how to highlight the selected Item of Recycler View?

Question

I have a Recycler View with the Images loaded from the Internal Storage. I want to Highlight the selected item when clicked. I tried a lot of thing but it was not working. A

Answer 1

I have tried several ways for hours and here is the two solutions I came out with. Both solutions assume I have my RecyclerView declared as follows:

activity.xml

Nothing special here, just a regular RecyclerView declaration. Now let's see the other files, starting with the most easy and viable solution.

First solution (XML only)

layout/item.xml

The two important attributes here in the item's root ViewGroup are background and clickable.

    ...

drawable/selector_item.xml

Second solution (XML + Java)

item.xml

No background nor clickable attribute here.

    ...

Adapter.java

public class Adapter extends RecyclerView.Adapter {
    public class ViewHolder extends RecyclerView.ViewHolder {
        public ViewHolder(View itemView) {
            super(itemView);

            itemView.setOnTouchListener(itemTouchListener);
        }
    }

    ...
    private View.OnTouchListener itemTouchListener = new View.OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            switch (event.getAction()) {
                case MotionEvent.ACTION_DOWN:
                    v.setBackgroundResource(R.drawable.background_item_event_pressed);
                    break;
                case MotionEvent.ACTION_CANCEL:
                    // CANCEL triggers when you press the view for too long
                    // It prevents UP to trigger which makes the 'pressed' background permanent which isn't what we want
                case MotionEvent.ACTION_OUTSIDE:
                    // OUTSIDE triggers when the user's finger moves out of the view
                case MotionEvent.ACTION_UP:
                    v.setBackgroundResource(R.drawable.background_item_event);
                    break;
                default:
                    break;
            }

            return true;
        }
    };

    ...
}

I highly recommend using the first solution as it's easier to maintain and more powerful as it also allows you to add ripple effects (in the drawable/background_item... XML files), which I believe isn't possible with solution 2.