How do I animate the RecyclerView
when the items appear for first time and also when the user scrolls, just like the way it works for the google plus app or the
Without any outside libraries in RecycleView.Adapter on method onBindViewHolder use animation like in example:
if (position>lastAnimatedPosition) {
//set init transitionY to animate from it
holder.itemView.setTranslationY(holder.itemView.getHeight());
//animate to orginal position
holder.itemView.animate().translationYBy(- holder.itemView.getHeight()).start();
lastAnimatedPosition=position;
}
Above code will animate from bottom every row in list. Animation will be done only once, but onBindViewHolder is running on scrolling so first scrolling of list will be with animation effect.
Very important is to initialise view to start of animation, so in example i set:
holder.itemView.setTranslationY( + Y change);
then animation go backs to orginal position:
holder.itemView.animate().translationYBy(- Y change).start();
If you need alpha do this that way:
holder.itemView.setAlpha(0);
holder.itemView.animate().apha(1).start();
I did it this way. Might help someone. I don't know whether it's the best way to do it but works fine for me.
UPDATE:
To fix fast scrolling behaviour, override onViewDetachedFromWindow
method of the adapter and call clearAnimation
on the animated view (in this case, holder.itemView.clearAnimation()
).Like this:
@Override
public void onViewDetachedFromWindow(@NonNull ViewHolder holder) {
super.onViewDetachedFromWindow(holder);
holder.itemView.clearAnimation();
}
up_from_bottom.xml
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
android:shareInterpolator="@android:anim/decelerate_interpolator">
<translate
android:fromXDelta="0%" android:toXDelta="0%"
android:fromYDelta="100%" android:toYDelta="0%"
android:duration="400" />
</set>
down_from_top.xml
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
android:shareInterpolator="@android:anim/decelerate_interpolator">
<translate
android:fromXDelta="0%" android:toXDelta="0%"
android:fromYDelta="-100%" android:toYDelta="0%"
android:duration="400" />
</set>
And finally put this code in onBindViewHolder
of recyclerView
. Create a field called lastPosition and initialize it to -1.
Animation animation = AnimationUtils.loadAnimation(context,
(position > lastPosition) ? R.anim.up_from_bottom
: R.anim.down_from_top);
holder.itemView.startAnimation(animation);
lastPosition = position;
https://github.com/wasabeef/recyclerview-animators
In my code is something like this:
import jp.wasabeef.recyclerview.animators.adapters.AlphaInAnimationAdapter;
....
public function populate() {
// Get your recicleview
rv = (RecyclerView)findViewById(R.id.rv);
rv.setHasFixedSize(true);
// Populate your cursor with your own method...
Cursor myRecycleItems= null;
myRecycleItems= mDbHelper.getItems();
//create your
itemsAdapter= new ItemsAdapter(myRecycleItems, getApplicationContext());
//Finnaly apply your adapter to RV with AlphaInAnimationAdapter:
rv.setAdapter(new AlphaInAnimationAdapter(itemsAdapter));
}
You need to add dependencies to your gradle
dependencies {
// jCenter
......
your curent dependencies
....
compile 'jp.wasabeef:recyclerview-animators:2.0.0'
}
Read teh doc form https://github.com/wasabeef/recyclerview-animators to install it.
For down_from_top.xml it should be
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
android:shareInterpolator="@android:anim/decelerate_interpolator">
<translate
android:fromXDelta="0%" android:toXDelta="0%"
android:fromYDelta="-100%" android:toYDelta="0%"
android:duration="400" />
</set>