✨ 更新flutter_bloc 6.1.1

lib/app/utils/stream_ext/ext.dart

@@ -0,0 +1,84 @@
+import 'backpressure.dart';
+import 'timer_stream.dart';
+
+/// create by 张风捷特烈 on 2020/11/17
+/// contact me by email 1981462002@qq.com
+/// 说明: 
+
+/// Transforms a [Stream] so that will only emit items from the source sequence
+/// if a window has completed, without the source sequence emitting
+/// another item.
+///
+/// This window is created after the last debounced event was emitted.
+/// You can use the value of the last debounced event to determine
+/// the length of the next window.
+///
+/// A window is open until the first window event emits.
+///
+/// The debounce [StreamTransformer] filters out items emitted by the source
+/// Stream that are rapidly followed by another emitted item.
+///
+/// [Interactive marble diagram](http://rxmarbles.com/#debounce)
+///
+/// ### Example
+///
+///     Stream.fromIterable([1, 2, 3, 4])
+///       .debounceTime(Duration(seconds: 1))
+///       .listen(print); // prints 4
+class DebounceStreamTransformer<T> extends BackpressureStreamTransformer<T, T> {
+  /// Constructs a [StreamTransformer] which buffers events into a [List] and
+  /// emits this [List] whenever the current [window] fires.
+  ///
+  /// The [window] is reset whenever the [Stream] that is being transformed
+  /// emits an event.
+  DebounceStreamTransformer(Stream Function(T event) window)
+      : super(WindowStrategy.everyEvent, window,
+      onWindowEnd: (Iterable<T> queue) => queue.last) {
+    assert(window != null, 'window stream factory cannot be null');
+  }
+}
+
+/// Extends the Stream class with the ability to debounce events in various ways
+extension DebounceExtensions<T> on Stream<T> {
+  /// Transforms a [Stream] so that will only emit items from the source sequence
+  /// if a [window] has completed, without the source sequence emitting
+  /// another item.
+  ///
+  /// This [window] is created after the last debounced event was emitted.
+  /// You can use the value of the last debounced event to determine
+  /// the length of the next [window].
+  ///
+  /// A [window] is open until the first [window] event emits.
+  ///
+  /// debounce filters out items emitted by the source [Stream]
+  /// that are rapidly followed by another emitted item.
+  ///
+  /// [Interactive marble diagram](http://rxmarbles.com/#debounce)
+  ///
+  /// ### Example
+  ///
+  ///     Stream.fromIterable([1, 2, 3, 4])
+  ///       .debounce((_) => TimerStream(true, Duration(seconds: 1)))
+  ///       .listen(print); // prints 4
+  Stream<T> debounce(Stream Function(T event) window) =>
+      transform(DebounceStreamTransformer<T>(window));
+
+  /// Transforms a [Stream] so that will only emit items from the source
+  /// sequence whenever the time span defined by [duration] passes, without the
+  /// source sequence emitting another item.
+  ///
+  /// This time span start after the last debounced event was emitted.
+  ///
+  /// debounceTime filters out items emitted by the source [Stream] that are
+  /// rapidly followed by another emitted item.
+  ///
+  /// [Interactive marble diagram](http://rxmarbles.com/#debounceTime)
+  ///
+  /// ### Example
+  ///
+  ///     Stream.fromIterable([1, 2, 3, 4])
+  ///       .debounceTime(Duration(seconds: 1))
+  ///       .listen(print); // prints 4
+  Stream<T> debounceTime(Duration duration) => transform(
+      DebounceStreamTransformer<T>((_) => TimerStream<bool>(true, duration)));
+}