/// <summary>
/// Connect two connections together. This is the connection on the superior block.
/// </summary>
/// <param name="childConnection"></param>
private void ConnectInternal(Connection childConnection)
{
var parentConnection = this;
var parentBlock = parentConnection.SourceBlock;
var childBlock = childConnection.SourceBlock;
// Disconnect any existing parent on the child connection.
if (childConnection.IsConnected)
{
childConnection.Disconnect();
}
// Other connection is already connected to something.
// Disconnect it and reattach it or bump it as needed.
if (parentConnection.IsConnected)
{
Block orphanBlock = parentConnection.TargetBlock;
XmlNode shadowDom = parentConnection.ShadowDom;
parentConnection.ShadowDom = null;
if (orphanBlock.IsShadow)
{
// Save the shadow block so that field values are preserved.
shadowDom = Xml.BlockToDom(orphanBlock);
orphanBlock.Dispose();
orphanBlock = null;
}
else if (parentConnection.Type == Define.EConnection.InputValue)
{
//value connnections
if (orphanBlock.OutputConnection == null)
{
throw new Exception("Orphan block does not have an output connection.");
}
// Attempt to reattach the orphan at the end of the newly inserted
// block. Since this block may be a row, walk down to the end
// or to the first (and only) shadow block.
var connection = Connection.LastConnectionInRow(childBlock, orphanBlock);
if (connection != null)
{
orphanBlock.OutputConnection.Connect(connection);
orphanBlock = null;
}
}
else if (parentConnection.Type == Define.EConnection.NextStatement)
{
// Statement connections.
// Statement blocks may be inserted into the middle of a stack.
// Split the stack.
if (orphanBlock.PreviousConnection == null)
{
throw new Exception("Orphan block does not have a previous connection.");
}
// Attempt to reattach the orphan at the bottom of the newly inserted
// block. Since this block may be a stack, walk down to the end.
var newBlock = childBlock;
while (newBlock.NextConnection != null)
{
var nextBlock = newBlock.NextBlock;
if (nextBlock != null && !nextBlock.IsShadow)
{
newBlock = nextBlock;
}
else
{
if (orphanBlock.PreviousConnection.CheckType(newBlock.NextConnection))
{
newBlock.NextConnection.Connect(orphanBlock.PreviousConnection);
orphanBlock = null;
}
break;
}
}
}
if (orphanBlock != null)
{
// Unable to reattach orphan.
parentConnection.Disconnect();
Connection orphanBlockCon = orphanBlock.OutputConnection != null ? orphanBlock.OutputConnection : orphanBlock.PreviousConnection;
orphanBlockCon.FireUpdate(UpdateState.BumpedAway);
}
// Restore the shadow DOM.
parentConnection.ShadowDom = shadowDom;
}
// Establish the connections.
Connection.ConnectReciprocally(parentConnection, childConnection);
// Demote the inferior block so that one is a child of the superior one.
childBlock.SetParent(parentBlock);
FireUpdate(UpdateState.Connected);
}