Merge "Fix exception from DateTimeView unregisters receiver again" into pi-dev

        public void removeView(DateTimeView v) {

            synchronized (mAttachedViews) {

                mAttachedViews.remove(v);

                if (mAttachedViews.isEmpty()) {

                final boolean removed = mAttachedViews.remove(v);

                // Only unregister once when we remove the last view in the list otherwise we risk

                // trying to unregister a receiver that is no longer registered.

                if (removed && mAttachedViews.isEmpty()) {

                    unregister(getApplicationContextIfAvailable(v.getContext()));

                }

            }

/*

 * Copyright (C) 2018 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.widget;

import android.support.test.InstrumentationRegistry;

import android.support.test.annotation.UiThreadTest;

import android.support.test.filters.SmallTest;

import android.support.test.runner.AndroidJUnit4;

import org.junit.Test;

import org.junit.runner.RunWith;

@RunWith(AndroidJUnit4.class)

@SmallTest

public class DateTimeViewTest {

    @UiThreadTest

    @Test

    public void additionalOnDetachedFromWindow_noException() {

        final DateTimeView dateTimeView = new DateTimeView(InstrumentationRegistry.getContext());

        dateTimeView.onAttachedToWindow();

        dateTimeView.onAttachedToWindow();

        // Even there is an additional detach (abnormal), DateTimeView should not unregister

        // receiver again that raises "java.lang.IllegalArgumentException: Receiver not registered".

        dateTimeView.onDetachedFromWindow();

    }

}