Android APIs
public interface

IdlingResource

android.support.test.espresso.IdlingResource
Known Indirect Subclasses

Class Overview

Represents a resource of an application under test which can cause asynchronous background work to happen during test execution (e.g. an intent service that processes a button click). By default, Espresso synchronizes all view operations with the UI thread as well as AsyncTasks; however, it has no way of doing so with "hand-made" resources. In such cases, test authors can register the custom resource and Espresso will wait for the resource to become idle prior to executing a view operation.

Important Note: it is assumed that the resource stays idle most of the time.

Summary

Nested Classes
interface IdlingResource.ResourceCallback Registered by an IdlingResource to notify Espresso of a transition to idle. 
Public Methods
abstract String getName()
Returns the name of the resources (used for logging and idempotency of registration).
abstract boolean isIdleNow()
Returns true if resource is currently idle.
abstract void registerIdleTransitionCallback(IdlingResource.ResourceCallback callback)
Registers the given IdlingResource.ResourceCallback with the resource.

Public Methods

public abstract String getName ()

Returns the name of the resources (used for logging and idempotency of registration).

public abstract boolean isIdleNow ()

Returns true if resource is currently idle. Espresso will always call this method from the main thread, therefore it should be non-blocking and return immediately.

public abstract void registerIdleTransitionCallback (IdlingResource.ResourceCallback callback)

Registers the given IdlingResource.ResourceCallback with the resource. Espresso will call this method:

  • with its implementation of IdlingResource.ResourceCallback so it can be notified asynchronously that your resource is idle
  • from the main thread, but you are free to execute the callback's onTransitionToIdle from any thread
  • once (when it is initially given a reference to your IdlingResource)

You only need to call this upon transition from busy to idle - if the resource is already idle when the method is called invoking the call back is optional and has no significant impact.