CANCELLABLE.md

Cancellable and CancellableManager

One key concept of Trikot is the Cancellables. Cancellable are meant to be added into a CancellableManager that manage their lifecycle. When CancellableManager.cancel() is called, all Cancellable are cancelled.

Implementation detail

• When cancelled, any Cancellable added to the CancellableManager are automatically cancelled.
• Once cancelled are not meant to be reuse after cancel has been called.

class Bar: Cancellable {
	override fun cancel() {
		// Terminate all operations
	}
}

class Foo {
	private val cancellableManager = CancellableManager()
	private val Bar().also { cancellableManager.add(it) }

	fun doCompleted() {
		cancellableManager.cancel()
	}
}

CancellableManagerProvider

It's a common pattern to cancel a CancellableManager and create a new CancellableManager to replace it when resetting a state. This is the main use case of CancellableManagerProvider.

Implementation detail

• CancellableManagerProvider is a cancelable so it can be added to any other CancellableManager.
• Once cancelled, provided cancellableManager are automatically cancelled.

Calling cancelPreviousAndCreate will cancel any previous CancellableManager returned and provide a new one

val cancellableManagerProvider = CancellableManagerProvider()
val cancelableManager = CancellableManagerProvider.cancelPreviousAndCreate()
cancelableManager.add(...)