/// <summary>
/// Initializes the StateBase instance.
/// </summary>
/// <param name="token">The token that identifies the current state.</param>
public StateBase(StateToken token)
{
if (token == null)
{
throw new ArgumentNullException(nameof(token));
}
Token = token;
}
/// <summary>
/// Sets the initial state of the current state machine, and resets its internal state.
/// </summary>
/// <param name="initialState">The initial state.</param>
/// <param name="data">The data to be provided to the initial state.</param>
public void SetInitialState(StateToken initialState, object data)
{
if (initialState == null)
{
throw new ArgumentNullException(nameof(initialState));
}
RaiseOnExitEvent(null, null);
CurrentState = null;
PerformTransitionTo(initialState, data);
}
private void RunCallback(Action <StateToken, object> callback, StateToken stateToken, object data)
{
try
{
callback(stateToken, data);
}
finally
{
// ensure isHandlingAsync flag is properly restored
isHandlingAsync = false;
}
}
private void PerformTransitionTo(StateToken stateToken, object data)
{
StateToken targetStateToken = stateToken;
object targetData = data;
while (true)
{
TransitionInfo transition = TransitionTo(targetStateToken, targetData);
if (transition.TargetStateToken == null)
{
break;
}
targetStateToken = transition.TargetStateToken;
targetData = transition.TargetStateData;
}
}
private void RaiseOnExitEvent(StateToken stateToken, object data)
{
if (CurrentState != null)
{
var stateExitEventArgs = new StateExitEventArgs(stateToken, data);
isPerformActionLocked = true;
try
{
CurrentState.OnExit(stateExitEventArgs);
}
finally
{
isPerformActionLocked = false;
}
}
}
private TransitionInfo TransitionTo(StateToken stateToken, object data)
{
if (stateToken == null)
{
throw new ArgumentNullException(nameof(stateToken));
}
StateBase state = states.FirstOrDefault(s => s.Token == stateToken);
if (state == null)
{
throw new UnknownStateException(CurrentStateToken, stateToken);
}
RaiseOnExitEvent(stateToken, data);
StateBase oldState = CurrentState;
CurrentState = state;
var stateEnterEventArgs = new StateEnterEventArgs(oldState?.Token, data);
isPerformActionLocked = true;
try
{
OnStateChanged(new StateChangedEventArgs(oldState, CurrentState));
CurrentState.OnEnter(stateEnterEventArgs);
}
finally
{
isPerformActionLocked = false;
}
return(stateEnterEventArgs.Redirect);
}
/// <summary>
/// Initializes the StateExitEventArgs instance.
/// </summary>
/// <param name="to">The target state of the transition.</param>
/// <param name="data">The data provided to the target state.</param>
public StateExitEventArgs(StateToken to, object data)
{
To = to;
Data = data;
}
/// <summary>
/// Initializes the StateEnterEventArgs instance.
/// </summary>
/// <param name="from">The source state of the transition.</param>
/// <param name="data">The data provided from the source state, for the target state.</param>
public StateEnterEventArgs(StateToken from, object data)
{
Redirect = new TransitionInfo();
From = from;
Data = data;
}
/// <summary>
/// Sets the initial state of the current state machine, and resets its internal state.
/// </summary>
/// <param name="initialState">The initial state.</param>
public void SetInitialState(StateToken initialState)
{
SetInitialState(initialState, null);
}
/// <summary>
/// Initializes the UnknownActionException instance.
/// </summary>
/// <param name="actionToken">The token of the action that produced the error.</param>
/// <param name="stateToken">The token of the state that was active when the error has been produced.</param>
public UnknownActionException(ActionToken actionToken, StateToken stateToken)
: base(actionToken, stateToken)
{
}
/// <summary>
/// Initializes the IllegalActionException instance.
/// </summary>
/// <param name="actionToken">The token of the action that produced the error.</param>
/// <param name="stateToken">The token of the state that was active when the error has been produced.</param>
/// <param name="message">Custom message explaining the error.</param>
public IllegalActionException(ActionToken actionToken, StateToken stateToken, string message)
: base(actionToken, stateToken, message)
{
}
/// <summary>
/// Initializes the IllegalActionException instance.
/// </summary>
/// <param name="actionToken">The token of the action that produced the error.</param>
/// <param name="stateToken">The token of the state that was active when the error has been produced.</param>
public IllegalActionException(ActionToken actionToken, StateToken stateToken)
: base(actionToken, stateToken)
{
}
/// <summary>
/// Initializes the ActionExceptionBase instance.
/// </summary>
/// <param name="actionToken">The token of the action that produced the error.</param>
/// <param name="stateToken">The token of the state that was active when the error has been produced.</param>
/// <param name="message">Custom message explaining the error.</param>
protected ActionExceptionBase(ActionToken actionToken, StateToken stateToken, string message)
: base((message ?? string.Empty) + $" (action: {actionToken}, state: {stateToken})")
{
ActionToken = actionToken;
StateToken = stateToken;
}
/// <summary>
/// Initializes the ActionExceptionBase instance.
/// </summary>
/// <param name="actionToken">The token of the action that produced the error.</param>
/// <param name="stateToken">The token of the state that was active when the error has been produced.</param>
protected ActionExceptionBase(ActionToken actionToken, StateToken stateToken)
: this(actionToken, stateToken, null)
{
}
/// <summary>
/// Initializes the UnknownStateException instance.
/// </summary>
/// <param name="sourceStateToken">The token of the source state.</param>
/// <param name="unknownStateToken">The undeclared token that was targeting the new state.</param>
public UnknownStateException(StateToken sourceStateToken, StateToken unknownStateToken)
: base($"(source state: {sourceStateToken}, unknown state: {unknownStateToken})")
{
SourceStateToken = sourceStateToken;
UnknownStateToken = unknownStateToken;
}
