Nuclex.Support/Source/Tracking/SetProgression.cs

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#region CPL License
/*
Nuclex Framework
Copyright (C) 2002-2008 Nuclex Development Labs
This library is free software; you can redistribute it and/or
modify it under the terms of the IBM Common Public License as
published by the IBM Corporation; either version 1.0 of the
License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
IBM Common Public License for more details.
You should have received a copy of the IBM Common Public
License along with this library
*/
#endregion
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using Nuclex.Support.Collections;
namespace Nuclex.Support.Tracking {
/// <summary>Forms a single progression from a set of progressions</summary>
/// <typeparam name="ProgressionType">Type of progressions to manage as a set</typeparam>
public class SetProgression<ProgressionType> : Waitable, IDisposable, IProgressReporter
where ProgressionType : Waitable {
/// <summary>will be triggered to report when progress has been achieved</summary>
public event EventHandler<ProgressReportEventArgs> AsyncProgressChanged;
/// <summary>Initializes a new set progression</summary>
/// <param name="childs">Progressions to track with this set</param>
/// <remarks>
/// Uses a default weighting factor of 1.0 for all progressions.
/// </remarks>
public SetProgression(IEnumerable<ProgressionType> childs)
: this() {
// Construct a WeightedProgression with the default weight for each
// progression and wrap it in an ObservedProgression
foreach(ProgressionType progression in childs) {
this.children.Add(
new ObservedWeightedWaitable<ProgressionType>(
new WeightedWaitable<ProgressionType>(progression),
new ObservedWeightedWaitable<ProgressionType>.ReportDelegate(asyncProgressUpdated),
new ObservedWeightedWaitable<ProgressionType>.ReportDelegate(asyncEnded)
)
);
}
// Since all progressions have a weight of 1.0, the total weight is
// equal to the number of progressions in our list
this.totalWeight = (float)this.children.Count;
}
/// <summary>Initializes a new set progression</summary>
/// <param name="childs">Progressions to track with this set</param>
public SetProgression(
IEnumerable<WeightedWaitable<ProgressionType>> childs
)
: this() {
// Construct an ObservedProgression around each of the WeightedProgressions
foreach(WeightedWaitable<ProgressionType> progression in childs) {
this.children.Add(
new ObservedWeightedWaitable<ProgressionType>(
progression,
new ObservedWeightedWaitable<ProgressionType>.ReportDelegate(asyncProgressUpdated),
new ObservedWeightedWaitable<ProgressionType>.ReportDelegate(asyncEnded)
)
);
// Sum up the total weight
this.totalWeight += progression.Weight;
}
}
/// <summary>Performs common initialization for the public constructors</summary>
private SetProgression() {
this.children = new List<ObservedWeightedWaitable<ProgressionType>>();
}
/// <summary>Immediately releases all resources owned by the object</summary>
public void Dispose() {
if(this.children != null) {
// Dispose all the observed progressions, disconnecting the events from the
// actual progressions so the GC can more easily collect this class
for(int index = 0; index < this.children.Count; ++index)
this.children[index].Dispose();
this.children = null;
this.wrapper = null;
}
}
/// <summary>Childs contained in the progression set</summary>
public IList<WeightedWaitable<ProgressionType>> Children {
get {
// The wrapper is constructed only when needed. Most of the time, users will
// just create a SetProgression and monitor its progress without ever using
// the Childs collection.
if(this.wrapper == null) {
// This doesn't need a lock because it's a stateless wrapper.
// If it is constructed twice, then so be it, no problem at all.
this.wrapper = new WeightedProgressionWrapperCollection<ProgressionType>(
this.children
);
}
return this.wrapper;
}
}
/// <summary>Fires the progress update event</summary>
/// <param name="progress">Progress to report (ranging from 0.0 to 1.0)</param>
/// <remarks>
/// Informs the observers of this progression about the achieved progress.
/// </remarks>
protected virtual void OnAsyncProgressChanged(float progress) {
OnAsyncProgressChanged(new ProgressReportEventArgs(progress));
}
/// <summary>Fires the progress update event</summary>
/// <param name="eventArguments">Progress to report (ranging from 0.0 to 1.0)</param>
/// <remarks>
/// Informs the observers of this progression about the achieved progress.
/// Allows for classes derived from the Progression class to easily provide
/// a custom event arguments class that has been derived from the
/// Progression's ProgressUpdateEventArgs class.
/// </remarks>
protected virtual void OnAsyncProgressChanged(ProgressReportEventArgs eventArguments) {
EventHandler<ProgressReportEventArgs> copy = AsyncProgressChanged;
if(copy != null)
copy(this, eventArguments);
}
/// <summary>
/// Called when the progress of one of the observed progressions changes
/// </summary>
private void asyncProgressUpdated() {
float totalProgress = 0.0f;
// Calculate the sum of the progress reported by our child progressions,
// scaled to the weight each progression has assigned to it.
for(int index = 0; index < this.children.Count; ++index) {
totalProgress +=
this.children[index].Progress * this.children[index].WeightedWaitable.Weight;
}
// Calculate the actual combined progress
if(this.totalWeight > 0.0f)
totalProgress /= this.totalWeight;
// Send out the progress update
OnAsyncProgressChanged(totalProgress);
}
/// <summary>
/// Called when an observed progression ends
/// </summary>
private void asyncEnded() {
// If there's still at least one progression going, don't report that
// the SetProgression has finished yet.
for(int index = 0; index < this.children.Count; ++index)
if(!this.children[index].WeightedWaitable.Waitable.Ended)
return;
// All child progressions have ended, so the set has now ended as well
OnAsyncEnded();
}
/// <summary>Progressions being managed in the set</summary>
private List<ObservedWeightedWaitable<ProgressionType>> children;
/// <summary>
/// Wrapper collection for exposing the child progressions under the
/// WeightedProgression interface
/// </summary>
private volatile WeightedProgressionWrapperCollection<ProgressionType> wrapper;
/// <summary>Summed weight of all progressions in the set</summary>
private float totalWeight;
}
} // namespace Nuclex.Support.Tracking