Nuclex.Windows.Forms/Source/TrackingBar/TrackingBar.cs

134 lines
5.1 KiB
C#

#region CPL License
/*
Nuclex Framework
Copyright (C) 2002-2007 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.ComponentModel;
using System.Drawing;
using System.Data;
using System.Text;
using System.Windows.Forms;
using System.Threading;
using Nuclex.Support.Tracking;
namespace Nuclex.Windows.Forms {
/// <summary>Progress bar for tracking the progress of background operations</summary>
public partial class TrackingBar : AsyncProgressBar {
/// <summary>Initializes a new tracking bar</summary>
public TrackingBar() {
InitializeComponent();
// We start off being in the idle state (and thus, being invisible)
this.isIdle = true;
this.Visible = false;
// Initialize the delegates we use to update the control's state and those
// we use to register ourselfes to the tracker's events
this.updateIdleStateDelegate = new MethodInvoker(updateIdleState);
this.asyncIdleStateChangedDelegate = new EventHandler<IdleStateEventArgs>(
asyncIdleStateChanged
);
this.asyncProgressUpdateDelegate = new EventHandler<ProgressUpdateEventArgs>(
asyncProgressUpdated
);
// Create the tracker and attach ourselfes to its events
this.tracker = new ProgressionTracker();
this.tracker.AsyncIdleStateChanged += this.asyncIdleStateChangedDelegate;
this.tracker.AsyncProgressUpdated += this.asyncProgressUpdateDelegate;
}
/// <summary>Tracks the specified progression in the tracking bar</summary>
/// <param name="progression">Progression to be tracked</param>
public void Track(Progression progression) {
this.tracker.Track(progression);
}
/// <summary>Tracks the specified progression in the tracking bar</summary>
/// <param name="progression">Progression to be tracked</param>
/// <param name="weight">Weight of this progression in the total progress</param>
public void Track(Progression progression, float weight) {
this.tracker.Track(progression, weight);
}
/// <summary>Stops tracking the specified progression</summary>
/// <param name="progression">Progression to stop tracking</param>
public void Untrack(Progression progression) {
this.tracker.Untrack(progression);
}
/// <summary>
/// Called when the summed progressed of the tracked progressions has changed
/// </summary>
/// <param name="sender">Progression whose progress has changed</param>
/// <param name="arguments">Contains the progress achieved by the progression</param>
private void asyncProgressUpdated(
object sender, ProgressUpdateEventArgs arguments
) {
AsyncSetValue(arguments.Progress);
}
/// <summary>Called when the tracker becomes enters of leaves the idle state</summary>
/// <param name="sender">Tracker that has entered or left the idle state</param>
/// <param name="arguments">Contains the new idle state</param>
private void asyncIdleStateChanged(object sender, IdleStateEventArgs arguments) {
// Do a fully synchronous update of the idle state. This update must not be
// lost because otherwise, the progress bar might stay on-screen when in fact,
// the background operation has already finished and nothing is happening anymore.
this.isIdle = arguments.Idle;
// Update the bar's idle state
if(InvokeRequired)
Invoke(this.updateIdleStateDelegate);
else
updateIdleState();
}
/// <summary>
/// Updates the idle state of the progress bar
/// (controls whether the progress bar is shown or invisible)
/// </summary>
private void updateIdleState() {
// Only show the progress bar when something is happening
base.Visible = !this.isIdle;
}
/// <summary>Whether the progress bar is in the idle state</summary>
private volatile bool isIdle;
/// <summary>Tracker used to sum and update the total progress</summary>
private ProgressionTracker tracker;
/// <summary>Delegate for the idle state update method</summary>
private MethodInvoker updateIdleStateDelegate;
/// <summary>Delegate for the OnAsyncProgressionEnded method</summary>
private EventHandler<IdleStateEventArgs> asyncIdleStateChangedDelegate;
/// <summary>Delegate for the OnAsyncProgressionProgressUpdated method</summary>
private EventHandler<ProgressUpdateEventArgs> asyncProgressUpdateDelegate;
}
} // namespace Nuclex.Windows.Forms