Events for Unity AudioSource

This package adds helper classes to get notified when a Unity AudioSource starts playing, is paused or played until the end. Both C# events and a base class with callbacks are supported.

The following states are observed:

• Started
• Paused
• Resumed
• Stopped

Installation

The package can be installed via the Unity Package Manager. Simply follow this guide and use the following url: git+https://github.com/Moolt/UnityAudioSourceEvents?path=Packages/AudioSourceEvents

All scripts are contained within the AudioSourceEvents namespace.

Usage

The simplest way is to inherit from the AudioSourceObserver base class. It privides the OnAudioStart, OnAudioResume, OnAudioPaused, OnAudioStopped and OnAudioChanged callbacks which can be overridden with your custom logic.

OnAudioChanged combines all other callbacks by directly providing the current state.

In this example the state of the AudioSource is observed and displayed in the UI as text. The InheritanceExample script needs to be on the same object as the AudioSource you want to observe.

public class InheritanceExample : AudioSourceObserver
{
    [SerializeField] private Text text;

    protected override void OnAudioChanged(AudioState state)
    {
        base.OnAudioChanged(state);

        text.text = state.ToString();
    }
}

Alternatively C# events can be used to observe an AudioSource. Therefore a reference to the AudioSource is required to call the RequestEventHandlers method on. It will return an instance of IAudioEventSource containing C# events you can subscribe to.

Don't forget to unsubscribe from the events in the OnDestroy method.

[RequireComponent(typeof(AudioSource))]
public class EventExample : MonoBehaviour
{
    [SerializeField] private Text text;

    private AudioSource _audioSource;
    private IAudioEventSource _eventSource;

    private void Start()
    {
        _audioSource = GetComponent<AudioSource>();
        _eventSource = _audioSource.RequestEventHandlers();

        _eventSource.Changed += OnAudioSourceChanged;
    }

    private void OnDestroy()
    {
        _eventSource.Changed -= OnAudioSourceChanged;
    }

    private void OnAudioSourceChanged(object sender, AudioState state)
    {
        text.text = state.ToString();
    }
}

How does it work?

It's implemented using polling the isPlaying state of an AudioSource. While this may not be the most efficient method, it works and its performance impact is certainly insignificant.

Sample

This repository contains sample scenes where you can see the code provided above in action. ( Download zip )