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/*
* Copyright (C) 2014 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.support.test.espresso;
/**
* 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, {@link 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 {@link Espresso} will wait for the resource to
* become idle prior to executing a view operation.
* <br><br>
* <b>Important Note:</b> it is assumed that the resource stays idle most of the time.
*/
public interface IdlingResource {
/**
* Returns the name of the resources (used for logging and idempotency of registration).
*/
public String getName();
/**
* Returns {@code true} if resource is currently idle. Espresso will <b>always</b> call this
* method from the main thread, therefore it should be non-blocking and return immediately.
*/
public boolean isIdleNow();
/**
* Registers the given {@link ResourceCallback} with the resource. Espresso will call this method:
* <ul>
* <li>with its implementation of {@link ResourceCallback} so it can be notified asynchronously
* that your resource is idle
* <li>from the main thread, but you are free to execute the callback's onTransitionToIdle from
* any thread
* <li>once (when it is initially given a reference to your IdlingResource)
* </ul>
* <br>
* 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.
*/
public void registerIdleTransitionCallback(ResourceCallback callback);
/**
* Registered by an {@link IdlingResource} to notify Espresso of a transition to idle.
*/
public interface ResourceCallback {
/**
* Called when the resource goes from busy to idle.
*/
public void onTransitionToIdle();
}
}