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Do something with a delay using LaunchedEffect

Android, Jetpack, Compose, Kotlin1 min read

Here's a quick tip about doing something with a delay in Jetpack Compose - using LaunchedEffect.

As a quick refresher, LaunchedEffect allows you to run some code on your first composition - or every time a specific key changes:

1// Just once(but will be called again if you are using navigation and pop back etc.)
2LaunchedEffect(Unit) {
3 // Do something...
4}
5
6// With a key
7LaunchedEffect(key) {
8 // Do something...
9}

If you're new to Compose you might be surprised to learn that you can actually just add a delay call to the code inside your LaunchedEffect:

1// Just once
2LaunchedEffect(Unit) {
3 delay(10.seconds)
4 // Do something...
5}

And you're good to go! It's also worth keeping in mind that LaunchedEffect runs your code in a coroutine scope - so you won't get any warnings about using delay like you would if you were just using a normal(not suspended) function. I also wrote another post last week about using derivedStateOf, you can check it out here!