internal void OnQueryGroups(QueryGroupsEventArgs e)
 {
     if (this.QueryGroups != null)
     {
         this.QueryGroups(this, e);
     }
 }
        internal List <GroupNameCountPair> OnQueryGroups(DataGridVirtualizingCollectionViewGroup parentGroup)
        {
            ObservableCollection <GroupDescription> groupDescriptions = this.GroupDescriptions;
            int nextLevel = parentGroup.Level + 1;

            Debug.Assert((groupDescriptions != null) && (groupDescriptions.Count > nextLevel));

            QueryGroupsEventArgs e = new QueryGroupsEventArgs(this, parentGroup, groupDescriptions[nextLevel]);

            if (this.QueryGroups != null)
            {
                this.QueryGroups(this, e);
            }

            DataGridVirtualizingCollectionViewSource source = this.ParentCollectionViewSourceBase as DataGridVirtualizingCollectionViewSource;

            if (source != null)
            {
                source.OnQueryGroups(e);
            }

            return(e.ChildGroupNameCountPairs);
        }
    internal List<GroupNameCountPair> OnQueryGroups( DataGridVirtualizingCollectionViewGroup parentGroup )
    {
      ObservableCollection<GroupDescription> groupDescriptions = this.GroupDescriptions;
      int nextLevel = parentGroup.Level + 1;

      Debug.Assert( ( groupDescriptions != null ) && ( groupDescriptions.Count > nextLevel ) );

      QueryGroupsEventArgs e = new QueryGroupsEventArgs( this, parentGroup, groupDescriptions[ nextLevel ] );

      if( this.QueryGroups != null )
        this.QueryGroups( this, e );

      DataGridVirtualizingCollectionViewSource source = this.ParentCollectionViewSourceBase as DataGridVirtualizingCollectionViewSource;

      if( source != null )
        source.OnQueryGroups( e );

      return e.ChildGroupNameCountPairs;
    }
 internal void OnQueryGroups( QueryGroupsEventArgs e )
 {
   if( this.QueryGroups != null )
     this.QueryGroups( this, e );
 }