IssueTracker

Jetpack Compose version: bom 2023.10.01

Jetpack Compose component(s) used: remember

Kotlin version: 1.9.22

compose compiler: 1.5.8

The way remember treats Java method refs as keys differs with Intrinsic remember.

The Slider in the code below DOES work if intrinsic remember is disabled. but you can NOT slide the Slider if intrinsic remember is enabled (which is the default in 1.5.8)

The Slider also works with kotlin 1.9.20 and 1.5.5 (before intrinsic remember was enabled by default) .

Also, note that if you use a Kotlin class instead of a Java class here then the Slider works fine with intrinsic remember enabled.

The problem seems to be that remember thinks the methodRef key is changing on every recomposition when intrinsic remember is enabled .

This is a minimal reproducer.

@Preview
@Composable
fun JavaMethodRefPreview() {
    val javaClass = remember {
        JavaClass()
    }

    var sliderState by rememberSliderState(
        methodRef = javaClass::javaMethod,
    )
    Slider(
        modifier = Modifier.padding(horizontal = 32.dp),
        value = sliderState,
        onValueChange = {
            sliderState = it
        })
}


@Composable
private fun rememberSliderState(
    methodRef: (Float) -> Float,
): MutableState<Float> = remember(methodRef) { mutableStateOf(0f) }

public class JavaClass {
    float javaMethod(float x) {
        return x;
    }
}

Note: here is the config to disable intrinsicRemember

tasks.withType<org.jetbrains.kotlin.gradle.tasks.KotlinCompile> {
    compilerOptions.freeCompilerArgs.addAll(
        "-P",
        "plugin:androidx.compose.compiler.plugins.kotlin:intrinsicRemember=false",
    )
}