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Support range notifications #9568

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2820114
support range notifications
Mrxx99 Aug 13, 2024
cf0657c
fixed replacements
Mrxx99 Aug 17, 2024
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128 changes: 122 additions & 6 deletions ...ft.DotNet.Wpf/src/PresentationFramework/System/Windows/Controls/ItemContainerGenerator.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2400,25 +2400,25 @@ void OnCollectionChanged(object sender, NotifyCollectionChangedEventArgs args)
switch (args.Action)
{
case NotifyCollectionChangedAction.Add:
if (args.NewItems.Count != 1)
if (args.NewItems.Count < 1)
throw new NotSupportedException(SR.RangeActionsNotSupported);
OnItemAdded(args.NewItems[0], args.NewStartingIndex);
OnItemsAdded(args.NewItems, args.NewStartingIndex);
break;

case NotifyCollectionChangedAction.Remove:
if (args.OldItems.Count != 1)
if (args.OldItems.Count < 1)
throw new NotSupportedException(SR.RangeActionsNotSupported);
OnItemRemoved(args.OldItems[0], args.OldStartingIndex);
OnItemsRemoved(args.OldItems, args.OldStartingIndex);
break;

case NotifyCollectionChangedAction.Replace:
// Don't check arguments if app targets 4.0, for compat ( 726682)
if (!FrameworkCompatibilityPreferences.TargetsDesktop_V4_0)
{
if (args.OldItems.Count != 1)
if (args.OldItems.Count < 1)
throw new NotSupportedException(SR.RangeActionsNotSupported);
}
OnItemReplaced(args.OldItems[0], args.NewItems[0], args.NewStartingIndex);
OnItemsReplaced(args.OldItems, args.NewItems, args.NewStartingIndex);
break;

case NotifyCollectionChangedAction.Move:
Expand Down Expand Up @@ -2446,6 +2446,86 @@ void OnCollectionChanged(object sender, NotifyCollectionChangedEventArgs args)
}
}

// Called when an items are added to the items collection
void OnItemsAdded(IList items, int index)
{
if (_itemMap == null)
{
// reentrant call (from RemoveAllInternal) shouldn't happen,
// but if it does, don't crash
Debug.Assert(false, "unexpected reentrant call to OnItemAdded");
return;
}

ValidateAndCorrectIndex(items[0], ref index);

GeneratorPosition position = new GeneratorPosition(-1, 0);

// find the block containing the new item
ItemBlock block = _itemMap.Next;
int offsetFromBlockStart = index;
int unrealizedItemsSkipped = 0; // distance since last realized item
while (block != _itemMap && offsetFromBlockStart >= block.ItemCount)
{
offsetFromBlockStart -= block.ItemCount;
position.Index += block.ContainerCount;
unrealizedItemsSkipped = (block.ContainerCount > 0) ? 0 : unrealizedItemsSkipped + block.ItemCount;
block = block.Next;
}

position.Offset = unrealizedItemsSkipped + offsetFromBlockStart + 1;
// the position is now correct, except when pointing into a realized block;
// that case is fixed below

// if it's an unrealized block, add the item by bumping the count
UnrealizedItemBlock uib = block as UnrealizedItemBlock;
if (uib != null)
{
MoveItems(uib, offsetFromBlockStart, items.Count, uib, offsetFromBlockStart + 1, 0);
uib.ItemCount += items.Count;
}

// if the item can be added to a previous unrealized block, do so
else if ((offsetFromBlockStart == 0 || block == _itemMap) &&
((uib = block.Prev as UnrealizedItemBlock) != null))
{
uib.ItemCount += items.Count;
}

// otherwise, create a new unrealized block
else
{
uib = new UnrealizedItemBlock();
uib.ItemCount = items.Count;

// split the current realized block, if necessary
RealizedItemBlock rib;
if (offsetFromBlockStart > 0 && (rib = block as RealizedItemBlock) != null)
{
RealizedItemBlock newBlock = new RealizedItemBlock();
MoveItems(rib, offsetFromBlockStart, rib.ItemCount - offsetFromBlockStart, newBlock, 0, offsetFromBlockStart);
newBlock.InsertAfter(rib);
position.Index += block.ContainerCount;
position.Offset = 1;
block = newBlock;
}

uib.InsertBefore(block);
}

// tell generators what happened
if (MapChanged != null)
{
MapChanged(null, index, items.Count, uib, 0, 0);
}

// tell layout what happened
if (ItemsChanged != null)
{
ItemsChanged(this, new ItemsChangedEventArgs(NotifyCollectionChangedAction.Add, position, items.Count, 0));
}
}

// Called when an item is added to the items collection
void OnItemAdded(object item, int index)
{
Expand Down Expand Up @@ -2526,6 +2606,15 @@ void OnItemAdded(object item, int index)
}
}

// Called when items are removed from the items collection
// TODO this could probably be improved
void OnItemsRemoved(IList items, int itemIndex)
{
foreach (var item in items)
{
OnItemRemoved(item, itemIndex);
}
}

// Called when an item is removed from the items collection
void OnItemRemoved(object item, int itemIndex)
Expand Down Expand Up @@ -2592,6 +2681,33 @@ void OnItemRemoved(object item, int itemIndex)
}
}

// this could probably be optimized
void OnItemsReplaced(IList oldItems, IList newItems, int index)
{
// Handle replacements for the overlapping part
for (int i = 0; i < Math.Min(oldItems.Count, newItems.Count); i++)
{
OnItemReplaced(oldItems[i], newItems[i], index + i);
}

// Handle extra removals (oldItems has more elements)
if (oldItems.Count > newItems.Count)
{
for (int i = oldItems.Count - 1; i >= newItems.Count; i--)
{
OnItemRemoved(oldItems[i], index + i);
}
}
// Handle extra additions (newItems has more elements)
else if (newItems.Count > oldItems.Count)
{
for (int i = oldItems.Count; i < newItems.Count; i++)
{
OnItemAdded(newItems[i], index + i);
}
}
}

void OnItemReplaced(object oldItem, object newItem, int index)
{
// search for the replaced item
Expand Down
52 changes: 39 additions & 13 deletions src/Microsoft.DotNet.Wpf/src/PresentationFramework/System/Windows/Data/ListCollectionView.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1890,6 +1890,8 @@ void ProcessCollectionChangedWithAdjustedIndex(NotifyCollectionChangedEventArgs

object oldItem = (args.OldItems != null && args.OldItems.Count > 0) ? args.OldItems[0] : null;
object newItem = (args.NewItems != null && args.NewItems.Count > 0) ? args.NewItems[0] : null;
IList oldItems = args.OldItems ?? Array.Empty<object>();
IList newItems = args.NewItems ?? Array.Empty<object>();

LiveShapingList lsList = InternalList as LiveShapingList;
LiveShapingItem lsi;
Expand Down Expand Up @@ -1925,7 +1927,7 @@ void ProcessCollectionChangedWithAdjustedIndex(NotifyCollectionChangedEventArgs
if (!IsGrouping)
{
AdjustCurrencyForAdd(adjustedNewIndex);
args = new NotifyCollectionChangedEventArgs(effectiveAction, newItem, adjustedNewIndex);
args = new NotifyCollectionChangedEventArgs(effectiveAction, newItems, adjustedNewIndex);
}
else
{
Expand Down Expand Up @@ -1963,7 +1965,7 @@ void ProcessCollectionChangedWithAdjustedIndex(NotifyCollectionChangedEventArgs
if (!IsGrouping)
{
AdjustCurrencyForRemove(adjustedOldIndex);
args = new NotifyCollectionChangedEventArgs(effectiveAction, args.OldItems[0], adjustedOldIndex);
args = new NotifyCollectionChangedEventArgs(effectiveAction, oldItems, adjustedOldIndex);
}
else
{
Expand Down Expand Up @@ -1993,7 +1995,7 @@ void ProcessCollectionChangedWithAdjustedIndex(NotifyCollectionChangedEventArgs
if (!IsGrouping)
{
AdjustCurrencyForReplace(adjustedOldIndex);
args = new NotifyCollectionChangedEventArgs(effectiveAction, args.NewItems[0], args.OldItems[0], adjustedOldIndex);
args = new NotifyCollectionChangedEventArgs(effectiveAction, newItems, oldItems, adjustedOldIndex);
}
else
{
Expand Down Expand Up @@ -2392,34 +2394,58 @@ internal void AdjustShadowCopy(NotifyCollectionChangedEventArgs e)
case NotifyCollectionChangedAction.Add:
if (e.NewStartingIndex > _unknownIndex)
{
ShadowCollection.Insert(e.NewStartingIndex, e.NewItems[0]);
ShadowCollection.InsertRange(e.NewStartingIndex, e.NewItems);
}
else
{
ShadowCollection.Add(e.NewItems[0]);
ShadowCollection.AddRange(e.NewItems);
}
break;
case NotifyCollectionChangedAction.Remove:
if (e.OldStartingIndex > _unknownIndex)
{
ShadowCollection.RemoveAt(e.OldStartingIndex);
ShadowCollection.RemoveRange(e.OldStartingIndex, e.OldItems.Count);
}
else
{
ShadowCollection.Remove(e.OldItems[0]);
for (int i = e.OldStartingIndex; i < e.OldItems.Count; i++)
{
ShadowCollection.Remove(e.OldItems[i]);
}
}
break;
case NotifyCollectionChangedAction.Replace:
if (e.OldStartingIndex > _unknownIndex)
{
ShadowCollection[e.OldStartingIndex] = e.NewItems[0];
if (e.NewItems.Count == e.OldItems.Count)
{
for (int i = 0; i < e.NewItems.Count; i++)
{
ShadowCollection[e.OldStartingIndex + i] = e.NewItems[i];
}
}
else
{
if (e.OldItems.Count > 0)
{
ShadowCollection.RemoveRange(e.OldStartingIndex, e.OldItems.Count);
}

if (e.NewItems.Count > 0)
{
ShadowCollection.InsertRange(e.OldStartingIndex, e.NewItems);
}
}
}
else
{
// allow the ShadowCollection to throw the IndexOutOfRangeException
// if the item is not found.
tempIndex = ShadowCollection.IndexOf(e.OldItems[0]);
ShadowCollection[tempIndex] = e.NewItems[0];
for (int i = 0; i < e.OldItems.Count; i++)
{
tempIndex = ShadowCollection.IndexOf(e.OldItems[i]);
ShadowCollection[tempIndex] = e.NewItems[i];
}
}
break;
case NotifyCollectionChangedAction.Move:
Expand Down Expand Up @@ -2522,17 +2548,17 @@ private void ValidateCollectionChangedEventArgs(NotifyCollectionChangedEventArgs
switch (e.Action)
{
case NotifyCollectionChangedAction.Add:
if (e.NewItems.Count != 1)
if (e.NewItems.Count < 1)
throw new NotSupportedException(SR.RangeActionsNotSupported);
break;

case NotifyCollectionChangedAction.Remove:
if (e.OldItems.Count != 1)
if (e.OldItems.Count < 1)
throw new NotSupportedException(SR.RangeActionsNotSupported);
break;

case NotifyCollectionChangedAction.Replace:
if (e.NewItems.Count != 1 || e.OldItems.Count != 1)
if (e.NewItems.Count < 1 || e.OldItems.Count < 1)
throw new NotSupportedException(SR.RangeActionsNotSupported);
break;

Expand Down