/// <include file='doc\DataColumnCollection.uex' path='docs/doc[@for="DataColumnCollection.OnCollectionChanged"]/*' />
/// <devdoc>
/// <para>
/// Raises the <see cref='System.Data.DataColumnCollection.OnCollectionChanged'/> event.
/// </para>
/// </devdoc>
protected virtual void OnCollectionChanged(CollectionChangeEventArgs ccevent)
{
table.UpdatePropertyDescriptorCollectionCache();
if (!table.SchemaLoading && !table.fInitInProgress)
{
columnQueue = new ColumnQueue(table, columnQueue);
}
if (onCollectionChangedDelegate != null)
{
onCollectionChangedDelegate(this, ccevent);
}
}
internal ColumnQueue(DataTable table, ColumnQueue old)
{
Debug.Assert(table != null, "ColumnQueue: Invalid parameter (table == null)");
Debug.Assert(table.TableName != null, "ColumnQueue: Invalid parameter Where is the table name?");
#if DEBUG
if (CompModSwitches.DataExpression.TraceVerbose)
{
Debug.WriteLine("Create ColumnQueue for table " + table.TableName);
}
#endif
DataColumn[] allcolumns = new DataColumn[table.Columns.Count];
table.Columns.CopyTo(allcolumns, 0);
this.owner = table;
InitQueue(this, allcolumns);
#if DEBUG
if (CompModSwitches.DataExpression.TraceVerbose)
{
Debug.WriteLine("we have " + columnCount.ToString() + " column in the column queue");
}
//for (int i = 0; i < columnCount; i++) {
//UNDONE : Debug.WriteLineIf("DataExpression", i.ToString() + ", " + columns[i].ColumnName);
//}
#endif
// scan the old evaluation queue for the external dependencies,
// and add then at the end of the new evaluation queue.
if (old != null && old.columnCount != 0)
{
for (int i = 0; i < old.columnCount; i++)
{
if (old.columns[i] == null)
{
break;
}
if (old.columns[i].Table != null && old.columns[i].Table != owner)
{
AddColumn(old.columns[i]);
}
}
}
}
internal void RefreshComputedColumns(DataColumn start)
{
columnQueue = new ColumnQueue(table, columnQueue);
CalculateExpressions(columnQueue.columns, columnQueue.columnCount, start);
}
private static void InitQueue(ColumnQueue queue, DataColumn[] cols)
{
#if DEBUG
if (CompModSwitches.DataExpression.TraceVerbose)
{
Debug.WriteLine("InitQueue");
}
if (CompModSwitches.DataExpression.TraceVerbose)
{
Debug.WriteLine("Building columnQueue, current size is " + queue.columns.Length.ToString() + " next element " + queue.columnCount.ToString());
Debug.WriteLine("Dependencies..");
}
//for (int i = 0; i < cols.Length; i++) {
//UNDONE : Debug.WriteLineIf("DataExpression", cols[i].ColumnName);
//}
#endif
for (int i = 0; i < cols.Length; i++)
{
DataColumn column = cols[i];
// for all Computed columns, get the list of the dependencies
if (column.Computed)
{
#if DEBUG
if (CompModSwitches.DataExpression.TraceVerbose)
{
Debug.WriteLine("Looking at the expression column " + column.ColumnName + "=" + column.Expression);
}
#endif
DataColumn[] dependency = column.DataExpression.GetDependency();
int j;
// look through the expression dependencies in search of "foreign" columns
for (j = 0; j < dependency.Length; j++)
{
if (dependency[j].Table != queue.owner)
{
dependency[j].Table.Columns.ColumnQueue.AddColumn(column);
}
}
InitQueue(queue, dependency);
// add the current column to the queue, if its not there already
#if DEBUG
if (CompModSwitches.DataExpression.TraceVerbose)
{
Debug.WriteLine("InitQueue: Check if column [" + column.ColumnName + "] already in the list.");
}
#endif
for (j = 0; j < queue.columnCount; j++)
{
if (queue.columns[j] == column)
{
#if DEBUG
if (CompModSwitches.DataExpression.TraceVerbose)
{
Debug.WriteLine("Found column [" + column.ColumnName + "] in pos " + j.ToString());
}
#endif
break;
}
}
if (j >= queue.columnCount)
{
#if DEBUG
if (CompModSwitches.DataExpression.TraceVerbose)
{
Debug.WriteLine("Add column [" + column.ColumnName + "], columns = " + queue.columnCount.ToString());
}
#endif
queue.AddColumn(column);
#if DEBUG
if (CompModSwitches.DataExpression.TraceVerbose)
{
Debug.WriteLine("And now we have columns = " + queue.columnCount.ToString());
}
#endif
}
}
#if DEBUG
else if (CompModSwitches.DataExpression.TraceVerbose)
{
Debug.WriteLine("not computed column " + column.ColumnName);
}
#endif
}
}
