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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:ui' show lerpDouble;
import 'package:flutter/foundation.dart';
import 'package:flutter/widgets.dart';
import 'material_state.dart';
import 'theme.dart';
// Examples can assume:
// late BuildContext context;
/// Defines default property values for descendant [Scrollbar] widgets.
///
/// Descendant widgets obtain the current [ScrollbarThemeData] object with
/// `ScrollbarTheme.of(context)`. Instances of [ScrollbarThemeData] can be
/// customized with [ScrollbarThemeData.copyWith].
///
/// Typically the [ScrollbarThemeData] of a [ScrollbarTheme] is specified as
/// part of the overall [Theme] with [ThemeData.scrollbarTheme].
///
/// All [ScrollbarThemeData] properties are `null` by default. When null, the
/// [Scrollbar] computes its own default values, typically based on the overall
/// theme's [ThemeData.colorScheme].
///
/// See also:
///
/// * [ThemeData], which describes the overall theme information for the
/// application.
@immutable
class ScrollbarThemeData with Diagnosticable {
/// Creates a theme that can be used for [ThemeData.scrollbarTheme].
const ScrollbarThemeData({
this.thumbVisibility,
this.thickness,
this.trackVisibility,
this.radius,
this.thumbColor,
this.trackColor,
this.trackBorderColor,
this.crossAxisMargin,
this.mainAxisMargin,
this.minThumbLength,
this.interactive,
@Deprecated(
'Use ScrollbarThemeData.trackVisibility to resolve based on the current state instead. '
'This feature was deprecated after v3.4.0-19.0.pre.',
)
this.showTrackOnHover,
});
/// Overrides the default value of [Scrollbar.thumbVisibility] in all
/// descendant [Scrollbar] widgets.
final MaterialStateProperty<bool?>? thumbVisibility;
/// Overrides the default value of [Scrollbar.thickness] in all
/// descendant [Scrollbar] widgets.
///
/// Resolves in the following states:
/// * [MaterialState.hovered] on web and desktop platforms.
final MaterialStateProperty<double?>? thickness;
/// Overrides the default value of [Scrollbar.trackVisibility] in all
/// descendant [Scrollbar] widgets.
final MaterialStateProperty<bool?>? trackVisibility;
/// Overrides the default value of [Scrollbar.showTrackOnHover] in all
/// descendant [Scrollbar] widgets.
@Deprecated(
'Use ScrollbarThemeData.trackVisibility to resolve based on the current state instead. '
'This feature was deprecated after v3.4.0-19.0.pre.',
)
final bool? showTrackOnHover;
/// Overrides the default value of [Scrollbar.interactive] in all
/// descendant [Scrollbar] widgets.
final bool? interactive;
/// Overrides the default value of [Scrollbar.radius] in all
/// descendant widgets.
final Radius? radius;
/// Overrides the default [Color] of the [Scrollbar] thumb in all descendant
/// [Scrollbar] widgets.
///
/// Resolves in the following states:
/// * [MaterialState.dragged].
/// * [MaterialState.hovered] on web and desktop platforms.
final MaterialStateProperty<Color?>? thumbColor;
/// Overrides the default [Color] of the [Scrollbar] track when
/// [showTrackOnHover] is true in all descendant [Scrollbar] widgets.
///
/// Resolves in the following states:
/// * [MaterialState.hovered] on web and desktop platforms.
final MaterialStateProperty<Color?>? trackColor;
/// Overrides the default [Color] of the [Scrollbar] track border when
/// [showTrackOnHover] is true in all descendant [Scrollbar] widgets.
///
/// Resolves in the following states:
/// * [MaterialState.hovered] on web and desktop platforms.
final MaterialStateProperty<Color?>? trackBorderColor;
/// Overrides the default value of the [ScrollbarPainter.crossAxisMargin]
/// property in all descendant [Scrollbar] widgets.
///
/// See also:
///
/// * [ScrollbarPainter.crossAxisMargin], which sets the distance from the
/// scrollbar's side to the nearest edge in logical pixels.
final double? crossAxisMargin;
/// Overrides the default value of the [ScrollbarPainter.mainAxisMargin]
/// property in all descendant [Scrollbar] widgets.
///
/// See also:
///
/// * [ScrollbarPainter.mainAxisMargin], which sets the distance from the
/// scrollbar's start and end to the edge of the viewport in logical pixels.
final double? mainAxisMargin;
/// Overrides the default value of the [ScrollbarPainter.minLength]
/// property in all descendant [Scrollbar] widgets.
///
/// See also:
///
/// * [ScrollbarPainter.minLength], which sets the preferred smallest size
/// the scrollbar can shrink to when the total scrollable extent is large,
/// the current visible viewport is small, and the viewport is not
/// overscrolled.
final double? minThumbLength;
/// Creates a copy of this object with the given fields replaced with the
/// new values.
ScrollbarThemeData copyWith({
MaterialStateProperty<bool?>? thumbVisibility,
MaterialStateProperty<double?>? thickness,
MaterialStateProperty<bool?>? trackVisibility,
bool? interactive,
Radius? radius,
MaterialStateProperty<Color?>? thumbColor,
MaterialStateProperty<Color?>? trackColor,
MaterialStateProperty<Color?>? trackBorderColor,
double? crossAxisMargin,
double? mainAxisMargin,
double? minThumbLength,
@Deprecated(
'Use ScrollbarThemeData.trackVisibility to resolve based on the current state instead. '
'This feature was deprecated after v3.4.0-19.0.pre.',
)
bool? showTrackOnHover,
}) {
return ScrollbarThemeData(
thumbVisibility: thumbVisibility ?? this.thumbVisibility,
thickness: thickness ?? this.thickness,
trackVisibility: trackVisibility ?? this.trackVisibility,
showTrackOnHover: showTrackOnHover ?? this.showTrackOnHover,
interactive: interactive ?? this.interactive,
radius: radius ?? this.radius,
thumbColor: thumbColor ?? this.thumbColor,
trackColor: trackColor ?? this.trackColor,
trackBorderColor: trackBorderColor ?? this.trackBorderColor,
crossAxisMargin: crossAxisMargin ?? this.crossAxisMargin,
mainAxisMargin: mainAxisMargin ?? this.mainAxisMargin,
minThumbLength: minThumbLength ?? this.minThumbLength,
);
}
/// Linearly interpolate between two Scrollbar themes.
///
/// The argument `t` must not be null.
///
/// {@macro dart.ui.shadow.lerp}
static ScrollbarThemeData lerp(ScrollbarThemeData? a, ScrollbarThemeData? b, double t) {
if (identical(a, b) && a != null) {
return a;
}
return ScrollbarThemeData(
thumbVisibility: MaterialStateProperty.lerp<bool?>(a?.thumbVisibility, b?.thumbVisibility, t, _lerpBool),
thickness: MaterialStateProperty.lerp<double?>(a?.thickness, b?.thickness, t, lerpDouble),
trackVisibility: MaterialStateProperty.lerp<bool?>(a?.trackVisibility, b?.trackVisibility, t, _lerpBool),
showTrackOnHover: _lerpBool(a?.showTrackOnHover, b?.showTrackOnHover, t),
interactive: _lerpBool(a?.interactive, b?.interactive, t),
radius: Radius.lerp(a?.radius, b?.radius, t),
thumbColor: MaterialStateProperty.lerp<Color?>(a?.thumbColor, b?.thumbColor, t, Color.lerp),
trackColor: MaterialStateProperty.lerp<Color?>(a?.trackColor, b?.trackColor, t, Color.lerp),
trackBorderColor: MaterialStateProperty.lerp<Color?>(a?.trackBorderColor, b?.trackBorderColor, t, Color.lerp),
crossAxisMargin: lerpDouble(a?.crossAxisMargin, b?.crossAxisMargin, t),
mainAxisMargin: lerpDouble(a?.mainAxisMargin, b?.mainAxisMargin, t),
minThumbLength: lerpDouble(a?.minThumbLength, b?.minThumbLength, t),
);
}
@override
int get hashCode => Object.hash(
thumbVisibility,
thickness,
trackVisibility,
showTrackOnHover,
interactive,
radius,
thumbColor,
trackColor,
trackBorderColor,
crossAxisMargin,
mainAxisMargin,
minThumbLength,
);
@override
bool operator ==(Object other) {
if (identical(this, other)) {
return true;
}
if (other.runtimeType != runtimeType) {
return false;
}
return other is ScrollbarThemeData
&& other.thumbVisibility == thumbVisibility
&& other.thickness == thickness
&& other.trackVisibility == trackVisibility
&& other.showTrackOnHover == showTrackOnHover
&& other.interactive == interactive
&& other.radius == radius
&& other.thumbColor == thumbColor
&& other.trackColor == trackColor
&& other.trackBorderColor == trackBorderColor
&& other.crossAxisMargin == crossAxisMargin
&& other.mainAxisMargin == mainAxisMargin
&& other.minThumbLength == minThumbLength;
}
@override
void debugFillProperties(DiagnosticPropertiesBuilder properties) {
super.debugFillProperties(properties);
properties.add(DiagnosticsProperty<MaterialStateProperty<bool?>>('thumbVisibility', thumbVisibility, defaultValue: null));
properties.add(DiagnosticsProperty<MaterialStateProperty<double?>>('thickness', thickness, defaultValue: null));
properties.add(DiagnosticsProperty<MaterialStateProperty<bool?>>('trackVisibility', trackVisibility, defaultValue: null));
properties.add(DiagnosticsProperty<bool>('showTrackOnHover', showTrackOnHover, defaultValue: null));
properties.add(DiagnosticsProperty<bool>('interactive', interactive, defaultValue: null));
properties.add(DiagnosticsProperty<Radius>('radius', radius, defaultValue: null));
properties.add(DiagnosticsProperty<MaterialStateProperty<Color?>>('thumbColor', thumbColor, defaultValue: null));
properties.add(DiagnosticsProperty<MaterialStateProperty<Color?>>('trackColor', trackColor, defaultValue: null));
properties.add(DiagnosticsProperty<MaterialStateProperty<Color?>>('trackBorderColor', trackBorderColor, defaultValue: null));
properties.add(DiagnosticsProperty<double>('crossAxisMargin', crossAxisMargin, defaultValue: null));
properties.add(DiagnosticsProperty<double>('mainAxisMargin', mainAxisMargin, defaultValue: null));
properties.add(DiagnosticsProperty<double>('minThumbLength', minThumbLength, defaultValue: null));
}
}
bool? _lerpBool(bool? a, bool? b, double t) => t < 0.5 ? a : b;
/// Applies a scrollbar theme to descendant [Scrollbar] widgets.
///
/// Descendant widgets obtain the current theme's [ScrollbarThemeData] using
/// [ScrollbarTheme.of]. When a widget uses [ScrollbarTheme.of], it is
/// automatically rebuilt if the theme later changes.
///
/// A scrollbar theme can be specified as part of the overall Material theme
/// using [ThemeData.scrollbarTheme].
///
/// See also:
///
/// * [ScrollbarThemeData], which describes the configuration of a
/// scrollbar theme.
class ScrollbarTheme extends InheritedTheme {
/// Constructs a scrollbar theme that configures all descendant [Scrollbar]
/// widgets.
const ScrollbarTheme({
super.key,
required this.data,
required super.child,
});
/// The properties used for all descendant [Scrollbar] widgets.
final ScrollbarThemeData data;
/// Returns the configuration [data] from the closest [ScrollbarTheme]
/// ancestor. If there is no ancestor, it returns [ThemeData.scrollbarTheme].
///
/// Typical usage is as follows:
///
/// ```dart
/// ScrollbarThemeData theme = ScrollbarTheme.of(context);
/// ```
static ScrollbarThemeData of(BuildContext context) {
final ScrollbarTheme? scrollbarTheme = context.dependOnInheritedWidgetOfExactType<ScrollbarTheme>();
return scrollbarTheme?.data ?? Theme.of(context).scrollbarTheme;
}
@override
Widget wrap(BuildContext context, Widget child) {
return ScrollbarTheme(data: data, child: child);
}
@override
bool updateShouldNotify(ScrollbarTheme oldWidget) => data != oldWidget.data;
}