v7/recyclerview/tests/src/android/support/v7/widget/DefaultItemAnimatorTest.java - platform/frameworks/support - Git at Google

 /*
  * 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.v7.widget;

 import android.os.Looper;
 import android.test.ActivityInstrumentationTestCase2;
 import android.util.Log;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.TextView;

 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.Semaphore;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantLock;

 public class DefaultItemAnimatorTest extends ActivityInstrumentationTestCase2<TestActivity> {

     private static final String TAG = "DefaultItemAnimatorTest";
     Throwable mainThreadException;

     DefaultItemAnimator mAnimator;
     Adapter mAdapter;
     ViewGroup mDummyParent;
     List<RecyclerView.ViewHolder> mExpectedItems = new ArrayList<RecyclerView.ViewHolder>();

     Set<RecyclerView.ViewHolder> mRemoveFinished = new HashSet<RecyclerView.ViewHolder>();
     Set<RecyclerView.ViewHolder> mAddFinished = new HashSet<RecyclerView.ViewHolder>();
     Set<RecyclerView.ViewHolder> mMoveFinished = new HashSet<RecyclerView.ViewHolder>();
     Set<RecyclerView.ViewHolder> mChangeFinished = new HashSet<RecyclerView.ViewHolder>();

     Semaphore mExpectedItemCount = new Semaphore(0);

     public DefaultItemAnimatorTest() {
         super("android.support.v7.recyclerview", TestActivity.class);
     }

     @Override
     protected void setUp() throws Exception {
         super.setUp();
         mAnimator = new DefaultItemAnimator();
         mAdapter = new Adapter(20);
         mDummyParent = getActivity().mContainer;
         mAnimator.setListener(new RecyclerView.ItemAnimator.ItemAnimatorListener() {
             @Override
             public void onRemoveFinished(RecyclerView.ViewHolder item) {
                 try {
                     assertTrue(mRemoveFinished.add(item));
                     onFinished(item);
                 } catch (Throwable t) {
                     postExceptionToInstrumentation(t);
                 }
             }

             @Override
             public void onAddFinished(RecyclerView.ViewHolder item) {
                 try {
                     assertTrue(mAddFinished.add(item));
                     onFinished(item);
                 } catch (Throwable t) {
                     postExceptionToInstrumentation(t);
                 }
             }

             @Override
             public void onMoveFinished(RecyclerView.ViewHolder item) {
                 try {
                     assertTrue(mMoveFinished.add(item));
                     onFinished(item);
                 } catch (Throwable t) {
                     postExceptionToInstrumentation(t);
                 }
             }

             @Override
             public void onChangeFinished(RecyclerView.ViewHolder item) {
                 try {
                     assertTrue(mChangeFinished.add(item));
                     onFinished(item);
                 } catch (Throwable t) {
                     postExceptionToInstrumentation(t);
                 }
             }

             private void onFinished(RecyclerView.ViewHolder item) {
                 assertNotNull(mExpectedItems.remove(item));
                 mExpectedItemCount.release(1);
             }
         });
     }

     void checkForMainThreadException() throws Throwable {
         if (mainThreadException != null) {
             throw mainThreadException;
         }
     }

     @Override
     protected void tearDown() throws Exception {
         getInstrumentation().waitForIdleSync();
         super.tearDown();
         try {
             checkForMainThreadException();
         } catch (Exception e) {
             throw e;
         } catch (Throwable throwable) {
             throw new Exception(throwable);
         }
     }

     void expectItems(RecyclerView.ViewHolder... viewHolders) {
         mExpectedItems.addAll(Arrays.asList(viewHolders));
     }

     void runAndWait(int itemCount, int seconds) throws Throwable {
         runAndWait(itemCount, seconds, null);
     }

     void runAndWait(int itemCount, int seconds, final ThrowingRunnable postRun) throws Throwable {
         runTestOnUiThread(new Runnable() {
             @Override
             public void run() {
                 mAnimator.runPendingAnimations();
                 if (postRun != null) {
                     try {
                         postRun.run();
                     } catch (Throwable e) {
                         throw new RuntimeException(e);
                     }
                 }
             }
         });
         waitForItems(itemCount, seconds);
         checkForMainThreadException();
     }

     void waitForItems(int itemCount, int seconds) throws InterruptedException {
         assertTrue("all vh animations should end",
                 mExpectedItemCount.tryAcquire(itemCount, seconds, TimeUnit.SECONDS));
         assertEquals("all expected finish events should happen", 0, mExpectedItems.size());
         // wait one more second for unwanted
         assertFalse("should not receive any more permits",
                 mExpectedItemCount.tryAcquire(1, 2, TimeUnit.SECONDS));
     }

     public void testAnimateAdd() throws Throwable {
         ViewHolder vh = createViewHolder(1);
         expectItems(vh);
         assertTrue(animateAdd(vh));
         assertTrue(mAnimator.isRunning());
         runAndWait(1, 1);
     }

     public void testAnimateRemove() throws Throwable {
         ViewHolder vh = createViewHolder(1);
         expectItems(vh);
         assertTrue(animateRemove(vh));
         assertTrue(mAnimator.isRunning());
         runAndWait(1, 1);
     }

     public void testAnimateMove() throws Throwable {
         ViewHolder vh = createViewHolder(1);
         expectItems(vh);
         assertTrue(animateMove(vh, 0, 0, 100, 100));
         assertTrue(mAnimator.isRunning());
         runAndWait(1, 1);
     }

     public void testAnimateChange() throws Throwable {
         ViewHolder vh = createViewHolder(1);
         ViewHolder vh2 = createViewHolder(2);
         expectItems(vh, vh2);
         assertTrue(animateChange(vh, vh2, 0, 0, 100, 100));
         assertTrue(mAnimator.isRunning());
         runAndWait(2, 1);
     }

     public void cancelBefore(int count, final RecyclerView.ViewHolder... toCancel)
             throws Throwable {
         cancelTest(true, count, toCancel);
     }

     public void cancelAfter(int count, final RecyclerView.ViewHolder... toCancel)
             throws Throwable {
         cancelTest(false, count, toCancel);
     }

     public void cancelTest(boolean before, int count, final RecyclerView.ViewHolder... toCancel) throws Throwable {
         if (before) {
             endAnimations(toCancel);
             runAndWait(count, 1);
         } else {
             runAndWait(count, 1, new ThrowingRunnable() {
                 @Override
                 public void run() throws Throwable {
                     endAnimations(toCancel);
                 }
             });
         }
     }

     public void testCancelAddBefore() throws Throwable {
         final ViewHolder vh = createViewHolder(1);
         expectItems(vh);
         assertTrue(animateAdd(vh));
         cancelBefore(1, vh);
     }

     public void testCancelAddAfter() throws Throwable {
         final ViewHolder vh = createViewHolder(1);
         expectItems(vh);
         assertTrue(animateAdd(vh));
         cancelAfter(1, vh);
     }

     public void testCancelMoveBefore() throws Throwable {
         ViewHolder vh = createViewHolder(1);
         expectItems(vh);
         assertTrue(animateMove(vh, 10, 10, 100, 100));
         cancelBefore(1, vh);
     }

     public void testCancelMoveAfter() throws Throwable {
         ViewHolder vh = createViewHolder(1);
         expectItems(vh);
         assertTrue(animateMove(vh, 10, 10, 100, 100));
         cancelAfter(1, vh);
     }

     public void testCancelRemove() throws Throwable {
         ViewHolder vh = createViewHolder(1);
         expectItems(vh);
         assertTrue(animateRemove(vh));
         endAnimations(vh);
         runAndWait(1, 1);
     }

     public void testCancelChangeOldBefore() throws Throwable {
         cancelChangeOldTest(true);
     }
     public void testCancelChangeOldAfter() throws Throwable {
         cancelChangeOldTest(false);
     }

     public void cancelChangeOldTest(boolean before) throws Throwable {
         ViewHolder vh = createViewHolder(1);
         ViewHolder vh2 = createViewHolder(1);
         expectItems(vh, vh2);
         assertTrue(animateChange(vh, vh2, 20, 20, 100, 100));
         cancelTest(before, 2, vh);
     }

     public void testCancelChangeNewBefore() throws Throwable {
         cancelChangeNewTest(true);
     }

     public void testCancelChangeNewAfter() throws Throwable {
         cancelChangeNewTest(false);
     }

     public void cancelChangeNewTest(boolean before) throws Throwable {
         ViewHolder vh = createViewHolder(1);
         ViewHolder vh2 = createViewHolder(1);
         expectItems(vh, vh2);
         assertTrue(animateChange(vh, vh2, 20, 20, 100, 100));
         cancelTest(before, 2, vh2);
     }

     public void testCancelChangeBothBefore() throws Throwable {
         cancelChangeBothTest(true);
     }

     public void testCancelChangeBothAfter() throws Throwable {
         cancelChangeBothTest(false);
     }

     public void cancelChangeBothTest(boolean before) throws Throwable {
         ViewHolder vh = createViewHolder(1);
         ViewHolder vh2 = createViewHolder(1);
         expectItems(vh, vh2);
         assertTrue(animateChange(vh, vh2, 20, 20, 100, 100));
         cancelTest(before, 2, vh, vh2);
     }

     void endAnimations(final RecyclerView.ViewHolder... vhs) throws Throwable {
         runTestOnUiThread(new Runnable() {
             @Override
             public void run() {
                 for (RecyclerView.ViewHolder vh : vhs) {
                     mAnimator.endAnimation(vh);
                 }
             }
         });
     }

     boolean animateAdd(final RecyclerView.ViewHolder vh) throws Throwable {
         final boolean[] result = new boolean[1];
         runTestOnUiThread(new Runnable() {
             @Override
             public void run() {
                 result[0] = mAnimator.animateAdd(vh);
             }
         });
         return result[0];
     }

     boolean animateRemove(final RecyclerView.ViewHolder vh) throws Throwable {
         final boolean[] result = new boolean[1];
         runTestOnUiThread(new Runnable() {
             @Override
             public void run() {
                 result[0] = mAnimator.animateRemove(vh);
             }
         });
         return result[0];
     }

     boolean animateMove(final RecyclerView.ViewHolder vh, final int fromX, final int fromY,
             final int toX, final int toY) throws Throwable {
         final boolean[] result = new boolean[1];
         runTestOnUiThread(new Runnable() {
             @Override
             public void run() {
                 result[0] = mAnimator.animateMove(vh, fromX, fromY, toX, toY);
             }
         });
         return result[0];
     }

     boolean animateChange(final RecyclerView.ViewHolder oldHolder,
             final RecyclerView.ViewHolder newHolder,
             final int fromX, final int fromY, final int toX, final int toY) throws Throwable {
         final boolean[] result = new boolean[1];
         runTestOnUiThread(new Runnable() {
             @Override
             public void run() {
                 result[0] = mAnimator.animateChange(oldHolder, newHolder, fromX, fromY, toX, toY);
             }
         });
         return result[0];
     }

     private ViewHolder createViewHolder(final int pos) throws Throwable {
         final ViewHolder vh = mAdapter.createViewHolder(mDummyParent, 1);
         runTestOnUiThread(new Runnable() {
             @Override
             public void run() {
                 mAdapter.bindViewHolder(vh, pos);
                 mDummyParent.addView(vh.itemView);
             }
         });

         return vh;
     }

     void postExceptionToInstrumentation(Throwable t) {
         if (mainThreadException == null) {
             mainThreadException = t;
         } else {
             Log.e(TAG, "skipping secondary main thread exception", t);
         }
     }


     private class Adapter extends RecyclerView.Adapter<ViewHolder> {

         List<String> mItems;

         private Adapter(int count) {
             mItems = new ArrayList<String>();
             for (int i = 0; i < count; i++) {
                 mItems.add("item-" + i);
             }
         }

         @Override
         public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
             return new ViewHolder(new TextView(parent.getContext()));
         }

         @Override
         public void onBindViewHolder(ViewHolder holder, int position) {
             holder.bind(mItems.get(position));
         }

         @Override
         public int getItemCount() {
             return mItems.size();
         }
     }

     private class ViewHolder extends RecyclerView.ViewHolder {

         String mBindedText;

         public ViewHolder(View itemView) {
             super(itemView);
         }

         public void bind(String text) {
             mBindedText = text;
             ((TextView) itemView).setText(text);
         }
     }

     private interface ThrowingRunnable {
         public void run() throws Throwable;
     }

     @Override
     public void runTestOnUiThread(Runnable r) throws Throwable {
         if (Looper.myLooper() == Looper.getMainLooper()) {
             r.run();
         } else {
             super.runTestOnUiThread(r);
         }
     }
 }
	/*
	* 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.v7.widget;

	import android.os.Looper;
	import android.test.ActivityInstrumentationTestCase2;
	import android.util.Log;
	import android.view.View;
	import android.view.ViewGroup;
	import android.widget.TextView;

	import java.util.ArrayList;
	import java.util.Arrays;
	import java.util.HashSet;
	import java.util.List;
	import java.util.Set;
	import java.util.concurrent.CountDownLatch;
	import java.util.concurrent.Semaphore;
	import java.util.concurrent.TimeUnit;
	import java.util.concurrent.locks.Lock;
	import java.util.concurrent.locks.ReentrantLock;

	public class DefaultItemAnimatorTest extends ActivityInstrumentationTestCase2<TestActivity> {

	private static final String TAG = "DefaultItemAnimatorTest";
	Throwable mainThreadException;

	DefaultItemAnimator mAnimator;
	Adapter mAdapter;
	ViewGroup mDummyParent;
	List<RecyclerView.ViewHolder> mExpectedItems = new ArrayList<RecyclerView.ViewHolder>();

	Set<RecyclerView.ViewHolder> mRemoveFinished = new HashSet<RecyclerView.ViewHolder>();
	Set<RecyclerView.ViewHolder> mAddFinished = new HashSet<RecyclerView.ViewHolder>();
	Set<RecyclerView.ViewHolder> mMoveFinished = new HashSet<RecyclerView.ViewHolder>();
	Set<RecyclerView.ViewHolder> mChangeFinished = new HashSet<RecyclerView.ViewHolder>();

	Semaphore mExpectedItemCount = new Semaphore(0);

	public DefaultItemAnimatorTest() {
	super("android.support.v7.recyclerview", TestActivity.class);
	}

	@Override
	protected void setUp() throws Exception {
	super.setUp();
	mAnimator = new DefaultItemAnimator();
	mAdapter = new Adapter(20);
	mDummyParent = getActivity().mContainer;
	mAnimator.setListener(new RecyclerView.ItemAnimator.ItemAnimatorListener() {
	@Override
	public void onRemoveFinished(RecyclerView.ViewHolder item) {
	try {
	assertTrue(mRemoveFinished.add(item));
	onFinished(item);
	} catch (Throwable t) {
	postExceptionToInstrumentation(t);
	}
	}

	@Override
	public void onAddFinished(RecyclerView.ViewHolder item) {
	try {
	assertTrue(mAddFinished.add(item));
	onFinished(item);
	} catch (Throwable t) {
	postExceptionToInstrumentation(t);
	}
	}

	@Override
	public void onMoveFinished(RecyclerView.ViewHolder item) {
	try {
	assertTrue(mMoveFinished.add(item));
	onFinished(item);
	} catch (Throwable t) {
	postExceptionToInstrumentation(t);
	}
	}

	@Override
	public void onChangeFinished(RecyclerView.ViewHolder item) {
	try {
	assertTrue(mChangeFinished.add(item));
	onFinished(item);
	} catch (Throwable t) {
	postExceptionToInstrumentation(t);
	}
	}

	private void onFinished(RecyclerView.ViewHolder item) {
	assertNotNull(mExpectedItems.remove(item));
	mExpectedItemCount.release(1);
	}
	});
	}

	void checkForMainThreadException() throws Throwable {
	if (mainThreadException != null) {
	throw mainThreadException;
	}
	}

	@Override
	protected void tearDown() throws Exception {
	getInstrumentation().waitForIdleSync();
	super.tearDown();
	try {
	checkForMainThreadException();
	} catch (Exception e) {
	throw e;
	} catch (Throwable throwable) {
	throw new Exception(throwable);
	}
	}

	void expectItems(RecyclerView.ViewHolder... viewHolders) {
	mExpectedItems.addAll(Arrays.asList(viewHolders));
	}

	void runAndWait(int itemCount, int seconds) throws Throwable {
	runAndWait(itemCount, seconds, null);
	}

	void runAndWait(int itemCount, int seconds, final ThrowingRunnable postRun) throws Throwable {
	runTestOnUiThread(new Runnable() {
	@Override
	public void run() {
	mAnimator.runPendingAnimations();
	if (postRun != null) {
	try {
	postRun.run();
	} catch (Throwable e) {
	throw new RuntimeException(e);
	}
	}
	}
	});
	waitForItems(itemCount, seconds);
	checkForMainThreadException();
	}

	void waitForItems(int itemCount, int seconds) throws InterruptedException {
	assertTrue("all vh animations should end",
	mExpectedItemCount.tryAcquire(itemCount, seconds, TimeUnit.SECONDS));
	assertEquals("all expected finish events should happen", 0, mExpectedItems.size());
	// wait one more second for unwanted
	assertFalse("should not receive any more permits",
	mExpectedItemCount.tryAcquire(1, 2, TimeUnit.SECONDS));
	}

	public void testAnimateAdd() throws Throwable {
	ViewHolder vh = createViewHolder(1);
	expectItems(vh);
	assertTrue(animateAdd(vh));
	assertTrue(mAnimator.isRunning());
	runAndWait(1, 1);
	}

	public void testAnimateRemove() throws Throwable {
	ViewHolder vh = createViewHolder(1);
	expectItems(vh);
	assertTrue(animateRemove(vh));
	assertTrue(mAnimator.isRunning());
	runAndWait(1, 1);
	}

	public void testAnimateMove() throws Throwable {
	ViewHolder vh = createViewHolder(1);
	expectItems(vh);
	assertTrue(animateMove(vh, 0, 0, 100, 100));
	assertTrue(mAnimator.isRunning());
	runAndWait(1, 1);
	}

	public void testAnimateChange() throws Throwable {
	ViewHolder vh = createViewHolder(1);
	ViewHolder vh2 = createViewHolder(2);
	expectItems(vh, vh2);
	assertTrue(animateChange(vh, vh2, 0, 0, 100, 100));
	assertTrue(mAnimator.isRunning());
	runAndWait(2, 1);
	}

	public void cancelBefore(int count, final RecyclerView.ViewHolder... toCancel)
	throws Throwable {
	cancelTest(true, count, toCancel);
	}

	public void cancelAfter(int count, final RecyclerView.ViewHolder... toCancel)
	throws Throwable {
	cancelTest(false, count, toCancel);
	}

	public void cancelTest(boolean before, int count, final RecyclerView.ViewHolder... toCancel) throws Throwable {
	if (before) {
	endAnimations(toCancel);
	runAndWait(count, 1);
	} else {
	runAndWait(count, 1, new ThrowingRunnable() {
	@Override
	public void run() throws Throwable {
	endAnimations(toCancel);
	}
	});
	}
	}

	public void testCancelAddBefore() throws Throwable {
	final ViewHolder vh = createViewHolder(1);
	expectItems(vh);
	assertTrue(animateAdd(vh));
	cancelBefore(1, vh);
	}

	public void testCancelAddAfter() throws Throwable {
	final ViewHolder vh = createViewHolder(1);
	expectItems(vh);
	assertTrue(animateAdd(vh));
	cancelAfter(1, vh);
	}

	public void testCancelMoveBefore() throws Throwable {
	ViewHolder vh = createViewHolder(1);
	expectItems(vh);
	assertTrue(animateMove(vh, 10, 10, 100, 100));
	cancelBefore(1, vh);
	}

	public void testCancelMoveAfter() throws Throwable {
	ViewHolder vh = createViewHolder(1);
	expectItems(vh);
	assertTrue(animateMove(vh, 10, 10, 100, 100));
	cancelAfter(1, vh);
	}

	public void testCancelRemove() throws Throwable {
	ViewHolder vh = createViewHolder(1);
	expectItems(vh);
	assertTrue(animateRemove(vh));
	endAnimations(vh);
	runAndWait(1, 1);
	}

	public void testCancelChangeOldBefore() throws Throwable {
	cancelChangeOldTest(true);
	}
	public void testCancelChangeOldAfter() throws Throwable {
	cancelChangeOldTest(false);
	}

	public void cancelChangeOldTest(boolean before) throws Throwable {
	ViewHolder vh = createViewHolder(1);
	ViewHolder vh2 = createViewHolder(1);
	expectItems(vh, vh2);
	assertTrue(animateChange(vh, vh2, 20, 20, 100, 100));
	cancelTest(before, 2, vh);
	}

	public void testCancelChangeNewBefore() throws Throwable {
	cancelChangeNewTest(true);
	}

	public void testCancelChangeNewAfter() throws Throwable {
	cancelChangeNewTest(false);
	}

	public void cancelChangeNewTest(boolean before) throws Throwable {
	ViewHolder vh = createViewHolder(1);
	ViewHolder vh2 = createViewHolder(1);
	expectItems(vh, vh2);
	assertTrue(animateChange(vh, vh2, 20, 20, 100, 100));
	cancelTest(before, 2, vh2);
	}

	public void testCancelChangeBothBefore() throws Throwable {
	cancelChangeBothTest(true);
	}

	public void testCancelChangeBothAfter() throws Throwable {
	cancelChangeBothTest(false);
	}

	public void cancelChangeBothTest(boolean before) throws Throwable {
	ViewHolder vh = createViewHolder(1);
	ViewHolder vh2 = createViewHolder(1);
	expectItems(vh, vh2);
	assertTrue(animateChange(vh, vh2, 20, 20, 100, 100));
	cancelTest(before, 2, vh, vh2);
	}

	void endAnimations(final RecyclerView.ViewHolder... vhs) throws Throwable {
	runTestOnUiThread(new Runnable() {
	@Override
	public void run() {
	for (RecyclerView.ViewHolder vh : vhs) {
	mAnimator.endAnimation(vh);
	}
	}
	});
	}

	boolean animateAdd(final RecyclerView.ViewHolder vh) throws Throwable {
	final boolean[] result = new boolean[1];
	runTestOnUiThread(new Runnable() {
	@Override
	public void run() {
	result[0] = mAnimator.animateAdd(vh);
	}
	});
	return result[0];
	}

	boolean animateRemove(final RecyclerView.ViewHolder vh) throws Throwable {
	final boolean[] result = new boolean[1];
	runTestOnUiThread(new Runnable() {
	@Override
	public void run() {
	result[0] = mAnimator.animateRemove(vh);
	}
	});
	return result[0];
	}

	boolean animateMove(final RecyclerView.ViewHolder vh, final int fromX, final int fromY,
	final int toX, final int toY) throws Throwable {
	final boolean[] result = new boolean[1];
	runTestOnUiThread(new Runnable() {
	@Override
	public void run() {
	result[0] = mAnimator.animateMove(vh, fromX, fromY, toX, toY);
	}
	});
	return result[0];
	}

	boolean animateChange(final RecyclerView.ViewHolder oldHolder,
	final RecyclerView.ViewHolder newHolder,
	final int fromX, final int fromY, final int toX, final int toY) throws Throwable {
	final boolean[] result = new boolean[1];
	runTestOnUiThread(new Runnable() {
	@Override
	public void run() {
	result[0] = mAnimator.animateChange(oldHolder, newHolder, fromX, fromY, toX, toY);
	}
	});
	return result[0];
	}

	private ViewHolder createViewHolder(final int pos) throws Throwable {
	final ViewHolder vh = mAdapter.createViewHolder(mDummyParent, 1);
	runTestOnUiThread(new Runnable() {
	@Override
	public void run() {
	mAdapter.bindViewHolder(vh, pos);
	mDummyParent.addView(vh.itemView);
	}
	});

	return vh;
	}

	void postExceptionToInstrumentation(Throwable t) {
	if (mainThreadException == null) {
	mainThreadException = t;
	} else {
	Log.e(TAG, "skipping secondary main thread exception", t);
	}
	}


	private class Adapter extends RecyclerView.Adapter<ViewHolder> {

	List<String> mItems;

	private Adapter(int count) {
	mItems = new ArrayList<String>();
	for (int i = 0; i < count; i++) {
	mItems.add("item-" + i);
	}
	}

	@Override
	public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
	return new ViewHolder(new TextView(parent.getContext()));
	}

	@Override
	public void onBindViewHolder(ViewHolder holder, int position) {
	holder.bind(mItems.get(position));
	}

	@Override
	public int getItemCount() {
	return mItems.size();
	}
	}

	private class ViewHolder extends RecyclerView.ViewHolder {

	String mBindedText;

	public ViewHolder(View itemView) {
	super(itemView);
	}

	public void bind(String text) {
	mBindedText = text;
	((TextView) itemView).setText(text);
	}
	}

	private interface ThrowingRunnable {
	public void run() throws Throwable;
	}

	@Override
	public void runTestOnUiThread(Runnable r) throws Throwable {
	if (Looper.myLooper() == Looper.getMainLooper()) {
	r.run();
	} else {
	super.runTestOnUiThread(r);
	}
	}
	}