/// <summary>
/// Helper method which determines if the given in index
/// falls in the given block or in the next block
/// </summary>
private static bool InBlockOrNextBlock(List<RealizedColumnsBlock> blockList, int index, ref int blockIndex, ref RealizedColumnsBlock block, out bool pastLastBlock)
{
pastLastBlock = false;
bool exists = true;
if (index < block.StartIndex)
{
exists = false;
}
else if (index > block.EndIndex)
{
if (blockIndex == blockList.Count - 1)
{
blockIndex++;
pastLastBlock = true;
exists = false;
}
else
{
block = blockList[++blockIndex];
if (index < block.StartIndex ||
index > block.EndIndex)
{
exists = false;
}
}
}
return exists;
}
private bool InvalidateCellsPanelOnColumnChange()
{
if (InternalItemsHost == null)
{
return(false);
}
bool isVirtualizing = VirtualizingStackPanel.GetIsVirtualizing(this);
List <RealizedColumnsBlock> blockList = null;
if (isVirtualizing && !DataGridOwner.InternalColumns.RebuildRealizedColumnsBlockListForVirtualizedRows)
{
blockList = DataGridOwner.InternalColumns.RealizedColumnsBlockListForVirtualizedRows;
}
else if (!isVirtualizing && !DataGridOwner.InternalColumns.RebuildRealizedColumnsBlockListForNonVirtualizedRows)
{
blockList = DataGridOwner.InternalColumns.RealizedColumnsBlockListForNonVirtualizedRows;
}
// either RebuildRealizedColumnsBlockListForNonVirtualizedRows or RebuildRealizedColumnsBlockListForVirtualizedRows is true
if (blockList == null)
{
return(true);
}
IList children = InternalItemsHost.Children;
int lastRealizedColumnBlockIndex = 0, lastChildrenIndex = 0;
int childrenCount = children.Count;
int blockListCount = blockList.Count;
int allColumnsCount = DataGridOwner.Columns.Count;
bool foundInRealizedColumns, foundInCells;
for (int i = 0; i < allColumnsCount; i++)
{
foundInRealizedColumns = false;
foundInCells = false;
// find column in RealizedColumns
if (lastRealizedColumnBlockIndex < blockListCount)
{
RealizedColumnsBlock rcb = blockList[lastRealizedColumnBlockIndex];
if ((rcb.StartIndex <= i) && (i <= rcb.EndIndex))
{
foundInRealizedColumns = true;
// reached end of this block, start from next block
if (i == rcb.EndIndex)
{
lastRealizedColumnBlockIndex++;
}
}
}
// find column in Children
if (lastChildrenIndex < childrenCount)
{
DataGridCell cell = children[lastChildrenIndex] as DataGridCell;
if (DataGridOwner.Columns[i] == cell.Column)
{
foundInCells = true;
lastChildrenIndex++;
}
}
// if found in one but not the other or reached end of either list.
bool reachedEndofBlockList = (lastRealizedColumnBlockIndex == blockListCount);
bool reachedEndofChildrenList = (lastChildrenIndex == childrenCount);
if ((foundInCells != foundInRealizedColumns) || (reachedEndofBlockList != reachedEndofChildrenList))
{
return(true);
}
else if (reachedEndofBlockList == true)
{
//reached end of both columns and children lists
break;
}
}
return(false);
}
