Undo/redo (#96968)

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

@@ -205,6 +205,8 @@ class DefaultTextEditingShortcuts extends Shortcuts {
     const SingleActivator(LogicalKeyboardKey.keyC, control: true): CopySelectionTextIntent.copy,
     const SingleActivator(LogicalKeyboardKey.keyV, control: true): const PasteTextIntent(SelectionChangedCause.keyboard),
     const SingleActivator(LogicalKeyboardKey.keyA, control: true): const SelectAllTextIntent(SelectionChangedCause.keyboard),
+    const SingleActivator(LogicalKeyboardKey.keyZ, control: true): const UndoTextIntent(SelectionChangedCause.keyboard),
+    const SingleActivator(LogicalKeyboardKey.keyZ, shift: true, control: true): const RedoTextIntent(SelectionChangedCause.keyboard),
   };
 
   // The following key combinations have no effect on text editing on this
@@ -215,6 +217,7 @@ class DefaultTextEditingShortcuts extends Shortcuts {
   //   * Meta + C
   //   * Meta + V
   //   * Meta + A
+  //   * Meta + shift? + Z
   //   * Meta + shift? + arrow down
   //   * Meta + shift? + arrow left
   //   * Meta + shift? + arrow right
@@ -235,6 +238,7 @@ class DefaultTextEditingShortcuts extends Shortcuts {
   //   * Meta + C
   //   * Meta + V
   //   * Meta + A
+  //   * Meta + shift? + Z
   //   * Meta + shift? + arrow down
   //   * Meta + shift? + arrow left
   //   * Meta + shift? + arrow right
@@ -259,6 +263,7 @@ class DefaultTextEditingShortcuts extends Shortcuts {
     //   * Meta + C
     //   * Meta + V
     //   * Meta + A
+    //   * Meta + shift? + Z
     //   * Meta + shift? + arrow down
     //   * Meta + shift? + arrow left
     //   * Meta + shift? + arrow right
@@ -319,12 +324,15 @@ class DefaultTextEditingShortcuts extends Shortcuts {
     const SingleActivator(LogicalKeyboardKey.keyC, meta: true): CopySelectionTextIntent.copy,
     const SingleActivator(LogicalKeyboardKey.keyV, meta: true): const PasteTextIntent(SelectionChangedCause.keyboard),
     const SingleActivator(LogicalKeyboardKey.keyA, meta: true): const SelectAllTextIntent(SelectionChangedCause.keyboard),
+    const SingleActivator(LogicalKeyboardKey.keyZ, meta: true): const UndoTextIntent(SelectionChangedCause.keyboard),
+    const SingleActivator(LogicalKeyboardKey.keyZ, shift: true, meta: true): const RedoTextIntent(SelectionChangedCause.keyboard),
     // The following key combinations have no effect on text editing on this
     // platform:
     //   * End
     //   * Home
     //   * Control + shift? + end
     //   * Control + shift? + home
+    //   * Control + shift? + Z
   };
 
   // The following key combinations have no effect on text editing on this

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

@@ -231,6 +231,16 @@ class PasteTextIntent extends Intent {
   final SelectionChangedCause cause;
 }
 
+/// An [Intent] that represents a user interaction that attempts to go back to
+/// the previous editing state.
+class RedoTextIntent extends Intent {
+  /// Creates a [RedoTextIntent].
+  const RedoTextIntent(this.cause);
+
+  /// {@macro flutter.widgets.TextEditingIntents.cause}
+  final SelectionChangedCause cause;
+}
+
 /// An [Intent] that represents a user interaction that attempts to modify the
 /// current [TextEditingValue] in an input field.
 class ReplaceTextIntent extends Intent {
@@ -250,10 +260,20 @@ class ReplaceTextIntent extends Intent {
   final SelectionChangedCause cause;
 }
 
+/// An [Intent] that represents a user interaction that attempts to go back to
+/// the previous editing state.
+class UndoTextIntent extends Intent {
+  /// Creates an [UndoTextIntent].
+  const UndoTextIntent(this.cause);
+
+  /// {@macro flutter.widgets.TextEditingIntents.cause}
+  final SelectionChangedCause cause;
+}
+
 /// An [Intent] that represents a user interaction that attempts to change the
 /// selection in an input field.
 class UpdateSelectionIntent extends Intent {
-  /// Creates a [UpdateSelectionIntent].
+  /// Creates an [UpdateSelectionIntent].
   const UpdateSelectionIntent(this.currentTextEditingValue, this.newSelection, this.cause);
 
   /// The [TextEditingValue] that this [Intent]'s action should perform on.