alchemist/it.unibo.alchemist.model.observables/ObservableMutableMap

ObservableMutableMap

open class ObservableMutableMap<K, V>(initial: Map<K, V> = emptyMap()) : AbstractObservable<Map<K, V>> , ObservableMap<K, V>

A class that represents an observable, mutable map. Allows observation of map changes, including addition, removal, modifications of key-value pairs, and observation of particular keys for their value changes.

Type Parameters

The type of keys maintained by the map.

The type of mapped values.

Constructors

ObservableMutableMap

constructor(initial: Map<K, V> = emptyMap())

Types

ObservableMapExtensions

object ObservableMapExtensions

Simple utility function for the ObservableMaps.

Properties

current

open override val current: Map<K, V>

The current value: while observed, the latest value published; otherwise, a freshly computed one. Observables holding their own state may read it directly.

isObserved

open val isObserved: Boolean

Whether any callback is currently registered.

observerCount

override val observerCount: Int

How many callbacks are currently registered.

Functions

clearAndPutAll

fun clearAndPutAll(from: Map<K, V>)

Replaces the whole content of this map with from, like doing a clear followed by a putAll, * but without notifying per-key observers for keys that remain present (unless their value changes).

currentOrNull

fun <T> Observable<Option<T>>.currentOrNull(): T?

Retrieves the current value of the observable if present, or null if no value is available.

dispose

open override fun dispose()

Unregisters every callback registered with this observable.

get

open operator override fun get(key: K): Observable<Option<V>>

Retrieves the observable representation of the value associated with the specified key in the observable map. The resulting observable emits updates whenever the value for the given key changes, is added, or is removed.

map

open override fun <S> map(transform: (Map<K, V>) -> S): Observable<S>

Transforms the current observable into a new observable by applying the specified transformation function to its emitted values.

mergeWith

open override fun <O, R> mergeWith(other: Observable<O>, merge: (Map<K, V>, O) -> R): Observable<R>

Combines the current observable with another observable, producing a new observable that emits values derived by applying the provided merge function to the current values of both observables.

onChange

open override fun onChange(notifyOnRegistration: Boolean = true, callback: (Map<K, V>) -> Unit): Disposable

Registers callback to be invoked with every new value of this observable, and right away with the current one if notifyOnRegistration.

put

fun put(key: K, value: V)

Adds the specified key-value pair to the map. If the key already exists, the value is updated. Observers are notified if the value changes.

remove

fun remove(key: K): V?

Removes the mapping for the specified key from the map, if it exists. Notifies observers if the key had an associated value before removal.

set

operator fun set(key: K, value: V)

switchMap

@JvmStatic

fun <T, R> Observable<T>.switchMap(transform: (T) -> Observable<R>): Observable<R>

Maps the current value of this Observable to an inner observable through transform, and mirrors the inner observable of the most recent value only: whenever this observable emits, the previous inner observable is unsubscribed and the new one is followed.

updateOrNull

fun <K, V> ObservableMutableMap<K, V>.updateOrNull(key: K, valueUpdate: V.() -> Unit): V?

Updates the value associated with the given key in the map by applying the provided transformation function. If the key does not exist or its current value is null, no operation is performed, and null is returned.

upsertValue

fun <K, V> ObservableMutableMap<K, V>.upsertValue(key: K, valueUpdate: (V?) -> V)

Inserts or updates a key-value pair in the ObservableMutableMap. If the key already exists, its value is updated using the provided transformation function. If the key does not exist, a new key-value pair is added with the value derived from the transformation function.