/// <summary>
/// Create and add child nodes for subtables of this node and direct greater columns.
/// </summary>
public void ExpandTree(bool recursively = true)
{
if (Input == null) // We cannot expand the set but try to expand the existing children
{
if (!recursively)
{
return;
}
foreach (ColumnNode c in this)
{
if (!(c is SubtableTree))
{
continue;
}
((SubtableTree)c).ExpandTree(recursively);
}
return;
}
foreach (DcColumn sd in Input.SubColumns)
{
if (ExistsChild(sd))
{
continue;
}
// New child instances need to have the type of this instance (this instance can be an extension of this class so we do not know it)
ColumnNode child = (ColumnNode)Activator.CreateInstance(this.GetType(), new Object[] { sd, null });
this.AddChild(child);
if (recursively && (child is SubtableTree))
{
((SubtableTree)child).ExpandTree(recursively);
}
}
// Add child nodes for greater column (no recursion)
foreach (DcColumn gd in Input.Columns)
{
if (gd.IsSuper)
{
continue;
}
if (ExistsChild(gd))
{
continue;
}
// New child instances need to have the type of this instance (this instance can be an extension of this class so we do not know it)
ColumnNode child = (ColumnNode)Activator.CreateInstance(this.GetType(), new Object[] { gd, null });
this.AddChild(child);
}
}
public SubtableTree(DcColumn col, ColumnNode parent = null)
: base(col, parent)
{
// Register for events from the schema (or inside constructor?)
}
protected override void Input_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e) // Changes in our lesser set
{
if (!IsSubsetNode)
{
return; // Child nodes are added/deleted for only super-columns (for subset trees)
}
DcColumn col = null;
if (e.Action == NotifyCollectionChangedAction.Add) // Decide if this node has to add a new child node
{
col = e.NewItems != null && e.NewItems.Count > 0 ? (Column)e.NewItems[0] : null;
if (col == null)
{
return;
}
if (col.IsSuper) // Inclusion
{
if (col.Output == Column.Input) // Add a subset child node (recursively)
{
if (!ExistsChild(col))
{
// New child instances need to have the type of this instance (this instance can be an extension of this class so we do not know it)
ColumnNode child = (ColumnNode)Activator.CreateInstance(this.GetType(), new Object[] { col, null });
AddChild(child);
if (child is SubtableTree)
{
((SubtableTree)child).ExpandTree(true);
}
}
}
}
else // Poset
{
if (col.Input == Column.Input) // Add an attribute child node (non-recursively)
{
if (!ExistsChild(col))
{
// New child instances need to have the type of this instance (this instance can be an extension of this class so we do not know it)
ColumnNode child = (ColumnNode)Activator.CreateInstance(this.GetType(), new Object[] { col, null });
AddChild(child);
}
}
}
}
else if (e.Action == NotifyCollectionChangedAction.Remove)
{
col = e.OldItems != null && e.OldItems.Count > 0 ? (Column)e.OldItems[0] : null;
if (col == null)
{
return;
}
if (col.IsSuper) // Inclusion
{
if (col.Output == Column.Input) // Remove a subset child node (recursively)
{
ColumnNode child = GetChild(col);
if (child != null)
{
RemoveChild(child);
}
}
}
else // Poset
{
if (col.Input == Column.Input) // Add an attribute child node (non-recursively)
{
ColumnNode child = GetChild(col);
if (child != null)
{
RemoveChild(child);
}
}
}
}
}