/Trident/Product/ExecutionService/WFServiceLibrary/SchedulerLogic/TriggerCollection.cs

//*********************************************************

//

//    Copyright (c) Microsoft. All rights reserved.

//    This code is licensed under the Apache License, Version 2.0.

//    THIS CODE IS PROVIDED *AS IS* WITHOUT WARRANTY OF

//    ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING ANY

//    IMPLIED WARRANTIES OF FITNESS FOR A PARTICULAR

//    PURPOSE, MERCHANTABILITY, OR NON-INFRINGEMENT.

//

//*********************************************************



namespace Microsoft.Research.eResearch.WFServiceLibrary.SchedulerLogic

{

    using System;

    using System.Collections.Generic;

    using System.Runtime.InteropServices;

    using V1 = TaskScheduler.V1;

    using V2 = TaskScheduler;



    /// <summary>

    /// Collection of triggers.

    /// </summary>

    public sealed class TriggerCollection : IEnumerable<Trigger>, IDisposable

    {

        private V1.ITask v1TaskDefinition = null;



        /// <summary>

        /// 

        /// </summary>

        private V2.ITaskDefinition v2TaskDefinition = null;



        /// <summary>

        /// 

        /// </summary>

        private V2.ITriggerCollection triggerCollection = null;



        /// <summary>

        /// Gets the number of triggers in the collection.

        /// </summary>

        public int Count

        {

            get

            {

                int triggerCount = 0;

                if (this.triggerCollection != null)

                {

                    triggerCount = this.triggerCollection.Count;

                }



                return triggerCount;

            }

        }



        internal TriggerCollection(V1.ITask iTask)

        {

            v1TaskDefinition = iTask;

        }



        /// <summary>

        /// Initializes a new instance of the <see cref="TriggerCollection"/> class.

        /// </summary>

        /// <param name="iTaskDef">The i task def.</param>

        internal TriggerCollection(V2.ITaskDefinition iTaskDef)

        {

            this.v2TaskDefinition = iTaskDef;

            this.triggerCollection = this.v2TaskDefinition.Triggers;

        }



        /// <summary>

        /// Add an unbound <see cref="Trigger"/> to the task.

        /// </summary>

        /// <param name="unboundTrigger"><see cref="Trigger"/> derivative to add to the task.</param>

        /// <returns>Bound trigger.</returns>

        public Trigger Add(Trigger unboundTrigger)

        {

            if (this.v2TaskDefinition != null)

            {

                unboundTrigger.Bind(this.v2TaskDefinition);

            }

            else

            {

                unboundTrigger.Bind(v1TaskDefinition);

            }



            return unboundTrigger;

        }



        internal void Bind()

        {

            foreach (Trigger t in this)

                t.SetV1TriggerData();

        }



        /// <summary>

        /// Releases all resources used by this class.

        /// </summary>

        public void Dispose()

        {

            if (this.triggerCollection != null)

            {

                Marshal.ReleaseComObject(this.triggerCollection);

            }



            this.v2TaskDefinition = null;

            v1TaskDefinition = null;

        }



        /// <summary>

        /// Clears all triggers from the task.

        /// </summary>

        public void Clear()

        {

            if (this.triggerCollection != null)

            {

                this.triggerCollection.Clear();

            }

            else

            {

                for (int i = this.Count - 1; i >= 0; i--)

                {

                    this.RemoveAt(i);

                }

            }

        }



        /// <summary>

        /// Removes the trigger at a specified index.

        /// </summary>

        /// <param name="index">Index of trigger to remove.</param>

        /// <exception cref="ArgumentOutOfRangeException">Index out of range.</exception>

        public void RemoveAt(int index)

        {

            if (index >= this.Count)

            {

                throw new ArgumentOutOfRangeException("index", index, "Failed to remove Trigger. Index out of range.");

            }



            if (this.triggerCollection != null)

            {

                this.triggerCollection.Remove(++index);

            }

            else

            {

                v1TaskDefinition.DeleteTrigger((ushort)index); //Remove the trigger from the Task Scheduler

            }

        }



        /// <summary>

        /// Gets the collection enumerator for this collection.

        /// </summary>

        /// <returns>The <see cref="IEnumerator{T}"/> for this collection.</returns>

        public IEnumerator<Trigger> GetEnumerator()

        {

            IEnumerator<Trigger> taskTriggerEnum;

            if (v1TaskDefinition != null)

            {

                taskTriggerEnum = new V1TaskTriggerEnumerator(this.v1TaskDefinition);

            }

            else

            {

                taskTriggerEnum = new V2TaskTriggerEnumerator(this.triggerCollection);

            }



            return taskTriggerEnum;

        }



        #region IEnumerable<Trigger> Members



        #endregion



        #region IEnumerable Members



        /// <summary>

        /// Returns an enumerator that iterates through a collection.

        /// </summary>

        /// <returns>

        /// An <see cref="T:System.Collections.IEnumerator"/> object that can be used to iterate through the collection.

        /// </returns>

        System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()

        {

            return this.GetEnumerator();

        }



        internal sealed class V1TaskTriggerEnumerator : IEnumerator<Trigger>

        {

            private V1.ITask iTask;

            private short curItem = -1;



            /// <summary>

            /// Initializes a new instance of the <see cref="V1TaskTriggerEnumerator"/> class.

            /// </summary>

            /// <param name="task">The task.</param>

            internal V1TaskTriggerEnumerator(V1.ITask task)

            {

                this.iTask = task;

            }



            /// <summary>

            /// Gets the element in the collection at the current position of the enumerator.

            /// </summary>

            /// <value></value>

            /// <returns>

            /// The element in the collection at the current position of the enumerator.

            /// </returns>

            public Trigger Current

            {

                get

                {

                    return Trigger.CreateTrigger(this.iTask.GetTrigger((ushort)curItem));

                }

            }



            /// <summary>

            /// Releases all resources used by this class.

            /// </summary>

            public void Dispose()

            {

                this.iTask = null;

            }



            /// <summary>

            /// Gets the element in the collection at the current position of the enumerator.

            /// </summary>

            /// <value></value>

            /// <returns>

            /// The element in the collection at the current position of the enumerator.

            /// </returns>

            object System.Collections.IEnumerator.Current

            {

                get { return this.Current; }

            }



            /// <summary>

            /// Advances the enumerator to the next element of the collection.

            /// </summary>

            /// <returns>

            /// true if the enumerator was successfully advanced to the next element; false if the enumerator has passed the end of the collection.

            /// </returns>

            /// <exception cref="T:System.InvalidOperationException">

            /// The collection was modified after the enumerator was created.

            /// </exception>

            public bool MoveNext()

            {

                if (++this.curItem >= iTask.GetTriggerCount())

                    return false;

                return true;

            }



            /// <summary>

            /// Sets the enumerator to its initial position, which is before the first element in the collection.

            /// </summary>

            /// <exception cref="T:System.InvalidOperationException">

            /// The collection was modified after the enumerator was created.

            /// </exception>

            public void Reset()

            {

                this.curItem = -1;

            }

        }



        /// <summary>

        /// Supports a simple iteration over task trigger. 

        /// </summary>

        internal sealed class V2TaskTriggerEnumerator : IEnumerator<Trigger>

        {

            /// <summary>

            /// Newer version enumeration.

            /// </summary>

            private System.Collections.IEnumerator iEnum;



            /// <summary>

            /// Initializes a new instance of the <see cref="V2TaskTriggerEnumerator"/> class.

            /// </summary>

            /// <param name="iCollection">The i collection.</param>

            internal V2TaskTriggerEnumerator(V2.ITriggerCollection iCollection)

            {

                this.iEnum = iCollection.GetEnumerator();

            }



            #region IEnumerator<Trigger> Members



            /// <summary>

            /// Gets the element in the collection at the current position of the enumerator.

            /// </summary>

            /// <value></value>

            /// <returns>

            /// The element in the collection at the current position of the enumerator.

            /// </returns>

            public Trigger Current

            {

                get

                {

                    return Trigger.CreateTrigger((V2.ITrigger)this.iEnum.Current);

                }

            }



            #endregion



            #region IDisposable Members



            /// <summary>

            /// Releases all resources used by this class.

            /// </summary>

            public void Dispose()

            {

                this.iEnum = null;

            }



            #endregion



            #region IEnumerator Members



            /// <summary>

            /// Gets the element in the collection at the current position of the enumerator.

            /// </summary>

            /// <value></value>

            /// <returns>

            /// The element in the collection at the current position of the enumerator.

            /// </returns>

            object System.Collections.IEnumerator.Current

            {

                get { return this.Current; }

            }



            /// <summary>

            /// Advances the enumerator to the next element of the collection.

            /// </summary>

            /// <returns>

            /// true if the enumerator was successfully advanced to the next element; false if the enumerator has passed the end of the collection.

            /// </returns>

            /// <exception cref="T:System.InvalidOperationException">

            /// The collection was modified after the enumerator was created.

            /// </exception>

            public bool MoveNext()

            {

                return this.iEnum.MoveNext();

            }



            /// <summary>

            /// Sets the enumerator to its initial position, which is before the first element in the collection.

            /// </summary>

            /// <exception cref="T:System.InvalidOperationException">

            /// The collection was modified after the enumerator was created.

            /// </exception>

            public void Reset()

            {

                this.iEnum.Reset();

            }



            #endregion

        }



        #endregion

    }

}