Annotations

Jetpack Compose has several annotations that are used to provide additional functionality or to improve the development process.

Here are some of the most commonly used annotations:

• @Composable: This annotation is used to mark a function as a composable. It tells the compiler that the function can be used in the composition of the UI.

@Composable
fun MyButton() {
    Button(
         /* Perform action */ },
        text = "Click me!"
    )
}

• @Preview: This annotation is used to create a preview of a composable function in the Android Studio design editor. It allows developers to see the results of their code changes in the editor, without having to run the app on a device or emulator.

@Preview(name = "My Button Preview")
@Composable
fun MyButtonPreview() {
    MyButton()
}

• @Model: This annotation is used to mark a data class as a model for a composable function. It tells the compiler that the data class should be used as the source of truth for the composable function.

@Model
data class MyData(var text: String)

@Composable
fun MyText(data: MyData) {
    Text(data.text)
}

• @ExperimentalCoroutinesApi: This annotation is used to indicate that the code uses coroutines that are considered experimental. This annotation should be used when using the async and await functions.

@ExperimentalCoroutinesApi
fun myFunction() {
    GlobalScope.launch {
        // Coroutine code here
    }
}

These are just a few examples of the annotations that Jetpack Compose provides, and there are many other annotations that you can use depending on your needs.

It’s important to note that the use of some annotations may change between versions and it’s better to check the official documentation before using them.