Yandex MapKit SDK KMP/ru.sulgik.mapkit/WeakRef

WeakRef

actual class WeakRef<T : Any>(referent: T)

A weak reference to referent that does not prevent it from being collected.

MapKit does not retain the listeners passed to its subscription methods. Every subscription in this SDK therefore accepts a WeakRef instead of the listener itself, to make that contract explicit at the call site: it is your responsibility to keep a strong reference to the listener for as long as the subscription has to stay alive.

class MyScreen {
    private val tapListener = MapObjectTapListener { _, _ -> true }

    fun subscribe(mapObject: MapObject) {
        mapObject.addTapListener(tapListener.asWeakRef())
    }
}

Passing a listener that is not referenced anywhere else makes the subscription a no-op as soon as the listener is collected.

expect class WeakRef<T : Any>(referent: T)

A weak reference to referent that does not prevent it from being collected.

class MyScreen {
    private val tapListener = MapObjectTapListener { _, _ -> true }

    fun subscribe(mapObject: MapObject) {
        mapObject.addTapListener(tapListener.asWeakRef())
    }
}

Passing a listener that is not referenced anywhere else makes the subscription a no-op as soon as the listener is collected.

actual class WeakRef<T : Any>(referent: T)

A weak reference to referent that does not prevent it from being collected.

class MyScreen {
    private val tapListener = MapObjectTapListener { _, _ -> true }

    fun subscribe(mapObject: MapObject) {
        mapObject.addTapListener(tapListener.asWeakRef())
    }
}

Passing a listener that is not referenced anywhere else makes the subscription a no-op as soon as the listener is collected.

Constructors

WeakRef

actual constructor(referent: T)

expect constructor(referent: T)

actual constructor(referent: T)

Functions

get

actual fun get(): T?

The referent, or null if it has already been collected.

expect fun get(): T?

The referent, or null if it has already been collected.

actual fun get(): T?

The referent, or null if it has already been collected.

toNative

fun <T : NativeConvertible<N>, N : Any> WeakRef<T>.toNative(): WeakReference<N>

Converts this reference into the weak reference expected by the subscription methods of the original Yandex MapKit SDK.

fun <T : NativeConvertible<N>, N : Any> WeakRef<T>.toNative(): N?

Unwraps the referent into the object expected by the subscription methods of the original Yandex MapKit SDK, or returns null if it has already been collected.

withValue

inline fun <T : Any, R> WeakRef<T>.withValue(block: (T) -> R): R?

Runs block with the referent and returns its result, or returns null if the referent has already been collected.