LifecycleRegistry

Artifact: androidx.lifecycle:lifecycle-runtime

View Source

Added in 2.0.0

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Kotlin |Java

Common/AllAndroid/JVMNative/C/iOS

• Cmn

  open class LifecycleRegistry : Lifecycle

kotlin.Any
↳	androidx.lifecycle.Lifecycle
	↳	androidx.lifecycle.LifecycleRegistry

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An implementation of Lifecycle that can handle multiple observers.

It is used by Fragments and Support Library Activities. You can also directly use it if you have a custom LifecycleOwner.

Summary

Public companion functions
LifecycleRegistry	@VisibleForTesting createUnsafe(owner: LifecycleOwner) Creates a new LifecycleRegistry for the given provider, that doesn't check that its methods are called on the threads other than main.	Cmn android N

Public constructors
LifecycleRegistry(provider: LifecycleOwner)	Cmn android N

Public functions
open Unit	@MainThread addObserver(observer: LifecycleObserver) Adds a LifecycleObserver that will be notified when the LifecycleOwner changes state.	Cmn android N
open Unit	handleLifecycleEvent(event: Lifecycle.Event) Sets the current state and notifies the observers.	Cmn android N
open Unit	@MainThread markState(state: Lifecycle.State) This function is deprecated. Override [currentState].	android
open Unit	@MainThread removeObserver(observer: LifecycleObserver) Removes the given observer from the observers list.	Cmn android N

Public properties
open Lifecycle.State	currentState Returns the current state of the Lifecycle.	Cmn android N
open StateFlow<Lifecycle.State>	currentStateFlow Returns a StateFlow where the StateFlow.value represents the current State of this Lifecycle.	android
open <Error class: unknown class><Lifecycle.State>	currentStateFlow Returns a StateFlow where the StateFlow.value represents the current State of this Lifecycle.	N
open Int	observerCount The number of observers.	Cmn android N

Inherited properties
From androidx.lifecycle.Lifecycle open StateFlow<Lifecycle.State> currentStateFlow Returns a StateFlow where the StateFlow.value represents the current State of this Lifecycle. Cmn

Public companion functions

createUnsafe

Cmn android N

Added in 2.6.0

@VisibleForTesting
fun createUnsafe(owner: LifecycleOwner): LifecycleRegistry

Creates a new LifecycleRegistry for the given provider, that doesn't check that its methods are called on the threads other than main.

LifecycleRegistry is not synchronized: if multiple threads access this LifecycleRegistry, it must be synchronized externally.

Another possible use-case for this method is JVM testing, when main thread is not present.

Public constructors

LifecycleRegistry

Cmn android N

Added in 2.0.0

LifecycleRegistry(provider: LifecycleOwner)

Public functions

addObserver

Cmn android N

Added in 2.0.0

@MainThread
open fun addObserver(observer: LifecycleObserver): Unit

Adds a LifecycleObserver that will be notified when the LifecycleOwner changes state.

The given observer will be brought to the current state of the LifecycleOwner. For example, if the LifecycleOwner is in State.STARTED state, the given observer will receive Event.ON_CREATE, Event.ON_START events.

Parameters
observer: LifecycleObserver	The observer to notify.

handleLifecycleEvent

Cmn android N

Added in 2.0.0

open fun handleLifecycleEvent(event: Lifecycle.Event): Unit

Sets the current state and notifies the observers.

Note that if the currentState is the same state as the last call to this method, calling this method has no effect.

Parameters
event: Lifecycle.Event	The event that was received

markState

android

Added in 2.0.0

Deprecated in 2.1.0

@MainThread
open fun markState(state: Lifecycle.State): Unit

This function is deprecated.
Override [currentState].

Moves the Lifecycle to the given state and dispatches necessary events to the observers.

Parameters
state: Lifecycle.State	new state

removeObserver

Cmn android N

Added in 2.0.0

@MainThread
open fun removeObserver(observer: LifecycleObserver): Unit

Removes the given observer from the observers list.

If this method is called while a state change is being dispatched,

• If the given observer has not yet received that event, it will not receive it.

• If the given observer has more than 1 method that observes the currently dispatched event and at least one of them received the event, all of them will receive the event and the removal will happen afterwards.

Parameters
observer: LifecycleObserver	The observer to be removed.

Public properties

currentState

Cmn android N

Added in 2.0.0

open var currentState: Lifecycle.State

Returns the current state of the Lifecycle.

Returns
Lifecycle.State	The current state of the Lifecycle.

currentStateFlow

android

open val currentStateFlow: StateFlow<Lifecycle.State>

Returns a StateFlow where the StateFlow.value represents the current State of this Lifecycle.

Returns
StateFlow<Lifecycle.State>	StateFlow where the StateFlow.value represents the current State of this Lifecycle.

currentStateFlow

N

open val currentStateFlow: <Error class: unknown class><Lifecycle.State>

Returns a StateFlow where the StateFlow.value represents the current State of this Lifecycle.

Returns
<Error class: unknown class><Lifecycle.State>	StateFlow where the StateFlow.value represents the current State of this Lifecycle.

observerCount

Cmn android N

Added in 2.0.0

open val observerCount: Int

The number of observers.

Returns
Int	The number of observers.