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https://github.com/dart-lang/sdk
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912005267d
Change-Id: I46be49b2effec3e38a3dc44cd45cfe736f77fa78 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/182680 Commit-Queue: Sigmund Cherem <sigmund@google.com> Reviewed-by: Joshua Litt <joshualitt@google.com> Reviewed-by: Nicholas Shahan <nshahan@google.com> Reviewed-by: Stephen Adams <sra@google.com>
122 lines
3.2 KiB
Dart
122 lines
3.2 KiB
Dart
// Copyright (c) 2019, the Dart project authors. Please see the AUTHORS file
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// for details. All rights reserved. Use of this source code is governed by a
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// BSD-style license that can be found in the LICENSE file.
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// Regression test for issue 37267.
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typedef UpdateShouldNotify<T> = bool Function(T previous, T current);
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typedef ValueWidgetBuilder<T> = Widget Function(
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BuildContext context, T value, Widget child);
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class BuildContext {}
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class Widget {}
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abstract class ProxyWidget extends Widget {
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final Widget? child;
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ProxyWidget({this.child});
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}
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abstract class InheritedWidget extends ProxyWidget {
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InheritedWidget({Widget? child}) : super(child: child);
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}
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class InheritedProvider<T> extends InheritedWidget {
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final T? _value;
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final UpdateShouldNotify<T>? _updateShouldNotify;
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InheritedProvider(
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{T? value, UpdateShouldNotify<T>? updateShouldNotify, Widget? child})
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: _value = value,
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_updateShouldNotify = updateShouldNotify,
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super(child: child);
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}
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class StateDelegate {}
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abstract class ValueStateDelegate<T> extends StateDelegate {
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T get value;
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}
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class ValueStateDelegateImpl<T> implements ValueStateDelegate<T> {
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final T value;
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ValueStateDelegateImpl(this.value);
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}
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class DelegateWidget {
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final StateDelegate delegate;
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DelegateWidget(this.delegate);
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}
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abstract class Listenable {}
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abstract class ValueListenable<T> extends Listenable {
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T get value;
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}
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class ValueListenableImpl<T> implements ValueListenable<T> {
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final T value;
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ValueListenableImpl(this.value);
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}
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class ValueDelegateWidget<T> extends DelegateWidget {
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ValueDelegateWidget(ValueStateDelegate<T> delegate) : super(delegate);
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@pragma('dart2js:tryInline')
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ValueStateDelegate<T> get delegate => super.delegate as ValueStateDelegate<T>;
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}
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class ValueListenableProvider<T>
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extends ValueDelegateWidget<ValueListenable<T>> {
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final Widget? child;
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final UpdateShouldNotify<T>? updateShouldNotify;
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ValueListenableProvider(ValueStateDelegate<ValueListenable<T>> delegate,
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this.updateShouldNotify, this.child)
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: super(delegate);
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ValueListenableBuilder<T> build() {
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return ValueListenableBuilder<T>(
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valueListenable: delegate.value,
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builder: (_, value, child) {
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return InheritedProvider<T>(
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value: value,
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updateShouldNotify: updateShouldNotify,
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child: child,
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);
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},
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child: child,
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);
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}
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}
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class ValueListenableBuilder<T> extends Widget {
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final ValueListenable<T>? valueListenable;
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final ValueWidgetBuilder<T>? builder;
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final Widget? child;
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ValueListenableBuilder({this.valueListenable, this.builder, this.child});
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}
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void main() {
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print(create(42).valueListenable!.value);
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print(create('foo').valueListenable!.value);
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}
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ValueListenableBuilder<T> create<T>(T value) {
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ValueListenableImpl<T> valueListenable = ValueListenableImpl<T>(value);
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ValueStateDelegateImpl<ValueListenable<T>> valueStateDelegate =
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ValueStateDelegateImpl<ValueListenable<T>>(valueListenable);
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ValueListenableProvider<T> valueListenableProvider =
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ValueListenableProvider<T>(valueStateDelegate, null, null);
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ValueListenableBuilder<T> widget = valueListenableProvider.build();
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print(value);
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return widget;
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}
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