coordinatorlayout/src/androidTest/java/androidx/coordinatorlayout/widget/CoordinatorLayoutSortTest.java

/*
 * Copyright 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 androidx.coordinatorlayout.widget;

import static org.junit.Assert.assertEquals;

import android.app.Instrumentation;
import android.support.test.InstrumentationRegistry;
import android.support.test.filters.MediumTest;
import android.support.test.rule.ActivityTestRule;
import android.view.View;

import androidx.coordinatorlayout.testutils.CoordinatorLayoutUtils;

import org.junit.Rule;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;

@RunWith(Parameterized.class)
@MediumTest
public class CoordinatorLayoutSortTest {
    @Rule
    public final ActivityTestRule<CoordinatorLayoutActivity> mActivityTestRule;

    private static final int NUMBER_VIEWS_DEPENDENCY_SORT = 4;

    /**
     * All 27 permutations of a quad-tuple containing unique values in the range 0-3
     */
    @Parameterized.Parameters
    public static Collection<Object[]> data() {
        return Arrays.asList(new Object[][] {
                {0, 1, 2, 3}, {0, 1, 3, 2}, {0, 2, 1, 3}, {0, 2, 3, 1}, {0, 3, 1, 2}, {0, 3, 2, 1},
                {1, 0, 2, 3}, {1, 0, 3, 2}, {1, 2, 0, 3}, {1, 2, 3, 0}, {1, 3, 0, 2}, {1, 3, 2, 0},
                {2, 0, 1, 3}, {2, 0, 3, 1}, {2, 1, 0, 3}, {2, 1, 3, 0}, {2, 3, 0, 1}, {2, 3, 1, 0},
                {3, 0, 1, 2}, {3, 0, 2, 1}, {3, 1, 0, 2}, {3, 1, 2, 0}, {3, 2, 0, 1}, {3, 2, 1, 0}
        });
    }

    private int mFirstAddIndex;
    private int mSecondAddIndex;
    private int mThirdAddIndex;
    private int mFourthAddIndex;

    public CoordinatorLayoutSortTest(int firstIndex, int secondIndex, int thirdIndex,
            int fourthIndex) {
        mActivityTestRule = new ActivityTestRule<>(CoordinatorLayoutActivity.class);
        mFirstAddIndex = firstIndex;
        mSecondAddIndex = secondIndex;
        mThirdAddIndex = thirdIndex;
        mFourthAddIndex = fourthIndex;
    }

    @Test
    public void testDependencySortingOrder() throws Throwable {
        final CoordinatorLayout col = mActivityTestRule.getActivity().mCoordinatorLayout;

        // Let's create some views where each view depends on the previous view.
        // i.e C depends on B, B depends on A, A doesn't depend on anything.
        final List<View> views = new ArrayList<>();
        for (int i = 0; i < NUMBER_VIEWS_DEPENDENCY_SORT; i++) {
            // 65 == A in ASCII
            final String label = Character.toString((char) (65 + i));
            final View view = new View(col.getContext()) {
                @Override
                public String toString() {
                    return label;
                }
            };

            // Create a Behavior which depends on the previously added view
            View dependency = i > 0 ? views.get(i - 1) : null;
            final CoordinatorLayout.Behavior<View> behavior =
                    new CoordinatorLayoutUtils.DependentBehavior(dependency);

            // And set its LayoutParams to use the Behavior
            CoordinatorLayout.LayoutParams lp = col.generateDefaultLayoutParams();
            lp.setBehavior(behavior);
            view.setLayoutParams(lp);

            views.add(view);
        }

        // Now the add the views in the given order and assert that they still end up in
        // the expected order A, B, C, D
        final List<View> testOrder = new ArrayList<>();
        testOrder.add(views.get(mFirstAddIndex));
        testOrder.add(views.get(mSecondAddIndex));
        testOrder.add(views.get(mThirdAddIndex));
        testOrder.add(views.get(mFourthAddIndex));
        addViewsAndAssertOrdering(col, views, testOrder);
    }

    private void addViewsAndAssertOrdering(final CoordinatorLayout col,
            final List<View> expectedOrder, final List<View> addOrder) throws Throwable {
        final Instrumentation instrumentation = InstrumentationRegistry.getInstrumentation();

        // Add the Views in the given order
        mActivityTestRule.runOnUiThread(new Runnable() {
            @Override
            public void run() {
                for (int i = 0; i < addOrder.size(); i++) {
                    col.addView(addOrder.get(i));
                }
            }
        });
        instrumentation.waitForIdleSync();

        // Now assert that the dependency sorted order is correct
        assertEquals(expectedOrder, col.getDependencySortedChildren());

        // Finally remove all of the views
        mActivityTestRule.runOnUiThread(new Runnable() {
            @Override
            public void run() {
                col.removeAllViews();
            }
        });
    }
}