osu/osu.Game/Screens/OnlinePlay/OngoingOperationTracker.cs

83 lines
3.0 KiB
C#

// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
// See the LICENCE file in the repository root for full licence text.
using System;
using osu.Framework.Bindables;
using osu.Framework.Graphics;
namespace osu.Game.Screens.OnlinePlay
{
/// <summary>
/// Utility class to track ongoing online operations' progress.
/// Can be used to disable interactivity while waiting for a response from online sources.
/// </summary>
public class OngoingOperationTracker : Component
{
/// <summary>
/// Whether there is an online operation in progress.
/// </summary>
public IBindable<bool> InProgress => inProgress;
private readonly Bindable<bool> inProgress = new BindableBool();
private LeasedBindable<bool> leasedInProgress;
public OngoingOperationTracker()
{
AlwaysPresent = true;
}
/// <summary>
/// Begins tracking a new online operation.
/// </summary>
/// <returns>
/// An <see cref="IDisposable"/> that will automatically mark the operation as ended on disposal.
/// </returns>
/// <exception cref="InvalidOperationException">An operation has already been started.</exception>
public IDisposable BeginOperation()
{
if (leasedInProgress != null)
throw new InvalidOperationException("Cannot begin operation while another is in progress.");
leasedInProgress = inProgress.BeginLease(true);
leasedInProgress.Value = true;
return new OngoingOperation(this, leasedInProgress);
}
private void endOperationWithKnownLease(LeasedBindable<bool> lease)
{
// for extra safety, marshal the end of operation back to the update thread if necessary.
Scheduler.Add(() =>
{
if (lease != leasedInProgress)
return;
// UnbindAll() is purposefully used instead of Return() - the two do roughly the same thing, with one difference:
// the former won't throw if the lease has already been returned before.
// this matters because framework can unbind the lease via the internal UnbindAllBindables(), which is not always detectable
// (it is in the case of disposal, but not in the case of screen exit - at least not cleanly).
leasedInProgress?.UnbindAll();
leasedInProgress = null;
}, false);
}
private class OngoingOperation : IDisposable
{
private readonly OngoingOperationTracker tracker;
private readonly LeasedBindable<bool> lease;
public OngoingOperation(OngoingOperationTracker tracker, LeasedBindable<bool> lease)
{
this.tracker = tracker;
this.lease = lease;
}
public void Dispose()
{
tracker.endOperationWithKnownLease(lease);
}
}
}
}