Fragment transition with shared element supporting API 14+ example/tutorial

Now (27.0.0 support library) fragment can use support library versions of Transition for fragment transitions, including shared-element transitions.
https://developer.android.com/topic/libraries/support-library/revisions.html#27-0-0

Support android.transition classes provide transition API back to android API level 14.
https://developer.android.com/reference/android/support/transition/package-summary.html

Inspired by: Fragment Tricks (Google I/O ’17).

So let’s start with the build.gradle (support library 27.0.0+) :

implementation 'com.android.support:appcompat-v7:27.0.1'
implementation 'com.android.support:design:27.0.1'
implementation 'com.android.support.constraint:constraint-layout:1.0.2'

MainActivity XML:

...
 <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
                 android:id="@+id/fragment_container"
                 android:layout_width="match_parent"
                 android:layout_height="match_parent" />
...

MainActivity code:

public class MainActivity extends AppCompatActivity 
        implements MainFragment.MainFragmentInteraction {
  @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        setToolBarAndNavigation(); // Unrelated to our example

        if (savedInstanceState == null) {
            getSupportFragmentManager()
                    .beginTransaction()
                    .add(R.id.fragment_container, new MainFragment()).commit();
        }
    }

    //MainFragment.MainFragmentInteraction interface
    @Override
    public void onBtnClick(ImageView imageView) {
        FragmentManager fragmentManager = getSupportFragmentManager();
        MainFragment mainFragment = (MainFragment) fragmentManager
                .findFragmentById(R.id.fragment_container);
        mainFragment.setExitTransition(new Fade().setDuration(200));

        ArticleFragment articleFragment = new ArticleFragment();
        articleFragment.setSharedElementEnterTransition(
                new MyTransition().setDuration(700).setStartDelay(0));
        articleFragment.setSharedElementReturnTransition(
                new MyTransition().setDuration(400).setStartDelay(200));

        articleFragment.setEnterTransition(new Fade().setDuration(500));
        articleFragment.setEnterTransition(new Fade().setDuration(500));
        articleFragment.setExitTransition(new Fade().setDuration(100));

        fragmentManager.beginTransaction()
                .addSharedElement(imageView, ViewCompat.getTransitionName(imageView))
                .replace(R.id.fragment_container, articleFragment)
                .addToBackStack("TAG")
                .setReorderingAllowed(true) // Need for transition element
                .commit();
    }
}

MainFragment XML:

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ImageView
        android:id="@+id/imageViewA"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:layout_marginTop="70dp"
        android:contentDescription="desc"
        android:transitionName="@string/image_transition_name"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:srcCompat="@mipmap/ic_launcher"/>

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"/>

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginStart="8dp"
        android:text="Main Fragment"
        app:layout_constraintBottom_toTopOf="@+id/button"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"/>

</android.support.constraint.ConstraintLayout>

MainFragment code:

public class MainFragment extends Fragment {

    private MainFragmentInteraction mListener;
    private ImageView mImageView;

    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, 
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_main, container, false);
        mImageView = rootView.findViewById(R.id.imageViewA);
        rootView.findViewById(R.id.button).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                mListener.onBtnClick(mImageView);
            }
        });
        return rootView;
    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        if (context instanceof MainFragmentInteraction) {
            mListener = (MainFragmentInteraction) context;
        } else {
            throw new ClassCastException(context.toString() 
                    + " must implement MainFragmentInteraction");
        }
    }

    @Override
    public void onDetach() {
        super.onDetach();
        mListener = null;
    }

    public interface MainFragmentInteraction {
        void onBtnClick(ImageView view);
    }
}

ArticleFragment XML

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ImageView
        android:id="@+id/imageViewB"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_marginBottom="150dp"
        android:layout_marginEnd="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:transitionName="@string/image_transition_name"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:srcCompat="@mipmap/ic_launcher"/>

</android.support.constraint.ConstraintLayout>

ArticleFragment code:

public class ArticleFragment extends Fragment {
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, 
            Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_article, container, false);
    }
}

strings.xml

 <string name="image_transition_name">image_transition</string>