// 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:ui' as ui show BoxHeightStyle, BoxWidthStyle;

import 'package:flutter/cupertino.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/gestures.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter/services.dart';

import 'adaptive_text_selection_toolbar.dart';
import 'color_scheme.dart';
import 'colors.dart';
import 'debug.dart';
import 'desktop_text_selection.dart';
import 'feedback.dart';
import 'input_decorator.dart';
import 'magnifier.dart';
import 'material_localizations.dart';
import 'material_state.dart';
import 'selectable_text.dart' show iOSHorizontalOffset;
import 'spell_check_suggestions_toolbar.dart';
import 'text_selection.dart';
import 'theme.dart';

export 'package:flutter/services.dart' show SmartDashesType, SmartQuotesType, TextCapitalization, TextInputAction, TextInputType;

// Examples can assume:
// late BuildContext context;
// late FocusNode myFocusNode;

/// Signature for the [TextField.buildCounter] callback.
typedef InputCounterWidgetBuilder = Widget? Function(
  /// The build context for the TextField.
  BuildContext context, {
  /// The length of the string currently in the input.
  required int currentLength,
  /// The maximum string length that can be entered into the TextField.
  required int? maxLength,
  /// Whether or not the TextField is currently focused. Mainly provided for
  /// the [liveRegion] parameter in the [Semantics] widget for accessibility.
  required bool isFocused,
});

class _TextFieldSelectionGestureDetectorBuilder extends TextSelectionGestureDetectorBuilder {
  _TextFieldSelectionGestureDetectorBuilder({
    required _TextFieldState state,
  }) : _state = state,
       super(delegate: state);

  final _TextFieldState _state;

  @override
  void onForcePressStart(ForcePressDetails details) {
    super.onForcePressStart(details);
    if (delegate.selectionEnabled && shouldShowSelectionToolbar) {
      editableText.showToolbar();
    }
  }

  @override
  void onForcePressEnd(ForcePressDetails details) {
    // Not required.
  }

  @override
  void onSingleTapUp(TapDragUpDetails details) {
    super.onSingleTapUp(details);
    _state._requestKeyboard();
    _state.widget.onTap?.call();
  }

  @override
  void onSingleLongTapStart(LongPressStartDetails details) {
    super.onSingleLongTapStart(details);
    if (delegate.selectionEnabled) {
      switch (Theme.of(_state.context).platform) {
        case TargetPlatform.iOS:
        case TargetPlatform.macOS:
          break;
        case TargetPlatform.android:
        case TargetPlatform.fuchsia:
        case TargetPlatform.linux:
        case TargetPlatform.windows:
          Feedback.forLongPress(_state.context);
      }
    }
  }
}

/// A Material Design text field.
///
/// A text field lets the user enter text, either with hardware keyboard or with
/// an onscreen keyboard.
///
/// The text field calls the [onChanged] callback whenever the user changes the
/// text in the field. If the user indicates that they are done typing in the
/// field (e.g., by pressing a button on the soft keyboard), the text field
/// calls the [onSubmitted] callback.
///
/// To control the text that is displayed in the text field, use the
/// [controller]. For example, to set the initial value of the text field, use
/// a [controller] that already contains some text. The [controller] can also
/// control the selection and composing region (and to observe changes to the
/// text, selection, and composing region).
///
/// By default, a text field has a [decoration] that draws a divider below the
/// text field. You can use the [decoration] property to control the decoration,
/// for example by adding a label or an icon. If you set the [decoration]
/// property to null, the decoration will be removed entirely, including the
/// extra padding introduced by the decoration to save space for the labels.
///
/// If [decoration] is non-null (which is the default), the text field requires
/// one of its ancestors to be a [Material] widget.
///
/// To integrate the [TextField] into a [Form] with other [FormField] widgets,
/// consider using [TextFormField].
///
/// {@template flutter.material.textfield.wantKeepAlive}
/// When the widget has focus, it will prevent itself from disposing via its
/// underlying [EditableText]'s [AutomaticKeepAliveClientMixin.wantKeepAlive] in
/// order to avoid losing the selection. Removing the focus will allow it to be
/// disposed.
/// {@endtemplate}
///
/// Remember to call [TextEditingController.dispose] of the [TextEditingController]
/// when it is no longer needed. This will ensure we discard any resources used
/// by the object.
///
/// ## Obscured Input
///
/// {@tool dartpad}
/// This example shows how to create a [TextField] that will obscure input. The
/// [InputDecoration] surrounds the field in a border using [OutlineInputBorder]
/// and adds a label.
///
/// ** See code in examples/api/lib/material/text_field/text_field.0.dart **
/// {@end-tool}
///
/// ## Reading values
///
/// A common way to read a value from a TextField is to use the [onSubmitted]
/// callback. This callback is applied to the text field's current value when
/// the user finishes editing.
///
/// {@tool dartpad}
/// This sample shows how to get a value from a TextField via the [onSubmitted]
/// callback.
///
/// ** See code in examples/api/lib/material/text_field/text_field.1.dart **
/// {@end-tool}
///
/// {@macro flutter.widgets.EditableText.lifeCycle}
///
/// For most applications the [onSubmitted] callback will be sufficient for
/// reacting to user input.
///
/// The [onEditingComplete] callback also runs when the user finishes editing.
/// It's different from [onSubmitted] because it has a default value which
/// updates the text controller and yields the keyboard focus. Applications that
/// require different behavior can override the default [onEditingComplete]
/// callback.
///
/// Keep in mind you can also always read the current string from a TextField's
/// [TextEditingController] using [TextEditingController.text].
///
/// ## Handling emojis and other complex characters
/// {@macro flutter.widgets.EditableText.onChanged}
///
/// In the live Dartpad example above, try typing the emoji 👨‍👩‍👦
/// into the field and submitting. Because the example code measures the length
/// with `value.characters.length`, the emoji is correctly counted as a single
/// character.
///
/// {@macro flutter.widgets.editableText.showCaretOnScreen}
///
/// {@macro flutter.widgets.editableText.accessibility}
///
/// See also:
///
///  * [TextFormField], which integrates with the [Form] widget.
///  * [InputDecorator], which shows the labels and other visual elements that
///    surround the actual text editing widget.
///  * [EditableText], which is the raw text editing control at the heart of a
///    [TextField]. The [EditableText] widget is rarely used directly unless
///    you are implementing an entirely different design language, such as
///    Cupertino.
///  * <https://material.io/design/components/text-fields.html>
///  * Cookbook: [Create and style a text field](https://flutter.dev/docs/cookbook/forms/text-input)
///  * Cookbook: [Handle changes to a text field](https://flutter.dev/docs/cookbook/forms/text-field-changes)
///  * Cookbook: [Retrieve the value of a text field](https://flutter.dev/docs/cookbook/forms/retrieve-input)
///  * Cookbook: [Focus and text fields](https://flutter.dev/docs/cookbook/forms/focus)
class TextField extends StatefulWidget {
  /// Creates a Material Design text field.
  ///
  /// If [decoration] is non-null (which is the default), the text field requires
  /// one of its ancestors to be a [Material] widget.
  ///
  /// To remove the decoration entirely (including the extra padding introduced
  /// by the decoration to save space for the labels), set the [decoration] to
  /// null.
  ///
  /// 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 not be zero.
  ///
  /// The [maxLength] property is set to null by default, which means the
  /// number of characters allowed in the text field is not restricted. If
  /// [maxLength] is set a character counter will be displayed below the
  /// field showing how many characters have been entered. If the value is
  /// set to a positive integer it will also display the maximum allowed
  /// number of characters to be entered. If the value is set to
  /// [TextField.noMaxLength] then only the current length is displayed.
  ///
  /// After [maxLength] characters have been input, additional input
  /// is ignored, unless [maxLengthEnforcement] is set to
  /// [MaxLengthEnforcement.none].
  /// The text field enforces the length with a [LengthLimitingTextInputFormatter],
  /// which is evaluated after the supplied [inputFormatters], if any.
  /// The [maxLength] value must be either null or greater than zero.
  ///
  /// If [maxLengthEnforcement] is set to [MaxLengthEnforcement.none], then more
  /// than [maxLength] characters may be entered, and the error counter and
  /// divider will switch to the [decoration].errorStyle when the limit is
  /// exceeded.
  ///
  /// The text cursor is not shown if [showCursor] is false or if [showCursor]
  /// is null (the default) and [readOnly] is true.
  ///
  /// The [selectionHeightStyle] and [selectionWidthStyle] properties allow
  /// changing the shape of the selection highlighting. These properties default
  /// to [ui.BoxHeightStyle.tight] and [ui.BoxWidthStyle.tight] respectively and
  /// must not be null.
  ///
  /// The [textAlign], [autofocus], [obscureText], [readOnly], [autocorrect],
  /// [scrollPadding], [maxLines], [maxLength], [selectionHeightStyle],
  /// [selectionWidthStyle], [enableSuggestions], and
  /// [enableIMEPersonalizedLearning] arguments must not be null.
  ///
  /// See also:
  ///
  ///  * [maxLength], which discusses the precise meaning of "number of
  ///    characters" and how it may differ from the intuitive meaning.
  const TextField({
    super.key,
    this.controller,
    this.focusNode,
    this.undoController,
    this.decoration = const InputDecoration(),
    TextInputType? keyboardType,
    this.textInputAction,
    this.textCapitalization = TextCapitalization.none,
    this.style,
    this.strutStyle,
    this.textAlign = TextAlign.start,
    this.textAlignVertical,
    this.textDirection,
    this.readOnly = false,
    @Deprecated(
      'Use `contextMenuBuilder` instead. '
      'This feature was deprecated after v3.3.0-0.5.pre.',
    )
    this.toolbarOptions,
    this.showCursor,
    this.autofocus = false,
    this.obscuringCharacter = '•',
    this.obscureText = false,
    this.autocorrect = true,
    SmartDashesType? smartDashesType,
    SmartQuotesType? smartQuotesType,
    this.enableSuggestions = true,
    this.maxLines = 1,
    this.minLines,
    this.expands = false,
    this.maxLength,
    this.maxLengthEnforcement,
    this.onChanged,
    this.onEditingComplete,
    this.onSubmitted,
    this.onAppPrivateCommand,
    this.inputFormatters,
    this.enabled,
    this.cursorWidth = 2.0,
    this.cursorHeight,
    this.cursorRadius,
    this.cursorOpacityAnimates,
    this.cursorColor,
    this.selectionHeightStyle = ui.BoxHeightStyle.tight,
    this.selectionWidthStyle = ui.BoxWidthStyle.tight,
    this.keyboardAppearance,
    this.scrollPadding = const EdgeInsets.all(20.0),
    this.dragStartBehavior = DragStartBehavior.start,
    bool? enableInteractiveSelection,
    this.selectionControls,
    this.onTap,
    this.onTapOutside,
    this.mouseCursor,
    this.buildCounter,
    this.scrollController,
    this.scrollPhysics,
    this.autofillHints = const <String>[],
    this.contentInsertionConfiguration,
    this.clipBehavior = Clip.hardEdge,
    this.restorationId,
    this.scribbleEnabled = true,
    this.enableIMEPersonalizedLearning = true,
    this.contextMenuBuilder = _defaultContextMenuBuilder,
    this.canRequestFocus = true,
    this.spellCheckConfiguration,
    this.magnifierConfiguration,
  }) : assert(obscuringCharacter.length == 1),
       smartDashesType = smartDashesType ?? (obscureText ? SmartDashesType.disabled : SmartDashesType.enabled),
       smartQuotesType = smartQuotesType ?? (obscureText ? SmartQuotesType.disabled : SmartQuotesType.enabled),
       assert(maxLines == null || maxLines > 0),
       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.'),
       assert(maxLength == null || maxLength == TextField.noMaxLength || maxLength > 0),
       // Assert the following instead of setting it directly to avoid surprising the user by silently changing the value they set.
       assert(
         !identical(textInputAction, TextInputAction.newline) ||
         maxLines == 1 ||
         !identical(keyboardType, TextInputType.text),
         'Use keyboardType TextInputType.multiline when using TextInputAction.newline on a multiline TextField.',
       ),
       keyboardType = keyboardType ?? (maxLines == 1 ? TextInputType.text : TextInputType.multiline),
       enableInteractiveSelection = enableInteractiveSelection ?? (!readOnly || !obscureText);

  /// {@macro flutter.widgets.magnifier.TextMagnifierConfiguration.intro}
  ///
  /// {@macro flutter.widgets.magnifier.intro}
  ///
  /// {@macro flutter.widgets.magnifier.TextMagnifierConfiguration.details}
  ///
  /// By default, builds a [CupertinoTextMagnifier] on iOS and [TextMagnifier]
  /// on Android, and builds nothing on all other platforms. If it is desired to
  /// suppress the magnifier, consider passing [TextMagnifierConfiguration.disabled].
  ///
  /// {@tool dartpad}
  /// This sample demonstrates how to customize the magnifier that this text field uses.
  ///
  /// ** See code in examples/api/lib/widgets/text_magnifier/text_magnifier.0.dart **
  /// {@end-tool}
  final TextMagnifierConfiguration? magnifierConfiguration;

  /// Controls the text being edited.
  ///
  /// If null, this widget will create its own [TextEditingController].
  final TextEditingController? controller;

  /// Defines the keyboard focus for this widget.
  ///
  /// The [focusNode] is a long-lived object that's typically managed by a
  /// [StatefulWidget] parent. See [FocusNode] for more information.
  ///
  /// To give the keyboard focus to this widget, provide a [focusNode] and then
  /// use the current [FocusScope] to request the focus:
  ///
  /// ```dart
  /// FocusScope.of(context).requestFocus(myFocusNode);
  /// ```
  ///
  /// This happens automatically when the widget is tapped.
  ///
  /// To be notified when the widget gains or loses the focus, add a listener
  /// to the [focusNode]:
  ///
  /// ```dart
  /// myFocusNode.addListener(() { print(myFocusNode.hasFocus); });
  /// ```
  ///
  /// If null, this widget will create its own [FocusNode].
  ///
  /// ## Keyboard
  ///
  /// Requesting the focus will typically cause the keyboard to be shown
  /// if it's not showing already.
  ///
  /// On Android, the user can hide the keyboard - without changing the focus -
  /// with the system back button. They can restore the keyboard's visibility
  /// by tapping on a text field. The user might hide the keyboard and
  /// switch to a physical keyboard, or they might just need to get it
  /// out of the way for a moment, to expose something it's
  /// obscuring. In this case requesting the focus again will not
  /// cause the focus to change, and will not make the keyboard visible.
  ///
  /// This widget builds an [EditableText] and will ensure that the keyboard is
  /// showing when it is tapped by calling [EditableTextState.requestKeyboard()].
  final FocusNode? focusNode;

  /// The decoration to show around the text field.
  ///
  /// By default, draws a horizontal line under the text field but can be
  /// configured to show an icon, label, hint text, and error text.
  ///
  /// Specify null to remove the decoration entirely (including the
  /// extra padding introduced by the decoration to save space for the labels).
  final InputDecoration? decoration;

  /// {@macro flutter.widgets.editableText.keyboardType}
  final TextInputType keyboardType;

  /// The type of action button to use for the keyboard.
  ///
  /// Defaults to [TextInputAction.newline] if [keyboardType] is
  /// [TextInputType.multiline] and [TextInputAction.done] otherwise.
  final TextInputAction? textInputAction;

  /// {@macro flutter.widgets.editableText.textCapitalization}
  final TextCapitalization textCapitalization;

  /// The style to use for the text being edited.
  ///
  /// This text style is also used as the base style for the [decoration].
  ///
  /// If null, defaults to the `titleMedium` text style from the current [Theme].
  final TextStyle? style;

  /// {@macro flutter.widgets.editableText.strutStyle}
  final StrutStyle? strutStyle;

  /// {@macro flutter.widgets.editableText.textAlign}
  final TextAlign textAlign;

  /// {@macro flutter.material.InputDecorator.textAlignVertical}
  final TextAlignVertical? textAlignVertical;

  /// {@macro flutter.widgets.editableText.textDirection}
  final TextDirection? textDirection;

  /// {@macro flutter.widgets.editableText.autofocus}
  final bool autofocus;

  /// {@macro flutter.widgets.editableText.obscuringCharacter}
  final String obscuringCharacter;

  /// {@macro flutter.widgets.editableText.obscureText}
  final bool obscureText;

  /// {@macro flutter.widgets.editableText.autocorrect}
  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;

  /// {@macro flutter.widgets.editableText.maxLines}
  ///  * [expands], which determines whether the field should fill the height of
  ///    its parent.
  final int? maxLines;

  /// {@macro flutter.widgets.editableText.minLines}
  ///  * [expands], which determines whether the field should fill the height of
  ///    its parent.
  final int? minLines;

  /// {@macro flutter.widgets.editableText.expands}
  final bool expands;

  /// {@macro flutter.widgets.editableText.readOnly}
  final bool readOnly;

  /// Configuration of toolbar options.
  ///
  /// If not set, select all and paste will default to be enabled. Copy and cut
  /// will be disabled if [obscureText] is true. If [readOnly] is true,
  /// paste and cut will be disabled regardless.
  @Deprecated(
    'Use `contextMenuBuilder` instead. '
    'This feature was deprecated after v3.3.0-0.5.pre.',
  )
  final ToolbarOptions? toolbarOptions;

  /// {@macro flutter.widgets.editableText.showCursor}
  final bool? showCursor;

  /// If [maxLength] is set to this value, only the "current input length"
  /// part of the character counter is shown.
  static const int noMaxLength = -1;

  /// The maximum number of characters (Unicode grapheme clusters) to allow in
  /// the text field.
  ///
  /// If set, a character counter will be displayed below the
  /// field showing how many characters have been entered. If set to a number
  /// greater than 0, it will also display the maximum number allowed. If set
  /// to [TextField.noMaxLength] then only the current character count is displayed.
  ///
  /// After [maxLength] characters have been input, additional input
  /// is ignored, unless [maxLengthEnforcement] is set to
  /// [MaxLengthEnforcement.none].
  ///
  /// The text field enforces the length with a [LengthLimitingTextInputFormatter],
  /// which is evaluated after the supplied [inputFormatters], if any.
  ///
  /// This value must be either null, [TextField.noMaxLength], or greater than 0.
  /// If null (the default) then there is no limit to the number of characters
  /// that can be entered. If set to [TextField.noMaxLength], then no limit will
  /// be enforced, but the number of characters entered will still be displayed.
  ///
  /// Whitespace characters (e.g. newline, space, tab) are included in the
  /// character count.
  ///
  /// If [maxLengthEnforcement] is [MaxLengthEnforcement.none], then more than
  /// [maxLength] characters may be entered, but the error counter and divider
  /// will switch to the [decoration]'s [InputDecoration.errorStyle] when the
  /// limit is exceeded.
  ///
  /// {@macro flutter.services.lengthLimitingTextInputFormatter.maxLength}
  final int? maxLength;

  /// Determines how the [maxLength] limit should be enforced.
  ///
  /// {@macro flutter.services.textFormatter.effectiveMaxLengthEnforcement}
  ///
  /// {@macro flutter.services.textFormatter.maxLengthEnforcement}
  final MaxLengthEnforcement? maxLengthEnforcement;

  /// {@macro flutter.widgets.editableText.onChanged}
  ///
  /// See also:
  ///
  ///  * [inputFormatters], which are called before [onChanged]
  ///    runs and can validate and change ("format") the input value.
  ///  * [onEditingComplete], [onSubmitted]:
  ///    which are more specialized input change notifications.
  final ValueChanged<String>? onChanged;

  /// {@macro flutter.widgets.editableText.onEditingComplete}
  final VoidCallback? onEditingComplete;

  /// {@macro flutter.widgets.editableText.onSubmitted}
  ///
  /// See also:
  ///
  ///  * [TextInputAction.next] and [TextInputAction.previous], which
  ///    automatically shift the focus to the next/previous focusable item when
  ///    the user is done editing.
  final ValueChanged<String>? onSubmitted;

  /// {@macro flutter.widgets.editableText.onAppPrivateCommand}
  final AppPrivateCommandCallback? onAppPrivateCommand;

  /// {@macro flutter.widgets.editableText.inputFormatters}
  final List<TextInputFormatter>? inputFormatters;

  /// If false the text field is "disabled": it ignores taps and its
  /// [decoration] is rendered in grey.
  ///
  /// If non-null this property overrides the [decoration]'s
  /// [InputDecoration.enabled] property.
  final bool? enabled;

  /// {@macro flutter.widgets.editableText.cursorWidth}
  final double cursorWidth;

  /// {@macro flutter.widgets.editableText.cursorHeight}
  final double? cursorHeight;

  /// {@macro flutter.widgets.editableText.cursorRadius}
  final Radius? cursorRadius;

  /// {@macro flutter.widgets.editableText.cursorOpacityAnimates}
  final bool? cursorOpacityAnimates;

  /// The color of the cursor.
  ///
  /// The cursor indicates the current location of text insertion point in
  /// the field.
  ///
  /// If this is null it will default to the ambient
  /// [DefaultSelectionStyle.cursorColor]. If that is null, and the
  /// [ThemeData.platform] is [TargetPlatform.iOS] or [TargetPlatform.macOS]
  /// it will use [CupertinoThemeData.primaryColor]. Otherwise it will use
  /// the value of [ColorScheme.primary] of [ThemeData.colorScheme].
  final Color? cursorColor;

  /// 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.
  ///
  /// If unset, defaults to [ThemeData.brightness].
  final Brightness? keyboardAppearance;

  /// {@macro flutter.widgets.editableText.scrollPadding}
  final EdgeInsets scrollPadding;

  /// {@macro flutter.widgets.editableText.enableInteractiveSelection}
  final bool enableInteractiveSelection;

  /// {@macro flutter.widgets.editableText.selectionControls}
  final TextSelectionControls? selectionControls;

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

  /// {@macro flutter.widgets.editableText.selectionEnabled}
  bool get selectionEnabled => enableInteractiveSelection;

  /// {@template flutter.material.textfield.onTap}
  /// Called for each distinct tap except for every second tap of a double tap.
  ///
  /// The text field builds a [GestureDetector] to handle input events like tap,
  /// to trigger focus requests, to move the caret, adjust the selection, etc.
  /// Handling some of those events by wrapping the text field with a competing
  /// GestureDetector is problematic.
  ///
  /// To unconditionally handle taps, without interfering with the text field's
  /// internal gesture detector, provide this callback.
  ///
  /// If the text field is created with [enabled] false, taps will not be
  /// recognized.
  ///
  /// To be notified when the text field gains or loses the focus, provide a
  /// [focusNode] and add a listener to that.
  ///
  /// To listen to arbitrary pointer events without competing with the
  /// text field's internal gesture detector, use a [Listener].
  /// {@endtemplate}
  final GestureTapCallback? onTap;

  /// {@macro flutter.widgets.editableText.onTapOutside}
  ///
  /// {@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;

  /// The cursor for a mouse pointer when it enters or is hovering over the
  /// widget.
  ///
  /// If [mouseCursor] is a [MaterialStateProperty<MouseCursor>],
  /// [MaterialStateProperty.resolve] is used for the following [MaterialState]s:
  ///
  ///  * [MaterialState.error].
  ///  * [MaterialState.hovered].
  ///  * [MaterialState.focused].
  ///  * [MaterialState.disabled].
  ///
  /// If this property is null, [MaterialStateMouseCursor.textable] will be used.
  ///
  /// The [mouseCursor] is the only property of [TextField] that controls the
  /// appearance of the mouse pointer. All other properties related to "cursor"
  /// stand for the text cursor, which is usually a blinking vertical line at
  /// the editing position.
  final MouseCursor? mouseCursor;

  /// Callback that generates a custom [InputDecoration.counter] widget.
  ///
  /// See [InputCounterWidgetBuilder] for an explanation of the passed in
  /// arguments. The returned widget will be placed below the line in place of
  /// the default widget built when [InputDecoration.counterText] is specified.
  ///
  /// The returned widget will be wrapped in a [Semantics] widget for
  /// accessibility, but it also needs to be accessible itself. For example,
  /// if returning a Text widget, set the [Text.semanticsLabel] property.
  ///
  /// {@tool snippet}
  /// ```dart
  /// Widget counter(
  ///   BuildContext context,
  ///   {
  ///     required int currentLength,
  ///     required int? maxLength,
  ///     required bool isFocused,
  ///   }
  /// ) {
  ///   return Text(
  ///     '$currentLength of $maxLength characters',
  ///     semanticsLabel: 'character count',
  ///   );
  /// }
  /// ```
  /// {@end-tool}
  ///
  /// If buildCounter returns null, then no counter and no Semantics widget will
  /// be created at all.
  final InputCounterWidgetBuilder? buildCounter;

  /// {@macro flutter.widgets.editableText.scrollPhysics}
  final ScrollPhysics? scrollPhysics;

  /// {@macro flutter.widgets.editableText.scrollController}
  final ScrollController? scrollController;

  /// {@macro flutter.widgets.editableText.autofillHints}
  /// {@macro flutter.services.AutofillConfiguration.autofillHints}
  final Iterable<String>? autofillHints;

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

  /// {@template flutter.material.textfield.restorationId}
  /// Restoration ID to save and restore the state of the text field.
  ///
  /// If non-null, the text field will persist and restore its current scroll
  /// offset and - if no [controller] has been provided - the content of the
  /// text field. If a [controller] has been provided, it is the responsibility
  /// of the owner of that controller to persist and restore it, e.g. by using
  /// a [RestorableTextEditingController].
  ///
  /// The state of this widget is persisted in a [RestorationBucket] claimed
  /// from the surrounding [RestorationScope] using the provided restoration ID.
  ///
  /// See also:
  ///
  ///  * [RestorationManager], which explains how state restoration works in
  ///    Flutter.
  /// {@endtemplate}
  final String? restorationId;

  /// {@macro flutter.widgets.editableText.scribbleEnabled}
  final bool scribbleEnabled;

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

  /// {@macro flutter.widgets.editableText.contentInsertionConfiguration}
  final ContentInsertionConfiguration? contentInsertionConfiguration;

  /// {@macro flutter.widgets.EditableText.contextMenuBuilder}
  ///
  /// If not provided, will build a default menu based on the platform.
  ///
  /// See also:
  ///
  ///  * [AdaptiveTextSelectionToolbar], which is built by default.
  final EditableTextContextMenuBuilder? contextMenuBuilder;

  /// Determine whether this text field can request the primary focus.
  ///
  /// Defaults to true. If false, the text field will not request focus
  /// when tapped, or when its context menu is displayed. If false it will not
  /// be possible to move the focus to the text field with tab key.
  final bool canRequestFocus;

  /// {@macro flutter.widgets.undoHistory.controller}
  final UndoHistoryController? undoController;

  static Widget _defaultContextMenuBuilder(BuildContext context, EditableTextState editableTextState) {
    return AdaptiveTextSelectionToolbar.editableText(
      editableTextState: editableTextState,
    );
  }

  /// {@macro flutter.widgets.EditableText.spellCheckConfiguration}
  ///
  /// If [SpellCheckConfiguration.misspelledTextStyle] is not specified in this
  /// configuration, then [materialMisspelledTextStyle] is used by default.
  final SpellCheckConfiguration? spellCheckConfiguration;

  /// The [TextStyle] used to indicate misspelled words in the Material style.
  ///
  /// See also:
  ///  * [SpellCheckConfiguration.misspelledTextStyle], the style configured to
  ///    mark misspelled words with.
  ///  * [CupertinoTextField.cupertinoMisspelledTextStyle], the style configured
  ///    to mark misspelled words with in the Cupertino style.
  static const TextStyle materialMisspelledTextStyle =
    TextStyle(
      decoration: TextDecoration.underline,
      decorationColor: Colors.red,
      decorationStyle: TextDecorationStyle.wavy,
  );

  /// Default builder for the spell check suggestions toolbar in the Material
  /// style.
  ///
  /// See also:
  ///  * [SpellCheckConfiguration.spellCheckSuggestionsToolbarBuilder], the
  ///    builder configured to show a spell check suggestions toolbar.
  ///  * [CupertinoTextField.defaultSpellCheckSuggestionsToolbarBuilder], the builder
  ///    configured to show the Material style spell check suggestions toolbar.
  @visibleForTesting
  static Widget defaultSpellCheckSuggestionsToolbarBuilder(
    BuildContext context,
    EditableTextState editableTextState,
  ) {
    final Offset anchor =
      SpellCheckSuggestionsToolbar.getToolbarAnchor(editableTextState.contextMenuAnchors);
    final List<ContextMenuButtonItem>? buttonItems =
      SpellCheckSuggestionsToolbar.buildButtonItems(context, editableTextState);

    if (buttonItems == null){
      return const SizedBox.shrink();
    }

    return SpellCheckSuggestionsToolbar(
      anchor: anchor,
      buttonItems: buttonItems,
    );
  }

  @override
  State<TextField> createState() => _TextFieldState();

  @override
  void debugFillProperties(DiagnosticPropertiesBuilder properties) {
    super.debugFillProperties(properties);
    properties.add(DiagnosticsProperty<TextEditingController>('controller', controller, defaultValue: null));
    properties.add(DiagnosticsProperty<FocusNode>('focusNode', focusNode, defaultValue: null));
    properties.add(DiagnosticsProperty<UndoHistoryController>('undoController', undoController, defaultValue: null));
    properties.add(DiagnosticsProperty<bool>('enabled', enabled, defaultValue: null));
    properties.add(DiagnosticsProperty<InputDecoration>('decoration', decoration, defaultValue: const InputDecoration()));
    properties.add(DiagnosticsProperty<TextInputType>('keyboardType', keyboardType, defaultValue: TextInputType.text));
    properties.add(DiagnosticsProperty<TextStyle>('style', style, defaultValue: null));
    properties.add(DiagnosticsProperty<bool>('autofocus', autofocus, defaultValue: false));
    properties.add(DiagnosticsProperty<String>('obscuringCharacter', obscuringCharacter, defaultValue: '•'));
    properties.add(DiagnosticsProperty<bool>('obscureText', obscureText, 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));
    properties.add(IntProperty('maxLines', maxLines, defaultValue: 1));
    properties.add(IntProperty('minLines', minLines, defaultValue: null));
    properties.add(DiagnosticsProperty<bool>('expands', expands, defaultValue: false));
    properties.add(IntProperty('maxLength', maxLength, defaultValue: null));
    properties.add(EnumProperty<MaxLengthEnforcement>('maxLengthEnforcement', maxLengthEnforcement, defaultValue: null));
    properties.add(EnumProperty<TextInputAction>('textInputAction', textInputAction, defaultValue: null));
    properties.add(EnumProperty<TextCapitalization>('textCapitalization', textCapitalization, defaultValue: TextCapitalization.none));
    properties.add(EnumProperty<TextAlign>('textAlign', textAlign, defaultValue: TextAlign.start));
    properties.add(DiagnosticsProperty<TextAlignVertical>('textAlignVertical', textAlignVertical, defaultValue: null));
    properties.add(EnumProperty<TextDirection>('textDirection', textDirection, defaultValue: null));
    properties.add(DoubleProperty('cursorWidth', cursorWidth, defaultValue: 2.0));
    properties.add(DoubleProperty('cursorHeight', cursorHeight, defaultValue: null));
    properties.add(DiagnosticsProperty<Radius>('cursorRadius', cursorRadius, defaultValue: null));
    properties.add(DiagnosticsProperty<bool>('cursorOpacityAnimates', cursorOpacityAnimates, defaultValue: null));
    properties.add(ColorProperty('cursorColor', cursorColor, defaultValue: null));
    properties.add(DiagnosticsProperty<Brightness>('keyboardAppearance', keyboardAppearance, defaultValue: null));
    properties.add(DiagnosticsProperty<EdgeInsetsGeometry>('scrollPadding', scrollPadding, defaultValue: const EdgeInsets.all(20.0)));
    properties.add(FlagProperty('selectionEnabled', value: selectionEnabled, defaultValue: true, ifFalse: 'selection disabled'));
    properties.add(DiagnosticsProperty<TextSelectionControls>('selectionControls', selectionControls, defaultValue: null));
    properties.add(DiagnosticsProperty<ScrollController>('scrollController', scrollController, defaultValue: null));
    properties.add(DiagnosticsProperty<ScrollPhysics>('scrollPhysics', scrollPhysics, defaultValue: null));
    properties.add(DiagnosticsProperty<Clip>('clipBehavior', clipBehavior, defaultValue: Clip.hardEdge));
    properties.add(DiagnosticsProperty<bool>('scribbleEnabled', scribbleEnabled, defaultValue: true));
    properties.add(DiagnosticsProperty<bool>('enableIMEPersonalizedLearning', enableIMEPersonalizedLearning, defaultValue: true));
    properties.add(DiagnosticsProperty<SpellCheckConfiguration>('spellCheckConfiguration', spellCheckConfiguration, defaultValue: null));
    properties.add(DiagnosticsProperty<List<String>>('contentCommitMimeTypes', contentInsertionConfiguration?.allowedMimeTypes ?? const <String>[], defaultValue: contentInsertionConfiguration == null ? const <String>[] : kDefaultContentInsertionMimeTypes));
  }
}

class _TextFieldState extends State<TextField> with RestorationMixin implements TextSelectionGestureDetectorBuilderDelegate, AutofillClient {
  RestorableTextEditingController? _controller;
  TextEditingController get _effectiveController => widget.controller ?? _controller!.value;

  FocusNode? _focusNode;
  FocusNode get _effectiveFocusNode => widget.focusNode ?? (_focusNode ??= FocusNode());

  MaxLengthEnforcement get _effectiveMaxLengthEnforcement => widget.maxLengthEnforcement
    ?? LengthLimitingTextInputFormatter.getDefaultMaxLengthEnforcement(Theme.of(context).platform);

  bool _isHovering = false;

  bool get needsCounter => widget.maxLength != null
    && widget.decoration != null
    && widget.decoration!.counterText == null;

  bool _showSelectionHandles = false;

  late _TextFieldSelectionGestureDetectorBuilder _selectionGestureDetectorBuilder;

  // API for TextSelectionGestureDetectorBuilderDelegate.
  @override
  late bool forcePressEnabled;

  @override
  final GlobalKey<EditableTextState> editableTextKey = GlobalKey<EditableTextState>();

  @override
  bool get selectionEnabled => widget.selectionEnabled;
  // End of API for TextSelectionGestureDetectorBuilderDelegate.

  bool get _isEnabled =>  widget.enabled ?? widget.decoration?.enabled ?? true;

  int get _currentLength => _effectiveController.value.text.characters.length;

  bool get _hasIntrinsicError => widget.maxLength != null && widget.maxLength! > 0 && _effectiveController.value.text.characters.length > widget.maxLength!;

  bool get _hasError => widget.decoration?.errorText != null || _hasIntrinsicError;

  Color get _errorColor => widget.decoration?.errorStyle?.color ?? Theme.of(context).colorScheme.error;

  InputDecoration _getEffectiveDecoration() {
    final MaterialLocalizations localizations = MaterialLocalizations.of(context);
    final ThemeData themeData = Theme.of(context);
    final InputDecoration effectiveDecoration = (widget.decoration ?? const InputDecoration())
      .applyDefaults(themeData.inputDecorationTheme)
      .copyWith(
        enabled: _isEnabled,
        hintMaxLines: widget.decoration?.hintMaxLines ?? widget.maxLines,
      );

    // No need to build anything if counter or counterText were given directly.
    if (effectiveDecoration.counter != null || effectiveDecoration.counterText != null) {
      return effectiveDecoration;
    }

    // If buildCounter was provided, use it to generate a counter widget.
    Widget? counter;
    final int currentLength = _currentLength;
    if (effectiveDecoration.counter == null
        && effectiveDecoration.counterText == null
        && widget.buildCounter != null) {
      final bool isFocused = _effectiveFocusNode.hasFocus;
      final Widget? builtCounter = widget.buildCounter!(
        context,
        currentLength: currentLength,
        maxLength: widget.maxLength,
        isFocused: isFocused,
      );
      // If buildCounter returns null, don't add a counter widget to the field.
      if (builtCounter != null) {
        counter = Semantics(
          container: true,
          liveRegion: isFocused,
          child: builtCounter,
        );
      }
      return effectiveDecoration.copyWith(counter: counter);
    }

    if (widget.maxLength == null) {
      return effectiveDecoration;
    } // No counter widget

    String counterText = '$currentLength';
    String semanticCounterText = '';

    // Handle a real maxLength (positive number)
    if (widget.maxLength! > 0) {
      // Show the maxLength in the counter
      counterText += '/${widget.maxLength}';
      final int remaining = (widget.maxLength! - currentLength).clamp(0, widget.maxLength!); // ignore_clamp_double_lint
      semanticCounterText = localizations.remainingTextFieldCharacterCount(remaining);
    }

    if (_hasIntrinsicError) {
      return effectiveDecoration.copyWith(
        errorText: effectiveDecoration.errorText ?? '',
        counterStyle: effectiveDecoration.errorStyle
          ?? (themeData.useMaterial3 ? _m3CounterErrorStyle(context): _m2CounterErrorStyle(context)),
        counterText: counterText,
        semanticCounterText: semanticCounterText,
      );
    }

    return effectiveDecoration.copyWith(
      counterText: counterText,
      semanticCounterText: semanticCounterText,
    );
  }

  @override
  void initState() {
    super.initState();
    _selectionGestureDetectorBuilder = _TextFieldSelectionGestureDetectorBuilder(state: this);
    if (widget.controller == null) {
      _createLocalController();
    }
    _effectiveFocusNode.canRequestFocus = widget.canRequestFocus && _isEnabled;
    _effectiveFocusNode.addListener(_handleFocusChanged);
  }

  bool get _canRequestFocus {
    final NavigationMode mode = MediaQuery.maybeNavigationModeOf(context) ?? NavigationMode.traditional;
    switch (mode) {
      case NavigationMode.traditional:
        return widget.canRequestFocus && _isEnabled;
      case NavigationMode.directional:
        return true;
    }
  }

  @override
  void didChangeDependencies() {
    super.didChangeDependencies();
    _effectiveFocusNode.canRequestFocus = _canRequestFocus;
  }

  @override
  void didUpdateWidget(TextField oldWidget) {
    super.didUpdateWidget(oldWidget);
    if (widget.controller == null && oldWidget.controller != null) {
      _createLocalController(oldWidget.controller!.value);
    } else if (widget.controller != null && oldWidget.controller == null) {
      unregisterFromRestoration(_controller!);
      _controller!.dispose();
      _controller = null;
    }

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

    _effectiveFocusNode.canRequestFocus = _canRequestFocus;

    if (_effectiveFocusNode.hasFocus && widget.readOnly != oldWidget.readOnly && _isEnabled) {
      if(_effectiveController.selection.isCollapsed) {
        _showSelectionHandles = !widget.readOnly;
      }
    }
  }

  @override
  void restoreState(RestorationBucket? oldBucket, bool initialRestore) {
    if (_controller != null) {
      _registerController();
    }
  }

  void _registerController() {
    assert(_controller != null);
    registerForRestoration(_controller!, 'controller');
  }

  void _createLocalController([TextEditingValue? value]) {
    assert(_controller == null);
    _controller = value == null
        ? RestorableTextEditingController()
        : RestorableTextEditingController.fromValue(value);
    if (!restorePending) {
      _registerController();
    }
  }

  @override
  String? get restorationId => widget.restorationId;

  @override
  void dispose() {
    _effectiveFocusNode.removeListener(_handleFocusChanged);
    _focusNode?.dispose();
    _controller?.dispose();
    super.dispose();
  }

  EditableTextState? get _editableText => editableTextKey.currentState;

  void _requestKeyboard() {
    _editableText?.requestKeyboard();
  }

  bool _shouldShowSelectionHandles(SelectionChangedCause? cause) {
    // When the text field is activated by something that doesn't trigger the
    // selection overlay, we shouldn't show the handles either.
    if (!_selectionGestureDetectorBuilder.shouldShowSelectionToolbar) {
      return false;
    }

    if (cause == SelectionChangedCause.keyboard) {
      return false;
    }

    if (widget.readOnly && _effectiveController.selection.isCollapsed) {
      return false;
    }

    if (!_isEnabled) {
      return false;
    }

    if (cause == SelectionChangedCause.longPress || cause == SelectionChangedCause.scribble) {
      return true;
    }

    if (_effectiveController.text.isNotEmpty) {
      return true;
    }

    return false;
  }

  void _handleFocusChanged() {
    setState(() {
      // Rebuild the widget on focus change to show/hide the text selection
      // highlight.
    });
  }

  void _handleSelectionChanged(TextSelection selection, SelectionChangedCause? cause) {
    final bool willShowSelectionHandles = _shouldShowSelectionHandles(cause);
    if (willShowSelectionHandles != _showSelectionHandles) {
      setState(() {
        _showSelectionHandles = willShowSelectionHandles;
      });
    }

    switch (Theme.of(context).platform) {
      case TargetPlatform.iOS:
      case TargetPlatform.macOS:
      case TargetPlatform.linux:
      case TargetPlatform.windows:
      case TargetPlatform.fuchsia:
      case TargetPlatform.android:
        if (cause == SelectionChangedCause.longPress) {
          _editableText?.bringIntoView(selection.extent);
        }
    }

    switch (Theme.of(context).platform) {
      case TargetPlatform.iOS:
      case TargetPlatform.fuchsia:
      case TargetPlatform.android:
        break;
      case TargetPlatform.macOS:
      case TargetPlatform.linux:
      case TargetPlatform.windows:
        if (cause == SelectionChangedCause.drag) {
          _editableText?.hideToolbar();
        }
    }
  }

  /// Toggle the toolbar when a selection handle is tapped.
  void _handleSelectionHandleTapped() {
    if (_effectiveController.selection.isCollapsed) {
      _editableText!.toggleToolbar();
    }
  }

  void _handleHover(bool hovering) {
    if (hovering != _isHovering) {
      setState(() {
        _isHovering = hovering;
      });
    }
  }

  // AutofillClient implementation start.
  @override
  String get autofillId => _editableText!.autofillId;

  @override
  void autofill(TextEditingValue newEditingValue) => _editableText!.autofill(newEditingValue);

  @override
  TextInputConfiguration get textInputConfiguration {
    final List<String>? autofillHints = widget.autofillHints?.toList(growable: false);
    final AutofillConfiguration autofillConfiguration = autofillHints != null
      ? AutofillConfiguration(
          uniqueIdentifier: autofillId,
          autofillHints: autofillHints,
          currentEditingValue: _effectiveController.value,
          hintText: (widget.decoration ?? const InputDecoration()).hintText,
        )
      : AutofillConfiguration.disabled;

    return _editableText!.textInputConfiguration.copyWith(autofillConfiguration: autofillConfiguration);
  }
  // AutofillClient implementation end.

  Set<MaterialState> get _materialState {
    return <MaterialState>{
      if (!_isEnabled) MaterialState.disabled,
      if (_isHovering) MaterialState.hovered,
      if (_effectiveFocusNode.hasFocus) MaterialState.focused,
      if (_hasError) MaterialState.error,
    };
  }

  TextStyle _getInputStyleForState(TextStyle style) {
    final ThemeData theme = Theme.of(context);
    final TextStyle stateStyle = MaterialStateProperty.resolveAs(theme.useMaterial3 ? _m3StateInputStyle(context)! : _m2StateInputStyle(context)!, _materialState);
    final TextStyle providedStyle = MaterialStateProperty.resolveAs(style, _materialState);
    return providedStyle.merge(stateStyle);
  }

  @override
  Widget build(BuildContext context) {
    assert(debugCheckHasMaterial(context));
    assert(debugCheckHasMaterialLocalizations(context));
    assert(debugCheckHasDirectionality(context));
    assert(
      !(widget.style != null && widget.style!.inherit == false &&
        (widget.style!.fontSize == null || widget.style!.textBaseline == null)),
      'inherit false style must supply fontSize and textBaseline',
    );

    final ThemeData theme = Theme.of(context);
    final DefaultSelectionStyle selectionStyle = DefaultSelectionStyle.of(context);
    final TextStyle style = _getInputStyleForState(theme.useMaterial3 ? _m3InputStyle(context) : theme.textTheme.titleMedium!).merge(widget.style);
    final Brightness keyboardAppearance = widget.keyboardAppearance ?? theme.brightness;
    final TextEditingController controller = _effectiveController;
    final FocusNode focusNode = _effectiveFocusNode;
    final List<TextInputFormatter> formatters = <TextInputFormatter>[
      ...?widget.inputFormatters,
      if (widget.maxLength != null)
        LengthLimitingTextInputFormatter(
          widget.maxLength,
          maxLengthEnforcement: _effectiveMaxLengthEnforcement,
        ),
    ];

    // Set configuration as disabled if not otherwise specified. If specified,
    // ensure that configuration uses Material text style for misspelled words
    // unless a custom style is specified.
    final SpellCheckConfiguration spellCheckConfiguration =
      widget.spellCheckConfiguration != null &&
      widget.spellCheckConfiguration != const SpellCheckConfiguration.disabled()
        ? widget.spellCheckConfiguration!.copyWith(
            misspelledTextStyle: widget.spellCheckConfiguration!.misspelledTextStyle
              ?? TextField.materialMisspelledTextStyle,
            spellCheckSuggestionsToolbarBuilder:
              widget.spellCheckConfiguration!.spellCheckSuggestionsToolbarBuilder
                ?? TextField.defaultSpellCheckSuggestionsToolbarBuilder,
          )
        : const SpellCheckConfiguration.disabled();

    TextSelectionControls? textSelectionControls = widget.selectionControls;
    final bool paintCursorAboveText;
    bool? cursorOpacityAnimates = widget.cursorOpacityAnimates;
    Offset? cursorOffset;
    final Color cursorColor;
    final Color selectionColor;
    Color? autocorrectionTextRectColor;
    Radius? cursorRadius = widget.cursorRadius;
    VoidCallback? handleDidGainAccessibilityFocus;

    switch (theme.platform) {
      case TargetPlatform.iOS:
        final CupertinoThemeData cupertinoTheme = CupertinoTheme.of(context);
        forcePressEnabled = true;
        textSelectionControls ??= cupertinoTextSelectionHandleControls;
        paintCursorAboveText = true;
        cursorOpacityAnimates ??= true;
        cursorColor = _hasError ? _errorColor : widget.cursorColor ?? selectionStyle.cursorColor ?? cupertinoTheme.primaryColor;
        selectionColor = selectionStyle.selectionColor ?? cupertinoTheme.primaryColor.withOpacity(0.40);
        cursorRadius ??= const Radius.circular(2.0);
        cursorOffset = Offset(iOSHorizontalOffset / MediaQuery.devicePixelRatioOf(context), 0);
        autocorrectionTextRectColor = selectionColor;

      case TargetPlatform.macOS:
        final CupertinoThemeData cupertinoTheme = CupertinoTheme.of(context);
        forcePressEnabled = false;
        textSelectionControls ??= cupertinoDesktopTextSelectionHandleControls;
        paintCursorAboveText = true;
        cursorOpacityAnimates ??= false;
        cursorColor = _hasError ? _errorColor : widget.cursorColor ?? selectionStyle.cursorColor ?? cupertinoTheme.primaryColor;
        selectionColor = selectionStyle.selectionColor ?? cupertinoTheme.primaryColor.withOpacity(0.40);
        cursorRadius ??= const Radius.circular(2.0);
        cursorOffset = Offset(iOSHorizontalOffset / MediaQuery.devicePixelRatioOf(context), 0);
        handleDidGainAccessibilityFocus = () {
          // Automatically activate the TextField when it receives accessibility focus.
          if (!_effectiveFocusNode.hasFocus && _effectiveFocusNode.canRequestFocus) {
            _effectiveFocusNode.requestFocus();
          }
        };

      case TargetPlatform.android:
      case TargetPlatform.fuchsia:
        forcePressEnabled = false;
        textSelectionControls ??= materialTextSelectionHandleControls;
        paintCursorAboveText = false;
        cursorOpacityAnimates ??= false;
        cursorColor = _hasError ? _errorColor : widget.cursorColor ?? selectionStyle.cursorColor ?? theme.colorScheme.primary;
        selectionColor = selectionStyle.selectionColor ?? theme.colorScheme.primary.withOpacity(0.40);

      case TargetPlatform.linux:
        forcePressEnabled = false;
        textSelectionControls ??= desktopTextSelectionHandleControls;
        paintCursorAboveText = false;
        cursorOpacityAnimates ??= false;
        cursorColor = _hasError ? _errorColor : widget.cursorColor ?? selectionStyle.cursorColor ?? theme.colorScheme.primary;
        selectionColor = selectionStyle.selectionColor ?? theme.colorScheme.primary.withOpacity(0.40);

      case TargetPlatform.windows:
        forcePressEnabled = false;
        textSelectionControls ??= desktopTextSelectionHandleControls;
        paintCursorAboveText = false;
        cursorOpacityAnimates ??= false;
        cursorColor = _hasError ? _errorColor : widget.cursorColor ?? selectionStyle.cursorColor ?? theme.colorScheme.primary;
        selectionColor = selectionStyle.selectionColor ?? theme.colorScheme.primary.withOpacity(0.40);
        handleDidGainAccessibilityFocus = () {
          // Automatically activate the TextField when it receives accessibility focus.
          if (!_effectiveFocusNode.hasFocus && _effectiveFocusNode.canRequestFocus) {
            _effectiveFocusNode.requestFocus();
          }
        };
    }

    Widget child = RepaintBoundary(
      child: UnmanagedRestorationScope(
        bucket: bucket,
        child: EditableText(
          key: editableTextKey,
          readOnly: widget.readOnly || !_isEnabled,
          toolbarOptions: widget.toolbarOptions,
          showCursor: widget.showCursor,
          showSelectionHandles: _showSelectionHandles,
          controller: controller,
          focusNode: focusNode,
          undoController: widget.undoController,
          keyboardType: widget.keyboardType,
          textInputAction: widget.textInputAction,
          textCapitalization: widget.textCapitalization,
          style: style,
          strutStyle: widget.strutStyle,
          textAlign: widget.textAlign,
          textDirection: widget.textDirection,
          autofocus: widget.autofocus,
          obscuringCharacter: widget.obscuringCharacter,
          obscureText: widget.obscureText,
          autocorrect: widget.autocorrect,
          smartDashesType: widget.smartDashesType,
          smartQuotesType: widget.smartQuotesType,
          enableSuggestions: widget.enableSuggestions,
          maxLines: widget.maxLines,
          minLines: widget.minLines,
          expands: widget.expands,
          // Only show the selection highlight when the text field is focused.
          selectionColor: focusNode.hasFocus ? selectionColor : null,
          selectionControls: widget.selectionEnabled ? textSelectionControls : null,
          onChanged: widget.onChanged,
          onSelectionChanged: _handleSelectionChanged,
          onEditingComplete: widget.onEditingComplete,
          onSubmitted: widget.onSubmitted,
          onAppPrivateCommand: widget.onAppPrivateCommand,
          onSelectionHandleTapped: _handleSelectionHandleTapped,
          onTapOutside: widget.onTapOutside,
          inputFormatters: formatters,
          rendererIgnoresPointer: true,
          mouseCursor: MouseCursor.defer, // TextField will handle the cursor
          cursorWidth: widget.cursorWidth,
          cursorHeight: widget.cursorHeight,
          cursorRadius: cursorRadius,
          cursorColor: cursorColor,
          selectionHeightStyle: widget.selectionHeightStyle,
          selectionWidthStyle: widget.selectionWidthStyle,
          cursorOpacityAnimates: cursorOpacityAnimates,
          cursorOffset: cursorOffset,
          paintCursorAboveText: paintCursorAboveText,
          backgroundCursorColor: CupertinoColors.inactiveGray,
          scrollPadding: widget.scrollPadding,
          keyboardAppearance: keyboardAppearance,
          enableInteractiveSelection: widget.enableInteractiveSelection,
          dragStartBehavior: widget.dragStartBehavior,
          scrollController: widget.scrollController,
          scrollPhysics: widget.scrollPhysics,
          autofillClient: this,
          autocorrectionTextRectColor: autocorrectionTextRectColor,
          clipBehavior: widget.clipBehavior,
          restorationId: 'editable',
          scribbleEnabled: widget.scribbleEnabled,
          enableIMEPersonalizedLearning: widget.enableIMEPersonalizedLearning,
          contentInsertionConfiguration: widget.contentInsertionConfiguration,
          contextMenuBuilder: widget.contextMenuBuilder,
          spellCheckConfiguration: spellCheckConfiguration,
          magnifierConfiguration: widget.magnifierConfiguration ?? TextMagnifier.adaptiveMagnifierConfiguration,
        ),
      ),
    );

    if (widget.decoration != null) {
      child = AnimatedBuilder(
        animation: Listenable.merge(<Listenable>[ focusNode, controller ]),
        builder: (BuildContext context, Widget? child) {
          return InputDecorator(
            decoration: _getEffectiveDecoration(),
            baseStyle: widget.style,
            textAlign: widget.textAlign,
            textAlignVertical: widget.textAlignVertical,
            isHovering: _isHovering,
            isFocused: focusNode.hasFocus,
            isEmpty: controller.value.text.isEmpty,
            expands: widget.expands,
            child: child,
          );
        },
        child: child,
      );
    }
    final MouseCursor effectiveMouseCursor = MaterialStateProperty.resolveAs<MouseCursor>(
      widget.mouseCursor ?? MaterialStateMouseCursor.textable,
      _materialState,
    );

    final int? semanticsMaxValueLength;
    if (_effectiveMaxLengthEnforcement != MaxLengthEnforcement.none &&
      widget.maxLength != null &&
      widget.maxLength! > 0) {
      semanticsMaxValueLength = widget.maxLength;
    } else {
      semanticsMaxValueLength = null;
    }

    return MouseRegion(
      cursor: effectiveMouseCursor,
      onEnter: (PointerEnterEvent event) => _handleHover(true),
      onExit: (PointerExitEvent event) => _handleHover(false),
      child: TextFieldTapRegion(
        child: IgnorePointer(
          ignoring: !_isEnabled,
          child: AnimatedBuilder(
            animation: controller, // changes the _currentLength
            builder: (BuildContext context, Widget? child) {
              return Semantics(
                maxValueLength: semanticsMaxValueLength,
                currentValueLength: _currentLength,
                onTap: widget.readOnly ? null : () {
                  if (!_effectiveController.selection.isValid) {
                    _effectiveController.selection = TextSelection.collapsed(offset: _effectiveController.text.length);
                  }
                  _requestKeyboard();
                },
                onDidGainAccessibilityFocus: handleDidGainAccessibilityFocus,
                child: child,
              );
            },
            child: _selectionGestureDetectorBuilder.buildGestureDetector(
              behavior: HitTestBehavior.translucent,
              child: child,
            ),
          ),
        ),
      ),
    );
  }
}

TextStyle? _m2StateInputStyle(BuildContext context) => MaterialStateTextStyle.resolveWith((Set<MaterialState> states) {
  final ThemeData theme = Theme.of(context);
  if (states.contains(MaterialState.disabled)) {
    return TextStyle(color: theme.disabledColor);
  }
  return TextStyle(color: theme.textTheme.titleMedium?.color);
});

TextStyle _m2CounterErrorStyle(BuildContext context) =>
  Theme.of(context).textTheme.bodySmall!.copyWith(color: Theme.of(context).colorScheme.error);

// BEGIN GENERATED TOKEN PROPERTIES - TextField

// Do not edit by hand. The code between the "BEGIN GENERATED" and
// "END GENERATED" comments are generated from data in the Material
// Design token database by the script:
//   dev/tools/gen_defaults/bin/gen_defaults.dart.

// Token database version: v0_162

TextStyle? _m3StateInputStyle(BuildContext context) => MaterialStateTextStyle.resolveWith((Set<MaterialState> states) {
  if (states.contains(MaterialState.disabled)) {
    return TextStyle(color: Theme.of(context).textTheme.bodyLarge!.color?.withOpacity(0.38));
  }
  return TextStyle(color: Theme.of(context).textTheme.bodyLarge!.color);
});

TextStyle _m3InputStyle(BuildContext context) => Theme.of(context).textTheme.bodyLarge!;

TextStyle _m3CounterErrorStyle(BuildContext context) =>
  Theme.of(context).textTheme.bodySmall!.copyWith(color: Theme.of(context).colorScheme.error);

// END GENERATED TOKEN PROPERTIES - TextField
