packages/flutter/lib/src/material/text_field.dart - mirrors/flutter - Git at Google

 // Copyright 2015 The Chromium 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 'package:flutter/cupertino.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter/widgets.dart';

 import 'feedback.dart';
 import 'input_decorator.dart';
 import 'text_selection.dart';
 import 'theme.dart';

 export 'package:flutter/services.dart' show TextInputType;

 /// 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].
 ///
 /// See also:
 ///
 ///  * <https://material.google.com/components/text-fields.html>
 ///  * [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.)
 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. If [maxLines] is not one, then
   /// [keyboardType] is ignored, and the [TextInputType.multiline] keyboard
   /// type is used.
   ///
   /// 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 and how many are
   /// allowed. After [maxLength] characters have been input, additional input
   /// is ignored, unless [maxLengthEnforced] is set to false. The TextField
   /// 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 [keyboardType], [textAlign], [autofocus], [obscureText], and
   /// [autocorrect] 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({
     Key key,
     this.controller,
     this.focusNode,
     this.decoration: const InputDecoration(),
     TextInputType keyboardType: TextInputType.text,
     this.style,
     this.textAlign: TextAlign.start,
     this.autofocus: false,
     this.obscureText: false,
     this.autocorrect: true,
     this.maxLines: 1,
     this.maxLength,
     this.maxLengthEnforced: true,
     this.onChanged,
     this.onSubmitted,
     this.inputFormatters,
   }) : assert(keyboardType != null),
        assert(textAlign != null),
        assert(autofocus != null),
        assert(obscureText != null),
        assert(autocorrect != null),
        assert(maxLengthEnforced != null),
        assert(maxLines == null || maxLines > 0),
        assert(maxLength == null || maxLength > 0),
        keyboardType = maxLines == 1 ? keyboardType : TextInputType.multiline,
        super(key: key);

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

   /// Controls whether this widget has keyboard focus.
   ///
   /// If null, this widget will create its own [FocusNode].
   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.
   ///
   /// Set this field to null to remove the decoration entirely (including the
   /// extra padding introduced by the decoration to save space for the labels).
   final InputDecoration decoration;

   /// The type of keyboard to use for editing the text.
   ///
   /// Defaults to [TextInputType.text]. Must not be null. If
   /// [maxLines] is not one, then [keyboardType] is ignored, and the
   /// [TextInputType.multiline] keyboard type is used.
   final TextInputType keyboardType;

   /// 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 a text style from the current [Theme].
   final TextStyle style;

   /// How the text being edited should be aligned horizontally.
   ///
   /// Defaults to [TextAlign.start].
   final TextAlign textAlign;

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

   /// Whether to hide the text being edited (e.g., for passwords).
   ///
   /// When this is set to true, all the characters in the text field are
   /// replaced by U+2022 BULLET characters (•).
   ///
   /// Defaults to false. Cannot be null.
   final bool obscureText;

   /// Whether to enable autocorrection.
   ///
   /// Defaults to true. Cannot be null.
   final bool autocorrect;

   /// The maximum number of lines for the text to span, wrapping if necessary.
   ///
   /// If this is 1 (the default), the text will not wrap, but will scroll
   /// horizontally instead.
   ///
   /// If this is null, there is no limit to the number of lines. If it is not
   /// null, the value must be greater than zero.
   final int maxLines;

   /// 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 and how many are
   /// allowed. After [maxLength] characters have been input, additional input
   /// is ignored, unless [maxLengthEnforced] is set to false. The TextField
   /// enforces the length with a [LengthLimitingTextInputFormatter], which is
   /// evaluated after the supplied [inputFormatters], if any.
   ///
   /// This value must be either null or greater than zero. If set to null
   /// (the default), there is no limit to the number of characters allowed.
   ///
   /// Whitespace characters (e.g. newline, space, tab) are included in the
   /// character count.
   ///
   /// If [maxLengthEnforced] is set to false, then more than [maxLength]
   /// characters may be entered, but the error counter and divider will
   /// switch to the [decoration.errorStyle] when the limit is exceeded.
   ///
   /// The TextField does not currently count Unicode grapheme clusters (i.e.
   /// characters visible to the user), it counts Unicode scalar values, which
   /// leaves out a number of useful possible characters (like many emoji and
   /// composed characters), so this will be inaccurate in the presence of those
   /// characters. If you expect to encounter these kinds of characters, be
   /// generous in the maxLength used.
   ///
   /// For instance, the character "ö" can be represented as '\u{006F}\u{0308}',
   /// which is the letter "o" followed by a composed diaeresis "¨", or it can
   /// be represented as '\u{00F6}', which is the Unicode scalar value "LATIN
   /// SMALL LETTER O WITH DIAERESIS".  In the first case, the text field will
   /// count two characters, and the second case will be counted as one
   /// character, even though the user can see no difference in the input.
   ///
   /// Similarly, some emoji are represented by multiple scalar values. The
   /// Unicode "THUMBS UP SIGN + MEDIUM SKIN TONE MODIFIER", "👍🏽", should be
   /// counted as a single character, but because it is a combination of two
   /// Unicode scalar values, '\u{1F44D}\u{1F3FD}', it is counted as two
   /// characters.
   ///
   /// See also:
   ///
   ///  * [LengthLimitingTextInputFormatter] for more information on how it
   ///    counts characters, and how it may differ from the intuitive meaning.
   final int maxLength;

   /// If true, prevents the field from allowing more than [maxLength]
   /// characters.
   ///
   /// 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.
   final bool maxLengthEnforced;

   /// Called when the text being edited changes.
   final ValueChanged<String> onChanged;

   /// Called when the user indicates that they are done editing the text in the
   /// field.
   final ValueChanged<String> onSubmitted;

   /// Optional input validation and formatting overrides.
   ///
   /// Formatters are run in the provided order when the text input changes.
   final List<TextInputFormatter> inputFormatters;

   @override
   _TextFieldState createState() => new _TextFieldState();

   @override
   void debugFillProperties(DiagnosticPropertiesBuilder description) {
     super.debugFillProperties(description);
     description.add(new DiagnosticsProperty<TextEditingController>('controller', controller, defaultValue: null));
     description.add(new DiagnosticsProperty<FocusNode>('focusNode', focusNode, defaultValue: null));
     description.add(new DiagnosticsProperty<InputDecoration>('decoration', decoration));
     description.add(new EnumProperty<TextInputType>('keyboardType', keyboardType, defaultValue: TextInputType.text));
     description.add(new DiagnosticsProperty<TextStyle>('style', style, defaultValue: null));
     description.add(new DiagnosticsProperty<bool>('autofocus', autofocus, defaultValue: false));
     description.add(new DiagnosticsProperty<bool>('obscureText', obscureText, defaultValue: false));
     description.add(new DiagnosticsProperty<bool>('autocorrect', autocorrect, defaultValue: false));
     description.add(new IntProperty('maxLines', maxLines, defaultValue: 1));
     description.add(new IntProperty('maxLength', maxLength, defaultValue: null));
     description.add(new FlagProperty('maxLengthEnforced', value: maxLengthEnforced, ifTrue: 'max length enforced'));
   }
 }

 class _TextFieldState extends State<TextField> {
   final GlobalKey<EditableTextState> _editableTextKey = new GlobalKey<EditableTextState>();

   TextEditingController _controller;
   TextEditingController get _effectiveController => widget.controller ?? _controller;

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

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

   InputDecoration _getEffectiveDecoration() {
     if (!needsCounter)
       return widget.decoration;

     final InputDecoration effectiveDecoration = widget?.decoration ?? const InputDecoration();
     final String counterText = '${_effectiveController.value.text.runes.length} / ${widget.maxLength}';
     if (_effectiveController.value.text.runes.length > widget.maxLength) {
       final ThemeData themeData = Theme.of(context);
       return effectiveDecoration.copyWith(
         errorText: effectiveDecoration.errorText ?? '',
         counterStyle: effectiveDecoration.errorStyle
           ?? themeData.textTheme.caption.copyWith(color: themeData.errorColor),
         counterText: counterText,
       );
     }
     return effectiveDecoration.copyWith(counterText: counterText);
   }

   @override
   void initState() {
     super.initState();
     if (widget.controller == null)
       _controller = new TextEditingController();
   }

   @override
   void didUpdateWidget(TextField oldWidget) {
     super.didUpdateWidget(oldWidget);
     if (widget.controller == null && oldWidget.controller != null)
       _controller = new TextEditingController.fromValue(oldWidget.controller.value);
     else if (widget.controller != null && oldWidget.controller == null)
       _controller = null;
   }

   @override
   void dispose() {
     _focusNode?.dispose();
     super.dispose();
   }

   void _requestKeyboard() {
     _editableTextKey.currentState?.requestKeyboard();
   }

   void _onSelectionChanged(BuildContext context, bool longPress) {
     if (longPress)
       Feedback.forLongPress(context);
   }

   @override
   Widget build(BuildContext context) {
     final ThemeData themeData = Theme.of(context);
     final TextStyle style = widget.style ?? themeData.textTheme.subhead;
     final TextEditingController controller = _effectiveController;
     final FocusNode focusNode = _effectiveFocusNode;
     final List<TextInputFormatter> formatters = widget.inputFormatters ?? <TextInputFormatter>[];
     if (widget.maxLength != null && widget.maxLengthEnforced)
       formatters.add(new LengthLimitingTextInputFormatter(widget.maxLength));

     Widget child = new RepaintBoundary(
       child: new EditableText(
         key: _editableTextKey,
         controller: controller,
         focusNode: focusNode,
         keyboardType: widget.keyboardType,
         style: style,
         textAlign: widget.textAlign,
         autofocus: widget.autofocus,
         obscureText: widget.obscureText,
         autocorrect: widget.autocorrect,
         maxLines: widget.maxLines,
         cursorColor: themeData.textSelectionColor,
         selectionColor: themeData.textSelectionColor,
         selectionControls: themeData.platform == TargetPlatform.iOS
             ? cupertinoTextSelectionControls
             : materialTextSelectionControls,
         onChanged: widget.onChanged,
         onSubmitted: widget.onSubmitted,
         onSelectionChanged: (TextSelection _, bool longPress) => _onSelectionChanged(context, longPress),
         inputFormatters: formatters,
       ),
     );

     if (widget.decoration != null) {
       child = new AnimatedBuilder(
         animation: new Listenable.merge(<Listenable>[ focusNode, controller ]),
         builder: (BuildContext context, Widget child) {
           return new InputDecorator(
             decoration: _getEffectiveDecoration(),
             baseStyle: widget.style,
             textAlign: widget.textAlign,
             isFocused: focusNode.hasFocus,
             isEmpty: controller.value.text.isEmpty,
             child: child,
           );
         },
         child: child,
       );
     }

     return new GestureDetector(
       behavior: HitTestBehavior.opaque,
       onTap: _requestKeyboard,
       child: child,
     );
   }
 }
	// Copyright 2015 The Chromium 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 'package:flutter/cupertino.dart';
	import 'package:flutter/foundation.dart';
	import 'package:flutter/services.dart';
	import 'package:flutter/widgets.dart';

	import 'feedback.dart';
	import 'input_decorator.dart';
	import 'text_selection.dart';
	import 'theme.dart';

	export 'package:flutter/services.dart' show TextInputType;

	/// 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].
	///
	/// See also:
	///
	/// * <https://material.google.com/components/text-fields.html>
	/// * [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.)
	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. If [maxLines] is not one, then
	/// [keyboardType] is ignored, and the [TextInputType.multiline] keyboard
	/// type is used.
	///
	/// 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 and how many are
	/// allowed. After [maxLength] characters have been input, additional input
	/// is ignored, unless [maxLengthEnforced] is set to false. The TextField
	/// 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 [keyboardType], [textAlign], [autofocus], [obscureText], and
	/// [autocorrect] 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({
	Key key,
	this.controller,
	this.focusNode,
	this.decoration: const InputDecoration(),
	TextInputType keyboardType: TextInputType.text,
	this.style,
	this.textAlign: TextAlign.start,
	this.autofocus: false,
	this.obscureText: false,
	this.autocorrect: true,
	this.maxLines: 1,
	this.maxLength,
	this.maxLengthEnforced: true,
	this.onChanged,
	this.onSubmitted,
	this.inputFormatters,
	}) : assert(keyboardType != null),
	assert(textAlign != null),
	assert(autofocus != null),
	assert(obscureText != null),
	assert(autocorrect != null),
	assert(maxLengthEnforced != null),
	assert(maxLines == null \|\| maxLines > 0),
	assert(maxLength == null \|\| maxLength > 0),
	keyboardType = maxLines == 1 ? keyboardType : TextInputType.multiline,
	super(key: key);

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

	/// Controls whether this widget has keyboard focus.
	///
	/// If null, this widget will create its own [FocusNode].
	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.
	///
	/// Set this field to null to remove the decoration entirely (including the
	/// extra padding introduced by the decoration to save space for the labels).
	final InputDecoration decoration;

	/// The type of keyboard to use for editing the text.
	///
	/// Defaults to [TextInputType.text]. Must not be null. If
	/// [maxLines] is not one, then [keyboardType] is ignored, and the
	/// [TextInputType.multiline] keyboard type is used.
	final TextInputType keyboardType;

	/// 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 a text style from the current [Theme].
	final TextStyle style;

	/// How the text being edited should be aligned horizontally.
	///
	/// Defaults to [TextAlign.start].
	final TextAlign textAlign;

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

	/// Whether to hide the text being edited (e.g., for passwords).
	///
	/// When this is set to true, all the characters in the text field are
	/// replaced by U+2022 BULLET characters (•).
	///
	/// Defaults to false. Cannot be null.
	final bool obscureText;

	/// Whether to enable autocorrection.
	///
	/// Defaults to true. Cannot be null.
	final bool autocorrect;

	/// The maximum number of lines for the text to span, wrapping if necessary.
	///
	/// If this is 1 (the default), the text will not wrap, but will scroll
	/// horizontally instead.
	///
	/// If this is null, there is no limit to the number of lines. If it is not
	/// null, the value must be greater than zero.
	final int maxLines;

	/// 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 and how many are
	/// allowed. After [maxLength] characters have been input, additional input
	/// is ignored, unless [maxLengthEnforced] is set to false. The TextField
	/// enforces the length with a [LengthLimitingTextInputFormatter], which is
	/// evaluated after the supplied [inputFormatters], if any.
	///
	/// This value must be either null or greater than zero. If set to null
	/// (the default), there is no limit to the number of characters allowed.
	///
	/// Whitespace characters (e.g. newline, space, tab) are included in the
	/// character count.
	///
	/// If [maxLengthEnforced] is set to false, then more than [maxLength]
	/// characters may be entered, but the error counter and divider will
	/// switch to the [decoration.errorStyle] when the limit is exceeded.
	///
	/// The TextField does not currently count Unicode grapheme clusters (i.e.
	/// characters visible to the user), it counts Unicode scalar values, which
	/// leaves out a number of useful possible characters (like many emoji and
	/// composed characters), so this will be inaccurate in the presence of those
	/// characters. If you expect to encounter these kinds of characters, be
	/// generous in the maxLength used.
	///
	/// For instance, the character "ö" can be represented as '\u{006F}\u{0308}',
	/// which is the letter "o" followed by a composed diaeresis "¨", or it can
	/// be represented as '\u{00F6}', which is the Unicode scalar value "LATIN
	/// SMALL LETTER O WITH DIAERESIS". In the first case, the text field will
	/// count two characters, and the second case will be counted as one
	/// character, even though the user can see no difference in the input.
	///
	/// Similarly, some emoji are represented by multiple scalar values. The
	/// Unicode "THUMBS UP SIGN + MEDIUM SKIN TONE MODIFIER", "👍🏽", should be
	/// counted as a single character, but because it is a combination of two
	/// Unicode scalar values, '\u{1F44D}\u{1F3FD}', it is counted as two
	/// characters.
	///
	/// See also:
	///
	/// * [LengthLimitingTextInputFormatter] for more information on how it
	/// counts characters, and how it may differ from the intuitive meaning.
	final int maxLength;

	/// If true, prevents the field from allowing more than [maxLength]
	/// characters.
	///
	/// 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.
	final bool maxLengthEnforced;

	/// Called when the text being edited changes.
	final ValueChanged<String> onChanged;

	/// Called when the user indicates that they are done editing the text in the
	/// field.
	final ValueChanged<String> onSubmitted;

	/// Optional input validation and formatting overrides.
	///
	/// Formatters are run in the provided order when the text input changes.
	final List<TextInputFormatter> inputFormatters;

	@override
	_TextFieldState createState() => new _TextFieldState();

	@override
	void debugFillProperties(DiagnosticPropertiesBuilder description) {
	super.debugFillProperties(description);
	description.add(new DiagnosticsProperty<TextEditingController>('controller', controller, defaultValue: null));
	description.add(new DiagnosticsProperty<FocusNode>('focusNode', focusNode, defaultValue: null));
	description.add(new DiagnosticsProperty<InputDecoration>('decoration', decoration));
	description.add(new EnumProperty<TextInputType>('keyboardType', keyboardType, defaultValue: TextInputType.text));
	description.add(new DiagnosticsProperty<TextStyle>('style', style, defaultValue: null));
	description.add(new DiagnosticsProperty<bool>('autofocus', autofocus, defaultValue: false));
	description.add(new DiagnosticsProperty<bool>('obscureText', obscureText, defaultValue: false));
	description.add(new DiagnosticsProperty<bool>('autocorrect', autocorrect, defaultValue: false));
	description.add(new IntProperty('maxLines', maxLines, defaultValue: 1));
	description.add(new IntProperty('maxLength', maxLength, defaultValue: null));
	description.add(new FlagProperty('maxLengthEnforced', value: maxLengthEnforced, ifTrue: 'max length enforced'));
	}
	}

	class _TextFieldState extends State<TextField> {
	final GlobalKey<EditableTextState> _editableTextKey = new GlobalKey<EditableTextState>();

	TextEditingController _controller;
	TextEditingController get _effectiveController => widget.controller ?? _controller;

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

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

	InputDecoration _getEffectiveDecoration() {
	if (!needsCounter)
	return widget.decoration;

	final InputDecoration effectiveDecoration = widget?.decoration ?? const InputDecoration();
	final String counterText = '${_effectiveController.value.text.runes.length} / ${widget.maxLength}';
	if (_effectiveController.value.text.runes.length > widget.maxLength) {
	final ThemeData themeData = Theme.of(context);
	return effectiveDecoration.copyWith(
	errorText: effectiveDecoration.errorText ?? '',
	counterStyle: effectiveDecoration.errorStyle
	?? themeData.textTheme.caption.copyWith(color: themeData.errorColor),
	counterText: counterText,
	);
	}
	return effectiveDecoration.copyWith(counterText: counterText);
	}

	@override
	void initState() {
	super.initState();
	if (widget.controller == null)
	_controller = new TextEditingController();
	}

	@override
	void didUpdateWidget(TextField oldWidget) {
	super.didUpdateWidget(oldWidget);
	if (widget.controller == null && oldWidget.controller != null)
	_controller = new TextEditingController.fromValue(oldWidget.controller.value);
	else if (widget.controller != null && oldWidget.controller == null)
	_controller = null;
	}

	@override
	void dispose() {
	_focusNode?.dispose();
	super.dispose();
	}

	void _requestKeyboard() {
	_editableTextKey.currentState?.requestKeyboard();
	}

	void _onSelectionChanged(BuildContext context, bool longPress) {
	if (longPress)
	Feedback.forLongPress(context);
	}

	@override
	Widget build(BuildContext context) {
	final ThemeData themeData = Theme.of(context);
	final TextStyle style = widget.style ?? themeData.textTheme.subhead;
	final TextEditingController controller = _effectiveController;
	final FocusNode focusNode = _effectiveFocusNode;
	final List<TextInputFormatter> formatters = widget.inputFormatters ?? <TextInputFormatter>[];
	if (widget.maxLength != null && widget.maxLengthEnforced)
	formatters.add(new LengthLimitingTextInputFormatter(widget.maxLength));

	Widget child = new RepaintBoundary(
	child: new EditableText(
	key: _editableTextKey,
	controller: controller,
	focusNode: focusNode,
	keyboardType: widget.keyboardType,
	style: style,
	textAlign: widget.textAlign,
	autofocus: widget.autofocus,
	obscureText: widget.obscureText,
	autocorrect: widget.autocorrect,
	maxLines: widget.maxLines,
	cursorColor: themeData.textSelectionColor,
	selectionColor: themeData.textSelectionColor,
	selectionControls: themeData.platform == TargetPlatform.iOS
	? cupertinoTextSelectionControls
	: materialTextSelectionControls,
	onChanged: widget.onChanged,
	onSubmitted: widget.onSubmitted,
	onSelectionChanged: (TextSelection _, bool longPress) => _onSelectionChanged(context, longPress),
	inputFormatters: formatters,
	),
	);

	if (widget.decoration != null) {
	child = new AnimatedBuilder(
	animation: new Listenable.merge(<Listenable>[ focusNode, controller ]),
	builder: (BuildContext context, Widget child) {
	return new InputDecorator(
	decoration: _getEffectiveDecoration(),
	baseStyle: widget.style,
	textAlign: widget.textAlign,
	isFocused: focusNode.hasFocus,
	isEmpty: controller.value.text.isEmpty,
	child: child,
	);
	},
	child: child,
	);
	}

	return new GestureDetector(
	behavior: HitTestBehavior.opaque,
	onTap: _requestKeyboard,
	child: child,
	);
	}
	}