/// <summary>
/// Creates connection between from and to according to Definition
/// </summary>
/// <param name="from"></param>
/// <param name="to"></param>
/// <returns>Returns null if connection cannot be created</returns>
public ConnectionViewModel AddConnection(NodeBaseViewModel from, NodeBaseViewModel to)
{
var edge = Definition.CreateConnection(from, to);
if (edge == null)
{
return(null);
}
// prevent showing attach descriptors when their position is not calculated yet
// this can be possible not necessary if calculation their location was done before data binding of AttachDescriptors collection
// but then we would not have size of attach descriptors and size is necessary for calculating position
if (edge.FromDescriptor != null)
{
edge.FromDescriptor.Location = new Point(-1000, -1000);
}
if (edge.ToDescriptor != null)
{
edge.ToDescriptor.Location = new Point(-1000, -1000);
}
edge.ParentDiagram = this;
if (edge.FromDescriptor != null)
{
AttachDescriptors.Add(edge.FromDescriptor);
edge.FromDescriptor.Name = "from";
if (!IsInBatchMode)
{
ForceRedraw();
edge.FromDescriptor.RaiseInitialize();
}
}
if (edge.ToDescriptor != null)
{
AttachDescriptors.Add(edge.ToDescriptor);
edge.ToDescriptor.Name = "to";
if (!IsInBatchMode)
{
ForceRedraw();
edge.ToDescriptor.RaiseInitialize();
}
}
if (!IsInBatchMode)
{
ForceRedraw();
}
var sides = Definition.ConnectorSideStrategy.GetSidesForConnection(edge);
edge.AttachPointFrom = from.Attach(sides.FromSide, edge, edge.FromDescriptor);
edge.AttachPointTo = to.Attach(sides.ToSide, edge, edge.ToDescriptor);
Edges.Add(edge);
if (!IsInBatchMode)
{
edge.UpdateConnection();
}
from.RaiseConnectionAdded(edge);
to.RaiseConnectionAdded(edge);
return(edge);
}
