diff options
Diffstat (limited to 'src/Editor/Language/Def/Intellisense/FilteredObservableCollection.cs')
| -rw-r--r-- | src/Editor/Language/Def/Intellisense/FilteredObservableCollection.cs | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/src/Editor/Language/Def/Intellisense/FilteredObservableCollection.cs b/src/Editor/Language/Def/Intellisense/FilteredObservableCollection.cs new file mode 100644 index 0000000..70c7fb5 --- /dev/null +++ b/src/Editor/Language/Def/Intellisense/FilteredObservableCollection.cs @@ -0,0 +1,262 @@ +//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// +// Copyright (c) Microsoft Corporation. All rights reserved. +//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// + +using System; +using System.Collections; +using System.Collections.Generic; +using System.Collections.Specialized; + +namespace Microsoft.VisualStudio.Language.Intellisense +{ + public class FilteredObservableCollection<T> : IList, IList<T>, INotifyCollectionChanged + { + private IList<T> _underlyingList; + private bool _isFiltering = false; + private Predicate<T> _filterPredicate; + private List<T> _filteredList = new List<T>(); + + public FilteredObservableCollection(IList<T> underlyingList) + { + if (underlyingList == null) + throw new ArgumentNullException(nameof(underlyingList)); + if (!(underlyingList is INotifyCollectionChanged)) + throw new ArgumentException("Underlying collection must implement INotifyCollectionChanged", nameof(underlyingList)); + if (!(underlyingList is IList)) + throw new ArgumentException("Underlying collection must implement IList", nameof(underlyingList)); + + _underlyingList = underlyingList; + ((INotifyCollectionChanged)_underlyingList).CollectionChanged += this.OnUnderlyingList_CollectionChanged; + } + + public int Add(object value) + { + throw new InvalidOperationException("FilteredObservableCollections are read-only"); + } + + public bool Contains(object value) + { + return ((IList<T>)this).Contains((T)value); + } + + public int IndexOf(object value) + { + return ((IList<T>)this).IndexOf((T)value); + } + + public void Insert(int index, object value) + { + throw new InvalidOperationException("FilteredObservableCollections are read-only"); + } + + public bool IsFixedSize + { + get { return false; } + } + + public void Remove(object value) + { + throw new InvalidOperationException("FilteredObservableCollections are read-only"); + } + + object IList.this[int index] + { + get + { + return ((IList<T>)this)[index]; + } + set + { + throw new InvalidOperationException("FilteredObservableCollections are read-only"); + } + } + + public void CopyTo(Array array, int index) + { + if (_isFiltering) + { + if ((array.Length - index) < this.Count) + { + throw new ArgumentException("Array not big enough", nameof(array)); + } + + int i = index; + foreach (var item in _filteredList) + { + array.SetValue(item, i); + i++; + } + } + else + { + ((IList)_underlyingList).CopyTo(array, index); + } + } + + public bool IsSynchronized + { + get { return false; } + } + + public object SyncRoot + { + get + { + if (_isFiltering) + return ((IList)_filteredList).SyncRoot; + else + return ((IList)_underlyingList).SyncRoot; + } + } + + public int IndexOf(T item) + { + if (_isFiltering) + return _filteredList.IndexOf(item); + else + return _underlyingList.IndexOf(item); + } + + public void Insert(int index, T item) + { + throw new InvalidOperationException("FilteredObservableCollections are read-only"); + } + + public void RemoveAt(int index) + { + throw new InvalidOperationException("FilteredObservableCollections are read-only"); + } + + public T this[int index] + { + get + { + if (_isFiltering) + return _filteredList[index]; + else + return _underlyingList[index]; + } + set + { + throw new InvalidOperationException("FilteredObservableCollections are read-only"); + } + } + + public void Add(T item) + { + throw new InvalidOperationException("FilteredObservableCollections are read-only"); + } + + public void Clear() + { + throw new InvalidOperationException("FilteredObservableCollections are read-only"); + } + + public bool Contains(T item) + { + if (_isFiltering) + return _filteredList.Contains(item); + else + return _underlyingList.Contains(item); + } + + public void CopyTo(T[] array, int arrayIndex) + { + if (_isFiltering) + _filteredList.CopyTo(array, arrayIndex); + else + _underlyingList.CopyTo(array, arrayIndex); + } + + public int Count + { + get + { + if (_isFiltering) + return _filteredList.Count; + else + return _underlyingList.Count; + } + } + + public bool IsReadOnly + { + get { return true; } + } + + public bool Remove(T item) + { + throw new InvalidOperationException("FilteredObservableCollections are read-only"); + } + + public IEnumerator<T> GetEnumerator() + { + if (_isFiltering) + return _filteredList.GetEnumerator(); + else + return _underlyingList.GetEnumerator(); + } + + IEnumerator IEnumerable.GetEnumerator() + { + if (_isFiltering) + return ((IEnumerable)_filteredList).GetEnumerator(); + else + return ((IEnumerable)_underlyingList).GetEnumerator(); + } + + public event NotifyCollectionChangedEventHandler CollectionChanged; + + public void Filter(Predicate<T> filterPredicate) + { + if (filterPredicate == null) + throw new ArgumentNullException(nameof(filterPredicate)); + + _filterPredicate = filterPredicate; + _isFiltering = true; + this.UpdateFilteredItems(); + this.RaiseCollectionChanged(); + } + + public void StopFiltering() + { + if (_isFiltering) + { + _filterPredicate = null; + _isFiltering = false; + this.UpdateFilteredItems(); + this.RaiseCollectionChanged(); + } + } + + private void OnUnderlyingList_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e) + { + UpdateFilteredItems(); + this.RaiseCollectionChanged(); + } + + private void RaiseCollectionChanged() + { + NotifyCollectionChangedEventHandler tempHandler = this.CollectionChanged; + if (tempHandler != null) + { + tempHandler(this, new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset)); + } + } + + private void UpdateFilteredItems() + { + _filteredList.Clear(); + if (_isFiltering) + { + foreach (T underlyingItem in _underlyingList) + { + if (_filterPredicate(underlyingItem)) + { + _filteredList.Add(underlyingItem); + } + } + } + } + } +} |