/// <summary>
/// Finds a transition which matches the initial state, target state and rule condition in the existing transitions
/// </summary>
/// <param name="condition"></param>
/// <param name="initialState"></param>
/// <param name="targetState"></param>
/// <returns></returns>
private bool findMatchingTransition(Rules.RuleCondition condition, State initialState, State targetState)
{
bool retVal = false;
foreach (Transition t in Transitions)
{
if (t.RuleCondition == condition && t.Source == initialState && t.Target == targetState)
{
retVal = true;
break;
}
}
return(retVal);
}
/// <summary>
/// Adds a transition in the transitions sets
/// </summary>
/// <param name="update">The update state which provides the target of the transition</param>
/// <param name="target">The target state, as determined by the update statement</param>
/// <param name="filteredOut"></param>
/// <param name="preCondition">the precondition (if any) which is used to determine the initial state</param>
/// <param name="initial">The initial state</param>
/// <returns>
/// true if the transition has been filtered out. A transition can be filtered out if the target state is equal to the
/// initial state or the initial state is null
/// </returns>
private bool AddTransition(VariableUpdateStatement update, State target, PreCondition preCondition,
State initial)
{
bool retVal = false;
if (SameParentStateMachine(initial, target))
{
State initialState = StateMachine.StateInThisStateMachine(initial);
// TargetState is the target state either in this state machine or in a sub state machine
State targetState = StateMachine.StateInThisStateMachine(target);
// Determine the rule condition (if any) related to this state machine
Rules.RuleCondition condition = null;
if (update != null)
{
Action action = update.Root as Action;
condition = action.RuleCondition;
}
if (targetState != null || initialState != null)
{
// This transition is about this state machine.
if (initialState != targetState && initialState != null)
{
// Check that the transition is not yet present
// This case can occur when the same RuleCondition references two different states
// in a substate machine. Only draws the transition once.
if (!findMatchingTransition(condition, initialState, targetState))
{
Transitions.Add(new Transition(preCondition, initialState, update, targetState));
}
}
else
{
if (initialState == initial)
{
retVal = true;
}
}
}
}
return(retVal);
}
/// <summary>
/// Check if this rule corresponds to a transition for this state machine
/// </summary>
/// <param name="obj"></param>
/// <param name="visitSubNodes"></param>
public override void visit(RuleCondition obj, bool visitSubNodes)
{
Rules.RuleCondition ruleCondition = (Rules.RuleCondition)obj;
foreach (Action action in ruleCondition.Actions)
{
try
{
foreach (VariableUpdateStatement update in action.UpdateStatements)
{
Type targetType = update.TargetType;
if (targetType is StateMachine)
{
Expression expressionTree = update.Expression;
if (expressionTree != null)
{
// HaCK: This is a bit rough, but should be sufficient for now...
foreach (State stt1 in GetStates(expressionTree))
{
// TargetState is the target state either in this state machine or in a sub state machine
State targetState = StateMachine.StateInThisStateMachine(stt1);
int transitionCount = Transitions.Count;
bool filteredOut = false;
// Finds the enclosing state of this action to determine the source state of this transition
State enclosingState = EnclosingFinder <State> .find(action);
if (enclosingState != null)
{
filteredOut = filteredOut ||
AddTransition(update, stt1, null, enclosingState);
}
if (!filteredOut)
{
foreach (PreCondition preCondition in ruleCondition.AllPreConditions)
{
// A transition from one state to another has been found
foreach (State stt2 in GetStates(preCondition.Expression))
{
filteredOut = filteredOut ||
AddTransition(update, stt1, preCondition, stt2);
}
}
}
if (Transitions.Count == transitionCount)
{
if (targetState == stt1 && targetState.EnclosingStateMachine == StateMachine)
{
if (!filteredOut)
{
Action enclosingAction = update.Root as Action;
if (enclosingAction != null)
{
// No precondition could be found => one can reach this state at anytime
if (
!findMatchingTransition(enclosingAction.RuleCondition, null,
targetState))
{
Transitions.Add(new Transition(null, null, update,
targetState));
}
}
}
}
}
}
}
else
{
action.AddError("Cannot parse expression");
}
}
}
}
catch (Exception e)
{
}
}
base.visit(obj, visitSubNodes);
}
