// 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/widgets.dart'; import 'theme.dart'; /// Defines default property values for descendant [Card] widgets. /// /// Descendant widgets obtain the current [CardTheme] object using /// `CardTheme.of(context)`. Instances of [CardTheme] can be /// customized with [CardTheme.copyWith]. /// /// Typically a [CardTheme] is specified as part of the overall [Theme] /// with [ThemeData.cardTheme]. /// /// All [CardTheme] properties are `null` by default. When null, the [Card] /// will use the values from [ThemeData] if they exist, otherwise it will /// provide its own defaults. /// /// See also: /// /// * [ThemeData], which describes the overall theme information for the /// application. @immutable class CardTheme with Diagnosticable { /// Creates a theme that can be used for [ThemeData.cardTheme]. /// /// The [elevation] must be null or non-negative. const CardTheme({ this.clipBehavior, this.color, this.shadowColor, this.surfaceTintColor, this.elevation, this.margin, this.shape, }) : assert(elevation == null || elevation >= 0.0); /// Default value for [Card.clipBehavior]. /// /// If null, [Card] uses [Clip.none]. final Clip? clipBehavior; /// Default value for [Card.color]. /// /// If null, [Card] uses [ThemeData.cardColor]. final Color? color; /// Default value for [Card.shadowColor]. /// /// If null, [Card] defaults to fully opaque black. final Color? shadowColor; /// Default value for [Card.surfaceTintColor]. /// /// If null, [Card] will not display an overlay color. /// /// See [Material.surfaceTintColor] for more details. final Color? surfaceTintColor; /// Default value for [Card.elevation]. /// /// If null, [Card] uses a default of 1.0. final double? elevation; /// Default value for [Card.margin]. /// /// If null, [Card] uses a default margin of 4.0 logical pixels on all sides: /// `EdgeInsets.all(4.0)`. final EdgeInsetsGeometry? margin; /// Default value for [Card.shape]. /// /// If null, [Card] then uses a [RoundedRectangleBorder] with a circular /// corner radius of 4.0. final ShapeBorder? shape; /// Creates a copy of this object with the given fields replaced with the /// new values. CardTheme copyWith({ Clip? clipBehavior, Color? color, Color? shadowColor, Color? surfaceTintColor, double? elevation, EdgeInsetsGeometry? margin, ShapeBorder? shape, }) { return CardTheme( clipBehavior: clipBehavior ?? this.clipBehavior, color: color ?? this.color, shadowColor: shadowColor ?? this.shadowColor, surfaceTintColor: surfaceTintColor ?? this.surfaceTintColor, elevation: elevation ?? this.elevation, margin: margin ?? this.margin, shape: shape ?? this.shape, ); } /// The [ThemeData.cardTheme] property of the ambient [Theme]. static CardTheme of(BuildContext context) { return Theme.of(context).cardTheme; } /// Linearly interpolate between two Card themes. /// /// The argument `t` must not be null. /// /// {@macro dart.ui.shadow.lerp} static CardTheme lerp(CardTheme? a, CardTheme? b, double t) { assert(t != null); return CardTheme( clipBehavior: t < 0.5 ? a?.clipBehavior : b?.clipBehavior, color: Color.lerp(a?.color, b?.color, t), shadowColor: Color.lerp(a?.shadowColor, b?.shadowColor, t), surfaceTintColor: Color.lerp(a?.surfaceTintColor, b?.surfaceTintColor, t), elevation: lerpDouble(a?.elevation, b?.elevation, t), margin: EdgeInsetsGeometry.lerp(a?.margin, b?.margin, t), shape: ShapeBorder.lerp(a?.shape, b?.shape, t), ); } @override int get hashCode => Object.hash( clipBehavior, color, shadowColor, surfaceTintColor, elevation, margin, shape, ); @override bool operator ==(Object other) { if (identical(this, other)) { return true; } if (other.runtimeType != runtimeType) { return false; } return other is CardTheme && other.clipBehavior == clipBehavior && other.color == color && other.shadowColor == shadowColor && other.surfaceTintColor == surfaceTintColor && other.elevation == elevation && other.margin == margin && other.shape == shape; } @override void debugFillProperties(DiagnosticPropertiesBuilder properties) { super.debugFillProperties(properties); properties.add(DiagnosticsProperty<Clip>('clipBehavior', clipBehavior, defaultValue: null)); properties.add(ColorProperty('color', color, defaultValue: null)); properties.add(ColorProperty('shadowColor', shadowColor, defaultValue: null)); properties.add(ColorProperty('surfaceTintColor', surfaceTintColor, defaultValue: null)); properties.add(DiagnosticsProperty<double>('elevation', elevation, defaultValue: null)); properties.add(DiagnosticsProperty<EdgeInsetsGeometry>('margin', margin, defaultValue: null)); properties.add(DiagnosticsProperty<ShapeBorder>('shape', shape, defaultValue: null)); } }