Menambahkan view logic pada halaman login

Menambahkan event listener pada Button

...
buttonLogin.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //any code here...
            }
        });
textViewRegister.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //any code here...
            }
        });
...

Mengambil nilai String dari EditText

    String email=editTextEmail.getText().toString();
    String password=editTextPassword.getText().toString();

  if(email.equalsIgnoreCase("[email protected]") && password.equalsIgnoreCase(password)){
            startActivity(new Intent(LoginActivity.this,MainActivity.class));
  }else{
            Snackbar.make(buttonLogin,"login failed",Snackbar.LENGTH_SHORT).show();
  }

Memanggil halaman utama melalui Intent

Intent intent=new Intent(LoginActivity.this,MainActivity.class);
startActivity(intent);

code keseluruhan untuk halaman login sebagai berikut

public class LoginActivity extends AppCompatActivity {

    //deklarasi komponen dan variabel yang akan di control
    EditText editTextEmail,editTextPassword;
    Button buttonLogin;
    TextView textViewRegister;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);
        setupView();
        setupViewListener();
    }

    private void setupViewListener() {
        buttonLogin.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //any code here...
                processLogin();
            }
        });
        textViewRegister.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //any code here...
            }
        });
    }

    private void processLogin() {
        String email=editTextEmail.getText().toString();
        String password=editTextPassword.getText().toString();

        if(email.equalsIgnoreCase("[email protected]") && password.equalsIgnoreCase("1234")){
            Intent intent=new Intent(LoginActivity.this,MainActivity.class);
            startActivity(intent);
        }else{
            Snackbar.make(buttonLogin,"login failed",Snackbar.LENGTH_SHORT).show();
        }
    }

    private void setupView() {
        editTextEmail= (EditText) findViewById(R.id.editTextEmail);
        editTextPassword= (EditText) findViewById(R.id.editTextPassword);
        buttonLogin= (Button) findViewById(R.id.buttonLoagin);
        textViewRegister= (TextView) findViewById(R.id.textViewRegister);
    }
}