internal virtual GroupDescription GetSubGroupBy()
{
CollectionView collectionView = this.GetCollectionView();
ObservableCollection <GroupDescription> groupDescriptions = collectionView.GroupDescriptions;
int groupDescriptionsCount = (groupDescriptions == null) ? 0 : groupDescriptions.Count;
if (groupDescriptionsCount == 0)
{
return(null);
}
DataGridVirtualizingCollectionViewGroupBase parentCollectionViewGroup = this.Parent;
int level = 0;
while (parentCollectionViewGroup != null)
{
level++;
parentCollectionViewGroup = parentCollectionViewGroup.Parent;
}
Debug.Assert(groupDescriptionsCount >= level);
return(groupDescriptions[level]);
}
protected void UnlinkVirtualListAndCollectionViewGroup(VirtualList virtualList)
{
DataGridVirtualizingCollectionViewGroupBase collectionViewGroup = null;
if (m_virtualListVSCollectionViewGroupDictionary.TryGetValue(virtualList, out collectionViewGroup))
{
CollectionChangedEventManager.RemoveListener(virtualList, collectionViewGroup);
m_virtualListVSCollectionViewGroupDictionary.Remove(virtualList);
}
}
private void RaiseCollectionViewOnCommitItems(VirtualPage dispatchedPage, AsyncCommitInfo dispatchedCommitInfo)
{
DataGridVirtualizingCollectionViewBase collectionView = this.CollectionView as DataGridVirtualizingCollectionViewBase;
DataGridVirtualizingCollectionViewGroupBase collectionViewGroup =
this.GetLinkedCollectionViewGroup(dispatchedPage.ParentVirtualList) as DataGridVirtualizingCollectionViewGroupBase;
Debug.Assert((collectionViewGroup != null) && (collectionView != null));
collectionView.OnCommitItems(dispatchedCommitInfo);
}
internal DataGridVirtualizingCollectionViewGroupBase(
object name,
int initialItemsCount,
int startGlobalIndex,
DataGridVirtualizingCollectionViewGroupBase parent,
int level,
bool isBottomLevel)
: base(name)
{
m_parent = parent;
m_level = level;
m_isBottomLevel = isBottomLevel;
m_virtualItemCount = initialItemsCount;
m_startGlobalIndex = startGlobalIndex;
}
internal DataGridVirtualizingCollectionViewGroupBase(
object name,
int initialItemsCount,
int startGlobalIndex,
DataGridVirtualizingCollectionViewGroupBase parent,
int level,
bool isBottomLevel )
: base( name )
{
m_parent = parent;
m_level = level;
m_isBottomLevel = isBottomLevel;
m_virtualItemCount = initialItemsCount;
m_startGlobalIndex = startGlobalIndex;
}
private int GetSubLevelCount()
{
CollectionView collectionView = this.GetCollectionView();
ObservableCollection <GroupDescription> groupDescriptions = collectionView.GroupDescriptions;
int groupDescriptionsCount = (groupDescriptions == null) ? 0 : groupDescriptions.Count;
DataGridVirtualizingCollectionViewGroupBase parentCollectionViewGroup = this.Parent;
int level = 0;
while (parentCollectionViewGroup != null)
{
level++;
parentCollectionViewGroup = parentCollectionViewGroup.Parent;
}
Debug.Assert(groupDescriptionsCount >= level);
return(groupDescriptionsCount - level);
}
internal static SelectionRange GetRange(this CollectionViewGroup collectionViewGroup, DataGridContext dataGridContext)
{
int startIndex = -1;
int endIndex = -1;
DataGridVirtualizingCollectionViewGroupBase dataGridVirtualizingCollectionViewGroupBase = collectionViewGroup as DataGridVirtualizingCollectionViewGroupBase;
DataGridCollectionViewGroup dataGridCollectionViewGroup = collectionViewGroup as DataGridCollectionViewGroup;
if (dataGridVirtualizingCollectionViewGroupBase != null)
{
startIndex = dataGridVirtualizingCollectionViewGroupBase.StartGlobalIndex;
endIndex = startIndex + dataGridVirtualizingCollectionViewGroupBase.VirtualItemCount - 1;
}
else if (dataGridCollectionViewGroup != null)
{
startIndex = dataGridCollectionViewGroup.GetFirstRawItemGlobalSortedIndex();
endIndex = startIndex + dataGridCollectionViewGroup.GlobalRawItemCount - 1;
}
else if (collectionViewGroup.ItemCount > 0)
{
if (dataGridContext == null)
{
throw new DataGridInternalException("This collectionViewGroup require a DataGridContext instance");
}
var firstItem = collectionViewGroup.GetFirstLeafItem();
var lastItem = collectionViewGroup.GetLastLeafItem();
if (firstItem != null && lastItem != null)
{
startIndex = dataGridContext.Items.IndexOf(firstItem);
endIndex = dataGridContext.Items.IndexOf(lastItem);
}
}
return((startIndex >= 0) && (startIndex <= endIndex)
? new SelectionRange(startIndex, endIndex)
: SelectionRange.Empty);
}
public static IList <object> GetItems(this CollectionViewGroup collectionViewGroup)
{
DataGridVirtualizingCollectionViewGroupBase dataGridVirtualizingCollectionViewGroupBase = collectionViewGroup as DataGridVirtualizingCollectionViewGroupBase;
if (dataGridVirtualizingCollectionViewGroupBase != null)
{
return(dataGridVirtualizingCollectionViewGroupBase.VirtualItems);
}
DataGridCollectionViewGroup dataGridCollectionViewGroup = collectionViewGroup as DataGridCollectionViewGroup;
if (dataGridCollectionViewGroup != null)
{
// The Items property of the DataGridCollectionViewGroup has been optimized
// to allow faster IndexOf and Contains. Since this property we could not
// override the property, we had to new it thus, we need to cast the CollectionViewGroup
// in the right type before acecssing the property.
return(dataGridCollectionViewGroup.Items);
}
return(collectionViewGroup.Items);
}
public int GetGlobalIndexOf(object item)
{
ReadOnlyCollection <VirtualList> virtualItemLists = this.ManagedLists;
int virtualItemListsCount = virtualItemLists.Count;
for (int i = 0; i < virtualItemListsCount; i++)
{
VirtualList localList = virtualItemLists[i];
int localIndex = localList.IndexOf(item);
if (localIndex >= 0)
{
Debug.Assert(m_virtualListVSCollectionViewGroupDictionary.ContainsKey(localList));
DataGridVirtualizingCollectionViewGroupBase dgvcvg = m_virtualListVSCollectionViewGroupDictionary[localList];
return(localIndex + dgvcvg.StartGlobalIndex);
}
}
return(-1);
}
private object OperateOnGlobalIndex(int index, Func <int, DataGridVirtualizingCollectionViewGroupBase, object> function)
{
this.EnsureProtectedVirtualItems();
if (this.IsBottomLevel)
{
return(function(index, this));
}
else
{
// The Count property of the virtualItems collection will return the sub-group count since this is not the bottom level.
int count = m_protectedVirtualItems.Count;
for (int i = 0; i < count; i++)
{
DataGridVirtualizingCollectionViewGroupBase subGroup = m_protectedVirtualItems[i] as DataGridVirtualizingCollectionViewGroupBase;
if (subGroup == null)
{
throw new InvalidOperationException("Sub-group cannot be null (Nothing in Visual Basic).");
}
// VirtualItemCount will return the sum of data items contained in this group and its possible subgroups.
int subGroupItemCount = subGroup.VirtualItemCount;
if (index < subGroupItemCount)
{
return(subGroup.OperateOnGlobalIndex(index, function));
}
index -= subGroupItemCount;
}
}
throw new ArgumentOutOfRangeException("index");
}
internal override void ForceRefresh(bool sendResetNotification, bool initialLoad, bool setCurrentToFirstOnInitialLoad)
{
if (this.Refreshing)
{
throw new InvalidOperationException("An attempt was made to refresh the DataGridVirtualizingCollectionView while it is already in the process of refreshing.");
}
if (this.IsRefreshingDistinctValues)
{
throw new InvalidOperationException("An attempt was made to refresh the DataGridVirtualizingCollectionView while it is already in the process of refreshing distinct values.");
}
this.SetCurrentEditItem(null);
int oldCurrentPosition = -1;
if (!initialLoad)
{
this.SaveCurrentBeforeReset(out oldCurrentPosition);
}
using (this.DeferCurrencyEvent())
{
this.Refreshing = true;
try
{
lock (this.SyncRoot)
{
lock (this.DeferredOperationManager)
{
this.DeferredOperationManager.ClearDeferredOperations();
// We explicitly go through base so we do not end-up creating a RootGroup if there is none existing at the moment.
DataGridVirtualizingCollectionViewGroupBase rootGroup = base.RootGroup as DataGridVirtualizingCollectionViewGroupBase;
if (rootGroup != null)
{
DataGridPageManagerBase pageManager = rootGroup.GetVirtualPageManager();
// The pageManager can be null when no queryable source was set yet.
if (pageManager != null)
{
// Disconnect the PageManager so that subsequent Items/Count interrogations are not processed.
pageManager.Disconnect();
// Restart all virtual lists. The DataGridPageManagerBase will make a call to ForceRefresh once everything has been restarted if
// commit operations had to be made.
pageManager.Restart();
}
}
// Ensure to clear the DistinctValues cache when refreshing
// since the source could have changed
this.ResetDistinctValues();
base.RootGroup = this.CreateNewRootGroup();
// We set the current item to -1 to prevent the developper to get an invalid position.
// We will replace the current item to the correct one later.
this.SetCurrentItem(-1, null, false, false);
}
}
}
finally
{
this.Refreshing = false;
}
if (initialLoad)
{
this.Loaded = true;
}
else
{
this.AdjustCurrencyAfterReset(oldCurrentPosition);
}
if (sendResetNotification)
{
this.OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
}
}
}
internal void LinkVirtualListAndCollectionViewGroup(VirtualList virtualItemList, DataGridVirtualizingCollectionViewGroupBase collectionViewGroup)
{
Debug.Assert(!m_virtualListVSCollectionViewGroupDictionary.ContainsKey(virtualItemList));
Debug.Assert(!m_virtualListVSCollectionViewGroupDictionary.ContainsValue(collectionViewGroup));
m_virtualListVSCollectionViewGroupDictionary.Add(virtualItemList, collectionViewGroup);
CollectionChangedEventManager.AddListener(virtualItemList, collectionViewGroup);
}
