Awesome
Unity Timer
Run actions after a delay in Unity3D.
This library has been battle-tested and hardened throughout numerous projects, including the award-winning Pitfall Planet.
Written by Alexander Biggs + Adam Robinson-Yu.
Installation
To get the latest release of UnityTimer, head over to the Releases page and download the Timer.unitypackage file from the latest release. Then if you have a Unity project open, you can open the .unitypackage file to install the scripts into your project.
Alternatively, if you like to live on the bleeding edge, add https://github.com/akbiggs/UnityTimer.git
to your packages in Unity Package Manager. However, we do not guarantee this will give you a stable version.
Basic Example
The Unity Timer package provides the following method for creating timers:
/// <summary>
/// Register a new timer that should fire an event after a certain amount of time
/// has elapsed.
/// </summary>
/// <param name="duration">The time to wait before the timer should fire, in seconds.</param>
/// <param name="onComplete">An action to fire when the timer completes.</param>
public static Timer Register(float duration, Action onComplete);
The method is called like this:
// Log "Hello World" after five seconds.
Timer.Register(5f, () => Debug.Log("Hello World"));
Motivation
Out of the box, without this library, there are two main ways of handling timers in Unity:
- Use a coroutine with the WaitForSeconds method.
- Store the time that your timer started in a private variable (e.g.
startTime = Time.time
), then check in an Update call ifTime.time - startTime >= timerDuration
.
The first method is verbose, forcing you to refactor your code to use IEnumerator functions. Furthermore, it necessitates having access to a MonoBehaviour instance to start the coroutine, meaning that solution will not work in non-MonoBehaviour classes. Finally, there is no way to prevent WaitForSeconds from being affected by changes to the time scale.
The second method is error-prone, and hides away the actual game logic that you are trying to express.
This library alleviates both of these concerns, making it easy to add an easy-to-read, expressive timer to any class in your Unity project.
Features
Make a timer repeat by setting isLooped
to true.
// Call the player's jump method every two seconds.
Timer.Register(2f, player.Jump, isLooped: true);
Cancel a timer after calling it.
Timer timer;
void Start() {
timer = Timer.Register(2f, () => Debug.Log("You won't see this text if you press X."));
}
void Update() {
if (Input.GetKeyDown(KeyCode.X)) {
Timer.Cancel(timer);
}
}
Measure time by realtimeSinceStartup instead of scaled game time by setting useRealTime
to true.
// Let's say you pause your game by setting the timescale to 0.
Time.timeScale = 0f;
// ...Then set useRealTime so this timer will still fire even though the game time isn't progressing.
Timer.Register(1f, this.HandlePausedGameState, useRealTime: true);
Attach the timer to a MonoBehaviour so that the timer is destroyed when the MonoBehaviour is.
Very often, a timer called from a MonoBehaviour will manipulate that behaviour's state. Thus, it is common practice to cancel the timer in the OnDestroy method of the MonoBehaviour. We've added a convenient extension method that attaches a Timer to a MonoBehaviour such that it will automatically cancel the timer when the MonoBehaviour is detected as null.
public class CoolMonoBehaviour : MonoBehaviour {
void Start() {
// Use the AttachTimer extension method to create a timer that is destroyed when this
// object is destroyed.
this.AttachTimer(5f, () => {
// If this code runs after the object is destroyed, a null reference will be thrown,
// which could corrupt game state.
this.gameObject.transform.position = Vector3.zero;
});
}
void Update() {
// This code could destroy the object at any time!
if (Input.GetKeyDown(KeyCode.X)) {
GameObject.Destroy(this.gameObject);
}
}
}
Update a value gradually over time using the onUpdate
callback.
// Change a color from white to red over the course of five seconds.
Color color = Color.white;
float transitionDuration = 5f;
Timer.Register(transitionDuration,
onUpdate: secondsElapsed => color.r = 255 * (secondsElapsed / transitionDuration),
onComplete: () => Debug.Log("Color is now red"));
A number of other useful features are included!
- timer.Pause()
- timer.Resume()
- timer.GetTimeRemaining()
- timer.GetRatioComplete()
- timer.isDone
A test scene + script demoing all the features is included with the package in the Timer/Example
folder.
Usage Notes / Caveats
- All timers are destroyed when changing scenes. This behaviour is typically desired, and it happens because timers are updated by a TimerController that is also destroyed when the scene changes. Note that as a result of this, creating a Timer when the scene is being closed, e.g. in an object's OnDestroy method, will result in a Unity error when the TimerController is spawned.