# Shared Element Transitions
Here you find examples for transition between Activities
or Fragments
using a shared element. An example for this behaviour is the Google Play Store App which translates an App's icon from the list to the App's details view.
# Shared Element Transition between two Fragments
In this example, one of two different ImageViews
should be translated from the ChooserFragment
to the DetailFragment
.
In the ChooserFragment
layout we need the unique transitionName
attributes:
<ImageView
android:id="@+id/image_first"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/ic_first"
android:transitionName="fistImage" />
<ImageView
android:id="@+id/image_second"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/ic_second"
android:transitionName="secondImage" />
In the ChooserFragments
class, we need to pass the View
which was clicked and an ID to the parent Activity
wich is handling the replacement of the fragments (we need the ID to know which image resource to show in the DetailFragment
). How to pass information to a parent activity in detail is surely covered in another documentation.
view.findViewById(R.id.image_first).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if (mCallback != null) {
mCallback.showDetailFragment(view, 1);
}
}
});
view.findViewById(R.id.image_second).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if (mCallback != null) {
mCallback.showDetailFragment(view, 2);
}
}
});
In the DetailFragment
, the ImageView
of the shared element also needs the unique transitionName
attribute.
<ImageView
android:id="@+id/image_shared"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:transitionName="sharedImage" />
In the onCreateView()
method of the DetailFragment
, we have to decide which image resource should be shown (if we don't do that, the shared element will disappear after the transition).
public static DetailFragment newInstance(Bundle args) {
DetailFragment fragment = new DetailFragment();
fragment.setArguments(args);
return fragment;
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
View view = inflater.inflate(R.layout.fragment_detail, container, false);
ImageView sharedImage = (ImageView) view.findViewById(R.id.image_shared);
// Check which resource should be shown.
int type = getArguments().getInt("type");
// Show image based on the type.
switch (type) {
case 1:
sharedImage.setBackgroundResource(R.drawable.ic_first);
break;
case 2:
sharedImage.setBackgroundResource(R.drawable.ic_second);
break;
}
return view;
}
The parent Activity
is receiving the callbacks and handles the replacement of the fragments.
@Override
public void showDetailFragment(View sharedElement, int type) {
// Get the chooser fragment, which is shown in the moment.
Fragment chooserFragment = getFragmentManager().findFragmentById(R.id.fragment_container);
// Set up the DetailFragment and put the type as argument.
Bundle args = new Bundle();
args.putInt("type", type);
Fragment fragment = DetailFragment.newInstance(args);
// Set up the transaction.
FragmentTransaction transaction = getFragmentManager().beginTransaction();
// Define the shared element transition.
fragment.setSharedElementEnterTransition(new DetailsTransition());
fragment.setSharedElementReturnTransition(new DetailsTransition());
// The rest of the views are just fading in/out.
fragment.setEnterTransition(new Fade());
chooserFragment.setExitTransition(new Fade());
// Now use the image's view and the target transitionName to define the shared element.
transaction.addSharedElement(sharedElement, "sharedImage");
// Replace the fragment.
transaction.replace(R.id.fragment_container, fragment, fragment.getClass().getSimpleName());
// Enable back navigation with shared element transitions.
transaction.addToBackStack(fragment.getClass().getSimpleName());
// Finally press play.
transaction.commit();
}
Not to forget - the Transition
itself. This example moves and scales the shared element.
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
public class DetailsTransition extends TransitionSet {
public DetailsTransition() {
setOrdering(ORDERING_TOGETHER);
addTransition(new ChangeBounds()).
addTransition(new ChangeTransform()).
addTransition(new ChangeImageTransform());
}
}
# Syntax
- transaction.addSharedElement(sharedElementView, "targetTransitionName");
- fragment.setSharedElementEnterTransition(new CustomTransaction());