How to display progressbar while load data and fill into recyclerview?

Question

I want display progress bar in activity while loading data and when loading complete, progress bar to be hide (GONE)! and try this code : (button click to load data)

private void allMoment() {
    BTN_ALL.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            try {
                TBL_MOMENT = new TableMoment(DB_HELPER);
             //   MOMENTS = TBL_MOMENT.MOMENT_LIST();
                new loadTask().execute();
                filterResult();
                EDT_SEARCH.setText("");
            } catch (Exception e) {
                displaySnackBar(v, "خطا:" + "\n" + e.toString());
            }
        }
    });
}

and Task method :

private class loadTask extends AsyncTask<String, Integer, Boolean> {
    @Override
    protected void onPreExecute() {
        PROGRESS_LOADER.setVisibility(View.VISIBLE);
        super.onPreExecute();
    }

    @Override
    protected void onPostExecute(Boolean result) {
        PROGRESS_LOADER.setVisibility(View.GONE);
        adapter.notifyDataSetChanged();
        super.onPostExecute(result);
    }

    @Override
    protected Boolean doInBackground(String... params) {
        MOMENTS = TBL_MOMENT.MOMENT_LIST();
        try {
            Thread.sleep(3000);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
}

and fill recycler with dapter :

private void filterResult() {
    try {
        adapter = new HistoryAdapter(this, MOMENTS);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));
        recyclerView.setItemAnimator(new DefaultItemAnimator());
        recyclerView.setAdapter(adapter);
    } catch (Exception e) {
        displayToast(this, "خطای آداپتر:" + "\n" + e.toString());
    }
}

but data become load and fill into recyclerview and don't show progress bar how to fix this problem ?

Answer 1

You have :

 new loadTask().execute();
 filterResult();
 EDT_SEARCH.setText("");

This execute() call returns inmediatly, if you execute an AsyncTask waiting for a result you don't have a result until AsyncTask.doInBackground() returns and AsyncTask.onPostExecuted() is called

Is this filterResult(); time consuming ? ... if the main UI thread is blocked then the UI will be not updated.