@ -55,15 +55,15 @@ namespace Avalonia.Collections
/// </remarks>
public class AvaloniaList < T > : IAvaloniaList < T > , IList , INotifyCollectionChangedDebug
{
private List < T > _ inner ;
private readonly List < T > _ inner ;
private NotifyCollectionChangedEventHandler _ collectionChanged ;
/// <summary>
/// Initializes a new instance of the <see cref="AvaloniaList{T}"/> class.
/// </summary>
public AvaloniaList ( )
: this ( Enumerable . Empty < T > ( ) )
{
_ inner = new List < T > ( ) ;
}
/// <summary>
@ -89,8 +89,8 @@ namespace Avalonia.Collections
/// </summary>
public event NotifyCollectionChangedEventHandler CollectionChanged
{
add { _ collectionChanged + = value ; }
remove { _ collectionChanged - = value ; }
add = > _ collectionChanged + = value ;
remove = > _ collectionChanged - = value ;
}
/// <summary>
@ -150,7 +150,7 @@ namespace Avalonia.Collections
T old = _ inner [ index ] ;
if ( ! objec t. Equals ( old , value ) )
if ( ! EqualityComparer < T > . Defaul t. Equals ( old , value ) )
{
_ inner [ index ] = value ;
@ -187,45 +187,38 @@ namespace Avalonia.Collections
Validate ? . Invoke ( item ) ;
int index = _ inner . Count ;
_ inner . Add ( item ) ;
NotifyAdd ( new [ ] { item } , index ) ;
NotifyAdd ( item , index ) ;
}
/// <summary>
/// Adds multiple items to the collection.
/// </summary>
/// <param name="items">The items.</param>
public virtual void AddRange ( IEnumerable < T > items )
{
Contract . Requires < ArgumentNullException > ( items ! = null ) ;
var list = ( items as IList ) ? ? items . ToList ( ) ;
if ( list . Count > 0 )
{
if ( Validate ! = null )
{
foreach ( var item in list )
{
Validate ( ( T ) item ) ;
}
}
int index = _ inner . Count ;
_ inner . AddRange ( items ) ;
NotifyAdd ( list , index ) ;
}
}
public virtual void AddRange ( IEnumerable < T > items ) = > InsertRange ( _ inner . Count , items ) ;
/// <summary>
/// Removes all items from the collection.
/// </summary>
public virtual void Clear ( )
{
if ( this . Count > 0 )
if ( Count > 0 )
{
var old = _ inner ;
_ inner = new List < T > ( ) ;
NotifyReset ( old ) ;
if ( _ collectionChanged ! = null )
{
var e = ResetBehavior = = ResetBehavior . Reset ?
EventArgsCache . ResetCollectionChanged :
new NotifyCollectionChangedEventArgs ( NotifyCollectionChangedAction . Remove , _ inner . ToList ( ) , 0 ) ;
_ inner . Clear ( ) ;
_ collectionChanged ( this , e ) ;
}
else
{
_ inner . Clear ( ) ;
}
NotifyCountChanged ( ) ;
}
}
@ -253,9 +246,20 @@ namespace Avalonia.Collections
/// Returns an enumerator that enumerates the items in the collection.
/// </summary>
/// <returns>An <see cref="IEnumerator{T}"/>.</returns>
public IEnumerator < T > GetEnumerator ( )
IEnumerator < T > IEnumerable < T > . GetEnumerator ( )
{
return _ inner . GetEnumerator ( ) ;
return new Enumerator ( _ inner ) ;
}
/// <inheritdoc/>
IEnumerator IEnumerable . GetEnumerator ( )
{
return new Enumerator ( _ inner ) ;
}
public Enumerator GetEnumerator ( )
{
return new Enumerator ( _ inner ) ;
}
/// <summary>
@ -289,7 +293,7 @@ namespace Avalonia.Collections
{
Validate ? . Invoke ( item ) ;
_ inner . Insert ( index , item ) ;
NotifyAdd ( new [ ] { item } , index ) ;
NotifyAdd ( item , index ) ;
}
/// <summary>
@ -301,20 +305,83 @@ namespace Avalonia.Collections
{
Contract . Requires < ArgumentNullException > ( items ! = null ) ;
var list = ( items as IList ) ? ? items . ToList ( ) ;
bool willRaiseCollectionChanged = _ collectionChanged ! = null ;
bool hasValidation = Validate ! = null ;
if ( list . Count > 0 )
if ( items is IList list )
{
if ( Validate ! = null )
if ( list . Count > 0 )
{
foreach ( var item in list )
if ( list is ICollection < T > collection )
{
Validate ( ( T ) item ) ;
if ( hasValidation )
{
foreach ( T item in collection )
{
Validate ( item ) ;
}
}
_ inner . InsertRange ( index , collection ) ;
NotifyAdd ( list , index ) ;
}
else
{
using ( IEnumerator < T > en = items . GetEnumerator ( ) )
{
int insertIndex = index ;
while ( en . MoveNext ( ) )
{
T item = en . Current ;
if ( hasValidation )
{
Validate ( item ) ;
}
_ inner . Insert ( insertIndex + + , item ) ;
}
}
NotifyAdd ( list , index ) ;
}
}
}
else
{
using ( IEnumerator < T > en = items . GetEnumerator ( ) )
{
if ( en . MoveNext ( ) )
{
// Avoid allocating list for collection notification if there is no event subscriptions.
List < T > notificationItems = willRaiseCollectionChanged ?
new List < T > ( ) :
null ;
int insertIndex = index ;
do
{
T item = en . Current ;
if ( hasValidation )
{
Validate ( item ) ;
}
_ inner . InsertRange ( index , items ) ;
NotifyAdd ( ( items as IList ) ? ? items . ToList ( ) , index ) ;
_ inner . Insert ( insertIndex + + , item ) ;
if ( willRaiseCollectionChanged )
{
notificationItems . Add ( item ) ;
}
} while ( en . MoveNext ( ) ) ;
NotifyAdd ( notificationItems , index ) ;
}
}
}
}
@ -382,7 +449,7 @@ namespace Avalonia.Collections
if ( index ! = - 1 )
{
_ inner . RemoveAt ( index ) ;
NotifyRemove ( new [ ] { item } , index ) ;
NotifyRemove ( item , index ) ;
return true ;
}
@ -412,7 +479,7 @@ namespace Avalonia.Collections
{
T item = _ inner [ index ] ;
_ inner . RemoveAt ( index ) ;
NotifyRemove ( new [ ] { item } , index ) ;
NotifyRemove ( item , index ) ;
}
/// <summary>
@ -480,12 +547,6 @@ namespace Avalonia.Collections
_ inner . CopyTo ( ( T [ ] ) array , index ) ;
}
/// <inheritdoc/>
IEnumerator IEnumerable . GetEnumerator ( )
{
return _ inner . GetEnumerator ( ) ;
}
/// <inheritdoc/>
Delegate [ ] INotifyCollectionChangedDebug . GetCollectionChangedSubscribers ( ) = > _ collectionChanged ? . GetInvocationList ( ) ;
@ -505,13 +566,29 @@ namespace Avalonia.Collections
NotifyCountChanged ( ) ;
}
/// <summary>
/// Raises the <see cref="CollectionChanged"/> event with a add action.
/// </summary>
/// <param name="item">The item that was added.</param>
/// <param name="index">The starting index.</param>
private void NotifyAdd ( T item , int index )
{
if ( _ collectionChanged ! = null )
{
var e = new NotifyCollectionChangedEventArgs ( NotifyCollectionChangedAction . Add , new [ ] { item } , index ) ;
_ collectionChanged ( this , e ) ;
}
NotifyCountChanged ( ) ;
}
/// <summary>
/// Raises the <see cref="PropertyChanged"/> event when the <see cref="Count"/> property
/// changes.
/// </summary>
private void NotifyCountChanged ( )
{
PropertyChanged ? . Invoke ( this , new PropertyChangedEventArgs ( nameof ( Count ) ) ) ;
PropertyChanged ? . Invoke ( this , EventArgsCache . CountPropertyChanged ) ;
}
/// <summary>
@ -531,23 +608,57 @@ namespace Avalonia.Collections
}
/// <summary>
/// Raises the <see cref="CollectionChanged"/> event with a reset action.
/// Raises the <see cref="CollectionChanged"/> event with a remove action.
/// </summary>
/// <param name="t">The items that were removed.</param>
private void NotifyReset ( IList t )
/// <param name="item">The item that was removed.</param>
/// <param name="index">The starting index.</param>
private void NotifyRemove ( T item , int index )
{
if ( _ collectionChanged ! = null )
{
NotifyCollectionChangedEventArgs e ;
e = ResetBehavior = = ResetBehavior . Reset ?
new NotifyCollectionChangedEventArgs ( NotifyCollectionChangedAction . Reset ) :
new NotifyCollectionChangedEventArgs ( NotifyCollectionChangedAction . Remove , t , 0 ) ;
var e = new NotifyCollectionChangedEventArgs ( NotifyCollectionChangedAction . Remove , new [ ] { item } , index ) ;
_ collectionChanged ( this , e ) ;
}
NotifyCountChanged ( ) ;
}
/// <summary>
/// Enumerates the elements of a <see cref="AvaloniaList{T}"/>.
/// </summary>
public struct Enumerator : IEnumerator < T >
{
private List < T > . Enumerator _ innerEnumerator ;
public Enumerator ( List < T > inner )
{
_ innerEnumerator = inner . GetEnumerator ( ) ;
}
public bool MoveNext ( )
{
return _ innerEnumerator . MoveNext ( ) ;
}
void IEnumerator . Reset ( )
{
( ( IEnumerator ) _ innerEnumerator ) . Reset ( ) ;
}
public T Current = > _ innerEnumerator . Current ;
object IEnumerator . Current = > Current ;
public void Dispose ( )
{
_ innerEnumerator . Dispose ( ) ;
}
}
}
internal static class EventArgsCache
{
internal static readonly PropertyChangedEventArgs CountPropertyChanged = new PropertyChangedEventArgs ( nameof ( AvaloniaList < object > . Count ) ) ;
internal static readonly NotifyCollectionChangedEventArgs ResetCollectionChanged = new NotifyCollectionChangedEventArgs ( NotifyCollectionChangedAction . Reset ) ;
}
}
danwalmsley
7 years ago
GitHub