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// 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:math' as math;
import 'dart:ui' show lerpDouble;
import 'package:flutter/foundation.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter/widgets.dart';
import 'color_scheme.dart';
import 'colors.dart';
import 'constants.dart';
import 'icon_button.dart';
import 'icon_button_theme.dart';
import 'input_border.dart';
import 'material.dart';
import 'material_state.dart';
import 'text_theme.dart';
import 'theme.dart';
import 'theme_data.dart';
// Examples can assume:
// late Widget _myIcon;
// The duration value extracted from:
// https://github.com/material-components/material-components-android/blob/master/lib/java/com/google/android/material/textfield/TextInputLayout.java
const Duration _kTransitionDuration = Duration(milliseconds: 167);
const Curve _kTransitionCurve = Curves.fastOutSlowIn;
const double _kFinalLabelScale = 0.75;
// Defines the gap in the InputDecorator's outline border where the
// floating label will appear.
class _InputBorderGap extends ChangeNotifier {
double? _start;
double? get start => _start;
set start(double? value) {
if (value != _start) {
_start = value;
notifyListeners();
}
}
double _extent = 0.0;
double get extent => _extent;
set extent(double value) {
if (value != _extent) {
_extent = value;
notifyListeners();
}
}
@override
// ignore: avoid_equals_and_hash_code_on_mutable_classes, this class is not used in collection
bool operator ==(Object other) {
if (identical(this, other)) {
return true;
}
if (other.runtimeType != runtimeType) {
return false;
}
return other is _InputBorderGap
&& other.start == start
&& other.extent == extent;
}
@override
// ignore: avoid_equals_and_hash_code_on_mutable_classes, this class is not used in collection
int get hashCode => Object.hash(start, extent);
@override
String toString() => describeIdentity(this);
}
// Used to interpolate between two InputBorders.
class _InputBorderTween extends Tween<InputBorder> {
_InputBorderTween({super.begin, super.end});
@override
InputBorder lerp(double t) => ShapeBorder.lerp(begin, end, t)! as InputBorder;
}
// Passes the _InputBorderGap parameters along to an InputBorder's paint method.
class _InputBorderPainter extends CustomPainter {
_InputBorderPainter({
required Listenable repaint,
required this.borderAnimation,
required this.border,
required this.gapAnimation,
required this.gap,
required this.textDirection,
required this.fillColor,
required this.hoverAnimation,
required this.hoverColorTween,
}) : super(repaint: repaint);
final Animation<double> borderAnimation;
final _InputBorderTween border;
final Animation<double> gapAnimation;
final _InputBorderGap gap;
final TextDirection textDirection;
final Color fillColor;
final ColorTween hoverColorTween;
final Animation<double> hoverAnimation;
Color get blendedColor => Color.alphaBlend(hoverColorTween.evaluate(hoverAnimation)!, fillColor);
@override
void paint(Canvas canvas, Size size) {
final InputBorder borderValue = border.evaluate(borderAnimation);
final Rect canvasRect = Offset.zero & size;
final Color blendedFillColor = blendedColor;
if (blendedFillColor.alpha > 0) {
canvas.drawPath(
borderValue.getOuterPath(canvasRect, textDirection: textDirection),
Paint()
..color = blendedFillColor
..style = PaintingStyle.fill,
);
}
borderValue.paint(
canvas,
canvasRect,
gapStart: gap.start,
gapExtent: gap.extent,
gapPercentage: gapAnimation.value,
textDirection: textDirection,
);
}
@override
bool shouldRepaint(_InputBorderPainter oldPainter) {
return borderAnimation != oldPainter.borderAnimation
|| hoverAnimation != oldPainter.hoverAnimation
|| gapAnimation != oldPainter.gapAnimation
|| border != oldPainter.border
|| gap != oldPainter.gap
|| textDirection != oldPainter.textDirection;
}
@override
String toString() => describeIdentity(this);
}
// An analog of AnimatedContainer, which can animate its shaped border, for
// _InputBorder. This specialized animated container is needed because the
// _InputBorderGap, which is computed at layout time, is required by the
// _InputBorder's paint method.
class _BorderContainer extends StatefulWidget {
const _BorderContainer({
required this.border,
required this.gap,
required this.gapAnimation,
required this.fillColor,
required this.hoverColor,
required this.isHovering,
});
final InputBorder border;
final _InputBorderGap gap;
final Animation<double> gapAnimation;
final Color fillColor;
final Color hoverColor;
final bool isHovering;
@override
_BorderContainerState createState() => _BorderContainerState();
}
class _BorderContainerState extends State<_BorderContainer> with TickerProviderStateMixin {
static const Duration _kHoverDuration = Duration(milliseconds: 15);
late AnimationController _controller;
late AnimationController _hoverColorController;
late Animation<double> _borderAnimation;
late _InputBorderTween _border;
late Animation<double> _hoverAnimation;
late ColorTween _hoverColorTween;
@override
void initState() {
super.initState();
_hoverColorController = AnimationController(
duration: _kHoverDuration,
value: widget.isHovering ? 1.0 : 0.0,
vsync: this,
);
_controller = AnimationController(
duration: _kTransitionDuration,
vsync: this,
);
_borderAnimation = CurvedAnimation(
parent: _controller,
curve: _kTransitionCurve,
reverseCurve: _kTransitionCurve.flipped,
);
_border = _InputBorderTween(
begin: widget.border,
end: widget.border,
);
_hoverAnimation = CurvedAnimation(
parent: _hoverColorController,
curve: Curves.linear,
);
_hoverColorTween = ColorTween(begin: Colors.transparent, end: widget.hoverColor);
}
@override
void dispose() {
_controller.dispose();
_hoverColorController.dispose();
super.dispose();
}
@override
void didUpdateWidget(_BorderContainer oldWidget) {
super.didUpdateWidget(oldWidget);
if (widget.border != oldWidget.border) {
_border = _InputBorderTween(
begin: oldWidget.border,
end: widget.border,
);
_controller
..value = 0.0
..forward();
}
if (widget.hoverColor != oldWidget.hoverColor) {
_hoverColorTween = ColorTween(begin: Colors.transparent, end: widget.hoverColor);
}
if (widget.isHovering != oldWidget.isHovering) {
if (widget.isHovering) {
_hoverColorController.forward();
} else {
_hoverColorController.reverse();
}
}
}
@override
Widget build(BuildContext context) {
return CustomPaint(
foregroundPainter: _InputBorderPainter(
repaint: Listenable.merge(<Listenable>[
_borderAnimation,
widget.gap,
_hoverColorController,
]),
borderAnimation: _borderAnimation,
border: _border,
gapAnimation: widget.gapAnimation,
gap: widget.gap,
textDirection: Directionality.of(context),
fillColor: widget.fillColor,
hoverColorTween: _hoverColorTween,
hoverAnimation: _hoverAnimation,
),
);
}
}
// Used to "shake" the floating label to the left to the left and right
// when the errorText first appears.
class _Shaker extends AnimatedWidget {
const _Shaker({
required Animation<double> animation,
this.child,
}) : super(listenable: animation);
final Widget? child;
Animation<double> get animation => listenable as Animation<double>;
double get translateX {
const double shakeDelta = 4.0;
final double t = animation.value;
if (t <= 0.25) {
return -t * shakeDelta;
} else if (t < 0.75) {
return (t - 0.5) * shakeDelta;
} else {
return (1.0 - t) * 4.0 * shakeDelta;
}
}
@override
Widget build(BuildContext context) {
return Transform(
transform: Matrix4.translationValues(translateX, 0.0, 0.0),
child: child,
);
}
}
// Display the helper and error text. When the error text appears
// it fades and the helper text fades out. The error text also
// slides upwards a little when it first appears.
class _HelperError extends StatefulWidget {
const _HelperError({
this.textAlign,
this.helperText,
this.helperStyle,
this.helperMaxLines,
this.error,
this.errorText,
this.errorStyle,
this.errorMaxLines,
});
final TextAlign? textAlign;
final String? helperText;
final TextStyle? helperStyle;
final int? helperMaxLines;
final Widget? error;
final String? errorText;
final TextStyle? errorStyle;
final int? errorMaxLines;
@override
_HelperErrorState createState() => _HelperErrorState();
}
class _HelperErrorState extends State<_HelperError> with SingleTickerProviderStateMixin {
// If the height of this widget and the counter are zero ("empty") at
// layout time, no space is allocated for the subtext.
static const Widget empty = SizedBox.shrink();
late AnimationController _controller;
Widget? _helper;
Widget? _error;
bool get _hasError => widget.errorText != null || widget.error != null;
@override
void initState() {
super.initState();
_controller = AnimationController(
duration: _kTransitionDuration,
vsync: this,
);
if (_hasError) {
_error = _buildError();
_controller.value = 1.0;
} else if (widget.helperText != null) {
_helper = _buildHelper();
}
_controller.addListener(_handleChange);
}
@override
void dispose() {
_controller.dispose();
super.dispose();
}
void _handleChange() {
setState(() {
// The _controller's value has changed.
});
}
@override
void didUpdateWidget(_HelperError old) {
super.didUpdateWidget(old);
final Widget? newError = widget.error;
final String? newErrorText = widget.errorText;
final String? newHelperText = widget.helperText;
final Widget? oldError = old.error;
final String? oldErrorText = old.errorText;
final String? oldHelperText = old.helperText;
final bool errorStateChanged = (newError != null) != (oldError != null);
final bool errorTextStateChanged = (newErrorText != null) != (oldErrorText != null);
final bool helperTextStateChanged = newErrorText == null && (newHelperText != null) != (oldHelperText != null);
if (errorStateChanged || errorTextStateChanged || helperTextStateChanged) {
if (newError != null || newErrorText != null) {
_error = _buildError();
_controller.forward();
} else if (newHelperText != null) {
_helper = _buildHelper();
_controller.reverse();
} else {
_controller.reverse();
}
}
}
Widget _buildHelper() {
assert(widget.helperText != null);
return Semantics(
container: true,
child: FadeTransition(
opacity: Tween<double>(begin: 1.0, end: 0.0).animate(_controller),
child: Text(
widget.helperText!,
style: widget.helperStyle,
textAlign: widget.textAlign,
overflow: TextOverflow.ellipsis,
maxLines: widget.helperMaxLines,
),
),
);
}
Widget _buildError() {
assert(widget.error != null || widget.errorText != null);
return Semantics(
container: true,
child: FadeTransition(
opacity: _controller,
child: FractionalTranslation(
translation: Tween<Offset>(
begin: const Offset(0.0, -0.25),
end: Offset.zero,
).evaluate(_controller.view),
child: widget.error ?? Text(
widget.errorText!,
style: widget.errorStyle,
textAlign: widget.textAlign,
overflow: TextOverflow.ellipsis,
maxLines: widget.errorMaxLines,
),
),
),
);
}
@override
Widget build(BuildContext context) {
if (_controller.isDismissed) {
_error = null;
if (widget.helperText != null) {
return _helper = _buildHelper();
} else {
_helper = null;
return empty;
}
}
if (_controller.isCompleted) {
_helper = null;
if (_hasError) {
return _error = _buildError();
} else {
_error = null;
return empty;
}
}
if (_helper == null && _hasError) {
return _buildError();
}
if (_error == null && widget.helperText != null) {
return _buildHelper();
}
if (_hasError) {
return Stack(
children: <Widget>[
FadeTransition(
opacity: Tween<double>(begin: 1.0, end: 0.0).animate(_controller),
child: _helper,
),
_buildError(),
],
);
}
if (widget.helperText != null) {
return Stack(
children: <Widget>[
_buildHelper(),
FadeTransition(
opacity: _controller,
child: _error,
),
],
);
}
return empty;
}
}
/// Defines **how** the floating label should behave.
///
/// See also:
///
/// * [InputDecoration.floatingLabelBehavior] which defines the behavior for
/// [InputDecoration.label] or [InputDecoration.labelText].
/// * [FloatingLabelAlignment] which defines **where** the floating label
/// should displayed.
enum FloatingLabelBehavior {
/// The label will always be positioned within the content, or hidden.
never,
/// The label will float when the input is focused, or has content.
auto,
/// The label will always float above the content.
always,
}
/// Defines **where** the floating label should be displayed within an
/// [InputDecorator].
///
/// See also:
///
/// * [InputDecoration.floatingLabelAlignment] which defines the alignment for
/// [InputDecoration.label] or [InputDecoration.labelText].
/// * [FloatingLabelBehavior] which defines **how** the floating label should
/// behave.
@immutable
class FloatingLabelAlignment {
const FloatingLabelAlignment._(this._x) : assert(_x >= -1.0 && _x <= 1.0);
// -1 denotes start, 0 denotes center, and 1 denotes end.
final double _x;
/// Align the floating label on the leading edge of the [InputDecorator].
///
/// For left-to-right text ([TextDirection.ltr]), this is the left edge.
///
/// For right-to-left text ([TextDirection.rtl]), this is the right edge.
static const FloatingLabelAlignment start = FloatingLabelAlignment._(-1.0);
/// Aligns the floating label to the center of an [InputDecorator].
static const FloatingLabelAlignment center = FloatingLabelAlignment._(0.0);
@override
int get hashCode => _x.hashCode;
@override
bool operator ==(Object other) {
if (identical(this, other)) {
return true;
}
if (other.runtimeType != runtimeType) {
return false;
}
return other is FloatingLabelAlignment
&& _x == other._x;
}
static String _stringify(double x) {
if (x == -1.0) {
return 'FloatingLabelAlignment.start';
}
if (x == 0.0) {
return 'FloatingLabelAlignment.center';
}
return 'FloatingLabelAlignment(x: ${x.toStringAsFixed(1)})';
}
@override
String toString() => _stringify(_x);
}
// Identifies the children of a _RenderDecorationElement.
enum _DecorationSlot {
icon,
input,
label,
hint,
prefix,
suffix,
prefixIcon,
suffixIcon,
helperError,
counter,
container,
}
// An analog of InputDecoration for the _Decorator widget.
@immutable
class _Decoration {
const _Decoration({
required this.contentPadding,
required this.isCollapsed,
required this.floatingLabelHeight,
required this.floatingLabelProgress,
required this.floatingLabelAlignment,
required this.border,
required this.borderGap,
required this.alignLabelWithHint,
required this.isDense,
required this.visualDensity,
this.icon,
this.input,
this.label,
this.hint,
this.prefix,
this.suffix,
this.prefixIcon,
this.suffixIcon,
this.helperError,
this.counter,
this.container,
});
final EdgeInsetsGeometry contentPadding;
final bool isCollapsed;
final double floatingLabelHeight;
final double floatingLabelProgress;
final FloatingLabelAlignment floatingLabelAlignment;
final InputBorder border;
final _InputBorderGap borderGap;
final bool alignLabelWithHint;
final bool? isDense;
final VisualDensity visualDensity;
final Widget? icon;
final Widget? input;
final Widget? label;
final Widget? hint;
final Widget? prefix;
final Widget? suffix;
final Widget? prefixIcon;
final Widget? suffixIcon;
final Widget? helperError;
final Widget? counter;
final Widget? container;
@override
bool operator ==(Object other) {
if (identical(this, other)) {
return true;
}
if (other.runtimeType != runtimeType) {
return false;
}
return other is _Decoration
&& other.contentPadding == contentPadding
&& other.isCollapsed == isCollapsed
&& other.floatingLabelHeight == floatingLabelHeight
&& other.floatingLabelProgress == floatingLabelProgress
&& other.floatingLabelAlignment == floatingLabelAlignment
&& other.border == border
&& other.borderGap == borderGap
&& other.alignLabelWithHint == alignLabelWithHint
&& other.isDense == isDense
&& other.visualDensity == visualDensity
&& other.icon == icon
&& other.input == input
&& other.label == label
&& other.hint == hint
&& other.prefix == prefix
&& other.suffix == suffix
&& other.prefixIcon == prefixIcon
&& other.suffixIcon == suffixIcon
&& other.helperError == helperError
&& other.counter == counter
&& other.container == container;
}
@override
int get hashCode => Object.hash(
contentPadding,
floatingLabelHeight,
floatingLabelProgress,
floatingLabelAlignment,
border,
borderGap,
alignLabelWithHint,
isDense,
visualDensity,
icon,
input,
label,
hint,
prefix,
suffix,
prefixIcon,
suffixIcon,
helperError,
counter,
container,
);
}
// A container for the layout values computed by _RenderDecoration._layout.
// These values are used by _RenderDecoration.performLayout to position
// all of the renderer children of a _RenderDecoration.
class _RenderDecorationLayout {
const _RenderDecorationLayout({
required this.boxToBaseline,
required this.inputBaseline, // for InputBorderType.underline
required this.outlineBaseline, // for InputBorderType.outline
required this.subtextBaseline,
required this.containerHeight,
required this.subtextHeight,
});
final Map<RenderBox?, double> boxToBaseline;
final double inputBaseline;
final double outlineBaseline;
final double subtextBaseline; // helper/error counter
final double containerHeight;
final double subtextHeight;
}
// The workhorse: layout and paint a _Decorator widget's _Decoration.
class _RenderDecoration extends RenderBox with SlottedContainerRenderObjectMixin<_DecorationSlot, RenderBox> {
_RenderDecoration({
required _Decoration decoration,
required TextDirection textDirection,
required TextBaseline textBaseline,
required bool isFocused,
required bool expands,
required bool material3,
TextAlignVertical? textAlignVertical,
}) : _decoration = decoration,
_textDirection = textDirection,
_textBaseline = textBaseline,
_textAlignVertical = textAlignVertical,
_isFocused = isFocused,
_expands = expands,
_material3 = material3;
static const double subtextGap = 8.0;
RenderBox? get icon => childForSlot(_DecorationSlot.icon);
RenderBox? get input => childForSlot(_DecorationSlot.input);
RenderBox? get label => childForSlot(_DecorationSlot.label);
RenderBox? get hint => childForSlot(_DecorationSlot.hint);
RenderBox? get prefix => childForSlot(_DecorationSlot.prefix);
RenderBox? get suffix => childForSlot(_DecorationSlot.suffix);
RenderBox? get prefixIcon => childForSlot(_DecorationSlot.prefixIcon);
RenderBox? get suffixIcon => childForSlot(_DecorationSlot.suffixIcon);
RenderBox? get helperError => childForSlot(_DecorationSlot.helperError);
RenderBox? get counter => childForSlot(_DecorationSlot.counter);
RenderBox? get container => childForSlot(_DecorationSlot.container);
// The returned list is ordered for hit testing.
@override
Iterable<RenderBox> get children {
return <RenderBox>[
if (icon != null)
icon!,
if (input != null)
input!,
if (prefixIcon != null)
prefixIcon!,
if (suffixIcon != null)
suffixIcon!,
if (prefix != null)
prefix!,
if (suffix != null)
suffix!,
if (label != null)
label!,
if (hint != null)
hint!,
if (helperError != null)
helperError!,
if (counter != null)
counter!,
if (container != null)
container!,
];
}
_Decoration get decoration => _decoration;
_Decoration _decoration;
set decoration(_Decoration value) {
if (_decoration == value) {
return;
}
_decoration = value;
markNeedsLayout();
}
TextDirection get textDirection => _textDirection;
TextDirection _textDirection;
set textDirection(TextDirection value) {
if (_textDirection == value) {
return;
}
_textDirection = value;
markNeedsLayout();
}
TextBaseline get textBaseline => _textBaseline;
TextBaseline _textBaseline;
set textBaseline(TextBaseline value) {
if (_textBaseline == value) {
return;
}
_textBaseline = value;
markNeedsLayout();
}
TextAlignVertical get _defaultTextAlignVertical => _isOutlineAligned
? TextAlignVertical.center
: TextAlignVertical.top;
TextAlignVertical get textAlignVertical => _textAlignVertical ?? _defaultTextAlignVertical;
TextAlignVertical? _textAlignVertical;
set textAlignVertical(TextAlignVertical? value) {
if (_textAlignVertical == value) {
return;
}
// No need to relayout if the effective value is still the same.
if (textAlignVertical.y == (value?.y ?? _defaultTextAlignVertical.y)) {
_textAlignVertical = value;
return;
}
_textAlignVertical = value;
markNeedsLayout();
}
bool get isFocused => _isFocused;
bool _isFocused;
set isFocused(bool value) {
if (_isFocused == value) {
return;
}
_isFocused = value;
markNeedsSemanticsUpdate();
}
bool get expands => _expands;
bool _expands = false;
set expands(bool value) {
if (_expands == value) {
return;
}
_expands = value;
markNeedsLayout();
}
bool get material3 => _material3;
bool _material3 = false;
set material3(bool value) {
if (_material3 == value) {
return;
}
_material3 = value;
markNeedsLayout();
}
// Indicates that the decoration should be aligned to accommodate an outline
// border.
bool get _isOutlineAligned {
return !decoration.isCollapsed && decoration.border.isOutline;
}
@override
void visitChildrenForSemantics(RenderObjectVisitor visitor) {
if (icon != null) {
visitor(icon!);
}
if (prefix != null) {
visitor(prefix!);
}
if (prefixIcon != null) {
visitor(prefixIcon!);
}
if (label != null) {
visitor(label!);
}
if (hint != null) {
if (isFocused) {
visitor(hint!);
} else if (label == null) {
visitor(hint!);
}
}
if (input != null) {
visitor(input!);
}
if (suffixIcon != null) {
visitor(suffixIcon!);
}
if (suffix != null) {
visitor(suffix!);
}
if (container != null) {
visitor(container!);
}
if (helperError != null) {
visitor(helperError!);
}
if (counter != null) {
visitor(counter!);
}
}
@override
bool get sizedByParent => false;
static double _minWidth(RenderBox? box, double height) {
return box == null ? 0.0 : box.getMinIntrinsicWidth(height);
}
static double _maxWidth(RenderBox? box, double height) {
return box == null ? 0.0 : box.getMaxIntrinsicWidth(height);
}
static double _minHeight(RenderBox? box, double width) {
return box == null ? 0.0 : box.getMinIntrinsicHeight(width);
}
static Size _boxSize(RenderBox? box) => box == null ? Size.zero : box.size;
static BoxParentData _boxParentData(RenderBox box) => box.parentData! as BoxParentData;
EdgeInsets get contentPadding => decoration.contentPadding as EdgeInsets;
// Lay out the given box if needed, and return its baseline.
double _layoutLineBox(RenderBox? box, BoxConstraints constraints) {
if (box == null) {
return 0.0;
}
box.layout(constraints, parentUsesSize: true);
// Since internally, all layout is performed against the alphabetic baseline,
// (eg, ascents/descents are all relative to alphabetic, even if the font is
// an ideographic or hanging font), we should always obtain the reference
// baseline from the alphabetic baseline. The ideographic baseline is for
// use post-layout and is derived from the alphabetic baseline combined with
// the font metrics.
final double baseline = box.getDistanceToBaseline(TextBaseline.alphabetic)!;
assert(() {
if (baseline >= 0) {
return true;
}
throw FlutterError.fromParts(<DiagnosticsNode>[
ErrorSummary("One of InputDecorator's children reported a negative baseline offset."),
ErrorDescription(
'${box.runtimeType}, of size ${box.size}, reported a negative '
'alphabetic baseline of $baseline.',
),
]);
}());
return baseline;
}
// Returns a value used by performLayout to position all of the renderers.
// This method applies layout to all of the renderers except the container.
// For convenience, the container is laid out in performLayout().
_RenderDecorationLayout _layout(BoxConstraints layoutConstraints) {
assert(
layoutConstraints.maxWidth < double.infinity,
'An InputDecorator, which is typically created by a TextField, cannot '
'have an unbounded width.\n'
'This happens when the parent widget does not provide a finite width '
'constraint. For example, if the InputDecorator is contained by a Row, '
'then its width must be constrained. An Expanded widget or a SizedBox '
'can be used to constrain the width of the InputDecorator or the '
'TextField that contains it.',
);
// Margin on each side of subtext (counter and helperError)
final Map<RenderBox?, double> boxToBaseline = <RenderBox?, double>{};
final BoxConstraints boxConstraints = layoutConstraints.loosen();
// Layout all the widgets used by InputDecorator
boxToBaseline[icon] = _layoutLineBox(icon, boxConstraints);
final BoxConstraints containerConstraints = boxConstraints.copyWith(
maxWidth: boxConstraints.maxWidth - _boxSize(icon).width,
);
boxToBaseline[prefixIcon] = _layoutLineBox(prefixIcon, containerConstraints);
boxToBaseline[suffixIcon] = _layoutLineBox(suffixIcon, containerConstraints);
final BoxConstraints contentConstraints = containerConstraints.copyWith(
maxWidth: math.max(0.0, containerConstraints.maxWidth - contentPadding.horizontal),
);
boxToBaseline[prefix] = _layoutLineBox(prefix, contentConstraints);
boxToBaseline[suffix] = _layoutLineBox(suffix, contentConstraints);
final double inputWidth = math.max(
0.0,
constraints.maxWidth - (
_boxSize(icon).width
+ (prefixIcon != null ? 0 : (textDirection == TextDirection.ltr ? contentPadding.left : contentPadding.right))
+ _boxSize(prefixIcon).width
+ _boxSize(prefix).width
+ _boxSize(suffix).width
+ _boxSize(suffixIcon).width
+ (suffixIcon != null ? 0 : (textDirection == TextDirection.ltr ? contentPadding.right : contentPadding.left))),
);
// Increase the available width for the label when it is scaled down.
final double invertedLabelScale = lerpDouble(1.00, 1 / _kFinalLabelScale, decoration.floatingLabelProgress)!;
double suffixIconWidth = _boxSize(suffixIcon).width;
if (decoration.border.isOutline) {
suffixIconWidth = lerpDouble(suffixIconWidth, 0.0, decoration.floatingLabelProgress)!;
}
final double labelWidth = math.max(
0.0,
constraints.maxWidth - (
_boxSize(icon).width
+ contentPadding.left
+ _boxSize(prefixIcon).width
+ suffixIconWidth
+ contentPadding.right),
);
boxToBaseline[label] = _layoutLineBox(
label,
boxConstraints.copyWith(maxWidth: labelWidth * invertedLabelScale),
);
boxToBaseline[hint] = _layoutLineBox(
hint,
boxConstraints.copyWith(minWidth: inputWidth, maxWidth: inputWidth),
);
boxToBaseline[counter] = _layoutLineBox(counter, contentConstraints);
// The helper or error text can occupy the full width less the space
// occupied by the icon and counter.
boxToBaseline[helperError] = _layoutLineBox(
helperError,
contentConstraints.copyWith(
maxWidth: math.max(0.0, contentConstraints.maxWidth - _boxSize(counter).width),
),
);
// The height of the input needs to accommodate label above and counter and
// helperError below, when they exist.
final double labelHeight = label == null
? 0
: decoration.floatingLabelHeight;
final double topHeight = decoration.border.isOutline
? math.max(labelHeight - boxToBaseline[label]!, 0)
: labelHeight;
final double counterHeight = counter == null
? 0
: boxToBaseline[counter]! + subtextGap;
final bool helperErrorExists = helperError?.size != null
&& helperError!.size.height > 0;
final double helperErrorHeight = !helperErrorExists
? 0
: helperError!.size.height + subtextGap;
final double bottomHeight = math.max(
counterHeight,
helperErrorHeight,
);
final Offset densityOffset = decoration.visualDensity.baseSizeAdjustment;
boxToBaseline[input] = _layoutLineBox(
input,
boxConstraints.deflate(EdgeInsets.only(
top: contentPadding.top + topHeight + densityOffset.dy / 2,
bottom: contentPadding.bottom + bottomHeight + densityOffset.dy / 2,
)).copyWith(
minWidth: inputWidth,
maxWidth: inputWidth,
),
);
// The field can be occupied by a hint or by the input itself
final double hintHeight = hint?.size.height ?? 0;
final double inputDirectHeight = input?.size.height ?? 0;
final double inputHeight = math.max(hintHeight, inputDirectHeight);
final double inputInternalBaseline = math.max(
boxToBaseline[input]!,
boxToBaseline[hint]!,
);
// Calculate the amount that prefix/suffix affects height above and below
// the input.
final double prefixHeight = prefix?.size.height ?? 0;
final double suffixHeight = suffix?.size.height ?? 0;
final double fixHeight = math.max(
boxToBaseline[prefix]!,
boxToBaseline[suffix]!,
);
final double fixAboveInput = math.max(0, fixHeight - inputInternalBaseline);
final double fixBelowBaseline = math.max(
prefixHeight - boxToBaseline[prefix]!,
suffixHeight - boxToBaseline[suffix]!,
);
// TODO(justinmc): fixBelowInput should have no effect when there is no
// prefix/suffix below the input.
// https://github.com/flutter/flutter/issues/66050
final double fixBelowInput = math.max(
0,
fixBelowBaseline - (inputHeight - inputInternalBaseline),
);
// Calculate the height of the input text container.
final double prefixIconHeight = prefixIcon?.size.height ?? 0;
final double suffixIconHeight = suffixIcon?.size.height ?? 0;
final double fixIconHeight = math.max(prefixIconHeight, suffixIconHeight);
final double contentHeight = math.max(
fixIconHeight,
topHeight
+ contentPadding.top
+ fixAboveInput
+ inputHeight
+ fixBelowInput
+ contentPadding.bottom
+ densityOffset.dy,
);
final double minContainerHeight = decoration.isDense! || decoration.isCollapsed || expands
? 0.0
: kMinInteractiveDimension;
final double maxContainerHeight = math.max(0.0, boxConstraints.maxHeight - bottomHeight);
final double containerHeight = expands
? maxContainerHeight
: math.min(math.max(contentHeight, minContainerHeight), maxContainerHeight);
// Ensure the text is vertically centered in cases where the content is
// shorter than kMinInteractiveDimension.
final double interactiveAdjustment = minContainerHeight > contentHeight
? (minContainerHeight - contentHeight) / 2.0
: 0.0;
// Try to consider the prefix/suffix as part of the text when aligning it.
// If the prefix/suffix overflows however, allow it to extend outside of the
// input and align the remaining part of the text and prefix/suffix.
final double overflow = math.max(0, contentHeight - maxContainerHeight);
// Map textAlignVertical from -1:1 to 0:1 so that it can be used to scale
// the baseline from its minimum to maximum values.
final double textAlignVerticalFactor = (textAlignVertical.y + 1.0) / 2.0;
// Adjust to try to fit top overflow inside the input on an inverse scale of
// textAlignVertical, so that top aligned text adjusts the most and bottom
// aligned text doesn't adjust at all.
final double baselineAdjustment = fixAboveInput - overflow * (1 - textAlignVerticalFactor);
// The baselines that will be used to draw the actual input text content.
final double topInputBaseline = contentPadding.top
+ topHeight
+ inputInternalBaseline
+ baselineAdjustment
+ interactiveAdjustment
+ densityOffset.dy / 2.0;
final double maxContentHeight = containerHeight - contentPadding.vertical - topHeight - densityOffset.dy;
final double alignableHeight = fixAboveInput + inputHeight + fixBelowInput;
final double maxVerticalOffset = maxContentHeight - alignableHeight;
final double textAlignVerticalOffset = maxVerticalOffset * textAlignVerticalFactor;
final double inputBaseline = topInputBaseline + textAlignVerticalOffset;
// The three main alignments for the baseline when an outline is present are
//
// * top (-1.0): topmost point considering padding.
// * center (0.0): the absolute center of the input ignoring padding but
// accommodating the border and floating label.
// * bottom (1.0): bottommost point considering padding.
//
// That means that if the padding is uneven, center is not the exact
// midpoint of top and bottom. To account for this, the above center and
// below center alignments are interpolated independently.
final double outlineCenterBaseline = inputInternalBaseline
+ baselineAdjustment / 2.0
+ (containerHeight - (2.0 + inputHeight)) / 2.0;
final double outlineTopBaseline = topInputBaseline;
final double outlineBottomBaseline = topInputBaseline + maxVerticalOffset;
final double outlineBaseline = _interpolateThree(
outlineTopBaseline,
outlineCenterBaseline,
outlineBottomBaseline,
textAlignVertical,
);
// Find the positions of the text below the input when it exists.
double subtextCounterBaseline = 0;
double subtextHelperBaseline = 0;
double subtextCounterHeight = 0;
double subtextHelperHeight = 0;
if (counter != null) {
subtextCounterBaseline =
containerHeight + subtextGap + boxToBaseline[counter]!;
subtextCounterHeight = counter!.size.height + subtextGap;
}
if (helperErrorExists) {
subtextHelperBaseline =
containerHeight + subtextGap + boxToBaseline[helperError]!;
subtextHelperHeight = helperErrorHeight;
}
final double subtextBaseline = math.max(
subtextCounterBaseline,
subtextHelperBaseline,
);
final double subtextHeight = math.max(
subtextCounterHeight,
subtextHelperHeight,
);
return _RenderDecorationLayout(
boxToBaseline: boxToBaseline,
containerHeight: containerHeight,
inputBaseline: inputBaseline,
outlineBaseline: outlineBaseline,
subtextBaseline: subtextBaseline,
subtextHeight: subtextHeight,
);
}
// Interpolate between three stops using textAlignVertical. This is used to
// calculate the outline baseline, which ignores padding when the alignment is
// middle. When the alignment is less than zero, it interpolates between the
// centered text box's top and the top of the content padding. When the
// alignment is greater than zero, it interpolates between the centered box's
// top and the position that would align the bottom of the box with the bottom
// padding.
double _interpolateThree(double begin, double middle, double end, TextAlignVertical textAlignVertical) {
if (textAlignVertical.y <= 0) {
// It's possible for begin, middle, and end to not be in order because of
// excessive padding. Those cases are handled by using middle.
if (begin >= middle) {
return middle;
}
// Do a standard linear interpolation on the first half, between begin and
// middle.
final double t = textAlignVertical.y + 1;
return begin + (middle - begin) * t;
}
if (middle >= end) {
return middle;
}
// Do a standard linear interpolation on the second half, between middle and
// end.
final double t = textAlignVertical.y;
return middle + (end - middle) * t;
}
@override
double computeMinIntrinsicWidth(double height) {
return _minWidth(icon, height)
+ contentPadding.left
+ _minWidth(prefixIcon, height)
+ _minWidth(prefix, height)
+ math.max(_minWidth(input, height), _minWidth(hint, height))
+ _minWidth(suffix, height)
+ _minWidth(suffixIcon, height)
+ contentPadding.right;
}
@override
double computeMaxIntrinsicWidth(double height) {
return _maxWidth(icon, height)
+ contentPadding.left
+ _maxWidth(prefixIcon, height)
+ _maxWidth(prefix, height)
+ math.max(_maxWidth(input, height), _maxWidth(hint, height))
+ _maxWidth(suffix, height)
+ _maxWidth(suffixIcon, height)
+ contentPadding.right;
}
double _lineHeight(double width, List<RenderBox?> boxes) {
double height = 0.0;
for (final RenderBox? box in boxes) {
if (box == null) {
continue;
}
height = math.max(_minHeight(box, width), height);
}
return height;
// TODO(hansmuller): this should compute the overall line height for the
// boxes when they've been baseline-aligned.
// See https://github.com/flutter/flutter/issues/13715
}
@override
double computeMinIntrinsicHeight(double width) {
final double iconHeight = _minHeight(icon, width);
final double iconWidth = _minWidth(icon, iconHeight);
width = math.max(width - iconWidth, 0.0);
final double prefixIconHeight = _minHeight(prefixIcon, width);
final double prefixIconWidth = _minWidth(prefixIcon, prefixIconHeight);
final double suffixIconHeight = _minHeight(suffixIcon, width);
final double suffixIconWidth = _minWidth(suffixIcon, suffixIconHeight);
width = math.max(width - contentPadding.horizontal, 0.0);
final double counterHeight = _minHeight(counter, width);
final double counterWidth = _minWidth(counter, counterHeight);
final double helperErrorAvailableWidth = math.max(width - counterWidth, 0.0);
final double helperErrorHeight = _minHeight(helperError, helperErrorAvailableWidth);
double subtextHeight = math.max(counterHeight, helperErrorHeight);
if (subtextHeight > 0.0) {
subtextHeight += subtextGap;
}
final double prefixHeight = _minHeight(prefix, width);
final double prefixWidth = _minWidth(prefix, prefixHeight);
final double suffixHeight = _minHeight(suffix, width);
final double suffixWidth = _minWidth(suffix, suffixHeight);
final double availableInputWidth = math.max(width - prefixWidth - suffixWidth - prefixIconWidth - suffixIconWidth, 0.0);
final double inputHeight = _lineHeight(availableInputWidth, <RenderBox?>[input, hint]);
final double inputMaxHeight = <double>[inputHeight, prefixHeight, suffixHeight].reduce(math.max);
final Offset densityOffset = decoration.visualDensity.baseSizeAdjustment;
final double contentHeight = contentPadding.top
+ (label == null ? 0.0 : decoration.floatingLabelHeight)
+ inputMaxHeight
+ contentPadding.bottom
+ densityOffset.dy;
final double containerHeight = <double>[iconHeight, contentHeight, prefixIconHeight, suffixIconHeight].reduce(math.max);
final double minContainerHeight = decoration.isDense! || expands
? 0.0
: kMinInteractiveDimension;
return math.max(containerHeight, minContainerHeight) + subtextHeight;
}
@override
double computeMaxIntrinsicHeight(double width) {
return computeMinIntrinsicHeight(width);
}
@override
double computeDistanceToActualBaseline(TextBaseline baseline) {
return _boxParentData(input!).offset.dy + (input?.computeDistanceToActualBaseline(baseline) ?? 0.0);
}
// Records where the label was painted.
Matrix4? _labelTransform;
@override
Size computeDryLayout(BoxConstraints constraints) {
assert(debugCannotComputeDryLayout(
reason: 'Layout requires baseline metrics, which are only available after a full layout.',
));
return Size.zero;
}
ChildSemanticsConfigurationsResult _childSemanticsConfigurationDelegate(List<SemanticsConfiguration> childConfigs) {
final ChildSemanticsConfigurationsResultBuilder builder = ChildSemanticsConfigurationsResultBuilder();
List<SemanticsConfiguration>? prefixMergeGroup;
List<SemanticsConfiguration>? suffixMergeGroup;
for (final SemanticsConfiguration childConfig in childConfigs) {
if (childConfig.tagsChildrenWith(_InputDecoratorState._kPrefixSemanticsTag)) {
prefixMergeGroup ??= <SemanticsConfiguration>[];
prefixMergeGroup.add(childConfig);
} else if (childConfig.tagsChildrenWith(_InputDecoratorState._kSuffixSemanticsTag)) {
suffixMergeGroup ??= <SemanticsConfiguration>[];
suffixMergeGroup.add(childConfig);
} else {
builder.markAsMergeUp(childConfig);
}
}
if (prefixMergeGroup != null) {
builder.markAsSiblingMergeGroup(prefixMergeGroup);
}
if (suffixMergeGroup != null) {
builder.markAsSiblingMergeGroup(suffixMergeGroup);
}
return builder.build();
}
@override
void describeSemanticsConfiguration(SemanticsConfiguration config) {
config.childConfigurationsDelegate = _childSemanticsConfigurationDelegate;
}
@override
void performLayout() {
final BoxConstraints constraints = this.constraints;
_labelTransform = null;
final _RenderDecorationLayout layout = _layout(constraints);
final double overallWidth = constraints.maxWidth;
final double overallHeight = layout.containerHeight + layout.subtextHeight;
final RenderBox? container = this.container;
if (container != null) {
final BoxConstraints containerConstraints = BoxConstraints.tightFor(
height: layout.containerHeight,
width: overallWidth - _boxSize(icon).width,
);
container.layout(containerConstraints, parentUsesSize: true);
final double x;
switch (textDirection) {
case TextDirection.rtl:
x = 0.0;
case TextDirection.ltr:
x = _boxSize(icon).width;
}
_boxParentData(container).offset = Offset(x, 0.0);
}
late double height;
double centerLayout(RenderBox box, double x) {
_boxParentData(box).offset = Offset(x, (height - box.size.height) / 2.0);
return box.size.width;
}
late double baseline;
double baselineLayout(RenderBox box, double x) {
_boxParentData(box).offset = Offset(x, baseline - layout.boxToBaseline[box]!);
return box.size.width;
}
final double left = contentPadding.left;
final double right = overallWidth - contentPadding.right;
height = layout.containerHeight;
baseline = _isOutlineAligned ? layout.outlineBaseline : layout.inputBaseline;
if (icon != null) {
final double x;
switch (textDirection) {
case TextDirection.rtl:
x = overallWidth - icon!.size.width;
case TextDirection.ltr:
x = 0.0;
}
centerLayout(icon!, x);
}
switch (textDirection) {
case TextDirection.rtl: {
double start = right - _boxSize(icon).width;
double end = left;
if (prefixIcon != null) {
start += contentPadding.right;
start -= centerLayout(prefixIcon!, start - prefixIcon!.size.width);
}
if (label != null) {
if (decoration.alignLabelWithHint) {
baselineLayout(label!, start - label!.size.width);
} else {
centerLayout(label!, start - label!.size.width);
}
}
if (prefix != null) {
start -= baselineLayout(prefix!, start - prefix!.size.width);
}
if (input != null) {
baselineLayout(input!, start - input!.size.width);
}
if (hint != null) {
baselineLayout(hint!, start - hint!.size.width);
}
if (suffixIcon != null) {
end -= contentPadding.left;
end += centerLayout(suffixIcon!, end);
}
if (suffix != null) {
end += baselineLayout(suffix!, end);
}
break;
}
case TextDirection.ltr: {
double start = left + _boxSize(icon).width;
double end = right;
if (prefixIcon != null) {
start -= contentPadding.left;
start += centerLayout(prefixIcon!, start);
}
if (label != null) {
if (decoration.alignLabelWithHint) {
baselineLayout(label!, start);
} else {
centerLayout(label!, start);
}
}
if (prefix != null) {
start += baselineLayout(prefix!, start);
}
if (input != null) {
baselineLayout(input!, start);
}
if (hint != null) {
baselineLayout(hint!, start);
}
if (suffixIcon != null) {
end += contentPadding.right;
end -= centerLayout(suffixIcon!, end - suffixIcon!.size.width);
}
if (suffix != null) {
end -= baselineLayout(suffix!, end - suffix!.size.width);
}
break;
}
}
if (helperError != null || counter != null) {
height = layout.subtextHeight;
baseline = layout.subtextBaseline;
switch (textDirection) {
case TextDirection.rtl:
if (helperError != null) {
baselineLayout(helperError!, right - helperError!.size.width - _boxSize(icon).width);
}
if (counter != null) {
baselineLayout(counter!, left);
}
case TextDirection.ltr:
if (helperError != null) {
baselineLayout(helperError!, left + _boxSize(icon).width);
}
if (counter != null) {
baselineLayout(counter!, right - counter!.size.width);
}
}
}
if (label != null) {
final double labelX = _boxParentData(label!).offset.dx;
// +1 shifts the range of x from (-1.0, 1.0) to (0.0, 2.0).
final double floatAlign = decoration.floatingLabelAlignment._x + 1;
final double floatWidth = _boxSize(label).width * _kFinalLabelScale;
// When floating label is centered, its x is relative to
// _BorderContainer's x and is independent of label's x.
switch (textDirection) {
case TextDirection.rtl:
double offsetToPrefixIcon = 0.0;
if (prefixIcon != null && !decoration.alignLabelWithHint) {
offsetToPrefixIcon = material3 ? _boxSize(prefixIcon).width - left : 0;
}
decoration.borderGap.start = lerpDouble(labelX + _boxSize(label).width + offsetToPrefixIcon,
_boxSize(container).width / 2.0 + floatWidth / 2.0,
floatAlign);
case TextDirection.ltr:
// The value of _InputBorderGap.start is relative to the origin of the
// _BorderContainer which is inset by the icon's width. Although, when
// floating label is centered, it's already relative to _BorderContainer.
double offsetToPrefixIcon = 0.0;
if (prefixIcon != null && !decoration.alignLabelWithHint) {
offsetToPrefixIcon = material3 ? (-_boxSize(prefixIcon).width + left) : 0;
}
decoration.borderGap.start = lerpDouble(labelX - _boxSize(icon).width + offsetToPrefixIcon,
_boxSize(container).width / 2.0 - floatWidth / 2.0,
floatAlign);
}
decoration.borderGap.extent = label!.size.width * _kFinalLabelScale;
} else {
decoration.borderGap.start = null;
decoration.borderGap.extent = 0.0;
}
size = constraints.constrain(Size(overallWidth, overallHeight));
assert(size.width == constraints.constrainWidth(overallWidth));
assert(size.height == constraints.constrainHeight(overallHeight));
}
void _paintLabel(PaintingContext context, Offset offset) {
context.paintChild(label!, offset);
}
@override
void paint(PaintingContext context, Offset offset) {
void doPaint(RenderBox? child) {
if (child != null) {
context.paintChild(child, _boxParentData(child).offset + offset);
}
}
doPaint(container);
if (label != null) {
final Offset labelOffset = _boxParentData(label!).offset;
final double labelHeight = _boxSize(label).height;
final double labelWidth = _boxSize(label).width;
// +1 shifts the range of x from (-1.0, 1.0) to (0.0, 2.0).
final double floatAlign = decoration.floatingLabelAlignment._x + 1;
final double floatWidth = labelWidth * _kFinalLabelScale;
final double borderWeight = decoration.border.borderSide.width;
final double t = decoration.floatingLabelProgress;
// The center of the outline border label ends up a little below the
// center of the top border line.
final bool isOutlineBorder = decoration.border.isOutline;
// Temporary opt-in fix for https://github.com/flutter/flutter/issues/54028
// Center the scaled label relative to the border.
final double floatingY = isOutlineBorder ? (-labelHeight * _kFinalLabelScale) / 2.0 + borderWeight / 2.0 : contentPadding.top;
final double scale = lerpDouble(1.0, _kFinalLabelScale, t)!;
final double centeredFloatX = _boxParentData(container!).offset.dx +
_boxSize(container).width / 2.0 - floatWidth / 2.0;
final double startX;
double floatStartX;
switch (textDirection) {
case TextDirection.rtl: // origin is on the right
startX = labelOffset.dx + labelWidth * (1.0 - scale);
floatStartX = startX;
if (prefixIcon != null && !decoration.alignLabelWithHint && isOutlineBorder) {
floatStartX += material3 ? _boxSize(prefixIcon).width - contentPadding.left : 0.0;
}
case TextDirection.ltr: // origin on the left
startX = labelOffset.dx;
floatStartX = startX;
if (prefixIcon != null && !decoration.alignLabelWithHint && isOutlineBorder) {
floatStartX += material3 ? -_boxSize(prefixIcon).width + contentPadding.left : 0.0;
}
}
final double floatEndX = lerpDouble(floatStartX, centeredFloatX, floatAlign)!;
final double dx = lerpDouble(startX, floatEndX, t)!;
final double dy = lerpDouble(0.0, floatingY - labelOffset.dy, t)!;
_labelTransform = Matrix4.identity()
..translate(dx, labelOffset.dy + dy)
..scale(scale);
layer = context.pushTransform(
needsCompositing,
offset,
_labelTransform!,
_paintLabel,
oldLayer: layer as TransformLayer?,
);
} else {
layer = null;
}
doPaint(icon);
doPaint(prefix);
doPaint(suffix);
doPaint(prefixIcon);
doPaint(suffixIcon);
doPaint(hint);
doPaint(input);
doPaint(helperError);
doPaint(counter);
}
@override
bool hitTestSelf(Offset position) => true;
@override
bool hitTestChildren(BoxHitTestResult result, { required Offset position }) {
for (final RenderBox child in children) {
// The label must be handled specially since we've transformed it.
final Offset offset = _boxParentData(child).offset;
final bool isHit = result.addWithPaintOffset(
offset: offset,
position: position,
hitTest: (BoxHitTestResult result, Offset transformed) {
assert(transformed == position - offset);
return child.hitTest(result, position: transformed);
},
);
if (isHit) {
return true;
}
}
return false;
}
@override
void applyPaintTransform(RenderObject child, Matrix4 transform) {
if (child == label && _labelTransform != null) {
final Offset labelOffset = _boxParentData(label!).offset;
transform
..multiply(_labelTransform!)
..translate(-labelOffset.dx, -labelOffset.dy);
}
super.applyPaintTransform(child, transform);
}
}
class _Decorator extends SlottedMultiChildRenderObjectWidget<_DecorationSlot, RenderBox> {
const _Decorator({
required this.textAlignVertical,
required this.decoration,
required this.textDirection,
required this.textBaseline,
required this.isFocused,
required this.expands,
});
final _Decoration decoration;
final TextDirection textDirection;
final TextBaseline textBaseline;
final TextAlignVertical? textAlignVertical;
final bool isFocused;
final bool expands;
@override
Iterable<_DecorationSlot> get slots => _DecorationSlot.values;
@override
Widget? childForSlot(_DecorationSlot slot) {
switch (slot) {
case _DecorationSlot.icon:
return decoration.icon;
case _DecorationSlot.input:
return decoration.input;
case _DecorationSlot.label:
return decoration.label;
case _DecorationSlot.hint:
return decoration.hint;
case _DecorationSlot.prefix:
return decoration.prefix;
case _DecorationSlot.suffix:
return decoration.suffix;
case _DecorationSlot.prefixIcon:
return decoration.prefixIcon;
case _DecorationSlot.suffixIcon:
return decoration.suffixIcon;
case _DecorationSlot.helperError:
return decoration.helperError;
case _DecorationSlot.counter:
return decoration.counter;
case _DecorationSlot.container:
return decoration.container;
}
}
@override
_RenderDecoration createRenderObject(BuildContext context) {
return _RenderDecoration(
decoration: decoration,
textDirection: textDirection,
textBaseline: textBaseline,
textAlignVertical: textAlignVertical,
isFocused: isFocused,
expands: expands,
material3: Theme.of(context).useMaterial3,
);
}
@override
void updateRenderObject(BuildContext context, _RenderDecoration renderObject) {
renderObject
..decoration = decoration
..expands = expands
..isFocused = isFocused
..textAlignVertical = textAlignVertical
..textBaseline = textBaseline
..textDirection = textDirection;
}
}
class _AffixText extends StatelessWidget {
const _AffixText({
required this.labelIsFloating,
this.text,
this.style,
this.child,
this.semanticsSortKey,
required this.semanticsTag,
});
final bool labelIsFloating;
final String? text;
final TextStyle? style;
final Widget? child;
final SemanticsSortKey? semanticsSortKey;
final SemanticsTag semanticsTag;
@override
Widget build(BuildContext context) {
return DefaultTextStyle.merge(
style: style,
child: AnimatedOpacity(
duration: _kTransitionDuration,
curve: _kTransitionCurve,
opacity: labelIsFloating ? 1.0 : 0.0,
child: Semantics(
sortKey: semanticsSortKey,
tagForChildren: semanticsTag,
child: child ?? (text == null ? null : Text(text!, style: style)),
),
),
);
}
}
/// Defines the appearance of a Material Design text field.
///
/// [InputDecorator] displays the visual elements of a Material Design text
/// field around its input [child]. The visual elements themselves are defined
/// by an [InputDecoration] object and their layout and appearance depend
/// on the `baseStyle`, `textAlign`, `isFocused`, and `isEmpty` parameters.
///
/// [TextField] uses this widget to decorate its [EditableText] child.
///
/// [InputDecorator] can be used to create widgets that look and behave like a
/// [TextField] but support other kinds of input.
///
/// Requires one of its ancestors to be a [Material] widget. The [child] widget,
/// as well as the decorative widgets specified in [decoration], must have
/// non-negative baselines.
///
/// See also:
///
/// * [TextField], which uses an [InputDecorator] to display a border,
/// labels, and icons, around its [EditableText] child.
/// * [Decoration] and [DecoratedBox], for drawing arbitrary decorations
/// around other widgets.
class InputDecorator extends StatefulWidget {
/// Creates a widget that displays a border, labels, and icons,
/// for a [TextField].
///
/// The [isFocused], [isHovering], [expands], and [isEmpty] arguments must not
/// be null.
const InputDecorator({
super.key,
required this.decoration,
this.baseStyle,
this.textAlign,
this.textAlignVertical,
this.isFocused = false,
this.isHovering = false,
this.expands = false,
this.isEmpty = false,
this.child,
});
/// The text and styles to use when decorating the child.
///
/// Null [InputDecoration] properties are initialized with the corresponding
/// values from [ThemeData.inputDecorationTheme].
///
/// Must not be null.
final InputDecoration decoration;
/// The style on which to base the label, hint, counter, and error styles
/// if the [decoration] does not provide explicit styles.
///
/// If null, [baseStyle] defaults to the `titleMedium` style from the
/// current [Theme], see [ThemeData.textTheme].
///
/// The [TextStyle.textBaseline] of the [baseStyle] is used to determine
/// the baseline used for text alignment.
final TextStyle? baseStyle;
/// How the text in the decoration should be aligned horizontally.
final TextAlign? textAlign;
/// {@template flutter.material.InputDecorator.textAlignVertical}
/// How the text should be aligned vertically.
///
/// Determines the alignment of the baseline within the available space of
/// the input (typically a TextField). For example, TextAlignVertical.top will
/// place the baseline such that the text, and any attached decoration like
/// prefix and suffix, is as close to the top of the input as possible without
/// overflowing. The heights of the prefix and suffix are similarly included
/// for other alignment values. If the height is greater than the height
/// available, then the prefix and suffix will be allowed to overflow first
/// before the text scrolls.
/// {@endtemplate}
final TextAlignVertical? textAlignVertical;
/// Whether the input field has focus.
///
/// Determines the position of the label text and the color and weight of the
/// border.
///
/// Defaults to false.
///
/// See also:
///
/// * [InputDecoration.hoverColor], which is also blended into the focus
/// color and fill color when the [isHovering] is true to produce the final
/// color.
final bool isFocused;
/// Whether the input field is being hovered over by a mouse pointer.
///
/// Determines the container fill color, which is a blend of
/// [InputDecoration.hoverColor] with [InputDecoration.fillColor] when
/// true, and [InputDecoration.fillColor] when not.
///
/// Defaults to false.
final bool isHovering;
/// If true, the height of the input field will be as large as possible.
///
/// If wrapped in a widget that constrains its child's height, like Expanded
/// or SizedBox, the input field will only be affected if [expands] is set to
/// true.
///
/// See [TextField.minLines] and [TextField.maxLines] for related ways to
/// affect the height of an input. When [expands] is true, both must be null
/// in order to avoid ambiguity in determining the height.
///
/// Defaults to false.
final bool expands;
/// Whether the input field is empty.
///
/// Determines the position of the label text and whether to display the hint
/// text.
///
/// Defaults to false.
final bool isEmpty;
/// The widget below this widget in the tree.
///
/// Typically an [EditableText], [DropdownButton], or [InkWell].
final Widget? child;
/// Whether the label needs to get out of the way of the input, either by
/// floating or disappearing.
///
/// Will withdraw when not empty, or when focused while enabled.
bool get _labelShouldWithdraw => !isEmpty || (isFocused && decoration.enabled);
@override
State<InputDecorator> createState() => _InputDecoratorState();
/// The RenderBox that defines this decorator's "container". That's the
/// area which is filled if [InputDecoration.filled] is true. It's the area
/// adjacent to [InputDecoration.icon] and above the widgets that contain
/// [InputDecoration.helperText], [InputDecoration.errorText], and
/// [InputDecoration.counterText].
///
/// [TextField] renders ink splashes within the container.
static RenderBox? containerOf(BuildContext context) {
final _RenderDecoration? result = context.findAncestorRenderObjectOfType<_RenderDecoration>();
return result?.container;
}
@override
void debugFillProperties(DiagnosticPropertiesBuilder properties) {
super.debugFillProperties(properties);
properties.add(DiagnosticsProperty<InputDecoration>('decoration', decoration));
properties.add(DiagnosticsProperty<TextStyle>('baseStyle', baseStyle, defaultValue: null));
properties.add(DiagnosticsProperty<bool>('isFocused', isFocused));
properties.add(DiagnosticsProperty<bool>('expands', expands, defaultValue: false));
properties.add(DiagnosticsProperty<bool>('isEmpty', isEmpty));
}
}
class _InputDecoratorState extends State<InputDecorator> with TickerProviderStateMixin {
late final AnimationController _floatingLabelController;
late final Animation<double> _floatingLabelAnimation;
late final AnimationController _shakingLabelController;
final _InputBorderGap _borderGap = _InputBorderGap();
static const OrdinalSortKey _kPrefixSemanticsSortOrder = OrdinalSortKey(0);
static const OrdinalSortKey _kInputSemanticsSortOrder = OrdinalSortKey(1);
static const OrdinalSortKey _kSuffixSemanticsSortOrder = OrdinalSortKey(2);
static const SemanticsTag _kPrefixSemanticsTag = SemanticsTag('_InputDecoratorState.prefix');
static const SemanticsTag _kSuffixSemanticsTag = SemanticsTag('_InputDecoratorState.suffix');
@override
void initState() {
super.initState();
final bool labelIsInitiallyFloating = widget.decoration.floatingLabelBehavior == FloatingLabelBehavior.always
|| (widget.decoration.floatingLabelBehavior != FloatingLabelBehavior.never &&
widget._labelShouldWithdraw);
_floatingLabelController = AnimationController(
duration: _kTransitionDuration,
vsync: this,
value: labelIsInitiallyFloating ? 1.0 : 0.0,
);
_floatingLabelController.addListener(_handleChange);
_floatingLabelAnimation = CurvedAnimation(
parent: _floatingLabelController,
curve: _kTransitionCurve,
reverseCurve: _kTransitionCurve.flipped,
);
_shakingLabelController = AnimationController(
duration: _kTransitionDuration,
vsync: this,
);
}
@override
void didChangeDependencies() {
super.didChangeDependencies();
_effectiveDecoration = null;
}
@override
void dispose() {
_floatingLabelController.dispose();
_shakingLabelController.dispose();
super.dispose();
}
void _handleChange() {
setState(() {
// The _floatingLabelController's value has changed.
});
}
InputDecoration? _effectiveDecoration;
InputDecoration get decoration => _effectiveDecoration ??= widget.decoration.applyDefaults(Theme.of(context).inputDecorationTheme);
TextAlign? get textAlign => widget.textAlign;
bool get isFocused => widget.isFocused;
bool get isHovering => widget.isHovering && decoration.enabled;
bool get isEmpty => widget.isEmpty;
bool get _floatingLabelEnabled {
return decoration.floatingLabelBehavior != FloatingLabelBehavior.never;
}
@override
void didUpdateWidget(InputDecorator old) {
super.didUpdateWidget(old);
if (widget.decoration != old.decoration) {
_effectiveDecoration = null;
}
final bool floatBehaviorChanged = widget.decoration.floatingLabelBehavior != old.decoration.floatingLabelBehavior;
if (widget._labelShouldWithdraw != old._labelShouldWithdraw || floatBehaviorChanged) {
if (_floatingLabelEnabled
&& (widget._labelShouldWithdraw || widget.decoration.floatingLabelBehavior == FloatingLabelBehavior.always)) {
_floatingLabelController.forward();
} else {
_floatingLabelController.reverse();
}
}
final String? errorText = decoration.errorText;
final String? oldErrorText = old.decoration.errorText;
if (_floatingLabelController.isCompleted && errorText != null && errorText != oldErrorText) {
_shakingLabelController
..value = 0.0
..forward();
}
}
Color _getDefaultM2BorderColor(ThemeData themeData) {
if (!decoration.enabled && !isFocused) {
return ((decoration.filled ?? false) && !(decoration.border?.isOutline ?? false))
? Colors.transparent
: themeData.disabledColor;
}
if (decoration.errorText != null) {
return themeData.colorScheme.error;
}
if (isFocused) {
return themeData.colorScheme.primary;
}
if (decoration.filled!) {
return themeData.hintColor;
}
final Color enabledColor = themeData.colorScheme.onSurface.withOpacity(0.38);
if (isHovering) {
final Color hoverColor = decoration.hoverColor ?? themeData.inputDecorationTheme.hoverColor ?? themeData.hoverColor;
return Color.alphaBlend(hoverColor.withOpacity(0.12), enabledColor);
}
return enabledColor;
}
Color _getFillColor(ThemeData themeData, InputDecorationTheme defaults) {
if (decoration.filled != true) { // filled == null same as filled == false
return Colors.transparent;
}
if (decoration.fillColor != null) {
return MaterialStateProperty.resolveAs(decoration.fillColor!, materialState);
}
return MaterialStateProperty.resolveAs(defaults.fillColor!, materialState);
}
Color _getHoverColor(ThemeData themeData) {
if (decoration.filled == null || !decoration.filled! || isFocused || !decoration.enabled) {
return Colors.transparent;
}
return decoration.hoverColor ?? themeData.inputDecorationTheme.hoverColor ?? themeData.hoverColor;
}
Color _getIconColor(ThemeData themeData, InputDecorationTheme defaults) {
return MaterialStateProperty.resolveAs(decoration.iconColor, materialState)
?? MaterialStateProperty.resolveAs(themeData.inputDecorationTheme.iconColor, materialState)
?? MaterialStateProperty.resolveAs(defaults.iconColor!, materialState);
}
Color _getPrefixIconColor(ThemeData themeData, InputDecorationTheme defaults) {
return MaterialStateProperty.resolveAs(decoration.prefixIconColor, materialState)
?? MaterialStateProperty.resolveAs(themeData.inputDecorationTheme.prefixIconColor, materialState)
?? MaterialStateProperty.resolveAs(defaults.prefixIconColor!, materialState);
}
Color _getSuffixIconColor(ThemeData themeData, InputDecorationTheme defaults) {
return MaterialStateProperty.resolveAs(decoration.suffixIconColor, materialState)
?? MaterialStateProperty.resolveAs(themeData.inputDecorationTheme.suffixIconColor, materialState)
?? MaterialStateProperty.resolveAs(defaults.suffixIconColor!, materialState);
}
// True if the label will be shown and the hint will not.
// If we're not focused, there's no value, labelText was provided, and
// floatingLabelBehavior isn't set to always, then the label appears where the
// hint would.
bool get _hasInlineLabel {
return !widget._labelShouldWithdraw
&& (decoration.labelText != null || decoration.label != null)
&& decoration.floatingLabelBehavior != FloatingLabelBehavior.always;
}
// If the label is a floating placeholder, it's always shown.
bool get _shouldShowLabel => _hasInlineLabel || _floatingLabelEnabled;
// The base style for the inline label when they're displayed "inline",
// i.e. when they appear in place of the empty text field.
TextStyle _getInlineLabelStyle(ThemeData themeData, InputDecorationTheme defaults) {
final TextStyle defaultStyle = MaterialStateProperty.resolveAs(defaults.labelStyle!, materialState);
final TextStyle? style = MaterialStateProperty.resolveAs(decoration.labelStyle, materialState)
?? MaterialStateProperty.resolveAs(themeData.inputDecorationTheme.labelStyle, materialState);
return themeData.textTheme.titleMedium!
.merge(widget.baseStyle)
.merge(defaultStyle)
.merge(style)
.copyWith(height: 1);
}
// The base style for the inline hint when they're displayed "inline",
// i.e. when they appear in place of the empty text field.
TextStyle _getInlineHintStyle(ThemeData themeData, InputDecorationTheme defaults) {
final TextStyle defaultStyle = MaterialStateProperty.resolveAs(defaults.hintStyle!, materialState);
final TextStyle? style = MaterialStateProperty.resolveAs(decoration.hintStyle, materialState)
?? MaterialStateProperty.resolveAs(themeData.inputDecorationTheme.hintStyle, materialState);
return themeData.textTheme.titleMedium!
.merge(widget.baseStyle)
.merge(defaultStyle)
.merge(style);
}
TextStyle _getFloatingLabelStyle(ThemeData themeData, InputDecorationTheme defaults) {
TextStyle defaultTextStyle = MaterialStateProperty.resolveAs(defaults.floatingLabelStyle!, materialState);
if (decoration.errorText != null && decoration.errorStyle?.color != null) {
defaultTextStyle = defaultTextStyle.copyWith(color: decoration.errorStyle?.color);
}
defaultTextStyle = defaultTextStyle.merge(decoration.floatingLabelStyle ?? decoration.labelStyle);
final TextStyle? style = MaterialStateProperty.resolveAs(decoration.floatingLabelStyle, materialState)
?? MaterialStateProperty.resolveAs(themeData.inputDecorationTheme.floatingLabelStyle, materialState);
return themeData.textTheme.titleMedium!
.merge(widget.baseStyle)
.copyWith(height: 1)
.merge(defaultTextStyle)
.merge(style);
}
TextStyle _getHelperStyle(ThemeData themeData, InputDecorationTheme defaults) {
return MaterialStateProperty.resolveAs(defaults.helperStyle!, materialState)
.merge(MaterialStateProperty.resolveAs(decoration.helperStyle, materialState));
}
TextStyle _getErrorStyle(ThemeData themeData, InputDecorationTheme defaults) {
return MaterialStateProperty.resolveAs(defaults.errorStyle!, materialState)
.merge(decoration.errorStyle);
}
Set<MaterialState> get materialState {
return <MaterialState>{
if (!decoration.enabled) MaterialState.disabled,
if (isFocused) MaterialState.focused,
if (isHovering) MaterialState.hovered,
if (decoration.errorText != null) MaterialState.error,
};
}
InputBorder _getDefaultBorder(ThemeData themeData, InputDecorationTheme defaults) {
final InputBorder border = MaterialStateProperty.resolveAs(decoration.border, materialState)
?? const UnderlineInputBorder();
if (decoration.border is MaterialStateProperty<InputBorder>) {
return border;
}
if (border.borderSide == BorderSide.none) {
return border;
}
if (themeData.useMaterial3) {
if (decoration.filled!) {
return border.copyWith(
borderSide: MaterialStateProperty.resolveAs(defaults.activeIndicatorBorder, materialState),
);
} else {
return border.copyWith(
borderSide: MaterialStateProperty.resolveAs(defaults.outlineBorder, materialState),
);
}
}
else{
return border.copyWith(
borderSide: BorderSide(
color: _getDefaultM2BorderColor(themeData),
width: (decoration.isCollapsed || decoration.border == InputBorder.none || !decoration.enabled)
? 0.0
: isFocused ? 2.0 : 1.0,
),
);
}
}
@override
Widget build(BuildContext context) {
final ThemeData themeData = Theme.of(context);
final InputDecorationTheme defaults =
Theme.of(context).useMaterial3 ? _InputDecoratorDefaultsM3(context) : _InputDecoratorDefaultsM2(context);
final TextStyle labelStyle = _getInlineLabelStyle(themeData, defaults);
final TextBaseline textBaseline = labelStyle.textBaseline!;
final TextStyle hintStyle = _getInlineHintStyle(themeData, defaults);
final String? hintText = decoration.hintText;
final Widget? hint = hintText == null ? null : AnimatedOpacity(
opacity: (isEmpty && !_hasInlineLabel) ? 1.0 : 0.0,
duration: _kTransitionDuration,
curve: _kTransitionCurve,
child: Text(
hintText,
style: hintStyle,
textDirection: decoration.hintTextDirection,
overflow: hintStyle.overflow ?? TextOverflow.ellipsis,
textAlign: textAlign,
maxLines: decoration.hintMaxLines,
),
);
final bool isError = decoration.errorText != null;
InputBorder? border;
if (!decoration.enabled) {
border = isError ? decoration.errorBorder : decoration.disabledBorder;
} else if (isFocused) {
border = isError ? decoration.focusedErrorBorder : decoration.focusedBorder;
} else {
border = isError ? decoration.errorBorder : decoration.enabledBorder;
}
border ??= _getDefaultBorder(themeData, defaults);
final Widget container = _BorderContainer(
border: border,
gap: _borderGap,
gapAnimation: _floatingLabelAnimation,
fillColor: _getFillColor(themeData, defaults),
hoverColor: _getHoverColor(themeData),
isHovering: isHovering,
);
final Widget? label = decoration.labelText == null && decoration.label == null ? null : _Shaker(
animation: _shakingLabelController.view,
child: AnimatedOpacity(
duration: _kTransitionDuration,
curve: _kTransitionCurve,
opacity: _shouldShowLabel ? 1.0 : 0.0,
child: AnimatedDefaultTextStyle(
duration:_kTransitionDuration,
curve: _kTransitionCurve,
style: widget._labelShouldWithdraw
? _getFloatingLabelStyle(themeData, defaults)
: labelStyle,
child: decoration.label ?? Text(
decoration.labelText!,
overflow: TextOverflow.ellipsis,
textAlign: textAlign,
),
),
),
);
final bool hasPrefix = decoration.prefix != null || decoration.prefixText != null;
final bool hasSuffix = decoration.suffix != null || decoration.suffixText != null;
Widget? input = widget.child;
// If at least two out of the three are visible, it needs semantics sort
// order.
final bool needsSemanticsSortOrder = widget._labelShouldWithdraw && (input != null ? (hasPrefix || hasSuffix) : (hasPrefix && hasSuffix));
final Widget? prefix = hasPrefix
? _AffixText(
labelIsFloating: widget._labelShouldWithdraw,
text: decoration.prefixText,
style: MaterialStateProperty.resolveAs(decoration.prefixStyle, materialState) ?? hintStyle,
semanticsSortKey: needsSemanticsSortOrder ? _kPrefixSemanticsSortOrder : null,
semanticsTag: _kPrefixSemanticsTag,
child: decoration.prefix,
)
: null;
final Widget? suffix = hasSuffix
? _AffixText(
labelIsFloating: widget._labelShouldWithdraw,
text: decoration.suffixText,
style: MaterialStateProperty.resolveAs(decoration.suffixStyle, materialState) ?? hintStyle,
semanticsSortKey: needsSemanticsSortOrder ? _kSuffixSemanticsSortOrder : null,
semanticsTag: _kSuffixSemanticsTag,
child: decoration.suffix,
)
: null;
if (input != null && needsSemanticsSortOrder) {
input = Semantics(
sortKey: _kInputSemanticsSortOrder,
child: input,
);
}
final bool decorationIsDense = decoration.isDense ?? false;
final double iconSize = decorationIsDense ? 18.0 : 24.0;
final Widget? icon = decoration.icon == null ? null :
MouseRegion(
cursor: SystemMouseCursors.basic,
child: Padding(
padding: const EdgeInsetsDirectional.only(end: 16.0),
child: IconTheme.merge(
data: IconThemeData(
color: _getIconColor(themeData, defaults),
size: iconSize,
),
child: decoration.icon!,
),
),
);
final Widget? prefixIcon = decoration.prefixIcon == null ? null :
Center(
widthFactor: 1.0,
heightFactor: 1.0,
child: MouseRegion(
cursor: SystemMouseCursors.basic,
child: ConstrainedBox(
constraints: decoration.prefixIconConstraints ??
themeData.visualDensity.effectiveConstraints(
const BoxConstraints(
minWidth: kMinInteractiveDimension,
minHeight: kMinInteractiveDimension,
),
),
child: IconTheme.merge(
data: IconThemeData(
color: _getPrefixIconColor(themeData, defaults),
size: iconSize,
),
child: IconButtonTheme(
data: IconButtonThemeData(
style: IconButton.styleFrom(
foregroundColor: _getPrefixIconColor(themeData, defaults),
iconSize: iconSize,
),
),
child: Semantics(
child: decoration.prefixIcon,
),
),
),
),
),
);
final Widget? suffixIcon = decoration.suffixIcon == null ? null :
Center(
widthFactor: 1.0,
heightFactor: 1.0,
child: MouseRegion(
cursor: SystemMouseCursors.basic,
child: ConstrainedBox(
constraints: decoration.suffixIconConstraints ??
themeData.visualDensity.effectiveConstraints(
const BoxConstraints(
minWidth: kMinInteractiveDimension,
minHeight: kMinInteractiveDimension,
),
),
child: IconTheme.merge(
data: IconThemeData(
color: _getSuffixIconColor(themeData, defaults),
size: iconSize,
),
child: IconButtonTheme(
data: IconButtonThemeData(
style: IconButton.styleFrom(
foregroundColor: _getSuffixIconColor(themeData, defaults),
iconSize: iconSize,
),
),
child: Semantics(
child: decoration.suffixIcon,
),
),
),
),
),
);
final Widget helperError = _HelperError(
textAlign: textAlign,
helperText: decoration.helperText,
helperStyle: _getHelperStyle(themeData, defaults),
helperMaxLines: decoration.helperMaxLines,
error: decoration.error,
errorText: decoration.errorText,
errorStyle: _getErrorStyle(themeData, defaults),
errorMaxLines: decoration.errorMaxLines,
);
Widget? counter;
if (decoration.counter != null) {
counter = decoration.counter;
} else if (decoration.counterText != null && decoration.counterText != '') {
counter = Semantics(
container: true,
liveRegion: isFocused,
child: Text(
decoration.counterText!,
style: _getHelperStyle(themeData, defaults).merge(MaterialStateProperty.resolveAs(decoration.counterStyle, materialState)),
overflow: TextOverflow.ellipsis,
semanticsLabel: decoration.semanticCounterText,
),
);
}
// The _Decoration widget and _RenderDecoration assume that contentPadding
// has been resolved to EdgeInsets.
final TextDirection textDirection = Directionality.of(context);
final EdgeInsets? decorationContentPadding = decoration.contentPadding?.resolve(textDirection);
final EdgeInsets contentPadding;
final double floatingLabelHeight;
if (decoration.isCollapsed) {
floatingLabelHeight = 0.0;
contentPadding = decorationContentPadding ?? EdgeInsets.zero;
} else if (!border.isOutline) {
// 4.0: the vertical gap between the inline elements and the floating label.
floatingLabelHeight = (4.0 + 0.75 * labelStyle.fontSize!) * MediaQuery.textScalerOf(context).textScaleFactor;
if (decoration.filled ?? false) {
contentPadding = decorationContentPadding ?? (decorationIsDense
? const EdgeInsets.fromLTRB(12.0, 8.0, 12.0, 8.0)
: const EdgeInsets.fromLTRB(12.0, 12.0, 12.0, 12.0));
} else {
// Not left or right padding for underline borders that aren't filled
// is a small concession to backwards compatibility. This eliminates
// the most noticeable layout change introduced by #13734.
contentPadding = decorationContentPadding ?? (decorationIsDense
? const EdgeInsets.fromLTRB(0.0, 8.0, 0.0, 8.0)
: const EdgeInsets.fromLTRB(0.0, 12.0, 0.0, 12.0));
}
} else {
floatingLabelHeight = 0.0;
contentPadding = decorationContentPadding ?? (decorationIsDense
? const EdgeInsets.fromLTRB(12.0, 20.0, 12.0, 12.0)
: const EdgeInsets.fromLTRB(12.0, 24.0, 12.0, 16.0));
}
final _Decorator decorator = _Decorator(
decoration: _Decoration(
contentPadding: contentPadding,
isCollapsed: decoration.isCollapsed,
floatingLabelHeight: floatingLabelHeight,
floatingLabelAlignment: decoration.floatingLabelAlignment!,
floatingLabelProgress: _floatingLabelAnimation.value,
border: border,
borderGap: _borderGap,
alignLabelWithHint: decoration.alignLabelWithHint ?? false,
isDense: decoration.isDense,
visualDensity: themeData.visualDensity,
icon: icon,
input: input,
label: label,
hint: hint,
prefix: prefix,
suffix: suffix,
prefixIcon: prefixIcon,
suffixIcon: suffixIcon,
helperError: helperError,
counter: counter,
container: container
),
textDirection: textDirection,
textBaseline: textBaseline,
textAlignVertical: widget.textAlignVertical,
isFocused: isFocused,
expands: widget.expands,
);
final BoxConstraints? constraints = decoration.constraints ?? themeData.inputDecorationTheme.constraints;
if (constraints != null) {
return ConstrainedBox(
constraints: constraints,
child: decorator,
);
}
return decorator;
}
}
/// The border, labels, icons, and styles used to decorate a Material
/// Design text field.
///
/// The [TextField] and [InputDecorator] classes use [InputDecoration] objects
/// to describe their decoration. (In fact, this class is merely the
/// configuration of an [InputDecorator], which does all the heavy lifting.)
///
/// {@tool dartpad}
/// This sample shows how to style a `TextField` using an `InputDecorator`. The
/// TextField displays a "send message" icon to the left of the input area,
/// which is surrounded by a border an all sides. It displays the `hintText`
/// inside the input area to help the user understand what input is required. It
/// displays the `helperText` and `counterText` below the input area.
///
/// ![](https://flutter.github.io/assets-for-api-docs/assets/material/input_decoration.png)
///
/// ** See code in examples/api/lib/material/input_decorator/input_decoration.0.dart **
/// {@end-tool}
///
/// {@tool dartpad}
/// This sample shows how to style a "collapsed" `TextField` using an
/// `InputDecorator`. The collapsed `TextField` surrounds the hint text and
/// input area with a border, but does not add padding around them.
///
/// ![](https://flutter.github.io/assets-for-api-docs/assets/material/input_decoration_collapsed.png)
///
/// ** See code in examples/api/lib/material/input_decorator/input_decoration.1.dart **
/// {@end-tool}
///
/// {@tool dartpad}
/// This sample shows how to create a `TextField` with hint text, a red border
/// on all sides, and an error message. To display a red border and error
/// message, provide `errorText` to the [InputDecoration] constructor.
///
/// ![](https://flutter.github.io/assets-for-api-docs/assets/material/input_decoration_error.png)
///
/// ** See code in examples/api/lib/material/input_decorator/input_decoration.2.dart **
/// {@end-tool}
///
/// {@tool dartpad}
/// This sample shows how to style a `TextField` with a round border and
/// additional text before and after the input area. It displays "Prefix" before
/// the input area, and "Suffix" after the input area.
///
/// ![](https://flutter.github.io/assets-for-api-docs/assets/material/input_decoration_prefix_suffix.png)
///
/// ** See code in examples/api/lib/material/input_decorator/input_decoration.3.dart **
/// {@end-tool}
///
/// {@tool dartpad}
/// This sample shows how to style a `TextField` with a prefixIcon that changes color
/// based on the `MaterialState`. The color defaults to gray, be blue while focused
/// and red if in an error state.
///
/// ** See code in examples/api/lib/material/input_decorator/input_decoration.material_state.0.dart **
/// {@end-tool}
///
/// {@tool dartpad}
/// This sample shows how to style a `TextField` with a prefixIcon that changes color
/// based on the `MaterialState` through the use of `ThemeData`. The color defaults
/// to gray, be blue while focused and red if in an error state.
///
/// ** See code in examples/api/lib/material/input_decorator/input_decoration.material_state.1.dart **
/// {@end-tool}
///
/// See also:
///
/// * [TextField], which is a text input widget that uses an
/// [InputDecoration].
/// * [InputDecorator], which is a widget that draws an [InputDecoration]
/// around an input child widget.
/// * [Decoration] and [DecoratedBox], for drawing borders and backgrounds
/// around a child widget.
@immutable
class InputDecoration {
/// Creates a bundle of the border, labels, icons, and styles used to
/// decorate a Material Design text field.
///
/// Unless specified by [ThemeData.inputDecorationTheme], [InputDecorator]
/// defaults [isDense] to false and [filled] to false. The default border is
/// an instance of [UnderlineInputBorder]. If [border] is [InputBorder.none]
/// then no border is drawn.
///
/// The [enabled] argument must not be null.
///
/// Only one of [prefix] and [prefixText] can be specified.
///
/// Similarly, only one of [suffix] and [suffixText] can be specified.
const InputDecoration({
this.icon,
this.iconColor,
this.label,
this.labelText,
this.labelStyle,
this.floatingLabelStyle,
this.helperText,
this.helperStyle,
this.helperMaxLines,
this.hintText,
this.hintStyle,
this.hintTextDirection,
this.hintMaxLines,
this.error,
this.errorText,
this.errorStyle,
this.errorMaxLines,
this.floatingLabelBehavior,
this.floatingLabelAlignment,
this.isCollapsed = false,
this.isDense,
this.contentPadding,
this.prefixIcon,
this.prefixIconConstraints,
this.prefix,
this.prefixText,
this.prefixStyle,
this.prefixIconColor,
this.suffixIcon,
this.suffix,
this.suffixText,
this.suffixStyle,
this.suffixIconColor,
this.suffixIconConstraints,
this.counter,
this.counterText,
this.counterStyle,
this.filled,
this.fillColor,
this.focusColor,
this.hoverColor,
this.errorBorder,
this.focusedBorder,
this.focusedErrorBorder,
this.disabledBorder,
this.enabledBorder,
this.border,
this.enabled = true,
this.semanticCounterText,
this.alignLabelWithHint,
this.constraints,
}) : assert(!(label != null && labelText != null), 'Declaring both label and labelText is not supported.'),
assert(!(prefix != null && prefixText != null), 'Declaring both prefix and prefixText is not supported.'),
assert(!(suffix != null && suffixText != null), 'Declaring both suffix and suffixText is not supported.'),
assert(!(error != null && errorText != null), 'Declaring both error and errorText is not supported.');
/// Defines an [InputDecorator] that is the same size as the input field.
///
/// This type of input decoration does not include a border by default.
///
/// Sets the [isCollapsed] property to true.
const InputDecoration.collapsed({
required this.hintText,
this.floatingLabelBehavior,
this.floatingLabelAlignment,
this.hintStyle,
this.hintTextDirection,
this.filled = false,
this.fillColor,
this.focusColor,
this.hoverColor,
this.border = InputBorder.none,
this.enabled = true,
}) : icon = null,
iconColor = null,
label = null,
labelText = null,
labelStyle = null,
floatingLabelStyle = null,
helperText = null,
helperStyle = null,
helperMaxLines = null,
hintMaxLines = null,
error = null,
errorText = null,
errorStyle = null,
errorMaxLines = null,
isDense = false,
contentPadding = EdgeInsets.zero,
isCollapsed = true,
prefixIcon = null,
prefix = null,
prefixText = null,
prefixStyle = null,
prefixIconColor = null,
prefixIconConstraints = null,
suffix = null,
suffixIcon = null,
suffixText = null,
suffixStyle = null,
suffixIconColor = null,
suffixIconConstraints = null,
counter = null,
counterText = null,
counterStyle = null,
errorBorder = null,
focusedBorder = null,
focusedErrorBorder = null,
disabledBorder = null,
enabledBorder = null,
semanticCounterText = null,
alignLabelWithHint = false,
constraints = null;
/// An icon to show before the input field and outside of the decoration's
/// container.
///
/// The size and color of the icon is configured automatically using an
/// [IconTheme] and therefore does not need to be explicitly given in the
/// icon widget.
///
/// The trailing edge of the icon is padded by 16dps.
///
/// The decoration's container is the area which is filled if [filled] is
/// true and bordered per the [border]. It's the area adjacent to
/// [icon] and above the widgets that contain [helperText],
/// [errorText], and [counterText].
///
/// See [Icon], [ImageIcon].
final Widget? icon;
/// The color of the [icon].
///
/// If [iconColor] is a [MaterialStateColor], then the effective
/// color can depend on the [MaterialState.focused] state, i.e.
/// if the [TextField] is focused or not.
final Color? iconColor;
/// Optional widget that describes the input field.
///
/// {@template flutter.material.inputDecoration.label}
/// When the input field is empty and unfocused, the label is displayed on
/// top of the input field (i.e., at the same location on the screen where
/// text may be entered in the input field). When the input field receives
/// focus (or if the field is non-empty), depending on [floatingLabelAlignment],
/// the label moves above, either vertically adjacent to, or to the center of
/// the input field.
/// {@endtemplate}
///
/// This can be used, for example, to add multiple [TextStyle]'s to a label that would
/// otherwise be specified using [labelText], which only takes one [TextStyle].
///
/// {@tool dartpad}
/// This example shows a `TextField` with a [Text.rich] widget as the [label].
/// The widget contains multiple [Text] widgets with different [TextStyle]'s.
///
/// ** See code in examples/api/lib/material/input_decorator/input_decoration.label.0.dart **
/// {@end-tool}
///
/// Only one of [label] and [labelText] can be specified.
final Widget? label;
/// Optional text that describes the input field.
///
/// {@macro flutter.material.inputDecoration.label}
///
/// If a more elaborate label is required, consider using [label] instead.
/// Only one of [label] and [labelText] can be specified.
final String? labelText;
/// {@template flutter.material.inputDecoration.labelStyle}
/// The style to use for [InputDecoration.labelText] when the label is on top
/// of the input field.
///
/// If [labelStyle] is a [MaterialStateTextStyle], then the effective
/// text style can depend on the [MaterialState.focused] state, i.e.
/// if the [TextField] is focused or not.
///
/// When the [InputDecoration.labelText] is above (i.e., vertically adjacent to)
/// the input field, the text uses the [floatingLabelStyle] instead.
///
/// If null, defaults to a value derived from the base [TextStyle] for the
/// input field and the current [Theme].
///
/// Specifying this style will override the default behavior
/// of [InputDecoration] that changes the color of the label to the
/// [InputDecoration.errorStyle] color or [ColorScheme.error].
///
/// {@tool dartpad}
/// It's possible to override the label style for just the error state, or
/// just the default state, or both.
///
/// In this example the [labelStyle] is specified with a [MaterialStateProperty]
/// which resolves to a text style whose color depends on the decorator's
/// error state.
///
/// ** See code in examples/api/lib/material/input_decorator/input_decoration.label_style_error.0.dart **
/// {@end-tool}
/// {@endtemplate}
final TextStyle? labelStyle;
/// {@template flutter.material.inputDecoration.floatingLabelStyle}
/// The style to use for [InputDecoration.labelText] when the label is
/// above (i.e., vertically adjacent to) the input field.
///
/// When the [InputDecoration.labelText] is on top of the input field, the
/// text uses the [labelStyle] instead.
///
/// If [floatingLabelStyle] is a [MaterialStateTextStyle], then the effective
/// text style can depend on the [MaterialState.focused] state, i.e.
/// if the [TextField] is focused or not.
///
/// If null, defaults to [labelStyle].
///
/// Specifying this style will override the default behavior
/// of [InputDecoration] that changes the color of the label to the
/// [InputDecoration.errorStyle] color or [ColorScheme.error].
///
/// {@tool dartpad}
/// It's possible to override the label style for just the error state, or
/// just the default state, or both.
///
/// In this example the [floatingLabelStyle] is specified with a
/// [MaterialStateProperty] which resolves to a text style whose color depends
/// on the decorator's error state.
///
/// ** See code in examples/api/lib/material/input_decorator/input_decoration.floating_label_style_error.0.dart **
/// {@end-tool}
/// {@endtemplate}
final TextStyle? floatingLabelStyle;
/// Text that provides context about the [InputDecorator.child]'s value, such
/// as how the value will be used.
///
/// If non-null, the text is displayed below the [InputDecorator.child], in
/// the same location as [errorText]. If a non-null [errorText] value is
/// specified then the helper text is not shown.
final String? helperText;
/// The style to use for the [helperText].
///
/// If [helperStyle] is a [MaterialStateTextStyle], then the effective
/// text style can depend on the [MaterialState.focused] state, i.e.
/// if the [TextField] is focused or not.
final TextStyle? helperStyle;
/// The maximum number of lines the [helperText] can occupy.
///
/// Defaults to null, which means that the [helperText] will be limited
/// to a single line with [TextOverflow.ellipsis].
///
/// This value is passed along to the [Text.maxLines] attribute
/// of the [Text] widget used to display the helper.
///
/// See also:
///
/// * [errorMaxLines], the equivalent but for the [errorText].
final int? helperMaxLines;
/// Text that suggests what sort of input the field accepts.
///
/// Displayed on top of the [InputDecorator.child] (i.e., at the same location
/// on the screen where text may be entered in the [InputDecorator.child])
/// when the input [isEmpty] and either (a) [labelText] is null or (b) the
/// input has the focus.
final String? hintText;
/// The style to use for the [hintText].
///
/// If [hintStyle] is a [MaterialStateTextStyle], then the effective
/// text style can depend on the [MaterialState.focused] state, i.e.
/// if the [TextField] is focused or not.
///
/// Also used for the [labelText] when the [labelText] is displayed on
/// top of the input field (i.e., at the same location on the screen where
/// text may be entered in the [InputDecorator.child]).
///
/// If null, defaults to a value derived from the base [TextStyle] for the
/// input field and the current [Theme].
final TextStyle? hintStyle;
/// The direction to use for the [hintText].
///
/// If null, defaults to a value derived from [Directionality] for the
/// input field and the current context.
final TextDirection? hintTextDirection;
/// The maximum number of lines the [hintText] can occupy.
///
/// Defaults to the value of [TextField.maxLines] attribute.
///
/// This value is passed along to the [Text.maxLines] attribute
/// of the [Text] widget used to display the hint text. [TextOverflow.ellipsis] is
/// used to handle the overflow when it is limited to single line.
final int? hintMaxLines;
/// Optional widget that appears below the [InputDecorator.child] and the border.
///
/// If non-null, the border's color animates to red and the [helperText] is not shown.
///
/// Only one of [error] and [errorText] can be specified.
final Widget? error;
/// Text that appears below the [InputDecorator.child] and the border.
///
/// If non-null, the border's color animates to red and the [helperText] is
/// not shown.
///
/// In a [TextFormField], this is overridden by the value returned from
/// [TextFormField.validator], if that is not null.
///
/// If a more elaborate error is required, consider using [error] instead.
///
/// Only one of [error] and [errorText] can be specified.
final String? errorText;
/// {@template flutter.material.inputDecoration.errorStyle}
/// The style to use for the [InputDecoration.errorText].
///
/// If null, defaults of a value derived from the base [TextStyle] for the
/// input field and the current [Theme].
///
/// By default the color of style will be used by the label of
/// [InputDecoration] if [InputDecoration.errorText] is not null. See
/// [InputDecoration.labelStyle] or [InputDecoration.floatingLabelStyle] for
/// an example of how to replicate this behavior when specifying those
/// styles.
/// {@endtemplate}
final TextStyle? errorStyle;
/// The maximum number of lines the [errorText] can occupy.
///
/// Defaults to null, which means that the [errorText] will be limited
/// to a single line with [TextOverflow.ellipsis].
///
/// This value is passed along to the [Text.maxLines] attribute
/// of the [Text] widget used to display the error.
///
/// See also:
///
/// * [helperMaxLines], the equivalent but for the [helperText].
final int? errorMaxLines;
/// {@template flutter.material.inputDecoration.floatingLabelBehavior}
/// Defines **how** the floating label should behave.
///
/// When [FloatingLabelBehavior.auto] the label will float to the top only when
/// the field is focused or has some text content, otherwise it will appear
/// in the field in place of the content.
///
/// When [FloatingLabelBehavior.always] the label will always float at the top
/// of the field above the content.
///
/// When [FloatingLabelBehavior.never] the label will always appear in an empty
/// field in place of the content.
/// {@endtemplate}
///
/// If null, [InputDecorationTheme.floatingLabelBehavior] will be used.
///
/// See also:
///
/// * [floatingLabelAlignment] which defines **where** the floating label
/// should be displayed.
final FloatingLabelBehavior? floatingLabelBehavior;
/// {@template flutter.material.inputDecoration.floatingLabelAlignment}
/// Defines **where** the floating label should be displayed.
///
/// [FloatingLabelAlignment.start] aligns the floating label to the leftmost
/// (when [TextDirection.ltr]) or rightmost (when [TextDirection.rtl]),
/// possible position, which is vertically adjacent to the label, on top of
/// the field.
///
/// [FloatingLabelAlignment.center] aligns the floating label to the center on
/// top of the field.
/// {@endtemplate}
///
/// If null, [InputDecorationTheme.floatingLabelAlignment] will be used.
///
/// See also:
///
/// * [floatingLabelBehavior] which defines **how** the floating label should
/// behave.
final FloatingLabelAlignment? floatingLabelAlignment;
/// Whether the [InputDecorator.child] is part of a dense form (i.e., uses less vertical
/// space).
///
/// Defaults to false.
final bool? isDense;
/// The padding for the input decoration's container.
///
/// {@macro flutter.material.input_decorator.container_description}
///
/// By default the [contentPadding] reflects [isDense] and the type of the
/// [border].
///
/// If [isCollapsed] is true then [contentPadding] is [EdgeInsets.zero].
///
/// If `isOutline` property of [border] is false and if [filled] is true then
/// [contentPadding] is `EdgeInsets.fromLTRB(12, 8, 12, 8)` when [isDense]
/// is true and `EdgeInsets.fromLTRB(12, 12, 12, 12)` when [isDense] is false.
/// If `isOutline` property of [border] is false and if [filled] is false then
/// [contentPadding] is `EdgeInsets.fromLTRB(0, 8, 0, 8)` when [isDense] is
/// true and `EdgeInsets.fromLTRB(0, 12, 0, 12)` when [isDense] is false.
///
/// If `isOutline` property of [border] is true then [contentPadding] is
/// `EdgeInsets.fromLTRB(12, 20, 12, 12)` when [isDense] is true
/// and `EdgeInsets.fromLTRB(12, 24, 12, 16)` when [isDense] is false.
final EdgeInsetsGeometry? contentPadding;
/// Whether the decoration is the same size as the input field.
///
/// A collapsed decoration cannot have [labelText], [errorText], an [icon].
///
/// To create a collapsed input decoration, use [InputDecoration.collapsed].
final bool isCollapsed;
/// An icon that appears before the [prefix] or [prefixText] and before
/// the editable part of the text field, within the decoration's container.
///
/// The size and color of the prefix icon is configured automatically using an
/// [IconTheme] and therefore does not need to be explicitly given in the
/// icon widget.
///
/// The prefix icon is constrained with a minimum size of 48px by 48px, but
/// can be expanded beyond that. Anything larger than 24px will require
/// additional padding to ensure it matches the Material Design spec of 12px
/// padding between the left edge of the input and leading edge of the prefix
/// icon. The following snippet shows how to pad the leading edge of the
/// prefix icon:
///
/// ```dart
/// prefixIcon: Padding(
/// padding: const EdgeInsetsDirectional.only(start: 12.0),
/// child: _myIcon, // _myIcon is a 48px-wide widget.
/// )
/// ```
///
/// {@macro flutter.material.input_decorator.container_description}
///
/// The prefix icon alignment can be changed using [Align] with a fixed `widthFactor` and
/// `heightFactor`.
///
/// {@tool dartpad}
/// This example shows how the prefix icon alignment can be changed using [Align] with
/// a fixed `widthFactor` and `heightFactor`.
///
/// ** See code in examples/api/lib/material/input_decorator/input_decoration.prefix_icon.0.dart **
/// {@end-tool}
///
/// See also:
///
/// * [Icon] and [ImageIcon], which are typically used to show icons.
/// * [prefix] and [prefixText], which are other ways to show content
/// before the text field (but after the icon).
/// * [suffixIcon], which is the same but on the trailing edge.
/// * [Align] A widget that aligns its child within itself and optionally
/// sizes itself based on the child's size.
final Widget? prefixIcon;
/// The constraints for the prefix icon.
///
/// This can be used to modify the [BoxConstraints] surrounding [prefixIcon].
///
/// This property is particularly useful for getting the decoration's height