Sequence.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / cdf / src / WF / Common / AuthoringOM / Sequence.cs / 1305376 / Sequence.cs
                        

                        
                            namespace System.Workflow.ComponentModel 
{
    #region Imports

    using System; 
    using System.Text;
    using System.Reflection; 
    using System.Collections; 
    using System.CodeDom;
    using System.ComponentModel; 
    using System.ComponentModel.Design;
    using System.Drawing;
    using System.Workflow.ComponentModel;
    using System.Workflow.ComponentModel.Design; 
    using System.Collections.Generic;
    using System.Workflow.ComponentModel.Compiler; 
 
    #endregion
 
    internal static class SequenceHelper
    {
        private static DependencyProperty ActiveChildQualifiedNameProperty = DependencyProperty.RegisterAttached("ActiveChildQualifiedName", typeof(String), typeof(SequenceHelper));
        private static DependencyProperty ActiveChildRemovedProperty = DependencyProperty.RegisterAttached("ActiveChildRemoved", typeof(bool), typeof(SequenceHelper), new PropertyMetadata(DependencyPropertyOptions.NonSerialized)); 

        public static ActivityExecutionStatus Execute(CompositeActivity activity, ActivityExecutionContext executionContext) 
        { 
            if (activity.EnabledActivities.Count == 0)
                return ActivityExecutionStatus.Closed; 
            else
            {
                activity.EnabledActivities[0].RegisterForStatusChange(Activity.ClosedEvent, (IActivityEventListener) activity);
                executionContext.ExecuteActivity(activity.EnabledActivities[0]); 
                activity.SetValue(ActiveChildQualifiedNameProperty, activity.EnabledActivities[0].QualifiedName);
                return ActivityExecutionStatus.Executing; 
            } 
        }
 
        public static ActivityExecutionStatus Cancel(CompositeActivity activity, ActivityExecutionContext executionContext)
        {
            for (int i = (activity.EnabledActivities.Count - 1); i >= 0; i--)
            { 
                Activity childActivity = activity.EnabledActivities[i];
 
                if (childActivity.ExecutionStatus == ActivityExecutionStatus.Executing) 
                {
                    executionContext.CancelActivity(childActivity); 
                    return activity.ExecutionStatus;
                }

                if (childActivity.ExecutionStatus == ActivityExecutionStatus.Canceling || 
                    childActivity.ExecutionStatus == ActivityExecutionStatus.Faulting)
                { 
                    return activity.ExecutionStatus; 
                }
 
                if (childActivity.ExecutionStatus == ActivityExecutionStatus.Closed)
                {
                    activity.RemoveProperty(ActiveChildQualifiedNameProperty);
                    return ActivityExecutionStatus.Closed; 
                }
            } 
            return ActivityExecutionStatus.Closed; 
        }
 
        public static void OnEvent(CompositeActivity activity, Object sender, ActivityExecutionStatusChangedEventArgs e)
        {
            ActivityExecutionContext context = sender as ActivityExecutionContext;
            e.Activity.UnregisterForStatusChange(Activity.ClosedEvent, (IActivityEventListener)activity); 

            if (activity.ExecutionStatus == ActivityExecutionStatus.Canceling || 
                activity.ExecutionStatus == ActivityExecutionStatus.Faulting || 
                activity.ExecutionStatus == ActivityExecutionStatus.Executing && !TryScheduleNextChild(activity, context))
            { 
                activity.RemoveProperty(ActiveChildQualifiedNameProperty);
                context.CloseActivity();
            }
        } 

        private static bool TryScheduleNextChild(CompositeActivity activity, ActivityExecutionContext executionContext) 
        { 
            IList children = activity.EnabledActivities;
 
            // Find index of next activity to run.
            int indexOfNextActivity = 0;
            for (int i = (children.Count - 1); i >= 0; i--)
            { 
                if (children[i].ExecutionStatus == ActivityExecutionStatus.Closed)
                { 
                    // Check whether this is last child? 
                    if (i == (children.Count - 1))
                        return false; 

                    indexOfNextActivity = i + 1;
                    break;
                } 
            }
 
            children[indexOfNextActivity].RegisterForStatusChange(Activity.ClosedEvent, (IActivityEventListener)activity); 
            executionContext.ExecuteActivity(children[indexOfNextActivity]);
            activity.SetValue(ActiveChildQualifiedNameProperty, children[indexOfNextActivity].QualifiedName); 
            return true;
        }

        public static void OnActivityChangeRemove(CompositeActivity activity, ActivityExecutionContext executionContext, Activity removedActivity) 
        {
            String activeChildQualifiedName = activity.GetValue(ActiveChildQualifiedNameProperty) as String; 
 
            if (removedActivity.QualifiedName.Equals(activeChildQualifiedName))
                activity.SetValue(ActiveChildRemovedProperty, true); 
        }

        public static void OnWorkflowChangesCompleted(CompositeActivity activity, ActivityExecutionContext executionContext)
        { 
            String activeChildQualifiedName = activity.GetValue(ActiveChildQualifiedNameProperty) as String;
            bool activeChildRemovedInDynamicUpdate = (bool)activity.GetValue(ActiveChildRemovedProperty); 
 
            if (activeChildQualifiedName != null && activeChildRemovedInDynamicUpdate)
            {   //We have our active child removed. 
                if (activity.ExecutionStatus == ActivityExecutionStatus.Canceling ||
                activity.ExecutionStatus == ActivityExecutionStatus.Faulting ||
                activity.ExecutionStatus == ActivityExecutionStatus.Executing && !TryScheduleNextChild(activity, executionContext))
                { 
                    activity.RemoveProperty(ActiveChildQualifiedNameProperty);
                    executionContext.CloseActivity(); 
                } 
            }
            activity.RemoveProperty(ActiveChildRemovedProperty); 
        }
    }
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.

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