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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 the routes used to display popup menus
/// as well as [PopupMenuItem] and [PopupMenuDivider] widgets.
///
/// Descendant widgets obtain the current [PopupMenuThemeData] object
/// using `PopupMenuTheme.of(context)`. Instances of
/// [PopupMenuThemeData] can be customized with
/// [PopupMenuThemeData.copyWith].
///
/// Typically, a [PopupMenuThemeData] is specified as part of the
/// overall [Theme] with [ThemeData.popupMenuTheme]. Otherwise,
/// [PopupMenuTheme] can be used to configure its own widget subtree.
///
/// All [PopupMenuThemeData] properties are `null` by default.
/// If any of these properties are null, the popup menu will provide its
/// own defaults.
///
/// See also:
///
/// * [ThemeData], which describes the overall theme information for the
/// application.
class PopupMenuThemeData with Diagnosticable {
/// Creates the set of properties used to configure [PopupMenuTheme].
const PopupMenuThemeData({
this.color,
this.shape,
this.elevation,
this.textStyle,
});
/// The background color of the popup menu.
final Color color;
/// The shape of the popup menu.
final ShapeBorder shape;
/// The elevation of the popup menu.
final double elevation;
/// The text style of items in the popup menu.
final TextStyle textStyle;
/// Creates a copy of this object with the given fields replaced with the
/// new values.
PopupMenuThemeData copyWith({
Color color,
ShapeBorder shape,
double elevation,
TextStyle textStyle,
}) {
return PopupMenuThemeData(
color: color ?? this.color,
shape: shape ?? this.shape,
elevation: elevation ?? this.elevation,
textStyle: textStyle ?? this.textStyle,
);
}
/// Linearly interpolate between two popup menu themes.
///
/// If both arguments are null, then null is returned.
///
/// {@macro dart.ui.shadow.lerp}
static PopupMenuThemeData lerp(PopupMenuThemeData a, PopupMenuThemeData b, double t) {
assert(t != null);
if (a == null && b == null)
return null;
return PopupMenuThemeData(
color: Color.lerp(a?.color, b?.color, t),
shape: ShapeBorder.lerp(a?.shape, b?.shape, t),
elevation: lerpDouble(a?.elevation, b?.elevation, t),
textStyle: TextStyle.lerp(a?.textStyle, b?.textStyle, t),
);
}
@override
int get hashCode {
return hashValues(
color,
shape,
elevation,
textStyle,
);
}
@override
bool operator ==(Object other) {
if (identical(this, other))
return true;
if (other.runtimeType != runtimeType)
return false;
return other is PopupMenuThemeData
&& other.elevation == elevation
&& other.color == color
&& other.shape == shape
&& other.textStyle == textStyle;
}
@override
void debugFillProperties(DiagnosticPropertiesBuilder properties) {
super.debugFillProperties(properties);
properties.add(ColorProperty('color', color, defaultValue: null));
properties.add(DiagnosticsProperty<ShapeBorder>('shape', shape, defaultValue: null));
properties.add(DoubleProperty('elevation', elevation, defaultValue: null));
properties.add(DiagnosticsProperty<TextStyle>('text style', textStyle, defaultValue: null));
}
}
/// An inherited widget that defines the configuration for
/// popup menus in this widget's subtree.
///
/// Values specified here are used for popup menu properties that are not
/// given an explicit non-null value.
class PopupMenuTheme extends InheritedTheme {
/// Creates a popup menu theme that controls the configurations for
/// popup menus in its widget subtree.
///
/// The data argument must not be null.
const PopupMenuTheme({
Key key,
@required this.data,
Widget child,
}) : assert(data != null), super(key: key, child: child);
/// The properties for descendant popup menu widgets.
final PopupMenuThemeData data;
/// The closest instance of this class's [data] value that encloses the given
/// context. If there is no ancestor, it returns [ThemeData.popupMenuTheme].
/// Applications can assume that the returned value will not be null.
///
/// Typical usage is as follows:
///
/// ```dart
/// PopupMenuThemeData theme = PopupMenuTheme.of(context);
/// ```
static PopupMenuThemeData of(BuildContext context) {
final PopupMenuTheme popupMenuTheme = context.dependOnInheritedWidgetOfExactType<PopupMenuTheme>();
return popupMenuTheme?.data ?? Theme.of(context).popupMenuTheme;
}
@override
Widget wrap(BuildContext context, Widget child) {
final PopupMenuTheme ancestorTheme = context.findAncestorWidgetOfExactType<PopupMenuTheme>();
return identical(this, ancestorTheme) ? child : PopupMenuTheme(data: data, child: child);
}
@override
bool updateShouldNotify(PopupMenuTheme oldWidget) => data != oldWidget.data;
}