Nuclex.Support/Source/Collections/ObservableSet.cs

342 lines
12 KiB
C#
Raw Normal View History

#region CPL License
/*
Nuclex Framework
Copyright (C) 2002-2014 Nuclex Development Labs
This library is free software; you can redistribute it and/or
modify it under the terms of the IBM Common Public License as
published by the IBM Corporation; either version 1.0 of the
License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
IBM Common Public License for more details.
You should have received a copy of the IBM Common Public
License along with this library
*/
#endregion
using System;
using System.Collections.Generic;
using System.Linq;
using System.Collections;
#if !NO_SPECIALIZED_COLLECTIONS
using System.Collections.Specialized;
#endif
#if !NO_SETS
namespace Nuclex.Support.Collections {
/// <summary>Set which fires events when items are removed or added to it</summary>
/// <typeparam name="TItem">Type of items to manage in the set</typeparam>
public class ObservableSet<TItem> :
ISet<TItem>,
ICollection<TItem>,
#if !NO_SPECIALIZED_COLLECTIONS
INotifyCollectionChanged,
#endif
IObservableCollection<TItem> {
/// <summary>Raised when an item has been added to the collection</summary>
public event EventHandler<ItemEventArgs<TItem>> ItemAdded;
/// <summary>Raised when an item is removed from the collection</summary>
public event EventHandler<ItemEventArgs<TItem>> ItemRemoved;
/// <summary>Raised when an item is replaced in the collection</summary>
public event EventHandler<ItemReplaceEventArgs<TItem>> ItemReplaced {
add { }
remove { }
}
/// <summary>Raised when the collection is about to be cleared</summary>
/// <remarks>
/// This could be covered by calling ItemRemoved for each item currently
/// contained in the collection, but it is often simpler and more efficient
/// to process the clearing of the entire collection as a special operation.
/// </remarks>
public event EventHandler Clearing;
/// <summary>Raised when the collection has been cleared</summary>
public event EventHandler Cleared;
#if !NO_SPECIALIZED_COLLECTIONS
/// <summary>Called when the collection has changed</summary>
public event NotifyCollectionChangedEventHandler CollectionChanged;
#endif
/// <summary>Initializes a new observable set based on a hashed set</summary>
public ObservableSet() : this(new HashSet<TItem>()) { }
/// <summary>
/// Initializes a new observable set forwarding operations to the specified set
/// </summary>
/// <param name="set">Set operations will be forwarded to</param>
public ObservableSet(ISet<TItem> set) {
this.set = set;
}
/// <summary>Adds an item to the set</summary>
/// <param name="item">Item that will be added to the set</param>
/// <returns>
/// True if the element was added, false if it was already contained in the set
/// </returns>
public bool Add(TItem item) {
bool wasAdded = this.set.Add(item);
if(wasAdded) {
OnAdded(item);
}
return wasAdded;
}
/// <summary>Removes all elements that are contained in the collection</summary>
/// <param name="other">Collection whose elements will be removed from this set</param>
public void ExceptWith(IEnumerable<TItem> other) {
if(other == this) {
Clear();
return;
}
foreach(TItem item in other) {
if(this.set.Remove(item)) {
OnRemoved(item);
}
}
}
/// <summary>
/// Only keeps those elements in this set that are contained in the collection
/// </summary>
/// <param name="other">Other set this set will be filtered by</param>
public void IntersectWith(IEnumerable<TItem> other) {
var otherSet = other as ISet<TItem>;
if(otherSet == null) {
otherSet = new HashSet<TItem>(other);
}
var itemsToRemove = new List<TItem>();
foreach(TItem item in this.set) {
if(!otherSet.Contains(item)) {
itemsToRemove.Add(item);
}
}
for(int index = 0; index < itemsToRemove.Count; ++index) {
this.set.Remove(itemsToRemove[index]);
OnRemoved(itemsToRemove[index]);
}
}
/// <summary>
/// Determines whether the current set is a proper (strict) subset of a collection
/// </summary>
/// <param name="other">Collection against which the set will be tested</param>
/// <returns>True if the set is a proper subset of the specified collection</returns>
public bool IsProperSubsetOf(IEnumerable<TItem> other) {
return this.set.IsProperSubsetOf(other);
}
/// <summary>
/// Determines whether the current set is a proper (strict) superset of a collection
/// </summary>
/// <param name="other">Collection against which the set will be tested</param>
/// <returns>True if the set is a proper superset of the specified collection</returns>
public bool IsProperSupersetOf(IEnumerable<TItem> other) {
return this.set.IsProperSupersetOf(other);
}
/// <summary>Determines whether the current set is a subset of a collection</summary>
/// <param name="other">Collection against which the set will be tested</param>
/// <returns>True if the set is a subset of the specified collection</returns>
public bool IsSubsetOf(IEnumerable<TItem> other) {
return this.set.IsSubsetOf(other);
}
/// <summary>Determines whether the current set is a superset of a collection</summary>
/// <param name="other">Collection against which the set will be tested</param>
/// <returns>True if the set is a superset of the specified collection</returns>
public bool IsSupersetOf(IEnumerable<TItem> other) {
return this.set.IsSupersetOf(other);
}
/// <summary>
/// Determines if the set shares at least one common element with the collection
/// </summary>
/// <param name="other">Collection the set will be tested against</param>
/// <returns>
/// True if the set shares at least one common element with the collection
/// </returns>
public bool Overlaps(IEnumerable<TItem> other) {
return this.set.Overlaps(other);
}
/// <summary>
/// Determines whether the set contains the same elements as the specified collection
/// </summary>
/// <param name="other">Collection the set will be tested against</param>
/// <returns>True if the set contains the same elements as the collection</returns>
public bool SetEquals(IEnumerable<TItem> other) {
return this.set.SetEquals(other);
}
/// <summary>
/// Modifies the current set so that it contains only elements that are present either
/// in the current set or in the specified collection, but not both
/// </summary>
/// <param name="other">Collection the set will be excepted with</param>
public void SymmetricExceptWith(IEnumerable<TItem> other) {
foreach(TItem item in other) {
if(this.set.Remove(item)) {
OnRemoved(item);
} else {
this.Add(item);
OnAdded(item);
}
}
}
/// <summary>
/// Modifies the current set so that it contains all elements that are present in both
/// the current set and in the specified collection
/// </summary>
/// <param name="other">Collection an union will be built with</param>
public void UnionWith(IEnumerable<TItem> other) {
foreach(TItem item in other) {
if(this.set.Add(item)) {
OnAdded(item);
}
}
}
/// <summary>Removes all items from the set</summary>
public void Clear() {
OnClearing();
this.set.Clear();
OnCleared();
}
/// <summary>Determines whether the set contains the specified item</summary>
/// <param name="item">Item the set will be tested for</param>
/// <returns>True if the set contains the specified item</returns>
public bool Contains(TItem item) {
return this.set.Contains(item);
}
/// <summary>Copies the contents of the set into an array</summary>
/// <param name="array">Array the set's contents will be copied to</param>
/// <param name="arrayIndex">
/// Index in the array the first copied element will be written to
/// </param>
public void CopyTo(TItem[] array, int arrayIndex) {
this.set.CopyTo(array, arrayIndex);
}
/// <summary>Counts the number of items contained in the set</summary>
public int Count {
get { return this.set.Count; }
}
/// <summary>Determines whether the set is readonly</summary>
public bool IsReadOnly {
get { return this.set.IsReadOnly; }
}
/// <summary>Removes an item from the set</summary>
/// <param name="item">Item that will be removed from the set</param>
/// <returns>
/// True if the item was contained in the set and is now removed
/// </returns>
public bool Remove(TItem item) {
bool wasRemoved = this.set.Remove(item);
if(wasRemoved) {
OnRemoved(item);
}
return wasRemoved;
}
/// <summary>Creates an enumerator for the set's contents</summary>
/// <returns>A new enumerator for the sets contents</returns>
public IEnumerator<TItem> GetEnumerator() {
return this.set.GetEnumerator();
}
/// <summary>Fires the 'ItemAdded' event</summary>
/// <param name="item">Item that has been added to the collection</param>
protected virtual void OnAdded(TItem item) {
if(ItemAdded != null) {
ItemAdded(this, new ItemEventArgs<TItem>(item));
}
#if !NO_SPECIALIZED_COLLECTIONS
if(CollectionChanged != null) {
CollectionChanged(
this,
new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, item)
);
}
#endif
}
/// <summary>Fires the 'ItemRemoved' event</summary>
/// <param name="item">Item that has been removed from the collection</param>
protected virtual void OnRemoved(TItem item) {
if(ItemRemoved != null) {
ItemRemoved(this, new ItemEventArgs<TItem>(item));
}
#if !NO_SPECIALIZED_COLLECTIONS
if(CollectionChanged != null) {
CollectionChanged(
this,
new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, item)
);
}
#endif
}
/// <summary>Fires the 'Clearing' event</summary>
protected virtual void OnClearing() {
if(Clearing != null) {
Clearing(this, EventArgs.Empty);
}
}
/// <summary>Fires the 'Cleared' event</summary>
protected virtual void OnCleared() {
if(Cleared != null) {
Cleared(this, EventArgs.Empty);
}
#if !NO_SPECIALIZED_COLLECTIONS
if(CollectionChanged != null) {
CollectionChanged(this, Constants.NotifyCollectionResetEventArgs);
}
#endif
}
#region ICollection<T> implementation
/// <summary>Adds an item to the set</summary>
/// <param name="item">Item that will be added to the set</param>
void ICollection<TItem>.Add(TItem item) {
this.set.Add(item);
}
#endregion // ICollection<T> implementation
#region IEnumerable implementation
/// <summary>Creates an enumerator for the set's contents</summary>
/// <returns>A new enumerator for the sets contents</returns>
IEnumerator IEnumerable.GetEnumerator() {
return this.set.GetEnumerator();
}
#endregion // IEnumerable implementation
/// <summary>The set being wrapped</summary>
private ISet<TItem> set;
}
} // namespace Nuclex.Support.Collections
#endif // !NO_SETS