public void SetVariableValue(String varName, object val)
{
if(varName == null) return;
Variable var;
VariableMap.TryGetValue(varName, out var);
if(var != null)
{
if(var.Value == val) return; // Variable already set to this element?
if(var.Value is IGraphElement)
DetachVariableFromElement(var);
if(val == null)
{
VariableMap.Remove(varName);
return;
}
var.Value = val;
}
else
{
if(val == null) return;
var = new Variable(varName, val);
VariableMap[varName] = var;
}
IGraphElement elem = val as IGraphElement;
if(elem == null) return;
LinkedList<Variable> newVarList;
if(!ElementMap.TryGetValue(elem, out newVarList))
{
newVarList = new LinkedList<Variable>();
ElementMap[elem] = newVarList;
}
newVarList.AddFirst(var);
LGSPNode node = elem as LGSPNode;
if(node != null)
node.lgspFlags |= (uint)LGSPElemFlags.HAS_VARIABLES;
else
{
LGSPEdge edge = (LGSPEdge)elem;
edge.lgspFlags |= (uint)LGSPElemFlags.HAS_VARIABLES;
}
}
/// <summary>
/// Detaches the specified variable from the according graph element.
/// If it was the last variable pointing to the element, the variable list for the element is removed.
/// This function may only called on variables pointing to graph elements.
/// </summary>
/// <param name="var">Variable to detach.</param>
private void DetachVariableFromElement(Variable var)
{
IGraphElement elem = (IGraphElement)var.Value;
LinkedList<Variable> oldVarList = ElementMap[elem];
oldVarList.Remove(var);
if(oldVarList.Count == 0)
{
ElementMap.Remove(elem);
LGSPNode oldNode = elem as LGSPNode;
if(oldNode != null) oldNode.lgspFlags &= ~(uint)LGSPElemFlags.HAS_VARIABLES;
else
{
LGSPEdge oldEdge = (LGSPEdge)elem;
oldEdge.lgspFlags &= ~(uint)LGSPElemFlags.HAS_VARIABLES;
}
}
}
