textBoundary = _linebreak(intent);
+    final TextSelection textBoundarySelection = textBoundary.textEditingValue.selection;
+    if (!textBoundarySelection.isValid) {
+      return;
+    }
+
+    final bool inOrder = textBoundarySelection.baseOffset <= textBoundarySelection.extentOffset;
+    final bool towardsExtent = intent.forward == inOrder;
+    final TextPosition position = towardsExtent
+        ? textBoundarySelection.extent
+        : textBoundarySelection.base;
+
+    final TextPosition newExtent = intent.forward
+      ? textBoundary.getTrailingTextBoundaryAt(position)
+      : textBoundary.getLeadingTextBoundaryAt(position);
+
+    final TextSelection newSelection = textBoundarySelection.expandTo(newExtent, textBoundarySelection.isCollapsed);
+    userUpdateTextEditingValue(
+      _value.copyWith(selection: newSelection),
+      SelectionChangedCause.keyboard,
+    );
+  }
+
   late final Map<Type, Action<Intent>> _actions = <Type, Action<Intent>>{
     DoNothingAndStopPropagationTextIntent: DoNothingAction(consumesKey: false),
     ReplaceTextIntent: _replaceTextAction,
@@ -2946,6 +2970,7 @@ class EditableTextState extends State<EditableText> with AutomaticKeepAliveClien
     ExtendSelectionByCharacterIntent: _makeOverridable(_UpdateTextSelectionAction<ExtendSelectionByCharacterIntent>(this, false, _characterBoundary,)),
     ExtendSelectionToNextWordBoundaryIntent: _makeOverridable(_UpdateTextSelectionAction<ExtendSelectionToNextWordBoundaryIntent>(this, true, _nextWordBoundary)),
     ExtendSelectionToLineBreakIntent: _makeOverridable(_UpdateTextSelectionAction<ExtendSelectionToLineBreakIntent>(this, true, _linebreak)),
+    ExpandSelectionToLineBreakIntent: _makeOverridable(CallbackAction<ExpandSelectionToLineBreakIntent>(onInvoke: _expandSelection)),
     ExtendSelectionVerticallyToAdjacentLineIntent: _makeOverridable(_adjacentLineAction),
     ExtendSelectionToDocumentBoundaryIntent: _makeOverridable(_UpdateTextSelectionAction<ExtendSelectionToDocumentBoundaryIntent>(this, true, _documentBoundary)),
     ExtendSelectionToNextWordBoundaryOrCaretLocationIntent: _makeOverridable(_ExtendSelectionOrCaretPositionAction(this, _nextWordBoundary)),

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

@@ -92,7 +92,7 @@ abstract class DirectionalCaretMovementIntent extends DirectionalTextEditingInte
   final bool collapseAtReversal;
 }
 
-/// Expands, or moves the current selection from the current
+/// Extends, or moves the current selection from the current
 /// [TextSelection.extent] position to the previous or the next character
 /// boundary.
 class ExtendSelectionByCharacterIntent extends DirectionalCaretMovementIntent {
@@ -103,7 +103,7 @@ class ExtendSelectionByCharacterIntent extends DirectionalCaretMovementIntent {
   }) : super(forward, collapseSelection);
 }
 
-/// Expands, or moves the current selection from the current
+/// Extends, or moves the current selection from the current
 /// [TextSelection.extent] position to the previous or the next word
 /// boundary.
 class ExtendSelectionToNextWordBoundaryIntent extends DirectionalCaretMovementIntent {
@@ -114,7 +114,7 @@ class ExtendSelectionToNextWordBoundaryIntent extends DirectionalCaretMovementIn
   }) : super(forward, collapseSelection);
 }
 
-/// Expands, or moves the current selection from the current
+/// Extends, or moves the current selection from the current
 /// [TextSelection.extent] position to the previous or the next word
 /// boundary, or the [TextSelection.base] position if it's closer in the move
 /// direction.
@@ -124,7 +124,7 @@ class ExtendSelectionToNextWordBoundaryIntent extends DirectionalCaretMovementIn
 /// when the order of [TextSelection.base] and [TextSelection.extent] would
 /// reverse.
 ///
-/// This is typically only used on macOS.
+/// This is typically only used on MacOS.
 class ExtendSelectionToNextWordBoundaryOrCaretLocationIntent extends DirectionalTextEditingIntent {
   /// Creates an [ExtendSelectionToNextWordBoundaryOrCaretLocationIntent].
   const ExtendSelectionToNextWordBoundaryOrCaretLocationIntent({
@@ -132,9 +132,33 @@ class ExtendSelectionToNextWordBoundaryOrCaretLocationIntent extends Directional
   }) : super(forward);
 }
 
-/// Expands, or moves the current selection from the current
+/// Expands the current selection to the closest line break in the direction
+/// given by [forward].
+///
+/// Either the base or extent can move, whichever is closer to the line break.
+/// The selection will never shrink.
+///
+/// This behavior is common on MacOS.
+///
+/// See also:
+///
+///   [ExtendSelectionToLineBreakIntent], which is similar but always moves the
+///   extent.
+class ExpandSelectionToLineBreakIntent extends DirectionalTextEditingIntent {
+  /// Creates an [ExpandSelectionToLineBreakIntent].
+  const ExpandSelectionToLineBreakIntent({
+    required bool forward,
+  }) : super(forward);
+}
+
+/// Extends, or moves the current selection from the current
 /// [TextSelection.extent] position to the closest line break in the direction
 /// given by [forward].
+///
+/// See also:
+///
+///   [ExpandSelectionToLineBreakIntent], which is similar but always increases
+///   the size of the selection.
 class ExtendSelectionToLineBreakIntent extends DirectionalCaretMovementIntent {
   /// Creates an [ExtendSelectionToLineBreakIntent].
   const ExtendSelectionToLineBreakIntent({
@@ -145,7 +169,7 @@ class ExtendSelectionToLineBreakIntent extends DirectionalCaretMovementIntent {
        super(forward, collapseSelection, collapseAtReversal);
 }
 
-/// Expands, or moves the current selection from the current
+/// Extends, or moves the current selection from the current
 /// [TextSelection.extent] position to the closest position on the adjacent
 /// line.
 class ExtendSelectionVerticallyToAdjacentLineIntent extends DirectionalCaretMovementIntent {
@@ -156,7 +180,7 @@ class ExtendSelectionVerticallyToAdjacentLineIntent extends DirectionalCaretMove
   }) : super(forward, collapseSelection);
 }
 
-/// Expands, or moves the current selection from the current
+/// Extends, or moves the current selection from the current
 /// [TextSelection.extent] position to the start or the end of the document.
 class ExtendSelectionToDocumentBoundaryIntent extends DirectionalCaretMovementIntent {
   /// Creates an [ExtendSelectionToDocumentBoundaryIntent].