How to hide an item from Recycler View on a particular condition?

Dhaval picture Dhaval · Dec 19, 2016 · Viewed 63.3k times · Source

I am using Firebase Recycler Adapter (Firebase UI Library) to populate Recycler View. I want to hide an item(row) on a condition. I have a LinearLayout containing a recycler view.

I set linear layout visibility to Gone in populateViewHolder() method of recycler view adapter.

@Override
protected void populateViewHolder(UsersViewHolder viewHolder, User user, int position) {

    if (user.getUserEmail().equals(Utils.decodeEmail(userEmail))) {
        viewHolder.llMain.setVisibility(View.GONE);
        return;
    }

    viewHolder.tvUserEmail.setText(user.getUserEmail());
}

It hides the LinearLayout but the row remains there with empty space.

Is there any method I should override to overcome this or is there any way to achieve the result?

Answer

incognito picture incognito · Sep 21, 2017

In some cases changing only visibility attribute might still end up as allocated blank space (because of parent view's padding, margins, inner elements etc). Then changing height of the parent view helps:

holder.itemView.setVisibility(View.GONE); 
holder.itemView.setLayoutParams(new RecyclerView.LayoutParams(0, 0));

Then be sure that in the condition that it should be visible, also set:

holder.itemView.setVisibility(View.VISIBLE);
holder.itemView.setLayoutParams(new RecyclerView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT));

You need to do that because the viewHolder is recycled as you scroll, if you change properties as this and never return them to their natural state, other elements will be already hidden in the event they reuse the same view.