| // Copyright (c) 2015, 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. |
| |
| /// Simple delegating wrapper around a [Sink]. |
| /// |
| /// Subclasses can override individual methods, or use this to expose only the |
| /// [Sink] methods of a subclass. |
| class DelegatingSink<T> implements Sink<T> { |
| final Sink _sink; |
| |
| /// Create a delegating sink forwarding calls to [sink]. |
| DelegatingSink(Sink<T> sink) : _sink = sink; |
| |
| DelegatingSink._(this._sink); |
| |
| /// Creates a wrapper that coerces the type of [sink]. |
| /// |
| /// Unlike [new DelegatingSink], this only requires its argument to be an |
| /// instance of `Sink`, not `Sink<T>`. This means that calls to [add] may |
| /// throw a [CastError] if the argument type doesn't match the reified type of |
| /// [sink]. |
| static Sink<T> typed<T>(Sink sink) => |
| sink is Sink<T> ? sink : new DelegatingSink._(sink); |
| |
| void add(T data) { |
| _sink.add(data); |
| } |
| |
| void close() { |
| _sink.close(); |
| } |
| } |