private bool ToggleColumnSort(ColumnBase column, bool resetSort)
{
ToggleColumnSortCommand.ThrowIfNull(column, "column");
this.ValidateToggleColumnSort();
using (var synchronizationContext = this.StartSynchronizing(this.GetSortDescriptionsSyncContext()))
{
this.ValidateSynchronizationContext(synchronizationContext);
using (var disposer = new Disposer())
{
this.DeferRestoreStateOnLevel(disposer);
// This will ensure that all DataGridCollectionViews mapped to the SortDescriptions collection will only refresh their sorting once!
var sortDescriptions = this.SortDescriptions;
disposer.Add(this.DeferResortHelper(sortDescriptions), DisposableType.DeferResort);
var newSortDirection = ToggleColumnSortCommand.GetNextSortDirection(column.SortDirection);
string columnName = column.FieldName;
int insertionIndex;
if ((resetSort) &&
((column.SortIndex == -1) || (sortDescriptions.Count > 1)))
{
insertionIndex = 0;
if (sortDescriptions.Count > 0)
{
sortDescriptions.Clear();
}
Debug.Assert(sortDescriptions.Count == 0);
}
else
{
for (insertionIndex = 0; insertionIndex < sortDescriptions.Count; insertionIndex++)
{
if (sortDescriptions[insertionIndex].PropertyName == columnName)
{
break;
}
}
}
if (insertionIndex < sortDescriptions.Count)
{
if (newSortDirection == SortDirection.None)
{
sortDescriptions.RemoveAt(insertionIndex);
}
else
{
sortDescriptions[insertionIndex] = new SortDescription(columnName, ToggleColumnSortCommand.Convert(newSortDirection));
}
}
else if (newSortDirection != SortDirection.None)
{
sortDescriptions.Add(new SortDescription(columnName, ToggleColumnSortCommand.Convert(newSortDirection)));
}
}
}
return(true);
}
