StateMachineHelpers.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / cdf / src / WF / Activities / StateMachineHelpers.cs / 1305376 / StateMachineHelpers.cs
                        
                        
                            #region Using directives 

using System;
using System.Collections;
using System.Collections.Generic; 
using System.Collections.Specialized;
using System.Reflection; 
using System.Diagnostics; 
using System.Runtime.Remoting.Messaging;
using System.Workflow.ComponentModel; 
using System.Workflow.ComponentModel.Design;
using System.Workflow.Runtime;
using System.Workflow.Runtime.Hosting;
 
#endregion Using directives
 
namespace System.Workflow.Activities 
{
    internal static class StateMachineHelpers 
    {
        internal static bool IsStateMachine(StateActivity state)
        {
            if (state == null) 
                throw new ArgumentNullException("state");
 
            return (state is StateMachineWorkflowActivity); 
        }
 
        internal static bool IsRootState(StateActivity state)
        {
            if (state == null)
                throw new ArgumentNullException("state"); 

            StateActivity parent = state.Parent as StateActivity; 
            return parent == null; 
        }
 
        internal static bool IsLeafState(StateActivity state)
        {
            if (state == null)
                throw new ArgumentNullException("state"); 

            if (IsRootState(state)) 
                return false; 

            foreach (Activity child in state.EnabledActivities) 
            {
                if (child is StateActivity)
                    return false;
            } 
            return true;
        } 
 
        internal static bool IsRootExecutionContext(ActivityExecutionContext context)
        { 
            return (context.Activity.Parent == null);
        }

        ///  
        /// Finds the enclosing state for this activity
        ///  
        ///  
        /// 
        internal static StateActivity FindEnclosingState(Activity activity) 
        {
            Debug.Assert(activity != null);
            Debug.Assert(activity.Parent != activity);
 
            StateActivity state = activity as StateActivity;
            if (state != null) 
                return state; 

            if (activity.Parent == null) 
                return null;

            return FindEnclosingState(activity.Parent);
        } 

        ///  
        /// Returns the root State activity 
        /// 
        ///  
        /// 
        internal static StateActivity GetRootState(StateActivity state)
        {
            Debug.Assert(state != null); 
            Debug.Assert(state.Parent != state);
 
            if (state.Parent == null) 
                return state;
 
            // this handles the case when the StateMachineWorkflow
            // is called using an Invoke activity
            if (!(state.Parent is StateActivity))
                return state; 

            return GetRootState((StateActivity)state.Parent); 
        } 

        internal static bool IsInitialState(StateActivity state) 
        {
            Debug.Assert(state != null);

            string initialStateName = GetInitialStateName(state); 
            if (initialStateName == null)
                return false; 
 
            return state.QualifiedName.Equals(initialStateName);
        } 

        internal static bool IsCompletedState(StateActivity state)
        {
            Debug.Assert(state != null); 

            string completedStateName = GetCompletedStateName(state); 
            if (completedStateName == null) 
                return false;
 
            return state.QualifiedName.Equals(completedStateName);
        }

        internal static string GetInitialStateName(StateActivity state) 
        {
            StateActivity rootState = GetRootState(state); 
            return (string)rootState.GetValue(StateMachineWorkflowActivity.InitialStateNameProperty); 
        }
 
        internal static string GetCompletedStateName(StateActivity state)
        {
            Debug.Assert(state != null);
            StateActivity rootState = GetRootState(state); 
            return (string)rootState.GetValue(StateMachineWorkflowActivity.CompletedStateNameProperty);
        } 
 
        /*
        internal static bool IsInInitialStatePath(StateActivity state) 
        {
            StateActivity rootState = GetRootState(state);
            string initialStateName = GetInitialStateName(rootState);
 
            StateActivity initialState = FindStateByName(rootState, initialStateName);
            CompositeActivity current = initialState; 
            while (current != null) 
            {
                if (current.QualifiedName == state.QualifiedName) 
                    return true;
                current = current.Parent;
            }
            return false; 
        }
         */ 
 
        /// 
        /// Returns the State activity that is currently executing 
        /// 
        /// 
        /// 
        static internal StateActivity GetCurrentState(ActivityExecutionContext context) 
        {
            StateActivity state = context.Activity as StateActivity; 
            if (state == null) 
                state = FindEnclosingState(context.Activity);
            Debug.Assert(state != null, "StateMachineHelpers.GetCurrentState: only valid to call this method from a State executor or a contained EventDriven"); 
            StateActivity rootState = GetRootState(state);

            StateMachineExecutionState executionState = StateMachineExecutionState.Get(rootState);
            string currentStateName = executionState.CurrentStateName; 
            if (currentStateName == null)
                return null; 
 
            StateActivity currentState = FindDynamicStateByName(rootState, currentStateName);
            Debug.Assert(currentState == null || IsLeafState(currentState)); 
            return currentState;
        }

        static internal StateActivity FindDynamicStateByName(StateActivity state, string stateQualifiedName) 
        {
            while (!state.QualifiedName.Equals(stateQualifiedName) && ContainsState(state, stateQualifiedName)) 
            { 
                foreach (Activity activity in state.EnabledActivities)
                { 
                    StateActivity childState = activity as StateActivity;
                    if (childState == null)
                        continue;
 
                    if (ContainsState(childState, stateQualifiedName))
                    { 
                        StateActivity dynamicChildState = (StateActivity)state.GetDynamicActivity(childState.QualifiedName); 
                        if (dynamicChildState == null)
                            return null; 
                        state = dynamicChildState;
                        break;
                    }
                } 
            }
            if (state.QualifiedName.Equals(stateQualifiedName)) 
                return state; 
            else
                return null; 
        }

        static internal StateActivity FindStateByName(StateActivity state, string qualifiedName)
        { 
            Debug.Assert(state != null);
            Debug.Assert(qualifiedName != null); 
            StateActivity found = FindActivityByName(state, qualifiedName) as StateActivity; 
            return found;
        } 

        static internal Activity FindActivityByName(CompositeActivity parentActivity, string qualifiedName)
        {
            return parentActivity.GetActivityByName(qualifiedName, true); 
        }
 
        static internal bool ContainsEventActivity(CompositeActivity compositeActivity) 
        {
            Debug.Assert(compositeActivity != null); 

            Queue activities = new Queue();
            activities.Enqueue(compositeActivity);
            while (activities.Count > 0) 
            {
                Activity activity = activities.Dequeue(); 
                if (activity is IEventActivity) 
                    return true;
 
                compositeActivity = activity as CompositeActivity;
                if (compositeActivity != null)
                {
                    foreach (Activity child in compositeActivity.Activities) 
                    {
                        if (child.Enabled) 
                            activities.Enqueue(child); 
                    }
                } 
            }
            return false;
        }
 
        static internal IEventActivity GetEventActivity(EventDrivenActivity eventDriven)
        { 
            CompositeActivity sequenceActivity = eventDriven as CompositeActivity; 
            Debug.Assert(eventDriven.EnabledActivities.Count > 0);
            IEventActivity eventActivity = sequenceActivity.EnabledActivities[0] as IEventActivity; 
            Debug.Assert(eventActivity != null);
            return eventActivity;
        }
 
        static internal EventDrivenActivity GetParentEventDriven(IEventActivity eventActivity)
        { 
            Activity activity = ((Activity)eventActivity).Parent; 
            while (activity != null)
            { 
                EventDrivenActivity eventDriven = activity as EventDrivenActivity;
                if (eventDriven != null)
                    return eventDriven;
 
                activity = activity.Parent;
            } 
            return null; 
        }
 
        static internal bool ContainsState(StateActivity state, string stateName)
        {
            if (state == null)
                throw new ArgumentNullException("state"); 
            if (String.IsNullOrEmpty(stateName))
                throw new ArgumentNullException("stateName"); 
 
            Queue states = new Queue();
            states.Enqueue(state); 
            while (states.Count > 0)
            {
                state = states.Dequeue();
                if (state.QualifiedName.Equals(stateName)) 
                    return true;
 
                foreach (Activity childActivity in state.EnabledActivities) 
                {
                    StateActivity childState = childActivity as StateActivity; 
                    if (childState != null)
                    {
                        states.Enqueue(childState);
                    } 
                }
            } 
            return false; 
        }
    } 

    #region StateMachineMessages
#if DEBUG
    /* 
     * this is only used for testing the State Machine related resource messages
     * 
    internal class StateMachineMessages 
    {
        internal static void PrintMessages() 
        {
            Console.WriteLine("GetInvalidUserDataInStateChangeTrackingRecord: {0}\n", SR.GetInvalidUserDataInStateChangeTrackingRecord());
            Console.WriteLine("GetError_EventDrivenInvalidFirstActivity: {0}\n", SR.GetError_EventDrivenInvalidFirstActivity());
            Console.WriteLine("GetError_InvalidLeafStateChild: {0}\n", SR.GetError_InvalidLeafStateChild()); 
            Console.WriteLine("GetError_InvalidCompositeStateChild: {0}\n", SR.GetError_InvalidCompositeStateChild());
            Console.WriteLine("GetError_SetStateOnlyWorksOnStateMachineWorkflow: {0}\n", SR.GetError_SetStateOnlyWorksOnStateMachineWorkflow()); 
            Console.WriteLine("GetError_SetStateMustPointToAState: {0}\n", SR.GetError_SetStateMustPointToAState()); 
            Console.WriteLine("GetError_InitialStateMustPointToAState: {0}\n", SR.GetError_InitialStateMustPointToAState());
            Console.WriteLine("GetError_CompletedStateMustPointToAState: {0}\n", SR.GetError_CompletedStateMustPointToAState()); 

            Console.WriteLine("GetError_SetStateMustPointToALeafNodeState: {0}\n", SR.GetError_SetStateMustPointToALeafNodeState());
            Console.WriteLine("GetError_InitialStateMustPointToALeafNodeState: {0}\n", SR.GetError_InitialStateMustPointToALeafNodeState());
            Console.WriteLine("GetError_CompletedStateMustPointToALeafNodeState: {0}\n", SR.GetError_CompletedStateMustPointToALeafNodeState()); 

            Console.WriteLine("GetError_StateInitializationParentNotState: {0}\n", SR.GetError_StateInitializationParentNotState()); 
            Console.WriteLine("GetError_StateFinalizationParentNotState: {0}\n", SR.GetError_StateFinalizationParentNotState()); 

            Console.WriteLine("GetError_EventActivityNotValidInStateInitialization: {0}\n", SR.GetError_EventActivityNotValidInStateInitialization()); 
            Console.WriteLine("GetError_EventActivityNotValidInStateFinalization: {0}\n", SR.GetError_EventActivityNotValidInStateFinalization());

            Console.WriteLine("GetError_MultipleStateInitializationActivities: {0}\n", SR.GetError_MultipleStateInitializationActivities());
            Console.WriteLine("GetError_MultipleStateFinalizationActivities: {0}\n", SR.GetError_MultipleStateFinalizationActivities()); 

            Console.WriteLine("GetError_InvalidTargetStateInStateInitialization: {0}\n", SR.GetError_InvalidTargetStateInStateInitialization()); 
            Console.WriteLine("GetError_CantRemoveState: {0}\n", SR.GetError_CantRemoveState()); 
            Console.WriteLine("GetSqlTrackingServiceRequired: {0}\n", SR.GetSqlTrackingServiceRequired());
 
            Console.WriteLine("GetStateMachineWorkflowMustHaveACurrentState: {0}\n", SR.GetStateMachineWorkflowMustHaveACurrentState());

            Console.WriteLine("GetInvalidActivityStatus: {0}\n", SR.GetInvalidActivityStatus(new Activity("Hello")));
            Console.WriteLine("GetStateMachineWorkflowRequired: {0}\n", SR.GetStateMachineWorkflowRequired()); 
            Console.WriteLine("GetError_EventDrivenParentNotListen: {0}\n", SR.GetError_EventDrivenParentNotListen());
 
            Console.WriteLine("GetGetUnableToTransitionToState: {0}\n", SR.GetUnableToTransitionToState("StateName")); 
            Console.WriteLine("GetInvalidStateTransitionPath: {0}\n", SR.GetInvalidStateTransitionPath());
            Console.WriteLine("GetInvalidSetStateInStateInitialization: {0}\n", SR.GetInvalidSetStateInStateInitialization()); 
            Console.WriteLine("GetStateAlreadySubscribesToThisEvent: {0}\n", SR.GetStateAlreadySubscribesToThisEvent("StateName", "QueueName"));
        }
    }
    */ 

#endif 
    #endregion 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
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StateMachineHelpers.cs source code in C# .NET

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