blob: facb994ed208e8523602759fbb9b3ee11ffdd5c4 [file] [log] [blame]
// Copyright (c) 2019, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
// Regression test for issue 37267.
typedef UpdateShouldNotify<T> = bool Function(T previous, T current);
typedef ValueWidgetBuilder<T> = Widget Function(
BuildContext context, T value, Widget child);
class BuildContext {}
class Widget {}
abstract class ProxyWidget extends Widget {
final Widget? child;
abstract class InheritedWidget extends ProxyWidget {
InheritedWidget({Widget? child}) : super(child: child);
class InheritedProvider<T> extends InheritedWidget {
final T? _value;
final UpdateShouldNotify<T>? _updateShouldNotify;
{T? value, UpdateShouldNotify<T>? updateShouldNotify, Widget? child})
: _value = value,
_updateShouldNotify = updateShouldNotify,
super(child: child);
class StateDelegate {}
abstract class ValueStateDelegate<T> extends StateDelegate {
T get value;
class ValueStateDelegateImpl<T> implements ValueStateDelegate<T> {
final T value;
class DelegateWidget {
final StateDelegate delegate;
abstract class Listenable {}
abstract class ValueListenable<T> extends Listenable {
T get value;
class ValueListenableImpl<T> implements ValueListenable<T> {
final T value;
class ValueDelegateWidget<T> extends DelegateWidget {
ValueDelegateWidget(ValueStateDelegate<T> delegate) : super(delegate);
ValueStateDelegate<T> get delegate => super.delegate as ValueStateDelegate<T>;
class ValueListenableProvider<T>
extends ValueDelegateWidget<ValueListenable<T>> {
final Widget? child;
final UpdateShouldNotify<T>? updateShouldNotify;
ValueListenableProvider(ValueStateDelegate<ValueListenable<T>> delegate,
this.updateShouldNotify, this.child)
: super(delegate);
ValueListenableBuilder<T> build() {
return ValueListenableBuilder<T>(
valueListenable: delegate.value,
builder: (_, value, child) {
return InheritedProvider<T>(
value: value,
updateShouldNotify: updateShouldNotify,
child: child,
child: child,
class ValueListenableBuilder<T> extends Widget {
final ValueListenable<T>? valueListenable;
final ValueWidgetBuilder<T>? builder;
final Widget? child;
ValueListenableBuilder({this.valueListenable, this.builder, this.child});
void main() {
ValueListenableBuilder<T> create<T>(T value) {
ValueListenableImpl<T> valueListenable = ValueListenableImpl<T>(value);
ValueStateDelegateImpl<ValueListenable<T>> valueStateDelegate =
ValueListenableProvider<T> valueListenableProvider =
ValueListenableProvider<T>(valueStateDelegate, null, null);
ValueListenableBuilder<T> widget =;
return widget;