radio_theme.dart 8.25 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'dart:ui' show lerpDouble;

import 'package:flutter/foundation.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter/widgets.dart';

import 'material_state.dart';
import 'theme.dart';
import 'theme_data.dart';

/// Defines default property values for descendant [Radio] widgets.
///
/// Descendant widgets obtain the current [RadioThemeData] object using
/// `RadioTheme.of(context)`. Instances of [RadioThemeData] can be customized
/// with [RadioThemeData.copyWith].
///
/// Typically a [RadioThemeData] is specified as part of the overall [Theme]
/// with [ThemeData.radioTheme].
///
/// All [RadioThemeData] properties are `null` by default. When null, the
/// [Radio] will use the values from [ThemeData] if they exist, otherwise it
/// will provide its own defaults based on the overall [Theme]'s colorScheme.
/// See the individual [Radio] properties for details.
///
/// See also:
///
///  * [ThemeData], which describes the overall theme information for the
///    application.
33 34
///  * [RadioTheme], which is used by descendants to obtain the
///    [RadioThemeData].
35 36 37 38 39 40 41 42 43 44 45 46 47 48
@immutable
class RadioThemeData with Diagnosticable {
  /// Creates a theme that can be used for [ThemeData.radioTheme].
  const RadioThemeData({
    this.mouseCursor,
    this.fillColor,
    this.overlayColor,
    this.splashRadius,
    this.materialTapTargetSize,
    this.visualDensity,
  });

  /// {@macro flutter.material.radio.mouseCursor}
  ///
49 50
  /// If specified, overrides the default value of [Radio.mouseCursor]. The
  /// default value is [MaterialStateMouseCursor.clickable].
51 52 53 54
  final MaterialStateProperty<MouseCursor?>? mouseCursor;

  /// {@macro flutter.material.radio.fillColor}
  ///
55 56 57 58
  /// If specified, overrides the default value of [Radio.fillColor]. The
  /// default value is the value of [ThemeData.disabledColor] in the disabled
  /// state, [ThemeData.toggleableActiveColor] in the selected state, and
  /// [ThemeData.unselectedWidgetColor] in the default state.
59 60
  final MaterialStateProperty<Color?>? fillColor;

61
  /// {@macro flutter.material.radio.overlayColor}
62
  ///
63 64 65 66
  /// If specified, overrides the default value of [Radio.overlayColor]. The
  /// default value is [ThemeData.toggleableActiveColor] with alpha
  /// [kRadialReactionAlpha], [ThemeData.focusColor] and [ThemeData.hoverColor]
  /// in the pressed, focused, and hovered state.
67 68 69 70
  final MaterialStateProperty<Color?>? overlayColor;

  /// {@macro flutter.material.radio.splashRadius}
  ///
71 72
  /// If specified, overrides the default value of [Radio.splashRadius]. The
  /// default value is [kRadialReactionRadius].
73 74 75 76 77
  final double? splashRadius;

  /// {@macro flutter.material.radio.materialTapTargetSize}
  ///
  /// If specified, overrides the default value of
78 79
  /// [Radio.materialTapTargetSize]. The default value is the value of
  /// [ThemeData.materialTapTargetSize].
80 81 82 83
  final MaterialTapTargetSize? materialTapTargetSize;

  /// {@macro flutter.material.radio.visualDensity}
  ///
84 85
  /// If specified, overrides the default value of [Radio.visualDensity]. The
  /// default value is the value of [ThemeData.visualDensity].
86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122
  final VisualDensity? visualDensity;

  /// Creates a copy of this object but with the given fields replaced with the
  /// new values.
  RadioThemeData copyWith({
    MaterialStateProperty<MouseCursor?>? mouseCursor,
    MaterialStateProperty<Color?>? fillColor,
    MaterialStateProperty<Color?>? overlayColor,
    double? splashRadius,
    MaterialTapTargetSize? materialTapTargetSize,
    VisualDensity? visualDensity,
  }) {
    return RadioThemeData(
      mouseCursor: mouseCursor ?? this.mouseCursor,
      fillColor: fillColor ?? this.fillColor,
      overlayColor: overlayColor ?? this.overlayColor,
      splashRadius: splashRadius ?? this.splashRadius,
      materialTapTargetSize: materialTapTargetSize ?? this.materialTapTargetSize,
      visualDensity: visualDensity ?? this.visualDensity,
    );
  }

  /// Linearly interpolate between two [RadioThemeData]s.
  ///
  /// {@macro dart.ui.shadow.lerp}
  static RadioThemeData lerp(RadioThemeData? a, RadioThemeData? b, double t) {
    return RadioThemeData(
      mouseCursor: t < 0.5 ? a?.mouseCursor : b?.mouseCursor,
      fillColor: _lerpProperties<Color?>(a?.fillColor, b?.fillColor, t, Color.lerp),
      materialTapTargetSize: t < 0.5 ? a?.materialTapTargetSize : b?.materialTapTargetSize,
      overlayColor: _lerpProperties<Color?>(a?.overlayColor, b?.overlayColor, t, Color.lerp),
      splashRadius: lerpDouble(a?.splashRadius, b?.splashRadius, t),
      visualDensity: t < 0.5 ? a?.visualDensity : b?.visualDensity,
    );
  }

  @override
123 124 125 126 127 128 129 130
  int get hashCode => Object.hash(
    mouseCursor,
    fillColor,
    overlayColor,
    splashRadius,
    materialTapTargetSize,
    visualDensity,
  );
131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202

  @override
  bool operator ==(Object other) {
    if (identical(this, other))
      return true;
    if (other.runtimeType != runtimeType)
      return false;
    return other is RadioThemeData
      && other.mouseCursor == mouseCursor
      && other.fillColor == fillColor
      && other.overlayColor == overlayColor
      && other.splashRadius == splashRadius
      && other.materialTapTargetSize == materialTapTargetSize
      && other.visualDensity == visualDensity;
  }

  @override
  void debugFillProperties(DiagnosticPropertiesBuilder properties) {
    super.debugFillProperties(properties);
    properties.add(DiagnosticsProperty<MaterialStateProperty<MouseCursor?>>('mouseCursor', mouseCursor, defaultValue: null));
    properties.add(DiagnosticsProperty<MaterialStateProperty<Color?>>('fillColor', fillColor, defaultValue: null));
    properties.add(DiagnosticsProperty<MaterialStateProperty<Color?>>('overlayColor', overlayColor, defaultValue: null));
    properties.add(DoubleProperty('splashRadius', splashRadius, defaultValue: null));
    properties.add(DiagnosticsProperty<MaterialTapTargetSize>('materialTapTargetSize', materialTapTargetSize, defaultValue: null));
    properties.add(DiagnosticsProperty<VisualDensity>('visualDensity', visualDensity, defaultValue: null));
  }

  static MaterialStateProperty<T>? _lerpProperties<T>(
    MaterialStateProperty<T>? a,
    MaterialStateProperty<T>? b,
    double t,
    T Function(T?, T?, double) lerpFunction,
  ) {
    // Avoid creating a _LerpProperties object for a common case.
    if (a == null && b == null)
      return null;
    return _LerpProperties<T>(a, b, t, lerpFunction);
  }
}

class _LerpProperties<T> implements MaterialStateProperty<T> {
  const _LerpProperties(this.a, this.b, this.t, this.lerpFunction);

  final MaterialStateProperty<T>? a;
  final MaterialStateProperty<T>? b;
  final double t;
  final T Function(T?, T?, double) lerpFunction;

  @override
  T resolve(Set<MaterialState> states) {
    final T? resolvedA = a?.resolve(states);
    final T? resolvedB = b?.resolve(states);
    return lerpFunction(resolvedA, resolvedB, t);
  }
}

/// Applies a radio theme to descendant [Radio] widgets.
///
/// Descendant widgets obtain the current theme's [RadioTheme] object using
/// [RadioTheme.of]. When a widget uses [RadioTheme.of], it is automatically
/// rebuilt if the theme later changes.
///
/// A radio theme can be specified as part of the overall Material theme using
/// [ThemeData.radioTheme].
///
/// See also:
///
///  * [RadioThemeData], which describes the actual configuration of a radio
///    theme.
class RadioTheme extends InheritedWidget {
  /// Constructs a radio theme that configures all descendant [Radio] widgets.
  const RadioTheme({
203
    super.key,
204
    required this.data,
205 206
    required super.child,
  });
207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226

  /// The properties used for all descendant [Radio] widgets.
  final RadioThemeData data;

  /// Returns the configuration [data] from the closest [RadioTheme] ancestor.
  /// If there is no ancestor, it returns [ThemeData.radioTheme].
  ///
  /// Typical usage is as follows:
  ///
  /// ```dart
  /// RadioThemeData theme = RadioTheme.of(context);
  /// ```
  static RadioThemeData of(BuildContext context) {
    final RadioTheme? radioTheme = context.dependOnInheritedWidgetOfExactType<RadioTheme>();
    return radioTheme?.data ?? Theme.of(context).radioTheme;
  }

  @override
  bool updateShouldNotify(RadioTheme oldWidget) => data != oldWidget.data;
}