extended_textfield.dart

library flutter_extended_text_field;

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

import 'package:flutter/cupertino.dart';
import 'package:flutter/gestures.dart'
    show
        DragStartBehavior,
        PointerDeviceKind,
        PointerEnterEvent,
        PointerExitEvent;
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart'
    show
        CaretChangedHandler,
        MouseCursor,
        RenderEditable,
        RevealedOffset,
        SystemMouseCursors,
        VerticalCaretMovementRun,
        ViewportOffset;
import 'package:flutter/scheduler.dart';
import 'package:flutter/services.dart';
import 'package:flutter/foundation.dart';

// part 'editable.dart';
part 'editable_text.dart';
part 'focus_node.dart';
part 'text_selection.dart';
part 'extended_selectable_text.dart';

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

  final _ExtendedTextFieldState _state;

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

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

  @override
  void onSingleLongTapMoveUpdate(LongPressMoveUpdateDetails details) {
    if (delegate.selectionEnabled) {
      switch (Theme.of(_state.context).platform) {
        case TargetPlatform.iOS:
        case TargetPlatform.macOS:
          renderEditable.selectPositionAt(
            from: details.globalPosition,
            cause: SelectionChangedCause.longPress,
          );
          break;
        case TargetPlatform.android:
        case TargetPlatform.fuchsia:
        case TargetPlatform.linux:
        case TargetPlatform.windows:
          renderEditable.selectWordsInRange(
            from: details.globalPosition - details.offsetFromOrigin,
            to: details.globalPosition,
            cause: SelectionChangedCause.longPress,
          );
          break;
      }
    }
  }

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

  @override
  void onSingleLongTapStart(LongPressStartDetails details) {
    if (delegate.selectionEnabled) {
      switch (Theme.of(_state.context).platform) {
        case TargetPlatform.iOS:
        case TargetPlatform.macOS:
          renderEditable.selectPositionAt(
            from: details.globalPosition,
            cause: SelectionChangedCause.longPress,
          );
          break;
        case TargetPlatform.android:
        case TargetPlatform.fuchsia:
        case TargetPlatform.linux:
        case TargetPlatform.windows:
          renderEditable.selectWord(cause: SelectionChangedCause.longPress);
          Feedback.forLongPress(_state.context);
          break;
      }
    }
  }
}

class ExtendedTextField 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 [maxLengthEnforced] is set to false, 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],
  /// [maxLengthEnforced], [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 ExtendedTextField({
    Key? key,
    this.controller,
    this.focusNode,
    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,
    ToolbarOptions? 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,
    @Deprecated(
      'Use maxLengthEnforcement parameter which provides more specific '
      'behavior related to the maxLength limit. '
      'This feature was deprecated after v1.25.0-5.0.pre.',
    )
        this.maxLengthEnforced = true,
    this.maxLengthEnforcement,
    this.onChanged,
    this.onEditingComplete,
    this.onSubmitted,
    this.onAppPrivateCommand,
    this.inputFormatters,
    this.enabled,
    this.cursorWidth = 2.0,
    this.cursorHeight,
    this.cursorRadius,
    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,
    this.enableInteractiveSelection = true,
    this.selectionControls,
    this.onTap,
    this.mouseCursor,
    this.buildCounter,
    this.scrollController,
    this.scrollPhysics,
    this.autofillHints = const <String>[],
    this.clipBehavior = Clip.hardEdge,
    this.restorationId,
    this.enableIMEPersonalizedLearning = true,
  })  : assert(textAlign != null),
        assert(readOnly != null),
        assert(autofocus != null),
        assert(obscuringCharacter != null && obscuringCharacter.length == 1),
        assert(obscureText != null),
        assert(autocorrect != null),
        smartDashesType = smartDashesType ??
            (obscureText ? SmartDashesType.disabled : SmartDashesType.enabled),
        smartQuotesType = smartQuotesType ??
            (obscureText ? SmartQuotesType.disabled : SmartQuotesType.enabled),
        assert(enableSuggestions != null),
        assert(enableInteractiveSelection != null),
        assert(maxLengthEnforced != null),
        assert(
          maxLengthEnforced || maxLengthEnforcement == null,
          'maxLengthEnforced is deprecated, use only maxLengthEnforcement',
        ),
        assert(scrollPadding != null),
        assert(dragStartBehavior != null),
        assert(selectionHeightStyle != null),
        assert(selectionWidthStyle != null),
        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 != null),
        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.',
        ),
        assert(clipBehavior != null),
        assert(enableIMEPersonalizedLearning != null),
        keyboardType = keyboardType ??
            (maxLines == 1 ? TextInputType.text : TextInputType.multiline),
        toolbarOptions = toolbarOptions ??
            (obscureText
                ? const ToolbarOptions(
                    selectAll: true,
                    paste: true,
                  )
                : const ToolbarOptions(
                    copy: true,
                    cut: true,
                    selectAll: true,
                    paste: true,
                  )),
        super(key: key);

  /// 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
  /// focusNode.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 `subtitle1` 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.
  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 scalar values) 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 [maxLengthEnforced] is set to false or [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;

  /// If [maxLength] is set, [maxLengthEnforced] indicates whether or not to
  /// enforce the limit, or merely provide a character counter and warning when
  /// [maxLength] is exceeded.
  ///
  /// If true, prevents the field from allowing more than [maxLength]
  /// characters.
  @Deprecated(
    'Use maxLengthEnforcement parameter which provides more specific '
    'behavior related to the maxLength limit. '
    'This feature was deprecated after v1.25.0-5.0.pre.',
  )
  final bool maxLengthEnforced;

  /// 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;

  /// 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
  /// [TextSelectionThemeData.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;

  /// 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.services.TextInputConfiguration.enableIMEPersonalizedLearning}
  final bool enableIMEPersonalizedLearning;

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

  @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<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(FlagProperty('maxLengthEnforced',
        value: maxLengthEnforced,
        defaultValue: true,
        ifFalse: 'maxLength not enforced'));
    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(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>(
        'enableIMEPersonalizedLearning', enableIMEPersonalizedLearning,
        defaultValue: true));
  }
}

class _ExtendedTextFieldState extends State<ExtendedTextField>
    with RestorationMixin
    implements
        ExtendedTextSelectionGestureDetectorBuilderDelegate,
        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<ExtendedEditableTextState> editableTextKey =
      GlobalKey<ExtendedEditableTextState>();

  @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;

  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!);
      semanticCounterText =
          localizations.remainingTextFieldCharacterCount(remaining);
    }

    if (_hasIntrinsicError) {
      return effectiveDecoration.copyWith(
        errorText: effectiveDecoration.errorText ?? '',
        counterStyle: effectiveDecoration.errorStyle ??
            themeData.textTheme.caption!.copyWith(color: themeData.errorColor),
        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 = _isEnabled;
    _effectiveFocusNode.addListener(_handleFocusChanged);
  }

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

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

  @override
  void didUpdateWidget(ExtendedTextField 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();
  }

  ExtendedEditableTextState? 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) 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:
        if (cause == SelectionChangedCause.longPress ||
            cause == SelectionChangedCause.drag) {
          _editableText?.bringIntoView(selection.extent);
        }
        return;
      case TargetPlatform.linux:
      case TargetPlatform.windows:
      case TargetPlatform.fuchsia:
      case TargetPlatform.android:
        if (cause == SelectionChangedCause.drag) {
          _editableText?.bringIntoView(selection.extent);
        }
        return;
    }
  }

  /// 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.

  @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 TextSelectionThemeData selectionTheme =
        TextSelectionTheme.of(context);
    final TextStyle style = theme.textTheme.subtitle1!.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 && widget.maxLengthEnforced)
        LengthLimitingTextInputFormatter(
          widget.maxLength,
          maxLengthEnforcement: _effectiveMaxLengthEnforcement,
        ),
    ];

    TextSelectionControls? textSelectionControls = widget.selectionControls;
    final bool paintCursorAboveText;
    final bool cursorOpacityAnimates;
    Offset? cursorOffset;
    Color? cursorColor = widget.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 ??= cupertinoTextSelectionControls;
        paintCursorAboveText = true;
        cursorOpacityAnimates = true;
        cursorColor ??=
            selectionTheme.cursorColor ?? cupertinoTheme.primaryColor;
        selectionColor = selectionTheme.selectionColor ??
            cupertinoTheme.primaryColor.withOpacity(0.40);
        cursorRadius ??= const Radius.circular(2.0);
        cursorOffset = Offset(
            iOSHorizontalOffset / MediaQuery.of(context).devicePixelRatio, 0);
        autocorrectionTextRectColor = selectionColor;
        break;

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

      case TargetPlatform.android:
      case TargetPlatform.fuchsia:
        forcePressEnabled = false;
        textSelectionControls ??= materialTextSelectionControls;
        paintCursorAboveText = false;
        cursorOpacityAnimates = false;
        cursorColor ??= selectionTheme.cursorColor ?? theme.colorScheme.primary;
        selectionColor = selectionTheme.selectionColor ??
            theme.colorScheme.primary.withOpacity(0.40);
        break;

      case TargetPlatform.linux:
        forcePressEnabled = false;
        textSelectionControls ??= desktopTextSelectionControls;
        paintCursorAboveText = false;
        cursorOpacityAnimates = false;
        cursorColor ??= selectionTheme.cursorColor ?? theme.colorScheme.primary;
        selectionColor = selectionTheme.selectionColor ??
            theme.colorScheme.primary.withOpacity(0.40);
        break;

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

    Widget child = RepaintBoundary(
      child: UnmanagedRestorationScope(
        bucket: bucket,
        child: ExtendedEditableText(
          key: editableTextKey,
          readOnly: widget.readOnly || !_isEnabled,
          toolbarOptions: widget.toolbarOptions,
          showCursor: widget.showCursor,
          showSelectionHandles: _showSelectionHandles,
          controller: controller,
          focusNode: focusNode,
          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,
          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',
          enableIMEPersonalizedLearning: widget.enableIMEPersonalizedLearning,
        ),
      ),
    );

    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>{
        if (!_isEnabled) MaterialState.disabled,
        if (_isHovering) MaterialState.hovered,
        if (focusNode.hasFocus) MaterialState.focused,
        if (_hasError) MaterialState.error,
      },
    );

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

    return FocusTrapArea(
      focusNode: focusNode,
      child: MouseRegion(
        cursor: effectiveMouseCursor,
        onEnter: (PointerEnterEvent event) => _handleHover(true),
        onExit: (PointerExitEvent event) => _handleHover(false),
        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,
            ),
          ),
        ),
      ),
    );
  }
}