| /Collections/Specialized/ObservableConcurrentQueue.cs |
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| // -------------------------------------------------------------------------------------------------------------------- |
| // <copyright file="ObservableConcurrentQueue.cs" company="BledSoft"> |
| // This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. |
| // To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/4.0/. |
| // </copyright> |
| // <Author> |
| // Cheikh Younes |
| // </Author> |
| // -------------------------------------------------------------------------------------------------------------------- |
| using System.Collections.Concurrent; |
| using System.Threading.Tasks; |
| |
| namespace wasSharp.Collections.Specialized |
| { |
| /// <summary> |
| /// The observable concurrent queue. |
| /// </summary> |
| /// <typeparam name="T"> |
| /// The content type |
| /// </typeparam> |
| public sealed class ObservableConcurrentQueue<T> : ConcurrentQueue<T> |
| { |
| #region Public Events |
| |
| /// <summary> |
| /// Occurs when concurrent queue elements [changed]. |
| /// </summary> |
| public event ConcurrentQueueChangedEventHandler<T> ContentChanged; |
| |
| #endregion |
| |
| #region Public Methods and Operators |
| |
| /// <summary> |
| /// Adds an object to the end of the <see cref="T:System.Collections.Concurrent.ConcurrentQueue`1"/>. |
| /// </summary> |
| /// <param name="item"> |
| /// The object to add to the end of the <see cref="T:System.Collections.Concurrent.ConcurrentQueue`1"/> |
| /// . The value can be a null reference (Nothing in Visual Basic) for reference types. |
| /// </param> |
| public new async Task Enqueue(T item) |
| { |
| await new Task(() => |
| { |
| base.Enqueue(item); |
| |
| // Raise event added event |
| this.OnContentChanged( |
| new NotifyConcurrentQueueChangedEventArgs<T>(NotifyConcurrentQueueChangedAction.Enqueue, item)); |
| }); |
| } |
| |
| /// <summary> |
| /// Attempts to remove and return the object at the beginning of the |
| /// <see cref="T:System.Collections.Concurrent.ConcurrentQueue`1"/>. |
| /// </summary> |
| /// <param name="result"> |
| /// When this method returns, if the operation was successful, <paramref name="result"/> contains the |
| /// object removed. If no object was available to be removed, the value is unspecified. |
| /// </param> |
| /// <returns> |
| /// true if an element was removed and returned from the beginning of the |
| /// <see cref="T:System.Collections.Concurrent.ConcurrentQueue`1"/> successfully; otherwise, false. |
| /// </returns> |
| public new bool TryDequeue(out T result) |
| { |
| if (!base.TryDequeue(out result)) |
| { |
| return false; |
| } |
| |
| // Raise item dequeued event |
| this.OnContentChanged( |
| new NotifyConcurrentQueueChangedEventArgs<T>(NotifyConcurrentQueueChangedAction.Dequeue, result)); |
| |
| if (this.IsEmpty) |
| { |
| // Raise Queue empty event |
| this.OnContentChanged( |
| new NotifyConcurrentQueueChangedEventArgs<T>(NotifyConcurrentQueueChangedAction.Empty)); |
| } |
| |
| return true; |
| } |
| |
| /// <summary> |
| /// Attempts to return an object from the beginning of the |
| /// <see cref="T:System.Collections.Concurrent.ConcurrentQueue`1"/> without removing it. |
| /// </summary> |
| /// <param name="result"> |
| /// When this method returns, <paramref name="result"/> contains an object from the beginning of the |
| /// <see cref="T:System.Collections.Concurrent.ConcurrentQueue`1"/> or an unspecified value if the operation failed. |
| /// </param> |
| /// <returns> |
| /// true if and object was returned successfully; otherwise, false. |
| /// </returns> |
| public new bool TryPeek(out T result) |
| { |
| var retValue = base.TryPeek(out result); |
| if (retValue) |
| { |
| // Raise item dequeued event |
| this.OnContentChanged( |
| new NotifyConcurrentQueueChangedEventArgs<T>(NotifyConcurrentQueueChangedAction.Peek, result)); |
| } |
| |
| return retValue; |
| } |
| |
| #endregion |
| |
| #region Methods |
| |
| /// <summary> |
| /// Raises the <see cref="E:Changed"/> event. |
| /// </summary> |
| /// <param name="args"> |
| /// The <see cref="NotifyConcurrentQueueChangedEventArgs{T}"/> instance containing the event data. |
| /// </param> |
| private void OnContentChanged(NotifyConcurrentQueueChangedEventArgs<T> args) |
| { |
| var handler = this.ContentChanged; |
| if (handler != null) |
| { |
| handler(this, args); |
| } |
| } |
| |
| #endregion |
| } |
| } |
