Android - Add UNDO SnackBar to Swipe to delete

Question

I have successfully implemented the swipe to delete action within my recyclerView.

The list I inflate the recyclerView with is locally stored and isn't in any database.

What I tried to do is to save the element to a temporary variable and if the user presses the undo button, I would restore it.

This is my code:

override fun onSwiped(viewHolder: RecyclerView.ViewHolder, direction: Int) {

                    val position = viewHolder.adapterPosition //get position which is swipe

                    if (direction == ItemTouchHelper.LEFT) {  //if swipe left
                        val tmp = activeSubs[position] //temporary variable
                        activeSubs.removeAt(position)
                        adapter!!.removeItem(position)

                        val layout = find<View>(R.id.active_subs_recycler)
                        Snackbar.make(layout, "Subscription Deleted", Snackbar.LENGTH_LONG)
                                .setAction("Undo", { _ ->
                                    activeSubs.add(position-1, tmp)
                                    adapter!!.notifyDataSetChanged()
                                })
                    }
                }

My problem is that the SnackBar isn't shown at all, but the element is saved in the temporary variable and deleted from the list.

What am I doing wrong?

P.S. I've looked into other answers here on SO but they suggested to use a Dialog. I really need to use a Snackbar though

Answer 1

After setAction you forgot to call .show() so your code will be like this:

 Snackbar.make(layout, "Subscription Deleted", Snackbar.LENGTH_LONG)
                                .setAction("Undo", { _ ->
                                    activeSubs.add(position-1, tmp)
                                    adapter!!.notifyDataSetChanged()
                                })
.show()

For example, I have achieved your goal using this scenario. In Main Activity

 tvTitle.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                tempValue = etUsername.getText().toString();
                etUsername.setText("");
                Snackbar.make(view, "Subscription Deleted", Snackbar.LENGTH_LONG)
                        .setAction("Undo", new editTextListener())
                .show();
            }
        });

Used inner class for listener:

private class editTextListener implements View.OnClickListener {
        @Override
        public void onClick(View view) {
            etUsername.setText(tempValue);
        }
    }