ItemAnimator for RecyclerView that animates changes between 2 states, edit and standard which is useful for multi select using check boxes. In edit mode a checkBox slides in from the left and an icon slides off screen to the right. In between an avatar and name view must adjust their positions. All 4 views are in a horizontal LinearLayout with w…

MultiSelectItemAnimator.java

public class MultiSelectItemAnimator extends DefaultItemAnimator {

    private static final long DURATION = 150;

    private final ArrayMap<RecyclerView.ViewHolder, AnimatorInfo> animatorMap = new ArrayMap<>();
    private final Animator.AnimatorListener resetListener = new ViewObjectAnimatorListener() {
        @Override
        public void onAnimationEnd(Animator animation, View view) {
            view.setTranslationX(0f);
        }
    };

    private final Animator.AnimatorListener hideListener = new ViewObjectAnimatorListener() {
        @Override
        public void onAnimationEnd(Animator animation, View view) {
            view.setVisibility(View.GONE);
            view.setTranslationX(0f);
        }

        @Override
        public void onAnimationStart(Animator animation, View view) {
            view.setVisibility(View.VISIBLE);
        }

        @Override
        public void onAnimationCancel(Animator animation, View view) {
            view.setTranslationX(0f);
            // Prevent onAnimationEnd being called which would hide the view
            animation.removeListener(this);
        }
    };

    @Override
    public boolean canReuseUpdatedViewHolder(@NonNull RecyclerView.ViewHolder viewHolder) {
        return viewHolder instanceof SelectableViewHolder;
    }

    @NonNull
    @Override
    public ItemHolderInfo recordPreLayoutInformation(@NonNull RecyclerView.State state,
                                                     @NonNull RecyclerView.ViewHolder viewHolder,
                                                     int changeFlags,
                                                     @NonNull List<Object> payloads
                                                    ) {
        MyItemHolderInfo info = (MyItemHolderInfo) super.recordPreLayoutInformation(state,
                                                                                    viewHolder,
                                                                                    changeFlags,
                                                                                    payloads
                                                                                   );
        if (viewHolder instanceof SelectableViewHolder) {
            info.inEdit = ((SelectableViewHolder) viewHolder).inEdit;
        }
        return info;
    }

    @NonNull
    @Override
    public ItemHolderInfo recordPostLayoutInformation(@NonNull RecyclerView.State state,
                                                      @NonNull RecyclerView.ViewHolder viewHolder
                                                     ) {
        MyItemHolderInfo info = (MyItemHolderInfo) super.recordPostLayoutInformation(state, viewHolder);
        if (viewHolder instanceof SelectableViewHolder) {
            info.inEdit = ((SelectableViewHolder) viewHolder).inEdit;
        }
        return info;
    }

    @Override
    public ItemHolderInfo obtainHolderInfo() {
        return new MyItemHolderInfo();
    }

    private static class MyItemHolderInfo extends ItemHolderInfo {
        boolean inEdit;
    }

    @Override
    public boolean animateChange(@NonNull final RecyclerView.ViewHolder oldHolder,
                                 @NonNull final RecyclerView.ViewHolder newHolder,
                                 @NonNull ItemHolderInfo preInfo, @NonNull ItemHolderInfo postInfo
                                ) {
        MyItemHolderInfo oldInfo = (MyItemHolderInfo) preInfo;
        MyItemHolderInfo newInfo = (MyItemHolderInfo) postInfo;
        if (oldHolder != newHolder || !(oldHolder instanceof SelectableViewHolder) || oldInfo.inEdit == newInfo.inEdit) {
            dispatchAnimationFinished(oldHolder);
            dispatchAnimationFinished(newHolder);
            return false;
        }
        final SelectableViewHolder viewHolder = (SelectableViewHolder) newHolder;

        long prevAnimPlayTime = 0;
        AnimatorInfo oldAnim = animatorMap.get(viewHolder);
        if (oldAnim != null) {
            prevAnimPlayTime = oldAnim.checkBoxAnim.getCurrentPlayTime();
            oldAnim.overallAnim.cancel();
        }

        ObjectAnimator checkBoxAnim;
        ObjectAnimator avatarAnim;
        ObjectAnimator nameAnim;
        ObjectAnimator iconAnim;
        int distance = viewHolder.checkBox.getWidth();
        if (newInfo.inEdit) {
            checkBoxAnim = translateX(viewHolder.checkBox, -distance, 0, resetListener, prevAnimPlayTime);
            avatarAnim = translateX(viewHolder.avatarView, -distance, 0, resetListener, prevAnimPlayTime);
            nameAnim = translateX(viewHolder.nameView, -distance, 0, resetListener, prevAnimPlayTime);
            iconAnim = translateX(viewHolder.iconView, 0, distance, hideListener, prevAnimPlayTime);
        } else {
            checkBoxAnim = translateX(viewHolder.checkBox, 0, -distance, hideListener, prevAnimPlayTime);
            avatarAnim = translateX(viewHolder.avatarView, 0, -distance, resetListener, prevAnimPlayTime);
            nameAnim = translateX(viewHolder.nameView, 0, -distance, resetListener, prevAnimPlayTime);
            iconAnim = translateX(viewHolder.iconView, distance, 0, resetListener, prevAnimPlayTime);
        }

        AnimatorSet overallAnim = new AnimatorSet();
        overallAnim.playTogether(checkBoxAnim, avatarAnim, nameAnim, iconAnim);
        overallAnim.addListener(new AnimatorListenerAdapter() {
            @Override
            public void onAnimationEnd(Animator animation) {
                dispatchAnimationFinished(viewHolder);
                animatorMap.remove(viewHolder);
            }
        });
        overallAnim.start();
        animatorMap.put(viewHolder, new AnimatorInfo(overallAnim, checkBoxAnim));
        return true;
    }

    private ObjectAnimator translateX(View view,
                                      int from,
                                      int to,
                                      Animator.AnimatorListener listener,
                                      long prevAnimPlayTime
                                     ) {
        ObjectAnimator anim = ObjectAnimator.ofFloat(view, "translationX", (float) from, (float) to);
        anim.addListener(listener);
        anim.setDuration(DURATION);
        if (prevAnimPlayTime > 0) {
            anim.setCurrentPlayTime(DURATION - prevAnimPlayTime);
        }
        return anim;
    }

    @Override
    public void endAnimation(RecyclerView.ViewHolder item) {
        super.endAnimation(item);
        if (animatorMap.containsKey(item)) {
            animatorMap.remove(item).overallAnim.cancel();
            dispatchAnimationFinished(item);
        }
    }

    @Override
    public boolean isRunning() {
        return super.isRunning() || !animatorMap.isEmpty();
    }

    @Override
    public void endAnimations() {
        super.endAnimations();
        if (!animatorMap.isEmpty()) {
            final int numRunning = animatorMap.size();
            for (int i = numRunning; i >= 0; i--) {
                animatorMap.valueAt(i).overallAnim
                        .cancel();
                dispatchAnimationFinished(animatorMap.keyAt(i));
            }
            animatorMap.clear();
        }
    }

    private static class AnimatorInfo {
        Animator overallAnim;
        ObjectAnimator checkBoxAnim;

        AnimatorInfo(Animator overallAnim, ObjectAnimator checkBoxAnim) {
            this.overallAnim = overallAnim;
            this.checkBoxAnim = checkBoxAnim;
        }
    }
}

ViewObjectAnimatorListener.java

public class ViewObjectAnimatorListener extends AnimatorListenerAdapter {

    @Override
    public void onAnimationCancel(Animator animation) {
        View target = (View) ((ObjectAnimator) animation).getTarget();
        if (target != null) {
            onAnimationCancel(animation, target);
        }
    }

    public void onAnimationCancel(Animator animation, View view) {
    }

    @Override
    public void onAnimationEnd(Animator animation) {
        View target = (View) ((ObjectAnimator) animation).getTarget();
        if (target != null) {
            onAnimationEnd(animation, target);
        }
    }

    public void onAnimationEnd(Animator animation, View view) {
    }

    @Override
    public void onAnimationRepeat(Animator animation) {
        View target = (View) ((ObjectAnimator) animation).getTarget();
        if (target != null) {
            onAnimationRepeat(animation, target);
        }
    }

    public void onAnimationRepeat(Animator animation, View view) {
    }

    @Override
    public void onAnimationStart(Animator animation) {
        View target = (View) ((ObjectAnimator) animation).getTarget();
        if (target != null) {
            onAnimationStart(animation, target);
        }
    }

    public void onAnimationStart(Animator animation, View view) {
    }

    @Override
    public void onAnimationPause(Animator animation) {
        View target = (View) ((ObjectAnimator) animation).getTarget();
        if (target != null) {
            onAnimationPause(animation, target);
        }
    }

    public void onAnimationPause(Animator animation, View view) {
    }

    @Override
    public void onAnimationResume(Animator animation) {
        View target = (View) ((ObjectAnimator) animation).getTarget();
        if (target != null) {
            onAnimationResume(animation, target);
        }
    }

    public void onAnimationResume(Animator animation, View view) {
    }
}