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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 'theme.dart';
/// Defines the visual properties of [Divider], [VerticalDivider], dividers
/// between [ListTile]s, and dividers between rows in [DataTable]s.
///
/// Descendant widgets obtain the current [DividerThemeData] object using
/// `DividerTheme.of(context)`. Instances of [DividerThemeData]
/// can be customized with [DividerThemeData.copyWith].
///
/// Typically a [DividerThemeData] is specified as part of the overall
/// [Theme] with [ThemeData.dividerTheme].
///
/// All [DividerThemeData] properties are `null` by default. When null,
/// the widgets will provide their own defaults.
///
/// See also:
///
/// * [ThemeData], which describes the overall theme information for the
/// application.
class DividerThemeData with Diagnosticable {
/// Creates a theme that can be used for [DividerTheme] or
/// [ThemeData.dividerTheme].
const DividerThemeData({
this.color,
this.space,
this.thickness,
this.indent,
this.endIndent,
});
/// The color of [Divider]s and [VerticalDivider]s, also
/// used between [ListTile]s, between rows in [DataTable]s, and so forth.
final Color color;
/// The [Divider]'s width or the [VerticalDivider]'s height.
///
/// This represents the amount of horizontal or vertical space the divider
/// takes up.
final double space;
/// The thickness of the line drawn within the divider.
final double thickness;
/// The amount of empty space at the leading edge of [Divider] or top edge of
/// [VerticalDivider].
final double indent;
/// The amount of empty space at the trailing edge of [Divider] or bottom edge
/// of [VerticalDivider].
final double endIndent;
/// Creates a copy of this object with the given fields replaced with the
/// new values.
DividerThemeData copyWith({
Color color,
double space,
double thickness,
double indent,
double endIndent,
}) {
return DividerThemeData(
color: color ?? this.color,
space: space ?? this.space,
thickness: thickness ?? this.thickness,
indent: indent ?? this.indent,
endIndent: endIndent ?? this.endIndent,
);
}
/// Linearly interpolate between two Divider themes.
///
/// The argument `t` must not be null.
///
/// {@macro dart.ui.shadow.lerp}
static DividerThemeData lerp(DividerThemeData a, DividerThemeData b, double t) {
assert(t != null);
return DividerThemeData(
color: Color.lerp(a?.color, b?.color, t),
space: lerpDouble(a?.space, b?.space, t),
thickness: lerpDouble(a?.thickness, b?.thickness, t),
indent: lerpDouble(a?.indent, b?.indent, t),
endIndent: lerpDouble(a?.endIndent, b?.endIndent, t),
);
}
@override
int get hashCode {
return hashValues(
color,
space,
thickness,
indent,
endIndent,
);
}
@override
bool operator ==(Object other) {
if (identical(this, other))
return true;
if (other.runtimeType != runtimeType)
return false;
return other is DividerThemeData
&& other.color == color
&& other.space == space
&& other.thickness == thickness
&& other.indent == indent
&& other.endIndent == endIndent;
}
@override
void debugFillProperties(DiagnosticPropertiesBuilder properties) {
super.debugFillProperties(properties);
properties.add(ColorProperty('color', color, defaultValue: null));
properties.add(DoubleProperty('space', space, defaultValue: null));
properties.add(DoubleProperty('thickness', thickness, defaultValue: null));
properties.add(DoubleProperty('indent', indent, defaultValue: null));
properties.add(DoubleProperty('endIndent', endIndent, defaultValue: null));
}
}
/// An inherited widget that defines the configuration for
/// [Divider]s, [VerticalDivider]s, dividers between [ListTile]s, and dividers
/// between rows in [DataTable]s in this widget's subtree.
class DividerTheme extends InheritedTheme {
/// Creates a divider theme that controls the configurations for
/// [Divider]s, [VerticalDivider]s, dividers between [ListTile]s, and dividers
/// between rows in [DataTable]s in its widget subtree.
const DividerTheme({
Key key,
@required this.data,
Widget child,
}) : assert(data != null),
super(key: key, child: child);
/// The properties for descendant [Divider]s, [VerticalDivider]s, dividers
/// between [ListTile]s, and dividers between rows in [DataTable]s.
final DividerThemeData data;
/// The closest instance of this class's [data] value that encloses the given
/// context.
///
/// If there is no ancestor, it returns [ThemeData.dividerTheme]. Applications
/// can assume that the returned value will not be null.
///
/// Typical usage is as follows:
///
/// ```dart
/// DividerThemeData theme = DividerTheme.of(context);
/// ```
static DividerThemeData of(BuildContext context) {
final DividerTheme dividerTheme = context.dependOnInheritedWidgetOfExactType<DividerTheme>();
return dividerTheme?.data ?? Theme.of(context).dividerTheme;
}
@override
Widget wrap(BuildContext context, Widget child) {
final DividerTheme ancestorTheme = context.findAncestorWidgetOfExactType<DividerTheme>();
return identical(this, ancestorTheme) ? child : DividerTheme(data: data, child: child);
}
@override
bool updateShouldNotify(DividerTheme oldWidget) => data != oldWidget.data;
}