An ExecutorService for Espresso

IdlingResourceExecutorService.java

/*
 * Copyright 2016, 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 com.example.android.testing.espresso.AdvancedIdlingResource;

import android.support.test.espresso.idling.CountingIdlingResource;

import java.util.concurrent.Callable;
import java.util.concurrent.ExecutorService;

public class IdlingResourceExecutorService extends GuavasWrappingExecutorService {

    private final CountingIdlingResource mIdlingResource;

    public IdlingResourceExecutorService(ExecutorService delegate,
            CountingIdlingResource idlingResource) {
        super(delegate);
        mIdlingResource = idlingResource;
    }

    @Override
    protected <T> Callable<T> wrapTask(Callable<T> callable) {
        return new WrappedCallable<>(callable);
    }

    private final class WrappedCallable<T> implements Callable<T> {
        private final Callable<T> delegate;


        public WrappedCallable(Callable<T> delegate) {
            this.delegate = delegate;
        }

        @Override
        public T call() throws Exception {
            mIdlingResource.increment();
            T call;
            try {
                call = delegate.call();
            } finally {
                mIdlingResource.decrement();
            }
            return call;
        }
    }
}