compose/androidx.compose.runtime/ComposableContract

ComposableContract

@Target(allowedTargets = [AnnotationTarget.FUNCTION, AnnotationTarget.PROPERTY, AnnotationTarget.PROPERTY_GETTER, AnnotationTarget.TYPE])

annotation class ComposableContract(restartable: Boolean, readonly: Boolean, tracked: Boolean, preventCapture: Boolean)

This annotation can be applied to Composable functions and provide metadata to the compiler that imply compose-specific contracts that the author of the function is guaranteeing the function complies with. This metadata can be used to generate more efficient code.

Caution: Use of this annotation means that the annotated declaration MUST comply with those contracts, or else the resulting code's behavior will be undefined.

Parameters

preventCapture

if true, this will prevent composable calls from happening inside of the function that it applies to. This is usually applied to lambda parameters of inline functions that ought to be safely inlined but cannot safely have composable calls in them

readonly

if true, no group will be generated around the body of the function it annotates . This is not safe unless the body of the function only executes "read" operations on the passed in composer..

restartable

if false, this will prevent code from being generated which allow this function's execution to be skipped or restarted. This may be desirable for small functions which just directly call another composable function and have very little machinery in them directly.

tracked

if false, this will disable lambda optimizations such as tracking execution of composable function expressions or remembering a function expression value based on its capture variables. This flag is only meaningful when applied to @Composable lambda expressions

Constructors

ComposableContract

common

fun ComposableContract(restartable: Boolean = true, readonly: Boolean = false, tracked: Boolean = true, preventCapture: Boolean = false)

if false, this will prevent code from being generated which allow this function's execution to be skipped or restarted.

Functions

equals

common

open operator fun equals(other: Any?): Boolean

hashCode

common

open fun hashCode(): Int

toString

common

open fun toString(): String

Properties

preventCapture

common

val preventCapture: Boolean = false

if true, this will prevent composable calls from happening inside of the function that it applies to.

readonly

common

val readonly: Boolean = false

if true, no group will be generated around the body of the function it annotates .

restartable

common

val restartable: Boolean = true

if false, this will prevent code from being generated which allow this function's execution to be skipped or restarted.

tracked

common

val tracked: Boolean = true

if false, this will disable lambda optimizations such as tracking execution of composable function expressions or remembering a function expression value based on its capture variables.