protected override void initializeFromSource()
		{
			if (_sourceInitialized)
			{
                Utils.disposeExpressionItemInfos(_itemInfos, _orderingValueSelectorExpressionСallCount, this);
                Utils.RemoveDownstreamConsumedComputing(_itemInfos, this);

				int capacity = Utils.disposeSource(
                    _sourceScalar, 
                    _source,
                    out _itemInfos,
                    out _sourcePositions, 
                    _sourceAsList, 
                    handleSourceCollectionChanged);

                Utils.construct(capacity, out _orderedItemInfos, out _orderedPositions, out _orderingValues);

				_items.Clear();

                _sourceInitialized = false;
            }

            Utils.changeSource(ref _source, _sourceScalar, _downstreamConsumedComputings, _consumers, this, ref _sourceAsList, false);

			if (_source != null && _isActive)
			{
                Utils.initializeFromObservableCollectionWithChangeMarker(
                    _source, 
                    ref _sourceAsList, 
                    ref _rootSourceWrapper, 
                    ref _lastProcessedSourceChangeMarker);

				int count = _sourceAsList.Count;
                TSourceItem[] sourceCopy = new TSourceItem[count];
                _sourceAsList.CopyTo(sourceCopy, 0);

                _sourceAsList.CollectionChanged += handleSourceCollectionChanged;

				int sourceIndex;
				for (sourceIndex = 0; sourceIndex < count; sourceIndex++)
				{
					registerSourceItem(sourceCopy[sourceIndex], sourceIndex, true);
				}

                _sourceInitialized = true;
            }

			reset();
		}
Esempio n. 2
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        //TODO Uncomment new feature and write test
        //[ObservableComputationsCall]
        //public Filtering<TSourceItem> TryConstructInsertOrRemoveRequestHandlers()
        //{
        //	ConstructInsertOrRemoveActionsVisitor
        //		constructInsertOrRemoveActionsVisitor =
        //			new ConstructInsertOrRemoveActionsVisitor();

        //	constructInsertOrRemoveActionsVisitor.Visit(_predicateExpressionOriginal);

        //	Action<TSourceItem> transformSourceItemIntoMember =
        //		constructInsertOrRemoveActionsVisitor.TransformSourceItemIntoMember;
        //	if (transformSourceItemIntoMember != null)
        //	{
        //		InsertItemRequestHandler = (index, item) => transformSourceItemIntoMember(item);
        //	}

        //	Action<TSourceItem> transformSourceItemNotIntoMember =
        //		constructInsertOrRemoveActionsVisitor.TransformSourceItemIntoNotMember;
        //	if (transformSourceItemNotIntoMember != null)
        //	{
        //		RemoveItemRequestHandler = index => transformSourceItemNotIntoMember(this[index]);
        //	}

        //	return this;
        //}

        //private class ConstructInsertOrRemoveActionsVisitor : ExpressionVisitor
        //{
        //	public Action<TSourceItem> TransformSourceItemIntoMember;
        //	public Action<TSourceItem> TransformSourceItemIntoNotMember;
        //	#region Overrides of ExpressionVisitor

        //	//TODO !sourceItem.NullableProp.HasValue должно преобразооваться в sourceItem.NullableProp ==  null
        //	// TODO обрабытывать выражения типа '25 == sourceItem.Id'
        //	protected override Expression VisitBinary(BinaryExpression node)
        //	{
        //		ExpressionType nodeType = node.NodeType;
        //		if (nodeType == ExpressionType.Equal || nodeType == ExpressionType.NotEqual)
        //		{
        //			if (node.Left is MemberExpression memberExpression)
        //			{
        //				Expression rightExpression = node.Right;

        //				// ReSharper disable once PossibleNullReferenceException
        //				MemberInfo memberExpressionMember = memberExpression.Member;
        //				Type declaringType = memberExpressionMember.DeclaringType;
        //				// ReSharper disable once PossibleNullReferenceException
        //				if (declaringType.IsConstructedGenericType
        //					&& declaringType.GetGenericTypeDefinition() == typeof(Nullable<>)
        //					&& memberExpressionMember.Name == "Value")
        //				{
        //					memberExpression = (MemberExpression) memberExpression.Expression;
        //					rightExpression = Expression.Convert(rightExpression,
        //						typeof (Nullable<>).MakeGenericType(node.Left.Type));
        //				}

        //				ParameterExpression parameterExpression = getParameterExpression(memberExpression);
        //				if (parameterExpression != null)
        //				{
        //					if (memberExpression.Type != rightExpression.Type)
        //					{
        //						rightExpression = Expression.Convert(rightExpression, memberExpression.Type);
        //					}

        //					if (!memberExpressionMember.IsReadOnly())
        //					{
        //						if (nodeType == ExpressionType.Equal)
        //						{
        //							TransformSourceItemIntoMember = Expression.Lambda<Action<TSourceItem>>(Expression.Assign(memberExpression, rightExpression), parameterExpression).Compile();
        //						}
        //						else if (nodeType == ExpressionType.NotEqual)
        //						{
        //							TransformSourceItemIntoNotMember = Expression.Lambda<Action<TSourceItem>>(Expression.Assign(memberExpression, rightExpression), parameterExpression).Compile();
        //						}
        //					}
        //				}
        //			}
        //		}

        //		return node;
        //	}


        //	private ParameterExpression getParameterExpression(MemberExpression memberExpression)
        //	{
        //		if (memberExpression.Expression is ParameterExpression parameterExpression)
        //		{
        //			return parameterExpression;
        //		}

        //		if (memberExpression.Expression is MemberExpression expressionMemberExpression)
        //		{
        //			return getParameterExpression(expressionMemberExpression); // memberExpression.Expression может быть не MemberExpression
        //		}

        //		return null;
        //	}


        //	#endregion
        //}

        protected override void processSource()
        {
            int originalCount = _items.Count;

            if (_sourceReadAndSubscribed)
            {
                Utils.disposeExpressionItemInfos(_itemInfos, _predicateExpressionCallCount, this);
                Utils.removeDownstreamConsumedComputing(_itemInfos, this);

                _filteredPositions = new Positions <Position>(new List <Position>(_initialCapacity));

                Utils.disposeSource(
                    _sourceScalar,
                    _source,
                    out _itemInfos,
                    out _sourcePositions,
                    _sourceAsList,
                    handleSourceCollectionChanged);

                _sourceReadAndSubscribed = false;
            }

            Utils.changeSource(ref _source, _sourceScalar, _downstreamConsumedComputings, _consumers, this, out _sourceAsList, false);

            if (_source != null && _isActive)
            {
                Utils.initializeFromObservableCollectionWithChangeMarker(
                    _source,
                    ref _sourceAsList,
                    ref _rootSourceWrapper,
                    ref _lastProcessedSourceChangeMarker);

                Position      nextItemPosition = _filteredPositions.Add();
                int           count            = _sourceAsList.Count;
                TSourceItem[] sourceCopy       = new TSourceItem[count];
                _sourceAsList.CopyTo(sourceCopy, 0);

                _sourceAsList.CollectionChanged += handleSourceCollectionChanged;

                int insertingIndex = 0;
                int sourceIndex;

                for (sourceIndex = 0; sourceIndex < count; sourceIndex++)
                {
                    TSourceItem sourceItem = sourceCopy[sourceIndex];
                    Position    currentFilteredItemPosition = null;

                    FilteringItemInfo itemInfo = registerSourceItem(sourceItem, sourceIndex, null, null);

                    if (_thisAsFiltering.applyPredicate(sourceItem, itemInfo.PredicateFunc))
                    {
                        if (originalCount > insertingIndex)
                        {
                            _items[insertingIndex++] = sourceItem;
                        }
                        else
                        {
                            _items.Insert(insertingIndex++, sourceItem);
                        }

                        currentFilteredItemPosition = nextItemPosition;
                        nextItemPosition            = _filteredPositions.Add();
                    }

                    itemInfo.FilteredPosition         = currentFilteredItemPosition;
                    itemInfo.NextFilteredItemPosition = nextItemPosition;
                }

                for (int index = originalCount - 1; index >= insertingIndex; index--)
                {
                    _items.RemoveAt(index);
                }

                _sourceReadAndSubscribed = true;
            }
            else
            {
                _items.Clear();
            }

            reset();
        }
Esempio n. 3
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        protected override void processSource()
        {
            int originalCount = _items.Count;

            if (_sourceReadAndSubscribed)
            {
                Utils.disposeExpressionItemInfos(_itemInfos, _selectorExpressionCallCount, this);
                Utils.removeDownstreamConsumedComputing(_itemInfos, this);

                Utils.disposeSource(
                    _sourceScalar,
                    _source,
                    out _itemInfos,
                    out _sourcePositions,
                    _sourceAsList,
                    handleSourceCollectionChanged);

                _sourceReadAndSubscribed = false;
            }

            Utils.changeSource(ref _source, _sourceScalar, _downstreamConsumedComputings, _consumers, this, out _sourceAsList, false);

            if (_source != null && _isActive)
            {
                Utils.initializeFromObservableCollectionWithChangeMarker(
                    _source,
                    ref _sourceAsList,
                    ref _rootSourceWrapper,
                    ref _lastProcessedSourceChangeMarker);

                int count = _sourceAsList.Count;

                TSourceItem[] sourceCopy = new TSourceItem[count];
                _sourceAsList.CopyTo(sourceCopy, 0);

                _sourceAsList.CollectionChanged += handleSourceCollectionChanged;

                int sourceIndex;
                for (sourceIndex = 0; sourceIndex < count; sourceIndex++)
                {
                    ItemInfo itemInfo = registerSourceItem(sourceCopy[sourceIndex], sourceIndex);

                    if (originalCount > sourceIndex)
                    {
                        _items[sourceIndex] = applySelector(itemInfo, sourceCopy[sourceIndex]);
                    }
                    else
                    {
                        _items.Insert(sourceIndex, applySelector(itemInfo, sourceCopy[sourceIndex]));
                    }
                }

                for (int index = originalCount - 1; index >= sourceIndex; index--)
                {
                    _items.RemoveAt(index);
                }

                _sourceReadAndSubscribed = true;
            }
            else
            {
                _items.Clear();
            }

            reset();
        }