Detect animation finish in Android's RecyclerView

Question

The RecyclerView, unlike to ListView, doesn\'t have a simple way to set an empty view to it, so one has to manage it manually, making empty view vi

Answer 1

There is a method in the ItemAnimator class that is called when all item animations are finished:

    /**
     * Method which returns whether there are any item animations currently running.
     * This method can be used to determine whether to delay other actions until
     * animations end.
     *
     * @return true if there are any item animations currently running, false otherwise.
     */
     public abstract boolean isRunning();

You can override it to detect when all item animations have ended:

recyclerView.itemAnimator = object : DefaultItemAnimator() {
    override fun isRunning(): Boolean {
        val isAnimationRunning = super.isRunning()
        if(!isAnimationRunning) {
            // YOUR CODE
        }
        return isAnimationRunning
    }
}

Answer 2

Extending Roman Petrenko's answer, if you are using androidx recycler view with kotlin, you can do something like that:

        taskListRecycler.apply {
            itemAnimator = object : DefaultItemAnimator() {
                override fun onAddFinished(item: RecyclerView.ViewHolder?) {
                    super.onAddFinished(item)
                    //Extend
                }

                override fun onRemoveFinished(item: RecyclerView.ViewHolder?) {
                    super.onRemoveFinished(item)
                    //Extend
                }
            }
            layoutManager = LinearLayoutManager(context)
            adapter = taskListAdapter
        }

Answer 3

Currently the only working way I've found to solve this problem is to extend ItemAnimator and pass it to RecyclerView like this:

recyclerView.setItemAnimator(new DefaultItemAnimator() {
    @Override
    public void onAnimationFinished(RecyclerView.ViewHolder viewHolder) {
        updateEmptyView();
    }
});

But this technique is not universal, because I have to extend from concrete ItemAnimator implementation being used by RecyclerView. In case of private inner CoolItemAnimator inside CoolRecyclerView, my method will not work at all.

---

PS: My colleague suggested to wrap ItemAnimator inside the decorator in a following manner:

recyclerView.setItemAnimator(new ListenableItemAnimator(recyclerView.getItemAnimator()));

It would be nice, despite seems like overkill for a such trivial task, but creating the decorator in this case is not possible anyway, because ItemAnimator has a method setListener() which is package protected so I obviously can't wrap it, as well as several final methods.