Classe ListaAlunosActivity

ListaAlunosActivity.java

public class ListaAlunosActivity extends AppCompatActivity {

    private ListView listaAlunos;
    private Aluno aluno;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_lista_alunos);


        //Pegando Refência do XML
        listaAlunos = (ListView) findViewById(R.id.lista_alunos);

        listaAlunos.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> lista, View item, int position, long id) {
                Aluno aluno = (Aluno) listaAlunos.getItemAtPosition(position);

                Intent intentVaiProFormulario = new Intent(ListaAlunosActivity.this, FormularioActivity.class);
                intentVaiProFormulario.putExtra("aluno", aluno);
                startActivity(intentVaiProFormulario);
            }
        });

        Button novoAluno = (Button) findViewById(R.id.novo_aluno);
        novoAluno.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intentVaiProFormulario = new Intent(ListaAlunosActivity.this, FormularioActivity.class);
                startActivity(intentVaiProFormulario);
            }
        });

        registerForContextMenu(listaAlunos);
    }

    private void carregaLista() {
        AlunoDAO dao = new AlunoDAO(this);
        List<Aluno> alunos = dao.buscaAlunos();
        dao.close();


        //convertendo String para View
        ArrayAdapter<Aluno> adapter = new ArrayAdapter<Aluno>(this, android.R.layout.simple_list_item_1, alunos);
        listaAlunos.setAdapter(adapter);
    }

    @Override
    protected void onResume() {
        super.onResume();
        carregaLista();

    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        switch (requestCode) {
            case 123:
                if (ActivityCompat.checkSelfPermission(this, Manifest.permission.CALL_PHONE) == PackageManager.PERMISSION_GRANTED) {
                    if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                        Intent intentLigar = new Intent(Intent.ACTION_CALL);
                        intentLigar.setData(Uri.parse("tel:" + aluno.getTelefone()));
                        startActivity(intentLigar);
                    }
                } else {
                    Toast.makeText(ListaAlunosActivity.this,
                            "A permissão é necessária",
                            Toast.LENGTH_LONG).show();
                }
                break;
        }
    }

    @Override
    public void onCreateContextMenu(ContextMenu menu, View v, final ContextMenu.ContextMenuInfo menuInfo) {

        AdapterView.AdapterContextMenuInfo info = (AdapterView.AdapterContextMenuInfo) menuInfo;
        aluno = (Aluno) listaAlunos.getItemAtPosition(info.position);

        //CALL PHONE
        MenuItem itemLigar = menu.add("Ligar");

        //ouvindo para pedir permissão
        itemLigar.setOnMenuItemClickListener(new MenuItem.OnMenuItemClickListener() {
            @Override
            public boolean onMenuItemClick(MenuItem menuItem) {
                if (ActivityCompat.checkSelfPermission(ListaAlunosActivity.this, Manifest.permission.CALL_PHONE)
                        != PackageManager.PERMISSION_GRANTED) {
                    ActivityCompat.requestPermissions(ListaAlunosActivity.this,
                            new String[]{Manifest.permission.CALL_PHONE}, 123);
                } else {
                    Intent intentLigar = new Intent(Intent.ACTION_CALL);
                    intentLigar.setData(Uri.parse("tel:" + aluno.getTelefone()));
                    startActivity(intentLigar);
                }

                return false;
            }
        });

        //SMS
        MenuItem itemSMS = menu.add("Enviar SMS");
        Intent intentSMS = new Intent(Intent.ACTION_VIEW);
        intentSMS.setData(Uri.parse("sms:" + aluno.getTelefone()));
        itemSMS.setIntent(intentSMS);

        //MAPA
        MenuItem itemMapa = menu.add("Visualizar no mapa");
        Intent intentMapa = new Intent(Intent.ACTION_VIEW);
        //Pegando o endereço com nivel de zoom
        //intentMapa.setData(Uri.parse("geo:0,0?z=14&q=" + aluno.getEndereco()));
        intentMapa.setData(Uri.parse("geo:0,0?q=" + aluno.getEndereco()));
        itemMapa.setIntent(intentMapa);

        //SITE
        MenuItem itemSite = menu.add("Visitar Site");
        Intent intentSite = new Intent(Intent.ACTION_VIEW);

        String site = aluno.getSite();
        if (!site.startsWith("http://")) {
            site = "http://" + site;
        }

        intentSite.setData(Uri.parse(site));

        itemSite.setIntent(intentSite);

        //DELETAR
        MenuItem deletar = menu.add("Deletar");

        deletar.setOnMenuItemClickListener(new MenuItem.OnMenuItemClickListener() {
            @Override
            public boolean onMenuItemClick(MenuItem menuItem) {

                AlunoDAO dao = new AlunoDAO(ListaAlunosActivity.this);
                dao.deleta(aluno);
                dao.close();

                carregaLista();

                return false;
            }
        });

    }
}