[framework] Add textField OCR support for framework side (#96637)

iOS OCR keyboard input support.

Author: luckysmg

packages/flutter/lib/services.dart

@@ -25,6 +25,7 @@ export 'src/services/hardware_keyboard.dart';
 export 'src/services/keyboard_inserted_content.dart';
 export 'src/services/keyboard_key.g.dart';
 export 'src/services/keyboard_maps.g.dart';
+export 'src/services/live_text.dart';
 export 'src/services/message_codec.dart';
 export 'src/services/message_codecs.dart';
 export 'src/services/mouse_cursor.dart';

packages/flutter/lib/src/cupertino/adaptive_text_selection_toolbar.dart

@@ -94,6 +94,7 @@ class CupertinoAdaptiveTextSelectionToolbar extends StatelessWidget {
     required VoidCallback? onCut,
     required VoidCallback? onPaste,
     required VoidCallback? onSelectAll,
+    required VoidCallback? onLiveTextInput,
     required this.anchors,
   }) : children = null,
        buttonItems = EditableText.getEditableButtonItems(
@@ -102,6 +103,7 @@ class CupertinoAdaptiveTextSelectionToolbar extends StatelessWidget {
          onCut: onCut,
          onPaste: onPaste,
          onSelectAll: onSelectAll,
+         onLiveTextInput: onLiveTextInput
        );
 
   /// Create an instance of [CupertinoAdaptiveTextSelectionToolbar] with the

packages/flutter/lib/src/cupertino/text_selection_toolbar_button.dart

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'dart:math';
+
 import 'package:flutter/widgets.dart';
 
 import 'button.dart';
@@ -103,6 +105,7 @@ class CupertinoTextSelectionToolbarButton extends StatefulWidget {
         return localizations.pasteButtonLabel;
       case ContextMenuButtonType.selectAll:
         return localizations.selectAllButtonLabel;
+      case ContextMenuButtonType.liveTextInput:
       case ContextMenuButtonType.delete:
       case ContextMenuButtonType.custom:
         return '';
@@ -131,6 +134,7 @@ class _CupertinoTextSelectionToolbarButtonState extends State<CupertinoTextSelec
 
   @override
   Widget build(BuildContext context) {
+    final Widget content = _getContentWidget(context);
     final Widget child = CupertinoButton(
       color: isPressed
         ? _kToolbarPressedColor.resolveFrom(context)
@@ -145,15 +149,7 @@ class _CupertinoTextSelectionToolbarButtonState extends State<CupertinoTextSelec
       // There's no foreground fade on iOS toolbar anymore, just the background
       // is darkened.
       pressedOpacity: 1.0,
-      child: widget.child ?? Text(
-         widget.text ?? CupertinoTextSelectionToolbarButton.getButtonLabel(context, widget.buttonItem!),
-         overflow: TextOverflow.ellipsis,
-         style: _kToolbarButtonFontStyle.copyWith(
-           color: widget.onPressed != null
-               ? _kToolbarTextColor.resolveFrom(context)
-               : CupertinoColors.inactiveGray,
-         ),
-       ),
+      child: content,
     );
 
     if (widget.onPressed != null) {
@@ -170,4 +166,85 @@ class _CupertinoTextSelectionToolbarButtonState extends State<CupertinoTextSelec
       return child;
     }
   }
+
+  Widget _getContentWidget(BuildContext context) {
+    if (widget.child != null) {
+      return widget.child!;
+    }
+    final Widget textWidget = Text(
+      widget.text ?? CupertinoTextSelectionToolbarButton.getButtonLabel(context, widget.buttonItem!),
+      overflow: TextOverflow.ellipsis,
+      style: _kToolbarButtonFontStyle.copyWith(
+        color: widget.onPressed != null
+            ? _kToolbarTextColor.resolveFrom(context)
+            : CupertinoColors.inactiveGray,
+      ),
+    );
+    if (widget.buttonItem == null) {
+      return textWidget;
+    }
+    switch (widget.buttonItem!.type) {
+      case ContextMenuButtonType.cut:
+      case ContextMenuButtonType.copy:
+      case ContextMenuButtonType.paste:
+      case ContextMenuButtonType.selectAll:
+      case ContextMenuButtonType.delete:
+      case ContextMenuButtonType.custom:
+        return textWidget;
+      case ContextMenuButtonType.liveTextInput:
+        return SizedBox(
+          width: 13.0,
+          height: 13.0,
+          child: CustomPaint(
+            painter: _LiveTextIconPainter(color: _kToolbarTextColor.resolveFrom(context)),
+          ),
+        );
+    }
+  }
+}
+
+class _LiveTextIconPainter extends CustomPainter {
+  _LiveTextIconPainter({required this.color});
+
+  final Color color;
+
+  final Paint _painter = Paint()
+    ..strokeCap = StrokeCap.round
+    ..strokeJoin = StrokeJoin.round
+    ..strokeWidth = 1.0
+    ..style = PaintingStyle.stroke;
+
+  @override
+  void paint(Canvas canvas, Size size) {
+    _painter.color = color;
+    canvas.save();
+    canvas.translate(size.width / 2.0, size.height / 2.0);
+
+    final Offset origin = Offset(-size.width / 2.0, -size.height / 2.0);
+    // Path for the one corner.
+    final Path path = Path()
+      ..moveTo(origin.dx, origin.dy + 3.5)
+      ..lineTo(origin.dx, origin.dy + 1.0)
+      ..arcToPoint(Offset(origin.dx + 1.0, origin.dy), radius: const Radius.circular(1))
+      ..lineTo(origin.dx + 3.5, origin.dy);
+
+    // Rotate to draw corner four times.
+    final Matrix4 rotationMatrix = Matrix4.identity()..rotateZ(pi / 2.0);
+    for (int i = 0; i < 4; i += 1) {
+      canvas.drawPath(path, _painter);
+      canvas.transform(rotationMatrix.storage);
+    }
+
+    // Draw three lines.
+    canvas.drawLine(const Offset(-3.0, -3.0), const Offset(3.0, -3.0), _painter);
+    canvas.drawLine(const Offset(-3.0, 0.0), const Offset(3.0, 0.0), _painter);
+    canvas.drawLine(const Offset(-3.0, 3.0), const Offset(1.0, 3.0), _painter);
+
+    canvas.restore();
+  }
+
+  @override
+  bool shouldRepaint(covariant _LiveTextIconPainter oldDelegate) {
+    return oldDelegate.color != color;
+  }
 }

packages/flutter/lib/src/material/adaptive_text_selection_toolbar.dart

@@ -103,6 +103,7 @@ class AdaptiveTextSelectionToolbar extends StatelessWidget {
     required VoidCallback? onCut,
     required VoidCallback? onPaste,
     required VoidCallback? onSelectAll,
+    required VoidCallback? onLiveTextInput,
     required this.anchors,
   }) : children = null,
        buttonItems = EditableText.getEditableButtonItems(
@@ -111,6 +112,7 @@ class AdaptiveTextSelectionToolbar extends StatelessWidget {
          onCut: onCut,
          onPaste: onPaste,
          onSelectAll: onSelectAll,
+         onLiveTextInput: onLiveTextInput
        );
 
   /// Create an instance of [AdaptiveTextSelectionToolbar] with the default
@@ -213,6 +215,8 @@ class AdaptiveTextSelectionToolbar extends StatelessWidget {
             return localizations.selectAllButtonLabel;
           case ContextMenuButtonType.delete:
             return localizations.deleteButtonTooltip.toUpperCase();
+          case ContextMenuButtonType.liveTextInput:
+            return localizations.scanTextButtonLabel;
           case ContextMenuButtonType.custom:
             return '';
         }
@@ -242,9 +246,8 @@ class AdaptiveTextSelectionToolbar extends StatelessWidget {
     switch (Theme.of(context).platform) {
       case TargetPlatform.iOS:
         return buttonItems.map((ContextMenuButtonItem buttonItem) {
-            return CupertinoTextSelectionToolbarButton.text(
-              onPressed: buttonItem.onPressed,
-              text: getButtonLabel(context, buttonItem),
+            return CupertinoTextSelectionToolbarButton.buttonItem(
+              buttonItem: buttonItem,
             );
           });
       case TargetPlatform.fuchsia:

packages/flutter/lib/src/material/material_localizations.dart

@@ -103,6 +103,9 @@ abstract class MaterialLocalizations {
   /// Label for "cut" edit buttons and menu items.
   String get cutButtonLabel;
 
+  /// Label for "scan text" OCR edit buttons and menu items.
+  String get scanTextButtonLabel;
+
   /// Label for OK buttons and menu items.
   String get okButtonLabel;
 
@@ -1159,6 +1162,9 @@ class DefaultMaterialLocalizations implements MaterialLocalizations {
   @override
   String get cutButtonLabel => 'Cut';
 
+  @override
+  String get scanTextButtonLabel => 'Scan text';
+
   @override
   String get okButtonLabel => 'OK';
 

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

@@ -0,0 +1,35 @@
+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'system_channels.dart';
+
+/// Utility methods for interacting with the system's Live Text.
+///
+/// For example, the Live Text input feature of iOS turns the keyboard into a camera view for
+/// directly inserting text obtained through OCR into the active field.
+///
+/// See also:
+///  * <https://developer.apple.com/documentation/uikit/uiresponder/3778577-capturetextfromcamera>
+///  * <https://support.apple.com/guide/iphone/use-live-text-iphcf0b71b0e/ios>
+class LiveText {
+  // This class is not meant to be instantiated or extended; this constructor
+  // prevents instantiation and extension.
+  LiveText._();
+
+  /// Returns true if the Live Text input feature is available on the current device.
+  static Future<bool> isLiveTextInputAvailable() async {
+    final bool supportLiveTextInput =
+        await SystemChannels.platform.invokeMethod('LiveText.isLiveTextInputAvailable') ?? false;
+    return supportLiveTextInput;
+  }
+
+  /// Start Live Text input.
+  ///
+  /// If any [TextInputConnection] is currently active, calling this method will tell the text field
+  /// to start Live Text input. If the current device doesn't support Live Text input,
+  /// nothing will happen.
+  static void startLiveTextInput() {
+    SystemChannels.textInput.invokeMethod('TextInput.startLiveTextInput');
+  }
+}

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

@@ -1050,6 +1050,13 @@ mixin TextSelectionDelegate {
   /// Whether select all is enabled, must not be null.
   bool get selectAllEnabled => true;
 
+  /// Whether Live Text input is enabled.
+  ///
+  /// See also:
+  ///  * [LiveText], where the availability of Live Text input can be obtained.
+  ///  * [LiveTextInputStatusNotifier], where the status of Live Text can be listened to.
+  bool get liveTextInputEnabled => false;
+
   /// Cut current selection to [Clipboard].
   ///
   /// If and only if [cause] is [SelectionChangedCause.toolbar], the toolbar

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

@@ -26,6 +26,13 @@ enum ContextMenuButtonType {
   /// A button that deletes the current text selection.
   delete,
 
+  /// A button for starting Live Text input.
+  ///
+  /// See also:
+  ///  * [LiveText], where the availability of Live Text input can be obtained.
+  ///  * [LiveTextInputStatusNotifier], where the status of Live Text can be listened to.
+  liveTextInput,
+
   /// Anything other than the default button types.
   custom,
 }