How to animate RecyclerView items when they appear

问题:

How can I animate the RecyclerView Items when there are appearing?

The default item animator only animates when a data is added or removed after the recycler data has been set. I\'m new developing applications and don\'t have any clue where to start.

Any ideas how to achieve this?

回答1:

EDIT :

According to the ItemAnimator documentation :

This class defines the animations that take place on items as changes are made to the adapter.

So unless you add your items one by one to your RecyclerView and refresh the view at each iteration, I don\'t think ItemAnimator is the solution to your need.

Here is how you can animate the RecyclerView items when they appear using a CustomAdapter :

public class CustomAdapter extends RecyclerView.Adapter<CustomAdapter.ViewHolder>
{
    private Context context;

    // The items to display in your RecyclerView
    private ArrayList<String> items;
    // Allows to remember the last item shown on screen
    private int lastPosition = -1;

    public static class ViewHolder extends RecyclerView.ViewHolder
    {
        TextView text;
        // You need to retrieve the container (ie the root ViewGroup from your custom_item_layout)
        // It\'s the view that will be animated
        FrameLayout container;

        public ViewHolder(View itemView)
        {
            super(itemView);
            container = (FrameLayout) itemView.findViewById(R.id.item_layout_container);
            text = (TextView) itemView.findViewById(R.id.item_layout_text);
        }
    }

    public CustomAdapter(ArrayList<String> items, Context context)
    {
        this.items = items;
        this.context = context;
    }

    @Override
    public CustomAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType)
    {
        View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.custom_item_layout, parent, false);
        return new ViewHolder(v);
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, int position)
    {
        holder.text.setText(items.get(position));

        // Here you apply the animation when the view is bound
        setAnimation(holder.itemView, position);
    }

    /**
     * Here is the key method to apply the animation
     */
    private void setAnimation(View viewToAnimate, int position)
    {
        // If the bound view wasn\'t previously displayed on screen, it\'s animated
        if (position > lastPosition)
        {
            Animation animation = AnimationUtils.loadAnimation(context, android.R.anim.slide_in_left);
            viewToAnimate.startAnimation(animation);
            lastPosition = position;
        }
    }
}

And your custom_item_layout would look like this :

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

    <TextView
        android:id=\"@+id/item_layout_text\"
        android:layout_width=\"match_parent\"
        android:layout_height=\"wrap_content\"
        android:textAppearance=\"?android:attr/textAppearanceListItemSmall\"
        android:gravity=\"center_vertical\"
        android:minHeight=\"?android:attr/listPreferredItemHeightSmall\"/>

</FrameLayout>

For more information about CustomAdapters and RecyclerView, refer to this training on the official documentation.

Problems on fast scroll

Using this method could cause problems with fast scrolling. The view could be reused while the animation is been happening. In order to avoid that is recommendable to clear the animation when is detached.

    @Override
    public void onViewDetachedFromWindow(final RecyclerView.ViewHolder holder)
    {
        ((CustomViewHolder)holder).clearAnimation();
    }

On CustomViewHolder:

    public void clearAnimation()
    {
        mRootLayout.clearAnimation();
    }

Old answer :

Give a look at Gabriele Mariotti\'s repo, I\'m pretty sure you\'ll find what you need. He provides simple ItemAnimators for the RecyclerView, such as SlideInItemAnimator or SlideScaleItemAnimator.

回答2:

I animated fading in of Recyclerview items when they first appear as shown in the code below. Perhaps this will be of use to someone.

private final static int FADE_DURATION = 1000; //FADE_DURATION in milliseconds

@Override
public void onBindViewHolder(ViewHolder holder, int position) {

    holder.getTextView().setText(\"some text\");

    // Set the view to fade in
    setFadeAnimation(holder.itemView);            
}

private void setFadeAnimation(View view) {
    AlphaAnimation anim = new AlphaAnimation(0.0f, 1.0f);
    anim.setDuration(FADE_DURATION);
    view.startAnimation(anim);
}

You can also replace setFadeAnimation() with the following setScaleAnimation() to animate appearance of items by scaling them from a point:

private void setScaleAnimation(View view) {
    ScaleAnimation anim = new ScaleAnimation(0.0f, 1.0f, 0.0f, 1.0f, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);
    anim.setDuration(FADE_DURATION);
    view.startAnimation(anim);
}

The code above has some warts in so far as when you scroll the RecyclerView items always fade or scale. If you wish you can add code to just allow the animation to happen when the fragment or activity containing the RecyclerView is first created (e.g. get the system time on creation and only allow animation for the first FADE_DURATION milliseconds).

回答3:

I created animation from pbm\'s answer with little modification to make the aninmation run only once

in the other word the Animation appear with you scroll down only

private int lastPosition = -1;

private void setAnimation(View viewToAnimate, int position) {
    // If the bound view wasn\'t previously displayed on screen, it\'s animated
    if (position > lastPosition) {
        ScaleAnimation anim = new ScaleAnimation(0.0f, 1.0f, 0.0f, 1.0f, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);
        anim.setDuration(new Random().nextInt(501));//to make duration random number between [0,501)
        viewToAnimate.startAnimation(anim);
        lastPosition = position;
    }
}

and in onBindViewHolder call the function

@Override
public void onBindViewHolder(ViewHolder holder, int position) {

holder.getTextView().setText(\"some text\");

// call Animation function
setAnimation(holder.itemView, position);            
}

回答4:

You can add a android:layoutAnimation=\"@anim/rv_item_animation\" attribute to RecyclerView like this:

<android.support.v7.widget.RecyclerView
    android:layout_width=\"match_parent\"
    android:layout_height=\"match_parent\"                                        
    android:layoutAnimation=\"@anim/layout_animation_fall_down\"
    />

thanks for the excellent article here: https://proandroiddev.com/enter-animation-using-recyclerview-and-layoutanimation-part-1-list-75a874a5d213

回答5:

A good place to start is this: https://github.com/wasabeef/recyclerview-animators/blob/master/animators/src/main/java/jp/wasabeef/recyclerview/adapters/AnimationAdapter.java

You don\'t even need the full library, that class is enough. Then if you just implement your Adapter class giving an animator like this:

@Override
protected Animator[] getAnimators(View view) {
    return new Animator[]{
            ObjectAnimator.ofFloat(view, \"translationY\", view.getMeasuredHeight(), 0)
    };
}

@Override
public long getItemId(final int position) {
    return getWrappedAdapter().getItemId(position);
}

you\'ll see items appearing from the bottom as they scroll, also avoiding the problem with the fast scroll.

回答6:

Animating items in the recyclerview when they are binded in the adapter might not be the best idea as that can cause the items in the recyclerview to animate at different speeds. In my case, the item at the end of the recyclerview animate to their position quicker then the ones at the top as the ones at the top have further to travel so it made it look untidy.

The original code that I used to animate each item into the recyclerview can be found here:

http://frogermcs.github.io/Instagram-with-Material-Design-concept-is-getting-real/

But I will copy and paste the code in case the link breaks.

STEP 1: Set this inside your onCreate method so that you ensure the animation only run once:

if (savedInstanceState == null) {
    pendingIntroAnimation = true;
}

STEP 2: You will need to put this code into the method where you want to start the animation:

if (pendingIntroAnimation) {
    pendingIntroAnimation = false;
    startIntroAnimation();
}

In the link, the writer is animating the toolbar icons, so he put it inside this method:

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.menu_main, menu);
    inboxMenuItem = menu.findItem(R.id.action_inbox);
    inboxMenuItem.setActionView(R.layout.menu_item_view);
    if (pendingIntroAnimation) {
        pendingIntroAnimation = false;
        startIntroAnimation();
    }
    return true;
}

STEP 3: Now write the logic for the startIntroAnimation():

private static final int ANIM_DURATION_TOOLBAR = 300;

private void startIntroAnimation() {
    btnCreate.setTranslationY(2 * getResources().getDimensionPixelOffset(R.dimen.btn_fab_size));

    int actionbarSize = Utils.dpToPx(56);
    toolbar.setTranslationY(-actionbarSize);
    ivLogo.setTranslationY(-actionbarSize);
    inboxMenuItem.getActionView().setTranslationY(-actionbarSize);

    toolbar.animate()
            .translationY(0)
            .setDuration(ANIM_DURATION_TOOLBAR)
            .setStartDelay(300);
    ivLogo.animate()
            .translationY(0)
            .setDuration(ANIM_DURATION_TOOLBAR)
            .setStartDelay(400);
    inboxMenuItem.getActionView().animate()
            .translationY(0)
            .setDuration(ANIM_DURATION_TOOLBAR)
            .setStartDelay(500)
            .setListener(new AnimatorListenerAdapter() {
                @Override
                public void onAnimationEnd(Animator animation) {
                    startContentAnimation();
                }
            })
            .start();
}

My preferred alternative:

I would rather animate the whole recyclerview instead of the items inside the recyclerview.

STEP 1 and 2 remains the same.

In STEP 3, as soon as your API call returns with your data, I would start the animation.

private void startIntroAnimation() {
    recyclerview.setTranslationY(latestPostRecyclerview.getHeight());
    recyclerview.setAlpha(0f);
    recyclerview.animate()
            .translationY(0)
            .setDuration(400)
            .alpha(1f)
            .setInterpolator(new AccelerateDecelerateInterpolator())
            .start();
}

This would animate your entire recyclerview so that it flys in from the bottom of the screen.

回答7:

Create this method into your recyclerview Adapter

private void setZoomInAnimation(View view) {
        Animation zoomIn = AnimationUtils.loadAnimation(context, R.anim.zoomin);// animation file 
        view.startAnimation(zoomIn);
    }

And finally add this line of code in onBindViewHolder

setZoomInAnimation(holder.itemView);

回答8:

Just extends your Adapter like below

public class RankingAdapter extends AnimatedRecyclerView<RankingAdapter.ViewHolder> 

And add super method to onBindViewHolder

@Override
    public void onBindViewHolder(ViewHolder holder, final int position) {
        super.onBindViewHolder(holder, position);

It\'s automate way to create animated adapter like \"Basheer AL-MOMANI\"

import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.Animation;
import android.view.animation.ScaleAnimation;

import java.util.Random;

/**
 * Created by eliaszkubala on 24.02.2017.
 */
public class AnimatedRecyclerView<T extends RecyclerView.ViewHolder> extends RecyclerView.Adapter<T> {


    @Override
    public T onCreateViewHolder(ViewGroup parent, int viewType) {
        return null;
    }

    @Override
    public void onBindViewHolder(T holder, int position) {
        setAnimation(holder.itemView, position);
    }

    @Override
    public int getItemCount() {
        return 0;
    }

    protected int mLastPosition = -1;

    protected void setAnimation(View viewToAnimate, int position) {
        if (position > mLastPosition) {
            ScaleAnimation anim = new ScaleAnimation(0.0f, 1.0f, 0.0f, 1.0f, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);
            anim.setDuration(new Random().nextInt(501));//to make duration random number between [0,501)
            viewToAnimate.startAnimation(anim);
            mLastPosition = position;
        }
    }

}

回答9:

Add this Line to RecyclerView.xml

android:animateLayoutChanges=\"true\"