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// Copyright 2015 The Chromium 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 'package:flutter/foundation.dart';
import 'basic.dart';
import 'framework.dart';
import 'icon_theme_data.dart';
/// Controls the default color, opacity, and size of icons in a widget subtree.
///
/// The icon theme is honored by [Icon] and [ImageIcon] widgets.
class IconTheme extends InheritedWidget {
/// Creates an icon theme that controls the color, opacity, and size of
/// descendant widgets.
///
/// Both [data] and [child] arguments must not be null.
const IconTheme({
Key key,
@required this.data,
@required Widget child,
}) : assert(data != null),
assert(child != null),
super(key: key, child: child);
/// Creates an icon theme that controls the color, opacity, and size of
/// descendant widgets, and merges in the current icon theme, if any.
///
/// The [data] and [child] arguments must not be null.
static Widget merge({
Key key,
@required IconThemeData data,
@required Widget child,
}) {
return new Builder(
builder: (BuildContext context) {
return new IconTheme(
key: key,
data: _getInheritedIconThemeData(context).merge(data),
child: child,
);
},
);
}
/// The color, opacity, and size to use for icons in this subtree.
final IconThemeData data;
/// The data from the closest instance of this class that encloses the given
/// context.
///
/// Defaults to the current [ThemeData.iconTheme].
///
/// Typical usage is as follows:
///
/// ```dart
/// IconThemeData theme = IconTheme.of(context);
/// ```
static IconThemeData of(BuildContext context) {
final IconThemeData iconThemeData = _getInheritedIconThemeData(context);
return iconThemeData.isConcrete ? iconThemeData : const IconThemeData.fallback().merge(iconThemeData);
}
static IconThemeData _getInheritedIconThemeData(BuildContext context) {
final IconTheme iconTheme = context.inheritFromWidgetOfExactType(IconTheme);
return iconTheme?.data ?? const IconThemeData.fallback();
}
@override
bool updateShouldNotify(IconTheme oldWidget) => data != oldWidget.data;
@override
void debugFillProperties(DiagnosticPropertiesBuilder properties) {
super.debugFillProperties(properties);
properties.add(new DiagnosticsProperty<IconThemeData>('data', data, showName: false));
}
}