Android-Spinner

package com.cs.dxm.basicview6;

import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    String[] presidents;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });
        presidents =
                getResources().getStringArray(R.array.presidents_array);
        Spinner s1 = (Spinner) findViewById(R.id.spinner1);
        ArrayAdapter adapter = new ArrayAdapter(this,
                android.R.layout.simple_list_item_single_choice, presidents);

        s1.setAdapter(adapter);
        s1.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView parent, View view, int position, long id) {
                int index = parent.getSelectedItemPosition();
                Toast.makeText(getBaseContext(),
                        "You have selected item : " + presidents[index],
                        Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onNothingSelected(AdapterView parent) {

            }
        });

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

/*****************************************************************/

/**********************************************************************/

    BasicView5
    Settings
    
        Dwight D. Eisenhower
        John F. Kennedy
        Lyndon B. Johnson
        Richard Nixon
        Gerald Ford
        Jimmy Carter
        Ronald Reagan
        George H. W. Bush
        Bill Clinton
        George W. Bush
        Barack Obama