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

// 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 'dart:async';
import 'dart:math' as math;
import 'dart:ui' as ui hide TextStyle;

import 'package:characters/characters.dart' show CharacterRange, StringCharacters;
import 'package:flutter/foundation.dart';
import 'package:flutter/gestures.dart' show DragStartBehavior;
import 'package:flutter/rendering.dart';
import 'package:flutter/scheduler.dart';
import 'package:flutter/services.dart';

import 'actions.dart';
import 'autofill.dart';
import 'automatic_keep_alive.dart';
import 'basic.dart';
import 'binding.dart';
import 'constants.dart';
import 'context_menu_button_item.dart';
import 'debug.dart';
import 'default_selection_style.dart';
import 'default_text_editing_shortcuts.dart';
import 'focus_manager.dart';
import 'focus_scope.dart';
import 'focus_traversal.dart';
import 'framework.dart';
import 'localizations.dart';
import 'magnifier.dart';
import 'media_query.dart';
import 'scroll_configuration.dart';
import 'scroll_controller.dart';
import 'scroll_physics.dart';
import 'scroll_position.dart';
import 'scrollable.dart';
import 'scrollable_helpers.dart';
import 'shortcuts.dart';
import 'spell_check.dart';
import 'tap_region.dart';
import 'text.dart';
import 'text_editing_intents.dart';
import 'text_selection.dart';
import 'text_selection_toolbar_anchors.dart';
import 'ticker_provider.dart';
import 'undo_history.dart';
import 'view.dart';
import 'widget_span.dart';

export 'package:flutter/services.dart' show KeyboardInsertedContent, SelectionChangedCause, SmartDashesType, SmartQuotesType, TextEditingValue, TextInputType, TextSelection;

// Examples can assume:
// late BuildContext context;
// late WidgetTester tester;

/// Signature for the callback that reports when the user changes the selection
/// (including the cursor location).
typedef SelectionChangedCallback = void Function(TextSelection selection, SelectionChangedCause? cause);

/// Signature for the callback that reports the app private command results.
typedef AppPrivateCommandCallback = void Function(String, Map<String, dynamic>);

/// Signature for a widget builder that builds a context menu for the given
/// [EditableTextState].
///
/// See also:
///
///  * [SelectableRegionContextMenuBuilder], which performs the same role for
///    [SelectableRegion].
typedef EditableTextContextMenuBuilder = Widget Function(
  BuildContext context,
  EditableTextState editableTextState,
);

// Signature for a function that determines the target location of the given
// [TextPosition] after applying the given [TextBoundary].
typedef _ApplyTextBoundary = TextPosition Function(TextPosition, bool, TextBoundary);

// The time it takes for the cursor to fade from fully opaque to fully
// transparent and vice versa. A full cursor blink, from transparent to opaque
// to transparent, is twice this duration.
const Duration _kCursorBlinkHalfPeriod = Duration(milliseconds: 500);

// Number of cursor ticks during which the most recently entered character
// is shown in an obscured text field.
const int _kObscureShowLatestCharCursorTicks = 3;

/// The default mime types to be used when allowedMimeTypes is not provided.
///
/// The default value supports inserting images of any supported format.
const List<String> kDefaultContentInsertionMimeTypes = <String>[
  'image/png',
  'image/bmp',
  'image/jpg',
  'image/tiff',
  'image/gif',
  'image/jpeg',
  'image/webp'
];

class _CompositionCallback extends SingleChildRenderObjectWidget {
  const _CompositionCallback({ required this.compositeCallback, required this.enabled, super.child });
  final CompositionCallback compositeCallback;
  final bool enabled;

  @override
  RenderObject createRenderObject(BuildContext context) {
    return _RenderCompositionCallback(compositeCallback, enabled);
  }
  @override
  void updateRenderObject(BuildContext context, _RenderCompositionCallback renderObject) {
    super.updateRenderObject(context, renderObject);
    // _EditableTextState always uses the same callback.
    assert(renderObject.compositeCallback == compositeCallback);
    renderObject.enabled = enabled;
  }
}

class _RenderCompositionCallback extends RenderProxyBox {
  _RenderCompositionCallback(this.compositeCallback, this._enabled);

  final CompositionCallback compositeCallback;
  VoidCallback? _cancelCallback;

  bool get enabled => _enabled;
  bool _enabled = false;
  set enabled(bool newValue) {
    _enabled = newValue;
    if (!newValue) {
      _cancelCallback?.call();
      _cancelCallback = null;
    } else if (_cancelCallback == null) {
      markNeedsPaint();
    }
  }

  @override
  void paint(PaintingContext context, ui.Offset offset) {
    if (enabled) {
      _cancelCallback ??= context.addCompositionCallback(compositeCallback);
    }
    super.paint(context, offset);
  }
}

/// A controller for an editable text field.
///
/// Whenever the user modifies a text field with an associated
/// [TextEditingController], the text field updates [value] and the controller
/// notifies its listeners. Listeners can then read the [text] and [selection]
/// properties to learn what the user has typed or how the selection has been
/// updated.
///
/// Similarly, if you modify the [text] or [selection] properties, the text
/// field will be notified and will update itself appropriately.
///
/// A [TextEditingController] can also be used to provide an initial value for a
/// text field. If you build a text field with a controller that already has
/// [text], the text field will use that text as its initial value.
///
/// The [value] (as well as [text] and [selection]) of this controller can be
/// updated from within a listener added to this controller. Be aware of
/// infinite loops since the listener will also be notified of the changes made
/// from within itself. Modifying the composing region from within a listener
/// can also have a bad interaction with some input methods. Gboard, for
/// example, will try to restore the composing region of the text if it was
/// modified programmatically, creating an infinite loop of communications
/// between the framework and the input method. Consider using
/// [TextInputFormatter]s instead for as-you-type text modification.
///
/// If both the [text] or [selection] properties need to be changed, set the
/// controller's [value] instead.
///
/// Remember to [dispose] of the [TextEditingController] when it is no longer
/// needed. This will ensure we discard any resources used by the object.
/// {@tool dartpad}
/// This example creates a [TextField] with a [TextEditingController] whose
/// change listener forces the entered text to be lower case and keeps the
/// cursor at the end of the input.
///
/// ** See code in examples/api/lib/widgets/editable_text/text_editing_controller.0.dart **
/// {@end-tool}
///
/// See also:
///
///  * [TextField], which is a Material Design text field that can be controlled
///    with a [TextEditingController].
///  * [EditableText], which is a raw region of editable text that can be
///    controlled with a [TextEditingController].
///  * Learn how to use a [TextEditingController] in one of our [cookbook recipes](https://flutter.dev/docs/cookbook/forms/text-field-changes#2-use-a-texteditingcontroller).
class TextEditingController extends ValueNotifier<TextEditingValue> {
  /// Creates a controller for an editable text field.
  ///
  /// This constructor treats a null [text] argument as if it were the empty
  /// string.
  TextEditingController({ String? text })
    : super(text == null ? TextEditingValue.empty : TextEditingValue(text: text));

  /// Creates a controller for an editable text field from an initial [TextEditingValue].
  ///
  /// This constructor treats a null [value] argument as if it were
  /// [TextEditingValue.empty].
  TextEditingController.fromValue(TextEditingValue? value)
    : assert(
        value == null || !value.composing.isValid || value.isComposingRangeValid,
        'New TextEditingValue $value has an invalid non-empty composing range '
        '${value.composing}. It is recommended to use a valid composing range, '
        'even for readonly text fields',
      ),
      super(value ?? TextEditingValue.empty);

  /// The current string the user is editing.
  String get text => value.text;
  /// Setting this will notify all the listeners of this [TextEditingController]
  /// that they need to update (it calls [notifyListeners]). For this reason,
  /// this value should only be set between frames, e.g. in response to user
  /// actions, not during the build, layout, or paint phases.
  ///
  /// This property can be set from a listener added to this
  /// [TextEditingController]; however, one should not also set [selection]
  /// in a separate statement. To change both the [text] and the [selection]
  /// change the controller's [value].
  set text(String newText) {
    value = value.copyWith(
      text: newText,
      selection: const TextSelection.collapsed(offset: -1),
      composing: TextRange.empty,
    );
  }

  @override
  set value(TextEditingValue newValue) {
    assert(
      !newValue.composing.isValid || newValue.isComposingRangeValid,
      'New TextEditingValue $newValue has an invalid non-empty composing range '
      '${newValue.composing}. It is recommended to use a valid composing range, '
      'even for readonly text fields',
    );
    super.value = newValue;
  }

  /// Builds [TextSpan] from current editing value.
  ///
  /// By default makes text in composing range appear as underlined. Descendants
  /// can override this method to customize appearance of text.
  TextSpan buildTextSpan({required BuildContext context, TextStyle? style , required bool withComposing}) {
    assert(!value.composing.isValid || !withComposing || value.isComposingRangeValid);
    // If the composing range is out of range for the current text, ignore it to
    // preserve the tree integrity, otherwise in release mode a RangeError will
    // be thrown and this EditableText will be built with a broken subtree.
    final bool composingRegionOutOfRange = !value.isComposingRangeValid || !withComposing;

    if (composingRegionOutOfRange) {
      return TextSpan(style: style, text: text);
    }

    final TextStyle composingStyle = style?.merge(const TextStyle(decoration: TextDecoration.underline))
        ?? const TextStyle(decoration: TextDecoration.underline);
    return TextSpan(
      style: style,
      children: <TextSpan>[
        TextSpan(text: value.composing.textBefore(value.text)),
        TextSpan(
          style: composingStyle,
          text: value.composing.textInside(value.text),
        ),
        TextSpan(text: value.composing.textAfter(value.text)),
      ],
    );
  }

  /// The currently selected [text].
  ///
  /// If the selection is collapsed, then this property gives the offset of the
  /// cursor within the text.
  TextSelection get selection => value.selection;
  /// Setting this will notify all the listeners of this [TextEditingController]
  /// that they need to update (it calls [notifyListeners]). For this reason,
  /// this value should only be set between frames, e.g. in response to user
  /// actions, not during the build, layout, or paint phases.
  ///
  /// This property can be set from a listener added to this
  /// [TextEditingController]; however, one should not also set [text]
  /// in a separate statement. To change both the [text] and the [selection]
  /// change the controller's [value].
  ///
  /// If the new selection is of non-zero length, or is outside the composing
  /// range, the composing range is cleared.
  set selection(TextSelection newSelection) {
    if (!isSelectionWithinTextBounds(newSelection)) {
      throw FlutterError('invalid text selection: $newSelection');
    }
    final TextRange newComposing =
        newSelection.isCollapsed && _isSelectionWithinComposingRange(newSelection)
            ? value.composing
            : TextRange.empty;
    value = value.copyWith(selection: newSelection, composing: newComposing);
  }

  /// Set the [value] to empty.
  ///
  /// After calling this function, [text] will be the empty string and the
  /// selection will be collapsed at zero offset.
  ///
  /// Calling this will notify all the listeners of this [TextEditingController]
  /// that they need to update (it calls [notifyListeners]). For this reason,
  /// this method should only be called between frames, e.g. in response to user
  /// actions, not during the build, layout, or paint phases.
  void clear() {
    value = const TextEditingValue(selection: TextSelection.collapsed(offset: 0));
  }

  /// Set the composing region to an empty range.
  ///
  /// The composing region is the range of text that is still being composed.
  /// Calling this function indicates that the user is done composing that
  /// region.
  ///
  /// Calling this will notify all the listeners of this [TextEditingController]
  /// that they need to update (it calls [notifyListeners]). For this reason,
  /// this method should only be called between frames, e.g. in response to user
  /// actions, not during the build, layout, or paint phases.
  void clearComposing() {
    value = value.copyWith(composing: TextRange.empty);
  }

  /// Check that the [selection] is inside of the bounds of [text].
  bool isSelectionWithinTextBounds(TextSelection selection) {
    return selection.start <= text.length && selection.end <= text.length;
  }

  /// Check that the [selection] is inside of the composing range.
  bool _isSelectionWithinComposingRange(TextSelection selection) {
    return selection.start >= value.composing.start && selection.end <= value.composing.end;
  }
}

/// Toolbar configuration for [EditableText].
///
/// Toolbar is a context menu that will show up when user right click or long
/// press the [EditableText]. It includes several options: cut, copy, paste,
/// and select all.
///
/// [EditableText] and its derived widgets have their own default [ToolbarOptions].
/// Create a custom [ToolbarOptions] if you want explicit control over the toolbar
/// option.
@Deprecated(
  'Use `contextMenuBuilder` instead. '
  'This feature was deprecated after v3.3.0-0.5.pre.',
)
class ToolbarOptions {
  /// Create a toolbar configuration with given options.
  ///
  /// All options default to false if they are not explicitly set.
  @Deprecated(
    'Use `contextMenuBuilder` instead. '
    'This feature was deprecated after v3.3.0-0.5.pre.',
  )
  const ToolbarOptions({
    this.copy = false,
    this.cut = false,
    this.paste = false,
    this.selectAll = false,
  });

  /// An instance of [ToolbarOptions] with no options enabled.
  static const ToolbarOptions empty = ToolbarOptions();

  /// Whether to show copy option in toolbar.
  ///
  /// Defaults to false. Must not be null.
  final bool copy;

  /// Whether to show cut option in toolbar.
  ///
  /// If [EditableText.readOnly] is set to true, cut will be disabled regardless.
  ///
  /// Defaults to false. Must not be null.
  final bool cut;

  /// Whether to show paste option in toolbar.
  ///
  /// If [EditableText.readOnly] is set to true, paste will be disabled regardless.
  ///
  /// Defaults to false. Must not be null.
  final bool paste;

  /// Whether to show select all option in toolbar.
  ///
  /// Defaults to false. Must not be null.
  final bool selectAll;
}

/// Configures the ability to insert media content through the soft keyboard.
///
/// The configuration provides a handler for any rich content inserted through
/// the system input method, and also provides the ability to limit the mime
/// types of the inserted content.
///
/// See also:
///
/// * [EditableText.contentInsertionConfiguration]
class ContentInsertionConfiguration {
  /// Creates a content insertion configuration with the specified options.
  ///
  /// A handler for inserted content, in the form of [onContentInserted], must
  /// be supplied.
  ///
  /// The allowable mime types of inserted content may also
  /// be provided via [allowedMimeTypes], which cannot be an empty list.
  ContentInsertionConfiguration({
    required this.onContentInserted,
    this.allowedMimeTypes = kDefaultContentInsertionMimeTypes,
  }) : assert(allowedMimeTypes.isNotEmpty);

  /// Called when a user inserts content through the virtual / on-screen keyboard,
  /// currently only used on Android.
  ///
  /// [KeyboardInsertedContent] holds the data representing the inserted content.
  ///
  /// {@tool dartpad}
  ///
  /// This example shows how to access the data for inserted content in your
  /// `TextField`.
  ///
  /// ** See code in examples/api/lib/widgets/editable_text/editable_text.on_content_inserted.0.dart **
  /// {@end-tool}
  ///
  /// See also:
  ///
  ///  * <https://developer.android.com/guide/topics/text/image-keyboard>
  final ValueChanged<KeyboardInsertedContent> onContentInserted;

  /// {@template flutter.widgets.contentInsertionConfiguration.allowedMimeTypes}
  /// Used when a user inserts image-based content through the device keyboard,
  /// currently only used on Android.
  ///
  /// The passed list of strings will determine which MIME types are allowed to
  /// be inserted via the device keyboard.
  ///
  /// The default mime types are given by [kDefaultContentInsertionMimeTypes].
  /// These are all the mime types that are able to be handled and inserted
  /// from keyboards.
  ///
  /// This field cannot be an empty list.
  ///
  /// {@tool dartpad}
  /// This example shows how to limit image insertion to specific file types.
  ///
  /// ** See code in examples/api/lib/widgets/editable_text/editable_text.on_content_inserted.0.dart **
  /// {@end-tool}
  ///
  /// See also:
  ///
  ///  * <https://developer.android.com/guide/topics/text/image-keyboard>
  /// {@endtemplate}
  final List<String> allowedMimeTypes;
}

// A time-value pair that represents a key frame in an animation.
class _KeyFrame {
  const _KeyFrame(this.time, this.value);
  // Values extracted from iOS 15.4 UIKit.
  static const List<_KeyFrame> iOSBlinkingCaretKeyFrames = <_KeyFrame>[
    _KeyFrame(0,       1),     // 0
    _KeyFrame(0.5,     1),     // 1
    _KeyFrame(0.5375,  0.75),  // 2
    _KeyFrame(0.575,   0.5),   // 3
    _KeyFrame(0.6125,  0.25),  // 4
    _KeyFrame(0.65,    0),     // 5
    _KeyFrame(0.85,    0),     // 6
    _KeyFrame(0.8875,  0.25),  // 7
    _KeyFrame(0.925,   0.5),   // 8
    _KeyFrame(0.9625,  0.75),  // 9
    _KeyFrame(1,       1),     // 10
  ];

  // The timing, in seconds, of the specified animation `value`.
  final double time;
  final double value;
}

class _DiscreteKeyFrameSimulation extends Simulation {
  _DiscreteKeyFrameSimulation.iOSBlinkingCaret() : this._(_KeyFrame.iOSBlinkingCaretKeyFrames, 1);
  _DiscreteKeyFrameSimulation._(this._keyFrames, this.maxDuration)
    : assert(_keyFrames.isNotEmpty),
      assert(_keyFrames.last.time <= maxDuration),
      assert(() {
        for (int i = 0; i < _keyFrames.length -1; i += 1) {
          if (_keyFrames[i].time > _keyFrames[i + 1].time) {
            return false;
          }
        }
        return true;
      }(), 'The key frame sequence must be sorted by time.');

  final double maxDuration;

  final List<_KeyFrame> _keyFrames;

  @override
  double dx(double time) => 0;

  @override
  bool isDone(double time) => time >= maxDuration;

  // The index of the KeyFrame corresponds to the most recent input `time`.
  int _lastKeyFrameIndex = 0;

  @override
  double x(double time) {
    final int length = _keyFrames.length;

    // Perform a linear search in the sorted key frame list, starting from the
    // last key frame found, since the input `time` usually monotonically
    // increases by a small amount.
    int searchIndex;
    final int endIndex;
    if (_keyFrames[_lastKeyFrameIndex].time > time) {
      // The simulation may have restarted. Search within the index range
      // [0, _lastKeyFrameIndex).
      searchIndex = 0;
      endIndex = _lastKeyFrameIndex;
    } else {
      searchIndex = _lastKeyFrameIndex;
      endIndex = length;
    }

    // Find the target key frame. Don't have to check (endIndex - 1): if
    // (endIndex - 2) doesn't work we'll have to pick (endIndex - 1) anyways.
    while (searchIndex < endIndex - 1) {
      assert(_keyFrames[searchIndex].time <= time);
      final _KeyFrame next = _keyFrames[searchIndex + 1];
      if (time < next.time) {
        break;
      }
      searchIndex += 1;
    }

    _lastKeyFrameIndex = searchIndex;
    return _keyFrames[_lastKeyFrameIndex].value;
  }
}

/// A basic text input field.
///
/// This widget interacts with the [TextInput] service to let the user edit the
/// text it contains. It also provides scrolling, selection, and cursor
/// movement. This widget does not provide any focus management (e.g.,
/// tap-to-focus).
///
/// ## Handling User Input
///
/// Currently the user may change the text this widget contains via keyboard or
/// the text selection menu. When the user inserted or deleted text, you will be
/// notified of the change and get a chance to modify the new text value:
///
/// * The [inputFormatters] will be first applied to the user input.
///
/// * The [controller]'s [TextEditingController.value] will be updated with the
///   formatted result, and the [controller]'s listeners will be notified.
///
/// * The [onChanged] callback, if specified, will be called last.
///
/// ## Input Actions
///
/// A [TextInputAction] can be provided to customize the appearance of the
/// action button on the soft keyboard for Android and iOS. The default action
/// is [TextInputAction.done].
///
/// Many [TextInputAction]s are common between Android and iOS. However, if a
/// [textInputAction] is provided that is not supported by the current
/// platform in debug mode, an error will be thrown when the corresponding
/// EditableText receives focus. For example, providing iOS's "emergencyCall"
/// action when running on an Android device will result in an error when in
/// debug mode. In release mode, incompatible [TextInputAction]s are replaced
/// either with "unspecified" on Android, or "default" on iOS. Appropriate
/// [textInputAction]s can be chosen by checking the current platform and then
/// selecting the appropriate action.
///
/// {@template flutter.widgets.EditableText.lifeCycle}
/// ## Lifecycle
///
/// Upon completion of editing, like pressing the "done" button on the keyboard,
/// two actions take place:
///
///   1st: Editing is finalized. The default behavior of this step includes
///   an invocation of [onChanged]. That default behavior can be overridden.
///   See [onEditingComplete] for details.
///
///   2nd: [onSubmitted] is invoked with the user's input value.
///
/// [onSubmitted] can be used to manually move focus to another input widget
/// when a user finishes with the currently focused input widget.
///
/// When the widget has focus, it will prevent itself from disposing via
/// [AutomaticKeepAliveClientMixin.wantKeepAlive] in order to avoid losing the
/// selection. Removing the focus will allow it to be disposed.
/// {@endtemplate}
///
/// Rather than using this widget directly, consider using [TextField], which
/// is a full-featured, material-design text input field with placeholder text,
/// labels, and [Form] integration.
///
/// ## Text Editing [Intent]s and Their Default [Action]s
///
/// This widget provides default [Action]s for handling common text editing
/// [Intent]s such as deleting, copying and pasting in the text field. These
/// [Action]s can be directly invoked using [Actions.invoke] or the
/// [Actions.maybeInvoke] method. The default text editing keyboard [Shortcuts]
/// also use these [Intent]s and [Action]s to perform the text editing
/// operations they are bound to.
///
/// The default handling of a specific [Intent] can be overridden by placing an
/// [Actions] widget above this widget. See the [Action] class and the
/// [Action.overridable] constructor for more information on how a pre-defined
/// overridable [Action] can be overridden.
///
/// ### Intents for Deleting Text and Their Default Behavior
///
/// | **Intent Class**                 | **Default Behavior when there's selected text**      | **Default Behavior when there is a [caret](https://en.wikipedia.org/wiki/Caret_navigation) (The selection is [TextSelection.collapsed])**  |
/// | :------------------------------- | :--------------------------------------------------- | :----------------------------------------------------------------------- |
/// | [DeleteCharacterIntent]          | Deletes the selected text                            | Deletes the user-perceived character before or after the caret location. |
/// | [DeleteToNextWordBoundaryIntent] | Deletes the selected text and the word before/after the selection's [TextSelection.extent] position | Deletes from the caret location to the previous or the next word boundary |
/// | [DeleteToLineBreakIntent]        | Deletes the selected text, and deletes to the start/end of the line from the selection's [TextSelection.extent] position | Deletes from the caret location to the logical start or end of the current line |
///
/// ### Intents for Moving the [Caret](https://en.wikipedia.org/wiki/Caret_navigation)
///
/// | **Intent Class**                                                                     | **Default Behavior when there's selected text**                  | **Default Behavior when there is a caret ([TextSelection.collapsed])**  |
/// | :----------------------------------------------------------------------------------- | :--------------------------------------------------------------- | :---------------------------------------------------------------------- |
/// | [ExtendSelectionByCharacterIntent](`collapseSelection: true`)                        | Collapses the selection to the logical start/end of the selection | Moves the caret past the user-perceived character before or after the current caret location. |
/// | [ExtendSelectionToNextWordBoundaryIntent](`collapseSelection: true`)                 | Collapses the selection to the word boundary before/after the selection's [TextSelection.extent] position | Moves the caret to the previous/next word boundary. |
/// | [ExtendSelectionToNextWordBoundaryOrCaretLocationIntent](`collapseSelection: true`)  | Collapses the selection to the word boundary before/after the selection's [TextSelection.extent] position, or [TextSelection.base], whichever is closest in the given direction | Moves the caret to the previous/next word boundary. |
/// | [ExtendSelectionToLineBreakIntent](`collapseSelection: true`)                        | Collapses the selection to the start/end of the line at the selection's [TextSelection.extent] position | Moves the caret to the start/end of the current line .|
/// | [ExtendSelectionVerticallyToAdjacentLineIntent](`collapseSelection: true`)           | Collapses the selection to the position closest to the selection's [TextSelection.extent], on the previous/next adjacent line | Moves the caret to the closest position on the previous/next adjacent line. |
/// | [ExtendSelectionVerticallyToAdjacentPageIntent](`collapseSelection: true`)           | Collapses the selection to the position closest to the selection's [TextSelection.extent], on the previous/next adjacent page | Moves the caret to the closest position on the previous/next adjacent page. |
/// | [ExtendSelectionToDocumentBoundaryIntent](`collapseSelection: true`)                 | Collapses the selection to the start/end of the document | Moves the caret to the start/end of the document. |
///
/// #### Intents for Extending the Selection
///
/// | **Intent Class**                                                                     | **Default Behavior when there's selected text**                  | **Default Behavior when there is a caret ([TextSelection.collapsed])**  |
/// | :----------------------------------------------------------------------------------- | :--------------------------------------------------------------- | :---------------------------------------------------------------------- |
/// | [ExtendSelectionByCharacterIntent](`collapseSelection: false`)                       | Moves the selection's [TextSelection.extent] past the user-perceived character before/after it |
/// | [ExtendSelectionToNextWordBoundaryIntent](`collapseSelection: false`)                | Moves the selection's [TextSelection.extent] to the previous/next word boundary |
/// | [ExtendSelectionToNextWordBoundaryOrCaretLocationIntent](`collapseSelection: false`) | Moves the selection's [TextSelection.extent] to the previous/next word boundary, or [TextSelection.base] whichever is closest in the given direction | Moves the selection's [TextSelection.extent] to the previous/next word boundary. |
/// | [ExtendSelectionToLineBreakIntent](`collapseSelection: false`)                       | Moves the selection's [TextSelection.extent] to the start/end of the line |
/// | [ExtendSelectionVerticallyToAdjacentLineIntent](`collapseSelection: false`)          | Moves the selection's [TextSelection.extent] to the closest position on the previous/next adjacent line |
/// | [ExtendSelectionVerticallyToAdjacentPageIntent](`collapseSelection: false`)          | Moves the selection's [TextSelection.extent] to the closest position on the previous/next adjacent page |
/// | [ExtendSelectionToDocumentBoundaryIntent](`collapseSelection: false`)                | Moves the selection's [TextSelection.extent] to the start/end of the document |
/// | [SelectAllTextIntent]  | Selects the entire document |
///
/// ### Other Intents
///
/// | **Intent Class**                        | **Default Behavior**                                 |
/// | :-------------------------------------- | :--------------------------------------------------- |
/// | [DoNothingAndStopPropagationTextIntent] | Does nothing in the input field, and prevents the key event from further propagating in the widget tree. |
/// | [ReplaceTextIntent]                     | Replaces the current [TextEditingValue] in the input field's [TextEditingController], and triggers all related user callbacks and [TextInputFormatter]s. |
/// | [UpdateSelectionIntent]                 | Updates the current selection in the input field's [TextEditingController], and triggers the [onSelectionChanged] callback. |
/// | [CopySelectionTextIntent]               | Copies or cuts the selected text into the clipboard |
/// | [PasteTextIntent]                       | Inserts the current text in the clipboard after the caret location, or replaces the selected text if the selection is not collapsed. |
///
/// ## Gesture Events Handling
///
/// This widget provides rudimentary, platform-agnostic gesture handling for
/// user actions such as tapping, long-pressing and scrolling when
/// [rendererIgnoresPointer] is false (false by default). To tightly conform
/// to the platform behavior with respect to input gestures in text fields, use
/// [TextField] or [CupertinoTextField]. For custom selection behavior, call
/// methods such as [RenderEditable.selectPosition],
/// [RenderEditable.selectWord], etc. programmatically.
///
/// {@template flutter.widgets.editableText.showCaretOnScreen}
/// ## Keep the caret visible when focused
///
/// When focused, this widget will make attempts to keep the text area and its
/// caret (even when [showCursor] is `false`) visible, on these occasions:
///
///  * When the user focuses this text field and it is not [readOnly].
///  * When the user changes the selection of the text field, or changes the
///    text when the text field is not [readOnly].
///  * When the virtual keyboard pops up.
/// {@endtemplate}
///
/// {@template flutter.widgets.editableText.accessibility}
/// ## Troubleshooting Common Accessibility Issues
///
/// ### Customizing User Input Accessibility Announcements
///
/// To customize user input accessibility announcements triggered by text
/// changes, use [SemanticsService.announce] to make the desired
/// accessibility announcement.
///
/// On iOS, the on-screen keyboard may announce the most recent input
/// incorrectly when a [TextInputFormatter] inserts a thousands separator to
/// a currency value text field. The following example demonstrates how to
/// suppress the default accessibility announcements by always announcing
/// the content of the text field as a US currency value (the `\$` inserts
/// a dollar sign, the `$newText interpolates the `newText` variable):
///
/// ```dart
/// onChanged: (String newText) {
///   if (newText.isNotEmpty) {
///     SemanticsService.announce('\$$newText', Directionality.of(context));
///   }
/// }
/// ```
///
/// {@endtemplate}
///
/// See also:
///
///  * [TextField], which is a full-featured, material-design text input field
///    with placeholder text, labels, and [Form] integration.
class EditableText extends StatefulWidget {
  /// Creates a basic text input control.
  ///
  /// The [maxLines] property can be set to null to remove the restriction on
  /// the number of lines. By default, it is one, meaning this is a single-line
  /// text field. [maxLines] must be null or greater than zero.
  ///
  /// If [keyboardType] is not set or is null, its value will be inferred from
  /// [autofillHints], if [autofillHints] is not empty. Otherwise it defaults to
  /// [TextInputType.text] if [maxLines] is exactly one, and
  /// [TextInputType.multiline] if [maxLines] is null or greater than one.
  ///
  /// The text cursor is not shown if [showCursor] is false or if [showCursor]
  /// is null (the default) and [readOnly] is true.
  ///
  /// The [controller], [focusNode], [obscureText], [autocorrect], [autofocus],
  /// [showSelectionHandles], [enableInteractiveSelection], [forceLine],
  /// [style], [cursorColor], [cursorOpacityAnimates], [backgroundCursorColor],
  /// [enableSuggestions], [paintCursorAboveText], [selectionHeightStyle],
  /// [selectionWidthStyle], [textAlign], [dragStartBehavior], [scrollPadding],
  /// [dragStartBehavior], [toolbarOptions], [rendererIgnoresPointer],
  /// [readOnly], and [enableIMEPersonalizedLearning] arguments must not be null.
  EditableText({
    super.key,
    required this.controller,
    required this.focusNode,
    this.readOnly = false,
    this.obscuringCharacter = '•',
    this.obscureText = false,
    this.autocorrect = true,
    SmartDashesType? smartDashesType,
    SmartQuotesType? smartQuotesType,
    this.enableSuggestions = true,
    required this.style,
    StrutStyle? strutStyle,
    required this.cursorColor,
    required this.backgroundCursorColor,
    this.textAlign = TextAlign.start,
    this.textDirection,
    this.locale,
    this.textScaleFactor,
    this.maxLines = 1,
    this.minLines,
    this.expands = false,
    this.forceLine = true,
    this.textHeightBehavior,
    this.textWidthBasis = TextWidthBasis.parent,
    this.autofocus = false,
    bool? showCursor,
    this.showSelectionHandles = false,
    this.selectionColor,
    this.selectionControls,
    TextInputType? keyboardType,
    this.textInputAction,
    this.textCapitalization = TextCapitalization.none,
    this.onChanged,
    this.onEditingComplete,
    this.onSubmitted,
    this.onAppPrivateCommand,
    this.onSelectionChanged,
    this.onSelectionHandleTapped,
    this.onTapOutside,
    List<TextInputFormatter>? inputFormatters,
    this.mouseCursor,
    this.rendererIgnoresPointer = false,
    this.cursorWidth = 2.0,
    this.cursorHeight,
    this.cursorRadius,
    this.cursorOpacityAnimates = false,
    this.cursorOffset,
    this.paintCursorAboveText = false,
    this.selectionHeightStyle = ui.BoxHeightStyle.tight,
    this.selectionWidthStyle = ui.BoxWidthStyle.tight,
    this.scrollPadding = const EdgeInsets.all(20.0),
    this.keyboardAppearance = Brightness.light,
    this.dragStartBehavior = DragStartBehavior.start,
    bool? enableInteractiveSelection,
    this.scrollController,
    this.scrollPhysics,
    this.autocorrectionTextRectColor,
    @Deprecated(
      'Use `contextMenuBuilder` instead. '
      'This feature was deprecated after v3.3.0-0.5.pre.',
    )
    ToolbarOptions? toolbarOptions,
    this.autofillHints = const <String>[],
    this.autofillClient,
    this.clipBehavior = Clip.hardEdge,
    this.restorationId,
    this.scrollBehavior,
    this.scribbleEnabled = true,
    this.enableIMEPersonalizedLearning = true,
    this.contentInsertionConfiguration,
    this.contextMenuBuilder,
    this.spellCheckConfiguration,
    this.magnifierConfiguration = TextMagnifierConfiguration.disabled,
    this.undoController,
  }) : assert(obscuringCharacter.length == 1),
       smartDashesType = smartDashesType ?? (obscureText ? SmartDashesType.disabled : SmartDashesType.enabled),
       smartQuotesType = smartQuotesType ?? (obscureText ? SmartQuotesType.disabled : SmartQuotesType.enabled),
       assert(minLines == null || minLines > 0),
       assert(
         (maxLines == null) || (minLines == null) || (maxLines >= minLines),
         "minLines can't be greater than maxLines",
       ),
       assert(
         !expands || (maxLines == null && minLines == null),
         'minLines and maxLines must be null when expands is true.',
       ),
       assert(!obscureText || maxLines == 1, 'Obscured fields cannot be multiline.'),
       enableInteractiveSelection = enableInteractiveSelection ?? (!readOnly || !obscureText),
       toolbarOptions = selectionControls is TextSelectionHandleControls && toolbarOptions == null ? ToolbarOptions.empty : toolbarOptions ??
           (obscureText
               ? (readOnly
                   // No point in even offering "Select All" in a read-only obscured
                   // field.
                   ? ToolbarOptions.empty
                   // Writable, but obscured.
                   : const ToolbarOptions(
                       selectAll: true,
                       paste: true,
                     ))
               : (readOnly
                   // Read-only, not obscured.
                   ? const ToolbarOptions(
                       selectAll: true,
                       copy: true,
                     )
                   // Writable, not obscured.
                   : const ToolbarOptions(
                       copy: true,
                       cut: true,
                       selectAll: true,
                       paste: true,
                     ))),
       assert(
          spellCheckConfiguration == null ||
          spellCheckConfiguration == const SpellCheckConfiguration.disabled() ||
          spellCheckConfiguration.misspelledTextStyle != null,
          'spellCheckConfiguration must specify a misspelledTextStyle if spell check behavior is desired',
       ),
       _strutStyle = strutStyle,
       keyboardType = keyboardType ?? _inferKeyboardType(autofillHints: autofillHints, maxLines: maxLines),
       inputFormatters = maxLines == 1
           ? <TextInputFormatter>[
               FilteringTextInputFormatter.singleLineFormatter,
               ...inputFormatters ?? const Iterable<TextInputFormatter>.empty(),
             ]
           : inputFormatters,
       showCursor = showCursor ?? !readOnly;

  /// Controls the text being edited.
  final TextEditingController controller;

  /// Controls whether this widget has keyboard focus.
  final FocusNode focusNode;

  /// {@template flutter.widgets.editableText.obscuringCharacter}
  /// Character used for obscuring text if [obscureText] is true.
  ///
  /// Must be only a single character.
  ///
  /// Defaults to the character U+2022 BULLET (•).
  /// {@endtemplate}
  final String obscuringCharacter;

  /// {@template flutter.widgets.editableText.obscureText}
  /// Whether to hide the text being edited (e.g., for passwords).
  ///
  /// When this is set to true, all the characters in the text field are
  /// replaced by [obscuringCharacter], and the text in the field cannot be
  /// copied with copy or cut. If [readOnly] is also true, then the text cannot
  /// be selected.
  ///
  /// Defaults to false. Cannot be null.
  /// {@endtemplate}
  final bool obscureText;

  /// {@macro dart.ui.textHeightBehavior}
  final TextHeightBehavior? textHeightBehavior;

  /// {@macro flutter.painting.textPainter.textWidthBasis}
  final TextWidthBasis textWidthBasis;

  /// {@template flutter.widgets.editableText.readOnly}
  /// Whether the text can be changed.
  ///
  /// When this is set to true, the text cannot be modified
  /// by any shortcut or keyboard operation. The text is still selectable.
  ///
  /// Defaults to false. Must not be null.
  /// {@endtemplate}
  final bool readOnly;

  /// Whether the text will take the full width regardless of the text width.
  ///
  /// When this is set to false, the width will be based on text width, which
  /// will also be affected by [textWidthBasis].
  ///
  /// Defaults to true. Must not be null.
  ///
  /// See also:
  ///
  ///  * [textWidthBasis], which controls the calculation of text width.
  final bool forceLine;

  /// Configuration of toolbar options.
  ///
  /// By default, all options are enabled. If [readOnly] is true, paste and cut
  /// will be disabled regardless. If [obscureText] is true, cut and copy will
  /// be disabled regardless. If [readOnly] and [obscureText] are both true,
  /// select all will also be disabled.
  final ToolbarOptions toolbarOptions;

  /// Whether to show selection handles.
  ///
  /// When a selection is active, there will be two handles at each side of
  /// boundary, or one handle if the selection is collapsed. The handles can be
  /// dragged to adjust the selection.
  ///
  /// See also:
  ///
  ///  * [showCursor], which controls the visibility of the cursor.
  final bool showSelectionHandles;

  /// {@template flutter.widgets.editableText.showCursor}
  /// Whether to show cursor.
  ///
  /// The cursor refers to the blinking caret when the [EditableText] is focused.
  /// {@endtemplate}
  ///
  /// See also:
  ///
  ///  * [showSelectionHandles], which controls the visibility of the selection handles.
  final bool showCursor;

  /// {@template flutter.widgets.editableText.autocorrect}
  /// Whether to enable autocorrection.
  ///
  /// Defaults to true. Cannot be null.
  /// {@endtemplate}
  final bool autocorrect;

  /// {@macro flutter.services.TextInputConfiguration.smartDashesType}
  final SmartDashesType smartDashesType;

  /// {@macro flutter.services.TextInputConfiguration.smartQuotesType}
  final SmartQuotesType smartQuotesType;

  /// {@macro flutter.services.TextInputConfiguration.enableSuggestions}
  final bool enableSuggestions;

  /// The text style to use for the editable text.
  final TextStyle style;

  /// Controls the undo state of the current editable text.
  ///
  /// If null, this widget will create its own [UndoHistoryController].
  final UndoHistoryController? undoController;

  /// {@template flutter.widgets.editableText.strutStyle}
  /// The strut style used for the vertical layout.
  ///
  /// [StrutStyle] is used to establish a predictable vertical layout.
  /// Since fonts may vary depending on user input and due to font
  /// fallback, [StrutStyle.forceStrutHeight] is enabled by default
  /// to lock all lines to the height of the base [TextStyle], provided by
  /// [style]. This ensures the typed text fits within the allotted space.
  ///
  /// If null, the strut used will inherit values from the [style] and will
  /// have [StrutStyle.forceStrutHeight] set to true. When no [style] is
  /// passed, the theme's [TextStyle] will be used to generate [strutStyle]
  /// instead.
  ///
  /// To disable strut-based vertical alignment and allow dynamic vertical
  /// layout based on the glyphs typed, use [StrutStyle.disabled].
  ///
  /// Flutter's strut is based on [typesetting strut](https://en.wikipedia.org/wiki/Strut_(typesetting))
  /// and CSS's [line-height](https://www.w3.org/TR/CSS2/visudet.html#line-height).
  /// {@endtemplate}
  ///
  /// Within editable text and text fields, [StrutStyle] will not use its standalone
  /// default values, and will instead inherit omitted/null properties from the
  /// [TextStyle] instead. See [StrutStyle.inheritFromTextStyle].
  StrutStyle get strutStyle {
    if (_strutStyle == null) {
      return StrutStyle.fromTextStyle(style, forceStrutHeight: true);
    }
    return _strutStyle!.inheritFromTextStyle(style);
  }
  final StrutStyle? _strutStyle;

  /// {@template flutter.widgets.editableText.textAlign}
  /// How the text should be aligned horizontally.
  ///
  /// Defaults to [TextAlign.start] and cannot be null.
  /// {@endtemplate}
  final TextAlign textAlign;

  /// {@template flutter.widgets.editableText.textDirection}
  /// The directionality of the text.
  ///
  /// This decides how [textAlign] values like [TextAlign.start] and
  /// [TextAlign.end] are interpreted.
  ///
  /// This is also used to disambiguate how to render bidirectional text. For
  /// example, if the text is an English phrase followed by a Hebrew phrase,
  /// in a [TextDirection.ltr] context the English phrase will be on the left
  /// and the Hebrew phrase to its right, while in a [TextDirection.rtl]
  /// context, the English phrase will be on the right and the Hebrew phrase on
  /// its left.
  ///
  /// Defaults to the ambient [Directionality], if any.
  /// {@endtemplate}
  final TextDirection? textDirection;

  /// {@template flutter.widgets.editableText.textCapitalization}
  /// Configures how the platform keyboard will select an uppercase or
  /// lowercase keyboard.
  ///
  /// Only supports text keyboards, other keyboard types will ignore this
  /// configuration. Capitalization is locale-aware.
  ///
  /// Defaults to [TextCapitalization.none]. Must not be null.
  ///
  /// See also:
  ///
  ///  * [TextCapitalization], for a description of each capitalization behavior.
  ///
  /// {@endtemplate}
  final TextCapitalization textCapitalization;

  /// Used to select a font when the same Unicode character can
  /// be rendered differently, depending on the locale.
  ///
  /// It's rarely necessary to set this property. By default its value
  /// is inherited from the enclosing app with `Localizations.localeOf(context)`.
  ///
  /// See [RenderEditable.locale] for more information.
  final Locale? locale;

  /// {@template flutter.widgets.editableText.textScaleFactor}
  /// The number of font pixels for each logical pixel.
  ///
  /// For example, if the text scale factor is 1.5, text will be 50% larger than
  /// the specified font size.
  ///
  /// Defaults to the [MediaQueryData.textScaleFactor] obtained from the ambient
  /// [MediaQuery], or 1.0 if there is no [MediaQuery] in scope.
  /// {@endtemplate}
  final double? textScaleFactor;

  /// The color to use when painting the cursor.
  ///
  /// Cannot be null.
  final Color cursorColor;

  /// The color to use when painting the autocorrection Rect.
  ///
  /// For [CupertinoTextField]s, the value is set to the ambient
  /// [CupertinoThemeData.primaryColor] with 20% opacity. For [TextField]s, the
  /// value is null on non-iOS platforms and the same color used in [CupertinoTextField]
  /// on iOS.
  ///
  /// Currently the autocorrection Rect only appears on iOS.
  ///
  /// Defaults to null, which disables autocorrection Rect painting.
  final Color? autocorrectionTextRectColor;

  /// The color to use when painting the background cursor aligned with the text
  /// while rendering the floating cursor.
  ///
  /// Cannot be null. By default it is the disabled grey color from
  /// CupertinoColors.
  final Color backgroundCursorColor;

  /// {@template flutter.widgets.editableText.maxLines}
  /// The maximum number of lines to show at one time, wrapping if necessary.
  ///
  /// This affects the height of the field itself and does not limit the number
  /// of lines that can be entered into the field.
  ///
  /// If this is 1 (the default), the text will not wrap, but will scroll
  /// horizontally instead.
  ///
  /// If this is null, there is no limit to the number of lines, and the text
  /// container will start with enough vertical space for one line and
  /// automatically grow to accommodate additional lines as they are entered, up
  /// to the height of its constraints.
  ///
  /// If this is not null, the value must be greater than zero, and it will lock
  /// the input to the given number of lines and take up enough horizontal space
  /// to accommodate that number of lines. Setting [minLines] as well allows the
  /// input to grow and shrink between the indicated range.
  ///
  /// The full set of behaviors possible with [minLines] and [maxLines] are as
  /// follows. These examples apply equally to [TextField], [TextFormField],
  /// [CupertinoTextField], and [EditableText].
  ///
  /// Input that occupies a single line and scrolls horizontally as needed.
  /// ```dart
  /// const TextField()
  /// ```
  ///
  /// Input whose height grows from one line up to as many lines as needed for
  /// the text that was entered. If a height limit is imposed by its parent, it
  /// will scroll vertically when its height reaches that limit.
  /// ```dart
  /// const TextField(maxLines: null)
  /// ```
  ///
  /// The input's height is large enough for the given number of lines. If
  /// additional lines are entered the input scrolls vertically.
  /// ```dart
  /// const TextField(maxLines: 2)
  /// ```
  ///
  /// Input whose height grows with content between a min and max. An infinite
  /// max is possible with `maxLines: null`.
  /// ```dart
  /// const TextField(minLines: 2, maxLines: 4)
  /// ```
  ///
  /// See also:
  ///
  ///  * [minLines], which sets the minimum number of lines visible.
  /// {@endtemplate}
  ///  * [expands], which determines whether the field should fill the height of
  ///    its parent.
  final int? maxLines;

  /// {@template flutter.widgets.editableText.minLines}
  /// The minimum number of lines to occupy when the content spans fewer lines.
  ///
  /// This affects the height of the field itself and does not limit the number
  /// of lines that can be entered into the field.
  ///
  /// If this is null (default), text container starts with enough vertical space
  /// for one line and grows to accommodate additional lines as they are entered.
  ///
  /// This can be used in combination with [maxLines] for a varying set of behaviors.
  ///
  /// If the value is set, it must be greater than zero. If the value is greater
  /// than 1, [maxLines] should also be set to either null or greater than
  /// this value.
  ///
  /// When [maxLines] is set as well, the height will grow between the indicated
  /// range of lines. When [maxLines] is null, it will grow as high as needed,
  /// starting from [minLines].
  ///
  /// A few examples of behaviors possible with [minLines] and [maxLines] are as follows.
  /// These apply equally to [TextField], [TextFormField], [CupertinoTextField],
  /// and [EditableText].
  ///
  /// Input that always occupies at least 2 lines and has an infinite max.
  /// Expands vertically as needed.
  /// ```dart
  /// TextField(minLines: 2)
  /// ```
  ///
  /// Input whose height starts from 2 lines and grows up to 4 lines at which
  /// point the height limit is reached. If additional lines are entered it will
  /// scroll vertically.
  /// ```dart
  /// const TextField(minLines:2, maxLines: 4)
  /// ```
  ///
  /// Defaults to null.
  ///
  /// See also:
  ///
  ///  * [maxLines], which sets the maximum number of lines visible, and has
  ///    several examples of how minLines and maxLines interact to produce
  ///    various behaviors.
  /// {@endtemplate}
  ///  * [expands], which determines whether the field should fill the height of
  ///    its parent.
  final int? minLines;

  /// {@template flutter.widgets.editableText.expands}
  /// Whether this widget's height will be sized to fill its parent.
  ///
  /// If set to true and wrapped in a parent widget like [Expanded] or
  /// [SizedBox], the input will expand to fill the parent.
  ///
  /// [maxLines] and [minLines] must both be null when this is set to true,
  /// otherwise an error is thrown.
  ///
  /// Defaults to false.
  ///
  /// See the examples in [maxLines] for the complete picture of how [maxLines],
  /// [minLines], and [expands] interact to produce various behaviors.
  ///
  /// Input that matches the height of its parent:
  /// ```dart
  /// const Expanded(
  ///   child: TextField(maxLines: null, expands: true),
  /// )
  /// ```
  /// {@endtemplate}
  final bool expands;

  /// {@template flutter.widgets.editableText.autofocus}
  /// Whether this text field should focus itself if nothing else is already
  /// focused.
  ///
  /// If true, the keyboard will open as soon as this text field obtains focus.
  /// Otherwise, the keyboard is only shown after the user taps the text field.
  ///
  /// Defaults to false. Cannot be null.
  /// {@endtemplate}
  // See https://github.com/flutter/flutter/issues/7035 for the rationale for this
  // keyboard behavior.
  final bool autofocus;

  /// The color to use when painting the selection.
  ///
  /// If this property is null, this widget gets the selection color from the
  /// [DefaultSelectionStyle].
  ///
  /// For [CupertinoTextField]s, the value is set to the ambient
  /// [CupertinoThemeData.primaryColor] with 20% opacity. For [TextField]s, the
  /// value is set to the ambient [TextSelectionThemeData.selectionColor].
  final Color? selectionColor;

  /// {@template flutter.widgets.editableText.selectionControls}
  /// Optional delegate for building the text selection handles and toolbar.
  ///
  /// The [EditableText] widget used on its own will not trigger the display
  /// of the selection toolbar by itself. The toolbar is shown by calling
  /// [EditableTextState.showToolbar] in response to an appropriate user event.
  ///
  /// See also:
  ///
  ///  * [CupertinoTextField], which wraps an [EditableText] and which shows the
  ///    selection toolbar upon user events that are appropriate on the iOS
  ///    platform.
  ///  * [TextField], a Material Design themed wrapper of [EditableText], which
  ///    shows the selection toolbar upon appropriate user events based on the
  ///    user's platform set in [ThemeData.platform].
  /// {@endtemplate}
  final TextSelectionControls? selectionControls;

  /// {@template flutter.widgets.editableText.keyboardType}
  /// The type of keyboard to use for editing the text.
  ///
  /// Defaults to [TextInputType.text] if [maxLines] is one and
  /// [TextInputType.multiline] otherwise.
  /// {@endtemplate}
  final TextInputType keyboardType;

  /// The type of action button to use with the soft keyboard.
  final TextInputAction? textInputAction;

  /// {@template flutter.widgets.editableText.onChanged}
  /// Called when the user initiates a change to the TextField's
  /// value: when they have inserted or deleted text.
  ///
  /// This callback doesn't run when the TextField's text is changed
  /// programmatically, via the TextField's [controller]. Typically it
  /// isn't necessary to be notified of such changes, since they're
  /// initiated by the app itself.
  ///
  /// To be notified of all changes to the TextField's text, cursor,
  /// and selection, one can add a listener to its [controller] with
  /// [TextEditingController.addListener].
  ///
  /// [onChanged] is called before [onSubmitted] when user indicates completion
  /// of editing, such as when pressing the "done" button on the keyboard. That
  /// default behavior can be overridden. See [onEditingComplete] for details.
  ///
  /// {@tool dartpad}
  /// This example shows how onChanged could be used to check the TextField's
  /// current value each time the user inserts or deletes a character.
  ///
  /// ** See code in examples/api/lib/widgets/editable_text/editable_text.on_changed.0.dart **
  /// {@end-tool}
  /// {@endtemplate}
  ///
  /// ## Handling emojis and other complex characters
  /// {@template flutter.widgets.EditableText.onChanged}
  /// It's important to always use
  /// [characters](https://pub.dev/packages/characters) when dealing with user
  /// input text that may contain complex characters. This will ensure that
  /// extended grapheme clusters and surrogate pairs are treated as single
  /// characters, as they appear to the user.
  ///
  /// For example, when finding the length of some user input, use
  /// `string.characters.length`. Do NOT use `string.length` or even
  /// `string.runes.length`. For the complex character "👨‍👩‍👦", this
  /// appears to the user as a single character, and `string.characters.length`
  /// intuitively returns 1. On the other hand, `string.length` returns 8, and
  /// `string.runes.length` returns 5!
  /// {@endtemplate}
  ///
  /// See also:
  ///
  ///  * [inputFormatters], which are called before [onChanged]
  ///    runs and can validate and change ("format") the input value.
  ///  * [onEditingComplete], [onSubmitted], [onSelectionChanged]:
  ///    which are more specialized input change notifications.
  ///  * [TextEditingController], which implements the [Listenable] interface
  ///    and notifies its listeners on [TextEditingValue] changes.
  final ValueChanged<String>? onChanged;

  /// {@template flutter.widgets.editableText.onEditingComplete}
  /// Called when the user submits editable content (e.g., user presses the "done"
  /// button on the keyboard).
  ///
  /// The default implementation of [onEditingComplete] executes 2 different
  /// behaviors based on the situation:
  ///
  ///  - When a completion action is pressed, such as "done", "go", "send", or
  ///    "search", the user's content is submitted to the [controller] and then
  ///    focus is given up.
  ///
  ///  - When a non-completion action is pressed, such as "next" or "previous",
  ///    the user's content is submitted to the [controller], but focus is not
  ///    given up because developers may want to immediately move focus to
  ///    another input widget within [onSubmitted].
  ///
  /// Providing [onEditingComplete] prevents the aforementioned default behavior.
  /// {@endtemplate}
  final VoidCallback? onEditingComplete;

  /// {@template flutter.widgets.editableText.onSubmitted}
  /// Called when the user indicates that they are done editing the text in the
  /// field.
  ///
  /// By default, [onSubmitted] is called after [onChanged] when the user
  /// has finalized editing; or, if the default behavior has been overridden,
  /// after [onEditingComplete]. See [onEditingComplete] for details.
  ///
  /// ## Testing
  /// The following is the recommended way to trigger [onSubmitted] in a test:
  ///
  /// ```dart
  /// await tester.testTextInput.receiveAction(TextInputAction.done);
  /// ```
  ///
  /// Sending a `LogicalKeyboardKey.enter` via `tester.sendKeyEvent` will not
  /// trigger [onSubmitted]. This is because on a real device, the engine
  /// translates the enter key to a done action, but `tester.sendKeyEvent` sends
  /// the key to the framework only.
  /// {@endtemplate}
  final ValueChanged<String>? onSubmitted;

  /// {@template flutter.widgets.editableText.onAppPrivateCommand}
  /// This is used to receive a private command from the input method.
  ///
  /// Called when the result of [TextInputClient.performPrivateCommand] is
  /// received.
  ///
  /// This can be used to provide domain-specific features that are only known
  /// between certain input methods and their clients.
  ///
  /// See also:
  ///   * [performPrivateCommand](https://developer.android.com/reference/android/view/inputmethod/InputConnection#performPrivateCommand\(java.lang.String,%20android.os.Bundle\)),
  ///     which is the Android documentation for performPrivateCommand, used to
  ///     send a command from the input method.
  ///   * [sendAppPrivateCommand](https://developer.android.com/reference/android/view/inputmethod/InputMethodManager#sendAppPrivateCommand),
  ///     which is the Android documentation for sendAppPrivateCommand, used to
  ///     send a command to the input method.
  /// {@endtemplate}
  final AppPrivateCommandCallback? onAppPrivateCommand;

  /// {@template flutter.widgets.editableText.onSelectionChanged}
  /// Called when the user changes the selection of text (including the cursor
  /// location).
  /// {@endtemplate}
  final SelectionChangedCallback? onSelectionChanged;

  /// {@macro flutter.widgets.SelectionOverlay.onSelectionHandleTapped}
  final VoidCallback? onSelectionHandleTapped;

  /// {@template flutter.widgets.editableText.onTapOutside}
  /// Called for each tap that occurs outside of the[TextFieldTapRegion] group
  /// when the text field is focused.
  ///
  /// If this is null, [FocusNode.unfocus] will be called on the [focusNode] for
  /// this text field when a [PointerDownEvent] is received on another part of
  /// the UI. However, it will not unfocus as a result of mobile application
  /// touch events (which does not include mouse clicks), to conform with the
  /// platform conventions. To change this behavior, a callback may be set here
  /// that operates differently from the default.
  ///
  /// When adding additional controls to a text field (for example, a spinner, a
  /// button that copies the selected text, or modifies formatting), it is
  /// helpful if tapping on that control doesn't unfocus the text field. In
  /// order for an external widget to be considered as part of the text field
  /// for the purposes of tapping "outside" of the field, wrap the control in a
  /// [TextFieldTapRegion].
  ///
  /// The [PointerDownEvent] passed to the function is the event that caused the
  /// notification. It is possible that the event may occur outside of the
  /// immediate bounding box defined by the text field, although it will be
  /// within the bounding box of a [TextFieldTapRegion] member.
  /// {@endtemplate}
  ///
  /// {@tool dartpad}
  /// This example shows how to use a `TextFieldTapRegion` to wrap a set of
  /// "spinner" buttons that increment and decrement a value in the [TextField]
  /// without causing the text field to lose keyboard focus.
  ///
  /// This example includes a generic `SpinnerField<T>` class that you can copy
  /// into your own project and customize.
  ///
  /// ** See code in examples/api/lib/widgets/tap_region/text_field_tap_region.0.dart **
  /// {@end-tool}
  ///
  /// See also:
  ///
  ///  * [TapRegion] for how the region group is determined.
  final TapRegionCallback? onTapOutside;

  /// {@template flutter.widgets.editableText.inputFormatters}
  /// Optional input validation and formatting overrides.
  ///
  /// Formatters are run in the provided order when the user changes the text
  /// this widget contains. When this parameter changes, the new formatters will
  /// not be applied until the next time the user inserts or deletes text.
  /// Similar to the [onChanged] callback, formatters don't run when the text is
  /// changed programmatically via [controller].
  ///
  /// See also:
  ///
  ///  * [TextEditingController], which implements the [Listenable] interface
  ///    and notifies its listeners on [TextEditingValue] changes.
  /// {@endtemplate}
  final List<TextInputFormatter>? inputFormatters;

  /// The cursor for a mouse pointer when it enters or is hovering over the
  /// widget.
  ///
  /// If this property is null, [SystemMouseCursors.text] will be used.
  ///
  /// The [mouseCursor] is the only property of [EditableText] that controls the
  /// appearance of the mouse pointer. All other properties related to "cursor"
  /// stands for the text cursor, which is usually a blinking vertical line at
  /// the editing position.
  final MouseCursor? mouseCursor;

  /// If true, the [RenderEditable] created by this widget will not handle
  /// pointer events, see [RenderEditable] and [RenderEditable.ignorePointer].
  ///
  /// This property is false by default.
  final bool rendererIgnoresPointer;

  /// {@template flutter.widgets.editableText.cursorWidth}
  /// How thick the cursor will be.
  ///
  /// Defaults to 2.0.
  ///
  /// The cursor will draw under the text. The cursor width will extend
  /// to the right of the boundary between characters for left-to-right text
  /// and to the left for right-to-left text. This corresponds to extending
  /// downstream relative to the selected position. Negative values may be used
  /// to reverse this behavior.
  /// {@endtemplate}
  final double cursorWidth;

  /// {@template flutter.widgets.editableText.cursorHeight}
  /// How tall the cursor will be.
  ///
  /// If this property is null, [RenderEditable.preferredLineHeight] will be used.
  /// {@endtemplate}
  final double? cursorHeight;

  /// {@template flutter.widgets.editableText.cursorRadius}
  /// How rounded the corners of the cursor should be.
  ///
  /// By default, the cursor has no radius.
  /// {@endtemplate}
  final Radius? cursorRadius;

  /// Whether the cursor will animate from fully transparent to fully opaque
  /// during each cursor blink.
  ///
  /// By default, the cursor opacity will animate on iOS platforms and will not
  /// animate on Android platforms.
  final bool cursorOpacityAnimates;

  ///{@macro flutter.rendering.RenderEditable.cursorOffset}
  final Offset? cursorOffset;

  ///{@macro flutter.rendering.RenderEditable.paintCursorAboveText}
  final bool paintCursorAboveText;

  /// Controls how tall the selection highlight boxes are computed to be.
  ///
  /// See [ui.BoxHeightStyle] for details on available styles.
  final ui.BoxHeightStyle selectionHeightStyle;

  /// Controls how wide the selection highlight boxes are computed to be.
  ///
  /// See [ui.BoxWidthStyle] for details on available styles.
  final ui.BoxWidthStyle selectionWidthStyle;

  /// The appearance of the keyboard.
  ///
  /// This setting is only honored on iOS devices.
  ///
  /// Defaults to [Brightness.light].
  final Brightness keyboardAppearance;

  /// {@template flutter.widgets.editableText.scrollPadding}
  /// Configures padding to edges surrounding a [Scrollable] when the Textfield scrolls into view.
  ///
  /// When this widget receives focus and is not completely visible (for example scrolled partially
  /// off the screen or overlapped by the keyboard)
  /// then it will attempt to make itself visible by scrolling a surrounding [Scrollable], if one is present.
  /// This value controls how far from the edges of a [Scrollable] the TextField will be positioned after the scroll.
  ///
  /// Defaults to EdgeInsets.all(20.0).
  /// {@endtemplate}
  final EdgeInsets scrollPadding;

  /// {@template flutter.widgets.editableText.enableInteractiveSelection}
  /// Whether to enable user interface affordances for changing the
  /// text selection.
  ///
  /// For example, setting this to true will enable features such as
  /// long-pressing the TextField to select text and show the
  /// cut/copy/paste menu, and tapping to move the text caret.
  ///
  /// When this is false, the text selection cannot be adjusted by
  /// the user, text cannot be copied, and the user cannot paste into
  /// the text field from the clipboard.
  ///
  /// Defaults to true.
  /// {@endtemplate}
  final bool enableInteractiveSelection;

  /// Setting this property to true makes the cursor stop blinking or fading
  /// on and off once the cursor appears on focus. This property is useful for
  /// testing purposes.
  ///
  /// It does not affect the necessity to focus the EditableText for the cursor
  /// to appear in the first place.
  ///
  /// Defaults to false, resulting in a typical blinking cursor.
  static bool debugDeterministicCursor = false;

  /// {@macro flutter.widgets.scrollable.dragStartBehavior}
  final DragStartBehavior dragStartBehavior;

  /// {@template flutter.widgets.editableText.scrollController}
  /// The [ScrollController] to use when vertically scrolling the input.
  ///
  /// If null, it will instantiate a new ScrollController.
  ///
  /// See [Scrollable.controller].
  /// {@endtemplate}
  final ScrollController? scrollController;

  /// {@template flutter.widgets.editableText.scrollPhysics}
  /// The [ScrollPhysics] to use when vertically scrolling the input.
  ///
  /// If not specified, it will behave according to the current platform.
  ///
  /// See [Scrollable.physics].
  /// {@endtemplate}
  ///
  /// If an explicit [ScrollBehavior] is provided to [scrollBehavior], the
  /// [ScrollPhysics] provided by that behavior will take precedence after
  /// [scrollPhysics].
  final ScrollPhysics? scrollPhysics;

  /// {@template flutter.widgets.editableText.scribbleEnabled}
  /// Whether iOS 14 Scribble features are enabled for this widget.
  ///
  /// Only available on iPads.
  ///
  /// Defaults to true.
  /// {@endtemplate}
  final bool scribbleEnabled;

  /// {@template flutter.widgets.editableText.selectionEnabled}
  /// Same as [enableInteractiveSelection].
  ///
  /// This getter exists primarily for consistency with
  /// [RenderEditable.selectionEnabled].
  /// {@endtemplate}
  bool get selectionEnabled => enableInteractiveSelection;

  /// {@template flutter.widgets.editableText.autofillHints}
  /// A list of strings that helps the autofill service identify the type of this
  /// text input.
  ///
  /// When set to null, this text input will not send its autofill information
  /// to the platform, preventing it from participating in autofills triggered
  /// by a different [AutofillClient], even if they're in the same
  /// [AutofillScope]. Additionally, on Android and web, setting this to null
  /// will disable autofill for this text field.
  ///
  /// The minimum platform SDK version that supports Autofill is API level 26
  /// for Android, and iOS 10.0 for iOS.
  ///
  /// Defaults to an empty list.
  ///
  /// ### Setting up iOS autofill:
  ///
  /// To provide the best user experience and ensure your app fully supports
  /// password autofill on iOS, follow these steps:
  ///
  /// * Set up your iOS app's
  ///   [associated domains](https://developer.apple.com/documentation/safariservices/supporting_associated_domains_in_your_app).
  /// * Some autofill hints only work with specific [keyboardType]s. For example,
  ///   [AutofillHints.name] requires [TextInputType.name] and [AutofillHints.email]
  ///   works only with [TextInputType.emailAddress]. Make sure the input field has a
  ///   compatible [keyboardType]. Empirically, [TextInputType.name] works well
  ///   with many autofill hints that are predefined on iOS.
  ///
  /// ### Troubleshooting Autofill
  ///
  /// Autofill service providers rely heavily on [autofillHints]. Make sure the
  /// entries in [autofillHints] are supported by the autofill service currently
  /// in use (the name of the service can typically be found in your mobile
  /// device's system settings).
  ///
  /// #### Autofill UI refuses to show up when I tap on the text field
  ///
  /// Check the device's system settings and make sure autofill is turned on,
  /// and there are available credentials stored in the autofill service.
  ///
  /// * iOS password autofill: Go to Settings -> Password, turn on "Autofill
  ///   Passwords", and add new passwords for testing by pressing the top right
  ///   "+" button. Use an arbitrary "website" if you don't have associated
  ///   domains set up for your app. As long as there's at least one password
  ///   stored, you should be able to see a key-shaped icon in the quick type
  ///   bar on the software keyboard, when a password related field is focused.
  ///
  /// * iOS contact information autofill: iOS seems to pull contact info from
  ///   the Apple ID currently associated with the device. Go to Settings ->
  ///   Apple ID (usually the first entry, or "Sign in to your iPhone" if you
  ///   haven't set up one on the device), and fill out the relevant fields. If
  ///   you wish to test more contact info types, try adding them in Contacts ->
  ///   My Card.
  ///
  /// * Android autofill: Go to Settings -> System -> Languages & input ->
  ///   Autofill service. Enable the autofill service of your choice, and make
  ///   sure there are available credentials associated with your app.
  ///
  /// #### I called `TextInput.finishAutofillContext` but the autofill save
  /// prompt isn't showing
  ///
  /// * iOS: iOS may not show a prompt or any other visual indication when it
  ///   saves user password. Go to Settings -> Password and check if your new
  ///   password is saved. Neither saving password nor auto-generating strong
  ///   password works without properly setting up associated domains in your
  ///   app. To set up associated domains, follow the instructions in
  ///   <https://developer.apple.com/documentation/safariservices/supporting_associated_domains_in_your_app>.
  ///
  /// {@endtemplate}
  /// {@macro flutter.services.AutofillConfiguration.autofillHints}
  final Iterable<String>? autofillHints;

  /// The [AutofillClient] that controls this input field's autofill behavior.
  ///
  /// When null, this widget's [EditableTextState] will be used as the
  /// [AutofillClient]. This property may override [autofillHints].
  final AutofillClient? autofillClient;

  /// {@macro flutter.material.Material.clipBehavior}
  ///
  /// Defaults to [Clip.hardEdge].
  final Clip clipBehavior;

  /// Restoration ID to save and restore the scroll offset of the
  /// [EditableText].
  ///
  /// If a restoration id is provided, the [EditableText] will persist its
  /// current scroll offset and restore it during state restoration.
  ///
  /// The scroll offset is persisted in a [RestorationBucket] claimed from
  /// the surrounding [RestorationScope] using the provided restoration ID.
  ///
  /// Persisting and restoring the content of the [EditableText] is the
  /// responsibility of the owner of the [controller], who may use a
  /// [RestorableTextEditingController] for that purpose.
  ///
  /// See also:
  ///
  ///  * [RestorationManager], which explains how state restoration works in
  ///    Flutter.
  final String? restorationId;

  /// {@template flutter.widgets.shadow.scrollBehavior}
  /// A [ScrollBehavior] that will be applied to this widget individually.
  ///
  /// Defaults to null, wherein the inherited [ScrollBehavior] is copied and
  /// modified to alter the viewport decoration, like [Scrollbar]s.
  /// {@endtemplate}
  ///
  /// [ScrollBehavior]s also provide [ScrollPhysics]. If an explicit
  /// [ScrollPhysics] is provided in [scrollPhysics], it will take precedence,
  /// followed by [scrollBehavior], and then the inherited ancestor
  /// [ScrollBehavior].
  ///
  /// The [ScrollBehavior] of the inherited [ScrollConfiguration] will be
  /// modified by default to only apply a [Scrollbar] if [maxLines] is greater
  /// than 1.
  final ScrollBehavior? scrollBehavior;

  /// {@macro flutter.services.TextInputConfiguration.enableIMEPersonalizedLearning}
  final bool enableIMEPersonalizedLearning;

  /// {@template flutter.widgets.editableText.contentInsertionConfiguration}
  /// Configuration of handler for media content inserted via the system input
  /// method.
  ///
  /// Defaults to null in which case media content insertion will be disabled,
  /// and the system will display a message informing the user that the text field
  /// does not support inserting media content.
  ///
  /// Set [ContentInsertionConfiguration.onContentInserted] to provide a handler.
  /// Additionally, set [ContentInsertionConfiguration.allowedMimeTypes]
  /// to limit the allowable mime types for inserted content.
  ///
  /// {@tool dartpad}
  ///
  /// This example shows how to access the data for inserted content in your
  /// `TextField`.
  ///
  /// ** See code in examples/api/lib/widgets/editable_text/editable_text.on_content_inserted.0.dart **
  /// {@end-tool}
  ///
  /// If [contentInsertionConfiguration] is not provided, by default
  /// an empty list of mime types will be sent to the Flutter Engine.
  /// A handler function must be provided in order to customize the allowable
  /// mime types for inserted content.
  ///
  /// If rich content is inserted without a handler, the system will display
  /// a message informing the user that the current text input does not support
  /// inserting rich content.
  /// {@endtemplate}
  final ContentInsertionConfiguration? contentInsertionConfiguration;

  /// {@template flutter.widgets.EditableText.contextMenuBuilder}
  /// Builds the text selection toolbar when requested by the user.
  ///
  /// `primaryAnchor` is the desired anchor position for the context menu, while
  /// `secondaryAnchor` is the fallback location if the menu doesn't fit.
  ///
  /// `buttonItems` represents the buttons that would be built by default for
  /// this widget.
  ///
  /// {@tool dartpad}
  /// This example shows how to customize the menu, in this case by keeping the
  /// default buttons for the platform but modifying their appearance.
  ///
  /// ** See code in examples/api/lib/material/context_menu/editable_text_toolbar_builder.0.dart **
  /// {@end-tool}
  ///
  /// {@tool dartpad}
  /// This example shows how to show a custom button only when an email address
  /// is currently selected.
  ///
  /// ** See code in examples/api/lib/material/context_menu/editable_text_toolbar_builder.1.dart **
  /// {@end-tool}
  ///
  /// See also:
  ///   * [AdaptiveTextSelectionToolbar], which builds the default text selection
  ///     toolbar for the current platform, but allows customization of the
  ///     buttons.
  ///   * [AdaptiveTextSelectionToolbar.getAdaptiveButtons], which builds the
  ///     button Widgets for the current platform given
  ///     [ContextMenuButtonItem]s.
  ///   * [BrowserContextMenu], which allows the browser's context menu on web
  ///     to be disabled and Flutter-rendered context menus to appear.
  /// {@endtemplate}
  ///
  /// If not provided, no context menu will be shown.
  final EditableTextContextMenuBuilder? contextMenuBuilder;

  /// {@template flutter.widgets.EditableText.spellCheckConfiguration}
  /// Configuration that details how spell check should be performed.
  ///
  /// Specifies the [SpellCheckService] used to spell check text input and the
  /// [TextStyle] used to style text with misspelled words.
  ///
  /// If the [SpellCheckService] is left null, spell check is disabled by
  /// default unless the [DefaultSpellCheckService] is supported, in which case
  /// it is used. It is currently supported only on Android and iOS.
  ///
  /// If this configuration is left null, then spell check is disabled by default.
  /// {@endtemplate}
  final SpellCheckConfiguration? spellCheckConfiguration;

  /// {@macro flutter.widgets.magnifier.TextMagnifierConfiguration.intro}
  ///
  /// {@macro flutter.widgets.magnifier.intro}
  ///
  /// {@macro flutter.widgets.magnifier.TextMagnifierConfiguration.details}
  final TextMagnifierConfiguration magnifierConfiguration;

  bool get _userSelectionEnabled => enableInteractiveSelection && (!readOnly || !obscureText);

  /// Returns the [ContextMenuButtonItem]s representing the buttons in this
  /// platform's default selection menu for an editable field.
  ///
  /// For example, [EditableText] uses this to generate the default buttons for
  /// its context menu.
  ///
  /// See also:
  ///
  /// * [EditableTextState.contextMenuButtonItems], which gives the
  ///   [ContextMenuButtonItem]s for a specific EditableText.
  /// * [SelectableRegion.getSelectableButtonItems], which performs a similar
  ///   role but for content that is selectable but not editable.
  /// * [AdaptiveTextSelectionToolbar], which builds the toolbar itself, and can
  ///   take a list of [ContextMenuButtonItem]s with
  ///   [AdaptiveTextSelectionToolbar.buttonItems].
  /// * [AdaptiveTextSelectionToolbar.getAdaptiveButtons], which builds the button
  ///   Widgets for the current platform given [ContextMenuButtonItem]s.
  static List<ContextMenuButtonItem> getEditableButtonItems({
    required final ClipboardStatus? clipboardStatus,
    required final VoidCallback? onCopy,
    required final VoidCallback? onCut,
    required final VoidCallback? onPaste,
    required final VoidCallback? onSelectAll,
  }) {
    // If the paste button is enabled, don't render anything until the state
    // of the clipboard is known, since it's used to determine if paste is
    // shown.
    if (onPaste != null && clipboardStatus == ClipboardStatus.unknown) {
      return <ContextMenuButtonItem>[];
    }

    return <ContextMenuButtonItem>[
      if (onCut != null)
        ContextMenuButtonItem(
          onPressed: onCut,
          type: ContextMenuButtonType.cut,
        ),
      if (onCopy != null)
        ContextMenuButtonItem(
          onPressed: onCopy,
          type: ContextMenuButtonType.copy,
        ),
      if (onPaste != null)
        ContextMenuButtonItem(
          onPressed: onPaste,
          type: ContextMenuButtonType.paste,
        ),
      if (onSelectAll != null)
        ContextMenuButtonItem(
          onPressed: onSelectAll,
          type: ContextMenuButtonType.selectAll,
        ),
    ];
  }

  // Infer the keyboard type of an `EditableText` if it's not specified.
  static TextInputType _inferKeyboardType({
    required Iterable<String>? autofillHints,
    required int? maxLines,
  }) {
    if (autofillHints == null || autofillHints.isEmpty) {
      return maxLines == 1 ? TextInputType.text : TextInputType.multiline;
    }

    final String effectiveHint = autofillHints.first;

    // On iOS oftentimes specifying a text content type is not enough to qualify
    // the input field for autofill. The keyboard type also needs to be compatible
    // with the content type. To get autofill to work by default on EditableText,
    // the keyboard type inference on iOS is done differently from other platforms.
    //
    // The entries with "autofill not working" comments are the iOS text content
    // types that should work with the specified keyboard type but won't trigger
    // (even within a native app). Tested on iOS 13.5.
    if (!kIsWeb) {
      switch (defaultTargetPlatform) {
        case TargetPlatform.iOS:
        case TargetPlatform.macOS:
          const Map<String, TextInputType> iOSKeyboardType = <String, TextInputType> {
            AutofillHints.addressCity : TextInputType.name,
            AutofillHints.addressCityAndState : TextInputType.name, // Autofill not working.
            AutofillHints.addressState : TextInputType.name,
            AutofillHints.countryName : TextInputType.name,
            AutofillHints.creditCardNumber : TextInputType.number,  // Couldn't test.
            AutofillHints.email : TextInputType.emailAddress,
            AutofillHints.familyName : TextInputType.name,
            AutofillHints.fullStreetAddress : TextInputType.name,
            AutofillHints.givenName : TextInputType.name,
            AutofillHints.jobTitle : TextInputType.name,            // Autofill not working.
            AutofillHints.location : TextInputType.name,            // Autofill not working.
            AutofillHints.middleName : TextInputType.name,          // Autofill not working.
            AutofillHints.name : TextInputType.name,
            AutofillHints.namePrefix : TextInputType.name,          // Autofill not working.
            AutofillHints.nameSuffix : TextInputType.name,          // Autofill not working.
            AutofillHints.newPassword : TextInputType.text,
            AutofillHints.newUsername : TextInputType.text,
            AutofillHints.nickname : TextInputType.name,            // Autofill not working.
            AutofillHints.oneTimeCode : TextInputType.number,
            AutofillHints.organizationName : TextInputType.text,    // Autofill not working.
            AutofillHints.password : TextInputType.text,
            AutofillHints.postalCode : TextInputType.name,
            AutofillHints.streetAddressLine1 : TextInputType.name,
            AutofillHints.streetAddressLine2 : TextInputType.name,  // Autofill not working.
            AutofillHints.sublocality : TextInputType.name,         // Autofill not working.
            AutofillHints.telephoneNumber : TextInputType.name,
            AutofillHints.url : TextInputType.url,                  // Autofill not working.
            AutofillHints.username : TextInputType.text,
          };

          final TextInputType? keyboardType = iOSKeyboardType[effectiveHint];
          if (keyboardType != null) {
            return keyboardType;
          }
          break;
        case TargetPlatform.android:
        case TargetPlatform.fuchsia:
        case TargetPlatform.linux:
        case TargetPlatform.windows:
          break;
      }
    }

    if (maxLines != 1) {
      return TextInputType.multiline;
    }

    const Map<String, TextInputType> inferKeyboardType = <String, TextInputType> {
      AutofillHints.addressCity : TextInputType.streetAddress,
      AutofillHints.addressCityAndState : TextInputType.streetAddress,
      AutofillHints.addressState : TextInputType.streetAddress,
      AutofillHints.birthday : TextInputType.datetime,
      AutofillHints.birthdayDay : TextInputType.datetime,
      AutofillHints.birthdayMonth : TextInputType.datetime,
      AutofillHints.birthdayYear : TextInputType.datetime,
      AutofillHints.countryCode : TextInputType.number,
      AutofillHints.countryName : TextInputType.text,
      AutofillHints.creditCardExpirationDate : TextInputType.datetime,
      AutofillHints.creditCardExpirationDay : TextInputType.datetime,
      AutofillHints.creditCardExpirationMonth : TextInputType.datetime,
      AutofillHints.creditCardExpirationYear : TextInputType.datetime,
      AutofillHints.creditCardFamilyName : TextInputType.name,
      AutofillHints.creditCardGivenName : TextInputType.name,
      AutofillHints.creditCardMiddleName : TextInputType.name,
      AutofillHints.creditCardName : TextInputType.name,
      AutofillHints.creditCardNumber : TextInputType.number,
      AutofillHints.creditCardSecurityCode : TextInputType.number,
      AutofillHints.creditCardType : TextInputType.text,
      AutofillHints.email : TextInputType.emailAddress,
      AutofillHints.familyName : TextInputType.name,
      AutofillHints.fullStreetAddress : TextInputType.streetAddress,
      AutofillHints.gender : TextInputType.text,
      AutofillHints.givenName : TextInputType.name,
      AutofillHints.impp : TextInputType.url,
      AutofillHints.jobTitle : TextInputType.text,
      AutofillHints.language : TextInputType.text,
      AutofillHints.location : TextInputType.streetAddress,
      AutofillHints.middleInitial : TextInputType.name,
      AutofillHints.middleName : TextInputType.name,
      AutofillHints.name : TextInputType.name,
      AutofillHints.namePrefix : TextInputType.name,
      AutofillHints.nameSuffix : TextInputType.name,
      AutofillHints.newPassword : TextInputType.text,
      AutofillHints.newUsername : TextInputType.text,
      AutofillHints.nickname : TextInputType.text,
      AutofillHints.oneTimeCode : TextInputType.text,
      AutofillHints.organizationName : TextInputType.text,
      AutofillHints.password : TextInputType.text,
      AutofillHints.photo : TextInputType.text,
      AutofillHints.postalAddress : TextInputType.streetAddress,
      AutofillHints.postalAddressExtended : TextInputType.streetAddress,
      AutofillHints.postalAddressExtendedPostalCode : TextInputType.number,
      AutofillHints.postalCode : TextInputType.number,
      AutofillHints.streetAddressLevel1 : TextInputType.streetAddress,
      AutofillHints.streetAddressLevel2 : TextInputType.streetAddress,
      AutofillHints.streetAddressLevel3 : TextInputType.streetAddress,
      AutofillHints.streetAddressLevel4 : TextInputType.streetAddress,
      AutofillHints.streetAddressLine1 : TextInputType.streetAddress,
      AutofillHints.streetAddressLine2 : TextInputType.streetAddress,
      AutofillHints.streetAddressLine3 : TextInputType.streetAddress,
      AutofillHints.sublocality : TextInputType.streetAddress,
      AutofillHints.telephoneNumber : TextInputType.phone,
      AutofillHints.telephoneNumberAreaCode : TextInputType.phone,
      AutofillHints.telephoneNumberCountryCode : TextInputType.phone,
      AutofillHints.telephoneNumberDevice : TextInputType.phone,
      AutofillHints.telephoneNumberExtension : TextInputType.phone,
      AutofillHints.telephoneNumberLocal : TextInputType.phone,
      AutofillHints.telephoneNumberLocalPrefix : TextInputType.phone,
      AutofillHints.telephoneNumberLocalSuffix : TextInputType.phone,
      AutofillHints.telephoneNumberNational : TextInputType.phone,
      AutofillHints.transactionAmount : TextInputType.numberWithOptions(decimal: true),
      AutofillHints.transactionCurrency : TextInputType.text,
      AutofillHints.url : TextInputType.url,
      AutofillHints.username : TextInputType.text,
    };

    return inferKeyboardType[effectiveHint] ?? TextInputType.text;
  }

  @override
  EditableTextState createState() => EditableTextState();

  @override
  void debugFillProperties(DiagnosticPropertiesBuilder properties) {
    super.debugFillProperties(properties);
    properties.add(DiagnosticsProperty<TextEditingController>('controller', controller));
    properties.add(DiagnosticsProperty<FocusNode>('focusNode', focusNode));
    properties.add(DiagnosticsProperty<bool>('obscureText', obscureText, defaultValue: false));
    properties.add(DiagnosticsProperty<bool>('readOnly', readOnly, defaultValue: false));
    properties.add(DiagnosticsProperty<bool>('autocorrect', autocorrect, defaultValue: true));
    properties.add(EnumProperty<SmartDashesType>('smartDashesType', smartDashesType, defaultValue: obscureText ? SmartDashesType.disabled : SmartDashesType.enabled));
    properties.add(EnumProperty<SmartQuotesType>('smartQuotesType', smartQuotesType, defaultValue: obscureText ? SmartQuotesType.disabled : SmartQuotesType.enabled));
    properties.add(DiagnosticsProperty<bool>('enableSuggestions', enableSuggestions, defaultValue: true));
    style.debugFillProperties(properties);
    properties.add(EnumProperty<TextAlign>('textAlign', textAlign, defaultValue: null));
    properties.add(EnumProperty<TextDirection>('textDirection', textDirection, defaultValue: null));
    properties.add(DiagnosticsProperty<Locale>('locale', locale, defaultValue: null));
    properties.add(DoubleProperty('textScaleFactor', textScaleFactor, defaultValue: null));
    properties.add(IntProperty('maxLines', maxLines, defaultValue: 1));
    properties.add(IntProperty('minLines', minLines, defaultValue: null));
    properties.add(DiagnosticsProperty<bool>('expands', expands, defaultValue: false));
    properties.add(DiagnosticsProperty<bool>('autofocus', autofocus, defaultValue: false));
    properties.add(DiagnosticsProperty<TextInputType>('keyboardType', keyboardType, defaultValue: null));
    properties.add(DiagnosticsProperty<ScrollController>('scrollController', scrollController, defaultValue: null));
    properties.add(DiagnosticsProperty<ScrollPhysics>('scrollPhysics', scrollPhysics, defaultValue: null));
    properties.add(DiagnosticsProperty<Iterable<String>>('autofillHints', autofillHints, defaultValue: null));
    properties.add(DiagnosticsProperty<TextHeightBehavior>('textHeightBehavior', textHeightBehavior, defaultValue: null));
    properties.add(DiagnosticsProperty<bool>('scribbleEnabled', scribbleEnabled, defaultValue: true));
    properties.add(DiagnosticsProperty<bool>('enableIMEPersonalizedLearning', enableIMEPersonalizedLearning, defaultValue: true));
    properties.add(DiagnosticsProperty<bool>('enableInteractiveSelection', enableInteractiveSelection, defaultValue: true));
    properties.add(DiagnosticsProperty<UndoHistoryController>('undoController', undoController, defaultValue: null));
    properties.add(DiagnosticsProperty<SpellCheckConfiguration>('spellCheckConfiguration', spellCheckConfiguration, defaultValue: null));
    properties.add(DiagnosticsProperty<List<String>>('contentCommitMimeTypes', contentInsertionConfiguration?.allowedMimeTypes ?? const <String>[], defaultValue: contentInsertionConfiguration == null ? const <String>[] : kDefaultContentInsertionMimeTypes));
  }
}

/// State for a [EditableText].
class EditableTextState extends State<EditableText> with AutomaticKeepAliveClientMixin<EditableText>, WidgetsBindingObserver, TickerProviderStateMixin<EditableText>, TextSelectionDelegate, TextInputClient implements AutofillClient {
  Timer? _cursorTimer;
  AnimationController get _cursorBlinkOpacityController {
    return _backingCursorBlinkOpacityController ??= AnimationController(
      vsync: this,
    )..addListener(_onCursorColorTick);
  }
  AnimationController? _backingCursorBlinkOpacityController;
  late final Simulation _iosBlinkCursorSimulation = _DiscreteKeyFrameSimulation.iOSBlinkingCaret();

  final ValueNotifier<bool> _cursorVisibilityNotifier = ValueNotifier<bool>(true);
  final GlobalKey _editableKey = GlobalKey();

  /// Detects whether the clipboard can paste.
  final ClipboardStatusNotifier clipboardStatus = ClipboardStatusNotifier();

  TextInputConnection? _textInputConnection;
  bool get _hasInputConnection => _textInputConnection?.attached ?? false;

  TextSelectionOverlay? _selectionOverlay;

  final GlobalKey _scrollableKey = GlobalKey();
  ScrollController? _internalScrollController;
  ScrollController get _scrollController => widget.scrollController ?? (_internalScrollController ??= ScrollController());

  final LayerLink _toolbarLayerLink = LayerLink();
  final LayerLink _startHandleLayerLink = LayerLink();
  final LayerLink _endHandleLayerLink = LayerLink();

  bool _didAutoFocus = false;

  AutofillGroupState? _currentAutofillScope;
  @override
  AutofillScope? get currentAutofillScope => _currentAutofillScope;

  AutofillClient get _effectiveAutofillClient => widget.autofillClient ?? this;

  late SpellCheckConfiguration _spellCheckConfiguration;
  late TextStyle _style;

  /// Configuration that determines how spell check will be performed.
  ///
  /// If possible, this configuration will contain a default for the
  /// [SpellCheckService] if it is not otherwise specified.
  ///
  /// See also:
  ///  * [DefaultSpellCheckService], the spell check service used by default.
  @visibleForTesting
  SpellCheckConfiguration get spellCheckConfiguration => _spellCheckConfiguration;

  /// Whether or not spell check is enabled.
  ///
  /// Spell check is enabled when a [SpellCheckConfiguration] has been specified
  /// for the widget.
  bool get spellCheckEnabled => _spellCheckConfiguration.spellCheckEnabled;

  /// The most up-to-date spell check results for text input.
  ///
  /// These results will be updated via calls to spell check through a
  /// [SpellCheckService] and used by this widget to build the [TextSpan] tree
  /// for text input and menus for replacement suggestions of misspelled words.
  SpellCheckResults? spellCheckResults;

  bool get _spellCheckResultsReceived => spellCheckEnabled && spellCheckResults != null && spellCheckResults!.suggestionSpans.isNotEmpty;

  /// Whether to create an input connection with the platform for text editing
  /// or not.
  ///
  /// Read-only input fields do not need a connection with the platform since
  /// there's no need for text editing capabilities (e.g. virtual keyboard).
  ///
  /// On the web, we always need a connection because we want some browser
  /// functionalities to continue to work on read-only input fields like:
  ///
  /// - Relevant context menu.
  /// - cmd/ctrl+c shortcut to copy.
  /// - cmd/ctrl+a to select all.
  /// - Changing the selection using a physical keyboard.
  bool get _shouldCreateInputConnection => kIsWeb || !widget.readOnly;

  // The time it takes for the floating cursor to snap to the text aligned
  // cursor position after the user has finished placing it.
  static const Duration _floatingCursorResetTime = Duration(milliseconds: 125);

  AnimationController? _floatingCursorResetController;

  Orientation? _lastOrientation;

  @override
  bool get wantKeepAlive => widget.focusNode.hasFocus;

  Color get _cursorColor => widget.cursorColor.withOpacity(_cursorBlinkOpacityController.value);

  @override
  bool get cutEnabled {
    if (widget.selectionControls is! TextSelectionHandleControls) {
      return widget.toolbarOptions.cut && !widget.readOnly && !widget.obscureText;
    }
    return !widget.readOnly
        && !widget.obscureText
        && !textEditingValue.selection.isCollapsed;
  }

  @override
  bool get copyEnabled {
    if (widget.selectionControls is! TextSelectionHandleControls) {
      return widget.toolbarOptions.copy && !widget.obscureText;
    }
    return !widget.obscureText
        && !textEditingValue.selection.isCollapsed;
  }

  @override
  bool get pasteEnabled {
    if (widget.selectionControls is! TextSelectionHandleControls) {
      return widget.toolbarOptions.paste && !widget.readOnly;
    }
    return !widget.readOnly
        && (clipboardStatus.value == ClipboardStatus.pasteable);
  }

  @override
  bool get selectAllEnabled {
    if (widget.selectionControls is! TextSelectionHandleControls) {
      return widget.toolbarOptions.selectAll && (!widget.readOnly || !widget.obscureText) && widget.enableInteractiveSelection;
    }

    if (!widget.enableInteractiveSelection
        || (widget.readOnly
            && widget.obscureText)) {
      return false;
    }

    switch (defaultTargetPlatform) {
      case TargetPlatform.macOS:
        return false;
      case TargetPlatform.iOS:
        return textEditingValue.text.isNotEmpty
            && textEditingValue.selection.isCollapsed;
      case TargetPlatform.android:
      case TargetPlatform.fuchsia:
      case TargetPlatform.linux:
      case TargetPlatform.windows:
        return textEditingValue.text.isNotEmpty
           && !(textEditingValue.selection.start == 0
               && textEditingValue.selection.end == textEditingValue.text.length);
    }
  }

  void _onChangedClipboardStatus() {
    setState(() {
      // Inform the widget that the value of clipboardStatus has changed.
    });
  }

  TextEditingValue get _textEditingValueforTextLayoutMetrics {
    final Widget? editableWidget =_editableKey.currentContext?.widget;
    if (editableWidget is! _Editable) {
      throw StateError('_Editable must be mounted.');
    }
    return editableWidget.value;
  }

  /// Copy current selection to [Clipboard].
  @override
  void copySelection(SelectionChangedCause cause) {
    final TextSelection selection = textEditingValue.selection;
    if (selection.isCollapsed || widget.obscureText) {
      return;
    }
    final String text = textEditingValue.text;
    Clipboard.setData(ClipboardData(text: selection.textInside(text)));
    if (cause == SelectionChangedCause.toolbar) {
      bringIntoView(textEditingValue.selection.extent);
      hideToolbar(false);

      switch (defaultTargetPlatform) {
        case TargetPlatform.iOS:
        case TargetPlatform.macOS:
        case TargetPlatform.linux:
        case TargetPlatform.windows:
          break;
        case TargetPlatform.android:
        case TargetPlatform.fuchsia:
          // Collapse the selection and hide the toolbar and handles.
          userUpdateTextEditingValue(
            TextEditingValue(
              text: textEditingValue.text,
              selection: TextSelection.collapsed(offset: textEditingValue.selection.end),
            ),
            SelectionChangedCause.toolbar,
          );
          break;
      }
    }
    clipboardStatus.update();
  }

  /// Cut current selection to [Clipboard].
  @override
  void cutSelection(SelectionChangedCause cause) {
    if (widget.readOnly || widget.obscureText) {
      return;
    }
    final TextSelection selection = textEditingValue.selection;
    final String text = textEditingValue.text;
    if (selection.isCollapsed) {
      return;
    }
    Clipboard.setData(ClipboardData(text: selection.textInside(text)));
    _replaceText(ReplaceTextIntent(textEditingValue, '', selection, cause));
    if (cause == SelectionChangedCause.toolbar) {
      // Schedule a call to bringIntoView() after renderEditable updates.
      SchedulerBinding.instance.addPostFrameCallback((_) {
        if (mounted) {
          bringIntoView(textEditingValue.selection.extent);
        }
      });
      hideToolbar();
    }
    clipboardStatus.update();
  }

  /// Paste text from [Clipboard].
  @override
  Future<void> pasteText(SelectionChangedCause cause) async {
    if (widget.readOnly) {
      return;
    }
    final TextSelection selection = textEditingValue.selection;
    if (!selection.isValid) {
      return;
    }
    // Snapshot the input before using `await`.
    // See https://github.com/flutter/flutter/issues/11427
    final ClipboardData? data = await Clipboard.getData(Clipboard.kTextPlain);
    if (data == null) {
      return;
    }

    // After the paste, the cursor should be collapsed and located after the
    // pasted content.
    final int lastSelectionIndex = math.max(selection.baseOffset, selection.extentOffset);
    final TextEditingValue collapsedTextEditingValue = textEditingValue.copyWith(
      selection: TextSelection.collapsed(offset: lastSelectionIndex),
    );

    userUpdateTextEditingValue(
      collapsedTextEditingValue.replaced(selection, data.text!),
      cause,
    );
    if (cause == SelectionChangedCause.toolbar) {
      // Schedule a call to bringIntoView() after renderEditable updates.
      SchedulerBinding.instance.addPostFrameCallback((_) {
        if (mounted) {
          bringIntoView(textEditingValue.selection.extent);
        }
      });
      hideToolbar();
    }
  }

  /// Select the entire text value.
  @override
  void selectAll(SelectionChangedCause cause) {
    if (widget.readOnly && widget.obscureText) {
      // If we can't modify it, and we can't copy it, there's no point in
      // selecting it.
      return;
    }
    userUpdateTextEditingValue(
      textEditingValue.copyWith(
        selection: TextSelection(baseOffset: 0, extentOffset: textEditingValue.text.length),
      ),
      cause,
    );

    if (cause == SelectionChangedCause.toolbar) {
      switch (defaultTargetPlatform) {
        case TargetPlatform.android:
        case TargetPlatform.iOS:
        case TargetPlatform.fuchsia:
          break;
        case TargetPlatform.macOS:
        case TargetPlatform.linux:
        case TargetPlatform.windows:
          hideToolbar();
      }
      switch (defaultTargetPlatform) {
        case TargetPlatform.android:
        case TargetPlatform.fuchsia:
        case TargetPlatform.linux:
        case TargetPlatform.windows:
          bringIntoView(textEditingValue.selection.extent);
          break;
        case TargetPlatform.macOS:
        case TargetPlatform.iOS:
          break;
      }
    }
  }

  /// Replace composing region with specified text.
  void replaceComposingRegion(SelectionChangedCause cause, String text) {
    // Replacement cannot be performed if the text is read only or obscured.
    assert(!widget.readOnly && !widget.obscureText);

    _replaceText(ReplaceTextIntent(textEditingValue, text, textEditingValue.composing, cause));

    if (cause == SelectionChangedCause.toolbar) {
      // Schedule a call to bringIntoView() after renderEditable updates.
      SchedulerBinding.instance.addPostFrameCallback((_) {
        if (mounted) {
          bringIntoView(textEditingValue.selection.extent);
        }
      });
      hideToolbar();
    }
  }

  /// Finds specified [SuggestionSpan] that matches the provided index using
  /// binary search.
  ///
  /// See also:
  ///
  ///  * [SpellCheckSuggestionsToolbar], the Material style spell check
  ///    suggestions toolbar that uses this method to render the correct
  ///    suggestions in the toolbar for a misspelled word.
  SuggestionSpan? findSuggestionSpanAtCursorIndex(int cursorIndex) {
    if (!_spellCheckResultsReceived
        || spellCheckResults!.suggestionSpans.last.range.end < cursorIndex) {
      // No spell check results have been received or the cursor index is out
      // of range that suggestionSpans covers.
      return null;
    }

    final List<SuggestionSpan> suggestionSpans = spellCheckResults!.suggestionSpans;
    int leftIndex = 0;
    int rightIndex = suggestionSpans.length - 1;
    int midIndex = 0;

    while (leftIndex <= rightIndex) {
      midIndex = ((leftIndex + rightIndex) / 2).floor();
      final int currentSpanStart = suggestionSpans[midIndex].range.start;
      final int currentSpanEnd = suggestionSpans[midIndex].range.end;

      if (cursorIndex <= currentSpanEnd && cursorIndex >= currentSpanStart) {
        return suggestionSpans[midIndex];
      }
      else if (cursorIndex <= currentSpanStart) {
        rightIndex = midIndex - 1;
      }
      else {
        leftIndex = midIndex + 1;
      }
    }
    return null;
  }

  /// Infers the [SpellCheckConfiguration] used to perform spell check.
  ///
  /// If spell check is enabled, this will try to infer a value for
  /// the [SpellCheckService] if left unspecified.
  static SpellCheckConfiguration _inferSpellCheckConfiguration(SpellCheckConfiguration? configuration) {
    if (configuration == null || configuration == const SpellCheckConfiguration.disabled()) {
      return const SpellCheckConfiguration.disabled();
    }

    SpellCheckService? spellCheckService = configuration.spellCheckService;

    assert(
      spellCheckService != null
      || WidgetsBinding.instance.platformDispatcher.nativeSpellCheckServiceDefined,
      'spellCheckService must be specified for this platform because no default service available',
    );

    spellCheckService = spellCheckService ?? DefaultSpellCheckService();

    return configuration.copyWith(spellCheckService: spellCheckService);
  }

  /// Returns the [ContextMenuButtonItem]s for the given [ToolbarOptions].
  @Deprecated(
    'Use `contextMenuBuilder` instead of `toolbarOptions`. '
    'This feature was deprecated after v3.3.0-0.5.pre.',
  )
  List<ContextMenuButtonItem>? buttonItemsForToolbarOptions([TargetPlatform? targetPlatform]) {
    final ToolbarOptions toolbarOptions = widget.toolbarOptions;
    if (toolbarOptions == ToolbarOptions.empty) {
      return null;
    }
    return <ContextMenuButtonItem>[
      if (toolbarOptions.cut && cutEnabled)
        ContextMenuButtonItem(
          onPressed: () {
            cutSelection(SelectionChangedCause.toolbar);
          },
          type: ContextMenuButtonType.cut,
        ),
      if (toolbarOptions.copy && copyEnabled)
        ContextMenuButtonItem(
          onPressed: () {
            copySelection(SelectionChangedCause.toolbar);
          },
          type: ContextMenuButtonType.copy,
        ),
      if (toolbarOptions.paste && pasteEnabled)
        ContextMenuButtonItem(
          onPressed: () {
            pasteText(SelectionChangedCause.toolbar);
          },
          type: ContextMenuButtonType.paste,
        ),
      if (toolbarOptions.selectAll && selectAllEnabled)
        ContextMenuButtonItem(
          onPressed: () {
            selectAll(SelectionChangedCause.toolbar);
          },
          type: ContextMenuButtonType.selectAll,
        ),
    ];
  }

  /// Gets the line heights at the start and end of the selection for the given
  /// [EditableTextState].
  _GlyphHeights _getGlyphHeights() {
    final TextSelection selection = textEditingValue.selection;

    // Only calculate handle rects if the text in the previous frame
    // is the same as the text in the current frame. This is done because
    // widget.renderObject contains the renderEditable from the previous frame.
    // If the text changed between the current and previous frames then
    // widget.renderObject.getRectForComposingRange might fail. In cases where
    // the current frame is different from the previous we fall back to
    // renderObject.preferredLineHeight.
    final InlineSpan span = renderEditable.text!;
    final String prevText = span.toPlainText();
    final String currText = textEditingValue.text;
    if (prevText != currText || !selection.isValid || selection.isCollapsed) {
      return _GlyphHeights(
        start: renderEditable.preferredLineHeight,
        end: renderEditable.preferredLineHeight,
      );
    }

    final String selectedGraphemes = selection.textInside(currText);
    final int firstSelectedGraphemeExtent = selectedGraphemes.characters.first.length;
    final Rect? startCharacterRect = renderEditable.getRectForComposingRange(TextRange(
      start: selection.start,
      end: selection.start + firstSelectedGraphemeExtent,
    ));
    final int lastSelectedGraphemeExtent = selectedGraphemes.characters.last.length;
    final Rect? endCharacterRect = renderEditable.getRectForComposingRange(TextRange(
      start: selection.end - lastSelectedGraphemeExtent,
      end: selection.end,
    ));
    return _GlyphHeights(
      start: startCharacterRect?.height ?? renderEditable.preferredLineHeight,
      end: endCharacterRect?.height ?? renderEditable.preferredLineHeight,
    );
  }

  /// {@template flutter.widgets.EditableText.getAnchors}
  /// Returns the anchor points for the default context menu.
  /// {@endtemplate}
  ///
  /// See also:
  ///
  ///  * [contextMenuButtonItems], which provides the [ContextMenuButtonItem]s
  ///    for the default context menu buttons.
  TextSelectionToolbarAnchors get contextMenuAnchors {
    if (renderEditable.lastSecondaryTapDownPosition != null) {
      return TextSelectionToolbarAnchors(
        primaryAnchor: renderEditable.lastSecondaryTapDownPosition!,
      );
    }

    final _GlyphHeights glyphHeights = _getGlyphHeights();
    final TextSelection selection = textEditingValue.selection;
    final List<TextSelectionPoint> points =
        renderEditable.getEndpointsForSelection(selection);
    return TextSelectionToolbarAnchors.fromSelection(
      renderBox: renderEditable,
      startGlyphHeight: glyphHeights.start,
      endGlyphHeight: glyphHeights.end,
      selectionEndpoints: points,
    );
  }

  /// Returns the [ContextMenuButtonItem]s representing the buttons in this
  /// platform's default selection menu for [EditableText].
  ///
  /// See also:
  ///
  /// * [EditableText.getEditableButtonItems], which performs a similar role,
  ///   but for any editable field, not just specifically EditableText.
  /// * [SelectableRegionState.contextMenuButtonItems], which performs a similar
  ///   role but for content that is selectable but not editable.
  /// * [contextMenuAnchors], which provides the anchor points for the default
  ///   context menu.
  /// * [AdaptiveTextSelectionToolbar], which builds the toolbar itself, and can
  ///   take a list of [ContextMenuButtonItem]s with
  ///   [AdaptiveTextSelectionToolbar.buttonItems].
  /// * [AdaptiveTextSelectionToolbar.getAdaptiveButtons], which builds the
  ///   button Widgets for the current platform given [ContextMenuButtonItem]s.
  List<ContextMenuButtonItem> get contextMenuButtonItems {
    return buttonItemsForToolbarOptions() ?? EditableText.getEditableButtonItems(
      clipboardStatus: clipboardStatus.value,
      onCopy: copyEnabled
          ? () => copySelection(SelectionChangedCause.toolbar)
          : null,
      onCut: cutEnabled
          ? () => cutSelection(SelectionChangedCause.toolbar)
          : null,
      onPaste: pasteEnabled
          ? () => pasteText(SelectionChangedCause.toolbar)
          : null,
      onSelectAll: selectAllEnabled
          ? () => selectAll(SelectionChangedCause.toolbar)
          : null,
    );
  }

  // State lifecycle:

  @override
  void initState() {
    super.initState();
    clipboardStatus.addListener(_onChangedClipboardStatus);
    widget.controller.addListener(_didChangeTextEditingValue);
    widget.focusNode.addListener(_handleFocusChanged);
    _scrollController.addListener(_onEditableScroll);
    _cursorVisibilityNotifier.value = widget.showCursor;
    _spellCheckConfiguration = _inferSpellCheckConfiguration(widget.spellCheckConfiguration);
  }

  // Whether `TickerMode.of(context)` is true and animations (like blinking the
  // cursor) are supposed to run.
  bool _tickersEnabled = true;

  @override
  void didChangeDependencies() {
    super.didChangeDependencies();

    _style = MediaQuery.boldTextOf(context)
        ? widget.style.merge(const TextStyle(fontWeight: FontWeight.bold))
        : widget.style;

    final AutofillGroupState? newAutofillGroup = AutofillGroup.maybeOf(context);
    if (currentAutofillScope != newAutofillGroup) {
      _currentAutofillScope?.unregister(autofillId);
      _currentAutofillScope = newAutofillGroup;
      _currentAutofillScope?.register(_effectiveAutofillClient);
    }

    if (!_didAutoFocus && widget.autofocus) {
      _didAutoFocus = true;
      SchedulerBinding.instance.addPostFrameCallback((_) {
        if (mounted && renderEditable.hasSize) {
          _flagInternalFocus();
          FocusScope.of(context).autofocus(widget.focusNode);
        }
      });
    }

    // Restart or stop the blinking cursor when TickerMode changes.
    final bool newTickerEnabled = TickerMode.of(context);
    if (_tickersEnabled != newTickerEnabled) {
      _tickersEnabled = newTickerEnabled;
      if (_tickersEnabled && _cursorActive) {
        _startCursorBlink();
      } else if (!_tickersEnabled && _cursorTimer != null) {
        // Cannot use _stopCursorBlink because it would reset _cursorActive.
        _cursorTimer!.cancel();
        _cursorTimer = null;
      }
    }

    if (defaultTargetPlatform != TargetPlatform.iOS && defaultTargetPlatform != TargetPlatform.android) {
      return;
    }

    // Hide the text selection toolbar on mobile when orientation changes.
    final Orientation orientation = MediaQuery.orientationOf(context);
    if (_lastOrientation == null) {
      _lastOrientation = orientation;
      return;
    }
    if (orientation != _lastOrientation) {
      _lastOrientation = orientation;
      if (defaultTargetPlatform == TargetPlatform.iOS) {
        hideToolbar(false);
      }
      if (defaultTargetPlatform == TargetPlatform.android) {
        hideToolbar();
      }
    }
  }

  @override
  void didUpdateWidget(EditableText oldWidget) {
    super.didUpdateWidget(oldWidget);
    if (widget.controller != oldWidget.controller) {
      oldWidget.controller.removeListener(_didChangeTextEditingValue);
      widget.controller.addListener(_didChangeTextEditingValue);
      _updateRemoteEditingValueIfNeeded();
    }
    if (widget.controller.selection != oldWidget.controller.selection) {
      _selectionOverlay?.update(_value);
    }
    _selectionOverlay?.handlesVisible = widget.showSelectionHandles;

    if (widget.autofillClient != oldWidget.autofillClient) {
      _currentAutofillScope?.unregister(oldWidget.autofillClient?.autofillId ?? autofillId);
      _currentAutofillScope?.register(_effectiveAutofillClient);
    }

    if (widget.focusNode != oldWidget.focusNode) {
      oldWidget.focusNode.removeListener(_handleFocusChanged);
      widget.focusNode.addListener(_handleFocusChanged);
      updateKeepAlive();
    }

    if (widget.scrollController != oldWidget.scrollController) {
      (oldWidget.scrollController ?? _internalScrollController)?.removeListener(_onEditableScroll);
      _scrollController.addListener(_onEditableScroll);
    }

    if (!_shouldCreateInputConnection) {
      _closeInputConnectionIfNeeded();
    } else if (oldWidget.readOnly && _hasFocus) {
      _openInputConnection();
    }

    if (kIsWeb && _hasInputConnection) {
      if (oldWidget.readOnly != widget.readOnly) {
        _textInputConnection!.updateConfig(_effectiveAutofillClient.textInputConfiguration);
      }
    }

    if (widget.style != oldWidget.style) {
      // The _textInputConnection will pick up the new style when it attaches in
      // _openInputConnection.
      _style = MediaQuery.boldTextOf(context)
          ? widget.style.merge(const TextStyle(fontWeight: FontWeight.bold))
          : widget.style;
      if (_hasInputConnection) {
        _textInputConnection!.setStyle(
          fontFamily: _style.fontFamily,
          fontSize: _style.fontSize,
          fontWeight: _style.fontWeight,
          textDirection: _textDirection,
          textAlign: widget.textAlign,
        );
      }
    }
    final bool canPaste = widget.selectionControls is TextSelectionHandleControls
        ? pasteEnabled
        : widget.selectionControls?.canPaste(this) ?? false;
    if (widget.selectionEnabled && pasteEnabled && canPaste) {
      clipboardStatus.update();
    }
  }

  @override
  void dispose() {
    _internalScrollController?.dispose();
    _currentAutofillScope?.unregister(autofillId);
    widget.controller.removeListener(_didChangeTextEditingValue);
    _floatingCursorResetController?.dispose();
    _floatingCursorResetController = null;
    _closeInputConnectionIfNeeded();
    assert(!_hasInputConnection);
    _cursorTimer?.cancel();
    _cursorTimer = null;
    _backingCursorBlinkOpacityController?.dispose();
    _backingCursorBlinkOpacityController = null;
    _selectionOverlay?.dispose();
    _selectionOverlay = null;
    widget.focusNode.removeListener(_handleFocusChanged);
    WidgetsBinding.instance.removeObserver(this);
    clipboardStatus.removeListener(_onChangedClipboardStatus);
    clipboardStatus.dispose();
    _cursorVisibilityNotifier.dispose();
    FocusManager.instance.removeListener(_unflagInternalFocus);
    super.dispose();
    assert(_batchEditDepth <= 0, 'unfinished batch edits: $_batchEditDepth');
  }

  // TextInputClient implementation:

  /// The last known [TextEditingValue] of the platform text input plugin.
  ///
  /// This value is updated when the platform text input plugin sends a new
  /// update via [updateEditingValue], or when [EditableText] calls
  /// [TextInputConnection.setEditingState] to overwrite the platform text input
  /// plugin's [TextEditingValue].
  ///
  /// Used in [_updateRemoteEditingValueIfNeeded] to determine whether the
  /// remote value is outdated and needs updating.
  TextEditingValue? _lastKnownRemoteTextEditingValue;

  @override
  TextEditingValue get currentTextEditingValue => _value;

  @override
  void updateEditingValue(TextEditingValue value) {
    // This method handles text editing state updates from the platform text
    // input plugin. The [EditableText] may not have the focus or an open input
    // connection, as autofill can update a disconnected [EditableText].

    // Since we still have to support keyboard select, this is the best place
    // to disable text updating.
    if (!_shouldCreateInputConnection) {
      return;
    }

    if (_checkNeedsAdjustAffinity(value)) {
      value = value.copyWith(selection: value.selection.copyWith(affinity: _value.selection.affinity));
    }

    if (widget.readOnly) {
      // In the read-only case, we only care about selection changes, and reject
      // everything else.
      value = _value.copyWith(selection: value.selection);
    }
    _lastKnownRemoteTextEditingValue = value;

    if (value == _value) {
      // This is possible, for example, when the numeric keyboard is input,
      // the engine will notify twice for the same value.
      // Track at https://github.com/flutter/flutter/issues/65811
      return;
    }

    if (value.text == _value.text && value.composing == _value.composing) {
      // `selection` is the only change.
      SelectionChangedCause cause;
      if (_textInputConnection?.scribbleInProgress ?? false) {
        cause = SelectionChangedCause.scribble;
      } else if (_pointOffsetOrigin != null) {
        cause = SelectionChangedCause.forcePress;
      } else {
        cause = SelectionChangedCause.keyboard;
      }
      _handleSelectionChanged(value.selection, cause);
    } else {
      if (value.text != _value.text) {
        // Hide the toolbar if the text was changed, but only hide the toolbar
        // overlay; the selection handle's visibility will be handled
        // by `_handleSelectionChanged`. https://github.com/flutter/flutter/issues/108673
        hideToolbar(false);
      }
      _currentPromptRectRange = null;

      final bool revealObscuredInput = _hasInputConnection
                                    && widget.obscureText
                                    && WidgetsBinding.instance.platformDispatcher.brieflyShowPassword
                                    && value.text.length == _value.text.length + 1;

      _obscureShowCharTicksPending = revealObscuredInput ? _kObscureShowLatestCharCursorTicks : 0;
      _obscureLatestCharIndex = revealObscuredInput ? _value.selection.baseOffset : null;
      _formatAndSetValue(value, SelectionChangedCause.keyboard);
    }

    // Wherever the value is changed by the user, schedule a showCaretOnScreen
    // to make sure the user can see the changes they just made. Programmatic
    // changes to `textEditingValue` do not trigger the behavior even if the
    // text field is focused.
    _scheduleShowCaretOnScreen(withAnimation: true);
    if (_hasInputConnection) {
      // To keep the cursor from blinking while typing, we want to restart the
      // cursor timer every time a new character is typed.
      _stopCursorBlink(resetCharTicks: false);
      _startCursorBlink();
    }
  }

  bool _checkNeedsAdjustAffinity(TextEditingValue value) {
    // Trust the engine affinity if the text changes or selection changes.
    return value.text == _value.text &&
      value.selection.isCollapsed == _value.selection.isCollapsed &&
      value.selection.start == _value.selection.start &&
      value.selection.affinity != _value.selection.affinity;
  }

  @override
  void performAction(TextInputAction action) {
    switch (action) {
      case TextInputAction.newline:
        // If this is a multiline EditableText, do nothing for a "newline"
        // action; The newline is already inserted. Otherwise, finalize
        // editing.
        if (!_isMultiline) {
          _finalizeEditing(action, shouldUnfocus: true);
        }
        break;
      case TextInputAction.done:
      case TextInputAction.go:
      case TextInputAction.next:
      case TextInputAction.previous:
      case TextInputAction.search:
      case TextInputAction.send:
        _finalizeEditing(action, shouldUnfocus: true);
        break;
      case TextInputAction.continueAction:
      case TextInputAction.emergencyCall:
      case TextInputAction.join:
      case TextInputAction.none:
      case TextInputAction.route:
      case TextInputAction.unspecified:
        // Finalize editing, but don't give up focus because this keyboard
        // action does not imply the user is done inputting information.
        _finalizeEditing(action, shouldUnfocus: false);
        break;
    }
  }

  @override
  void performPrivateCommand(String action, Map<String, dynamic> data) {
    widget.onAppPrivateCommand?.call(action, data);
  }

  @override
  void insertContent(KeyboardInsertedContent content) {
    assert(widget.contentInsertionConfiguration?.allowedMimeTypes.contains(content.mimeType) ?? false);
    widget.contentInsertionConfiguration?.onContentInserted.call(content);
  }

  // The original position of the caret on FloatingCursorDragState.start.
  Rect? _startCaretRect;

  // The most recent text position as determined by the location of the floating
  // cursor.
  TextPosition? _lastTextPosition;

  // The offset of the floating cursor as determined from the start call.
  Offset? _pointOffsetOrigin;

  // The most recent position of the floating cursor.
  Offset? _lastBoundedOffset;

  // Because the center of the cursor is preferredLineHeight / 2 below the touch
  // origin, but the touch origin is used to determine which line the cursor is
  // on, we need this offset to correctly render and move the cursor.
  Offset get _floatingCursorOffset => Offset(0, renderEditable.preferredLineHeight / 2);

  @override
  void updateFloatingCursor(RawFloatingCursorPoint point) {
    _floatingCursorResetController ??= AnimationController(
      vsync: this,
    )..addListener(_onFloatingCursorResetTick);
    switch(point.state) {
      case FloatingCursorDragState.Start:
        if (_floatingCursorResetController!.isAnimating) {
          _floatingCursorResetController!.stop();
          _onFloatingCursorResetTick();
        }
        // Stop cursor blinking and making it visible.
        _stopCursorBlink(resetCharTicks: false);
        _cursorBlinkOpacityController.value = 1.0;
        // We want to send in points that are centered around a (0,0) origin, so
        // we cache the position.
        _pointOffsetOrigin = point.offset;

        final TextPosition currentTextPosition = TextPosition(offset: renderEditable.selection!.baseOffset, affinity: renderEditable.selection!.affinity);
        _startCaretRect = renderEditable.getLocalRectForCaret(currentTextPosition);

        _lastBoundedOffset = _startCaretRect!.center - _floatingCursorOffset;
        _lastTextPosition = currentTextPosition;
        renderEditable.setFloatingCursor(point.state, _lastBoundedOffset!, _lastTextPosition!);
        break;
      case FloatingCursorDragState.Update:
        final Offset centeredPoint = point.offset! - _pointOffsetOrigin!;
        final Offset rawCursorOffset = _startCaretRect!.center + centeredPoint - _floatingCursorOffset;

        _lastBoundedOffset = renderEditable.calculateBoundedFloatingCursorOffset(rawCursorOffset);
        _lastTextPosition = renderEditable.getPositionForPoint(renderEditable.localToGlobal(_lastBoundedOffset! + _floatingCursorOffset));
        renderEditable.setFloatingCursor(point.state, _lastBoundedOffset!, _lastTextPosition!);
        break;
      case FloatingCursorDragState.End:
        // Resume cursor blinking.
        _startCursorBlink();
        // We skip animation if no update has happened.
        if (_lastTextPosition != null && _lastBoundedOffset != null) {
          _floatingCursorResetController!.value = 0.0;
          _floatingCursorResetController!.animateTo(1.0, duration: _floatingCursorResetTime, curve: Curves.decelerate);
        }
        break;
    }
  }

  void _onFloatingCursorResetTick() {
    final Offset finalPosition = renderEditable.getLocalRectForCaret(_lastTextPosition!).centerLeft - _floatingCursorOffset;
    if (_floatingCursorResetController!.isCompleted) {
      renderEditable.setFloatingCursor(FloatingCursorDragState.End, finalPosition, _lastTextPosition!);
      // Only change if the current selection range is collapsed, to prevent
      // overwriting the result of the iOS keyboard selection gesture.
      if (renderEditable.selection!.isCollapsed) {
        // The cause is technically the force cursor, but the cause is listed as tap as the desired functionality is the same.
        _handleSelectionChanged(TextSelection.fromPosition(_lastTextPosition!), SelectionChangedCause.forcePress);
      }
      _startCaretRect = null;
      _lastTextPosition = null;
      _pointOffsetOrigin = null;
      _lastBoundedOffset = null;
    } else {
      final double lerpValue = _floatingCursorResetController!.value;
      final double lerpX = ui.lerpDouble(_lastBoundedOffset!.dx, finalPosition.dx, lerpValue)!;
      final double lerpY = ui.lerpDouble(_lastBoundedOffset!.dy, finalPosition.dy, lerpValue)!;

      renderEditable.setFloatingCursor(FloatingCursorDragState.Update, Offset(lerpX, lerpY), _lastTextPosition!, resetLerpValue: lerpValue);
    }
  }

  @pragma('vm:notify-debugger-on-exception')
  void _finalizeEditing(TextInputAction action, {required bool shouldUnfocus}) {
    // Take any actions necessary now that the user has completed editing.
    if (widget.onEditingComplete != null) {
      try {
        widget.onEditingComplete!();
      } catch (exception, stack) {
        FlutterError.reportError(FlutterErrorDetails(
          exception: exception,
          stack: stack,
          library: 'widgets',
          context: ErrorDescription('while calling onEditingComplete for $action'),
        ));
      }
    } else {
      // Default behavior if the developer did not provide an
      // onEditingComplete callback: Finalize editing and remove focus, or move
      // it to the next/previous field, depending on the action.
      widget.controller.clearComposing();
      if (shouldUnfocus) {
        switch (action) {
          case TextInputAction.none:
          case TextInputAction.unspecified:
          case TextInputAction.done:
          case TextInputAction.go:
          case TextInputAction.search:
          case TextInputAction.send:
          case TextInputAction.continueAction:
          case TextInputAction.join:
          case TextInputAction.route:
          case TextInputAction.emergencyCall:
          case TextInputAction.newline:
            widget.focusNode.unfocus();
            break;
          case TextInputAction.next:
            widget.focusNode.nextFocus();
            break;
          case TextInputAction.previous:
            widget.focusNode.previousFocus();
            break;
        }
      }
    }

    final ValueChanged<String>? onSubmitted = widget.onSubmitted;
    if (onSubmitted == null) {
      return;
    }

    // Invoke optional callback with the user's submitted content.
    try {
      onSubmitted(_value.text);
    } catch (exception, stack) {
      FlutterError.reportError(FlutterErrorDetails(
        exception: exception,
        stack: stack,
        library: 'widgets',
        context: ErrorDescription('while calling onSubmitted for $action'),
      ));
    }

    // If `shouldUnfocus` is true, the text field should no longer be focused
    // after the microtask queue is drained. But in case the developer cancelled
    // the focus change in the `onSubmitted` callback by focusing this input
    // field again, reset the soft keyboard.
    // See https://github.com/flutter/flutter/issues/84240.
    //
    // `_restartConnectionIfNeeded` creates a new TextInputConnection to replace
    // the current one. This on iOS switches to a new input view and on Android
    // restarts the input method, and in both cases the soft keyboard will be
    // reset.
    if (shouldUnfocus) {
      _scheduleRestartConnection();
    }
  }

  int _batchEditDepth = 0;

  /// Begins a new batch edit, within which new updates made to the text editing
  /// value will not be sent to the platform text input plugin.
  ///
  /// Batch edits nest. When the outermost batch edit finishes, [endBatchEdit]
  /// will attempt to send [currentTextEditingValue] to the text input plugin if
  /// it detected a change.
  void beginBatchEdit() {
    _batchEditDepth += 1;
  }

  /// Ends the current batch edit started by the last call to [beginBatchEdit],
  /// and send [currentTextEditingValue] to the text input plugin if needed.
  ///
  /// Throws an error in debug mode if this [EditableText] is not in a batch
  /// edit.
  void endBatchEdit() {
    _batchEditDepth -= 1;
    assert(
      _batchEditDepth >= 0,
      'Unbalanced call to endBatchEdit: beginBatchEdit must be called first.',
    );
    _updateRemoteEditingValueIfNeeded();
  }

  void _updateRemoteEditingValueIfNeeded() {
    if (_batchEditDepth > 0 || !_hasInputConnection) {
      return;
    }
    final TextEditingValue localValue = _value;
    if (localValue == _lastKnownRemoteTextEditingValue) {
      return;
    }
    _textInputConnection!.setEditingState(localValue);
    _lastKnownRemoteTextEditingValue = localValue;
  }

  TextEditingValue get _value => widget.controller.value;
  set _value(TextEditingValue value) {
    widget.controller.value = value;
  }

  bool get _hasFocus => widget.focusNode.hasFocus;
  bool get _isMultiline => widget.maxLines != 1;

  // Finds the closest scroll offset to the current scroll offset that fully
  // reveals the given caret rect. If the given rect's main axis extent is too
  // large to be fully revealed in `renderEditable`, it will be centered along
  // the main axis.
  //
  // If this is a multiline EditableText (which means the Editable can only
  // scroll vertically), the given rect's height will first be extended to match
  // `renderEditable.preferredLineHeight`, before the target scroll offset is
  // calculated.
  RevealedOffset _getOffsetToRevealCaret(Rect rect) {
    if (!_scrollController.position.allowImplicitScrolling) {
      return RevealedOffset(offset: _scrollController.offset, rect: rect);
    }

    final Size editableSize = renderEditable.size;
    final double additionalOffset;
    final Offset unitOffset;

    if (!_isMultiline) {
      additionalOffset = rect.width >= editableSize.width
        // Center `rect` if it's oversized.
        ? editableSize.width / 2 - rect.center.dx
        // Valid additional offsets range from (rect.right - size.width)
        // to (rect.left). Pick the closest one if out of range.
        : clampDouble(0.0, rect.right - editableSize.width, rect.left);
      unitOffset = const Offset(1, 0);
    } else {
      // The caret is vertically centered within the line. Expand the caret's
      // height so that it spans the line because we're going to ensure that the
      // entire expanded caret is scrolled into view.
      final Rect expandedRect = Rect.fromCenter(
        center: rect.center,
        width: rect.width,
        height: math.max(rect.height, renderEditable.preferredLineHeight),
      );

      additionalOffset = expandedRect.height >= editableSize.height
        ? editableSize.height / 2 - expandedRect.center.dy
        : clampDouble(0.0, expandedRect.bottom - editableSize.height, expandedRect.top);
      unitOffset = const Offset(0, 1);
    }

    // No overscrolling when encountering tall fonts/scripts that extend past
    // the ascent.
    final double targetOffset = clampDouble(
      additionalOffset + _scrollController.offset,
      _scrollController.position.minScrollExtent,
      _scrollController.position.maxScrollExtent,
    );

    final double offsetDelta = _scrollController.offset - targetOffset;
    return RevealedOffset(rect: rect.shift(unitOffset * offsetDelta), offset: targetOffset);
  }

  /// Whether to send the autofill information to the autofill service. True by
  /// default.
  bool get _needsAutofill => _effectiveAutofillClient.textInputConfiguration.autofillConfiguration.enabled;

  void _openInputConnection() {
    if (!_shouldCreateInputConnection) {
      return;
    }
    if (!_hasInputConnection) {
      final TextEditingValue localValue = _value;

      // When _needsAutofill == true && currentAutofillScope == null, autofill
      // is allowed but saving the user input from the text field is
      // discouraged.
      //
      // In case the autofillScope changes from a non-null value to null, or
      // _needsAutofill changes to false from true, the platform needs to be
      // notified to exclude this field from the autofill context. So we need to
      // provide the autofillId.
      _textInputConnection = _needsAutofill && currentAutofillScope != null
        ? currentAutofillScope!.attach(this, _effectiveAutofillClient.textInputConfiguration)
        : TextInput.attach(this, _effectiveAutofillClient.textInputConfiguration);
      _updateSizeAndTransform();
      _schedulePeriodicPostFrameCallbacks();
      _textInputConnection!
        ..setStyle(
          fontFamily: _style.fontFamily,
          fontSize: _style.fontSize,
          fontWeight: _style.fontWeight,
          textDirection: _textDirection,
          textAlign: widget.textAlign,
        )
        ..setEditingState(localValue)
        ..show();
      if (_needsAutofill) {
        // Request autofill AFTER the size and the transform have been sent to
        // the platform text input plugin.
        _textInputConnection!.requestAutofill();
      }