Android MVP Architecture Simple Login Example in MVP
Example
Required package structure
XML activity_login
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center_vertical"
android:orientation="vertical"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin">
<EditText
android:id="@+id/et_login_username"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="USERNAME" />
<EditText
android:id="@+id/et_login_password"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="PASSWORD" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<Button
android:id="@+id/btn_login_login"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginRight="4dp"
android:layout_weight="1"
android:text="Login" />
<Button
android:id="@+id/btn_login_clear"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="4dp"
android:layout_weight="1"
android:text="Clear" />
</LinearLayout>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="3dp"
android:text="correct user: mvp, mvp" />
<ProgressBar
android:id="@+id/progress_login"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="40dp" />
</LinearLayout>
Activity Class LoginActivity.class
public class LoginActivity extends AppCompatActivity implements ILoginView, View.OnClickListener {
private EditText editUser;
private EditText editPass;
private Button btnLogin;
private Button btnClear;
private ILoginPresenter loginPresenter;
private ProgressBar progressBar;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
//find view
editUser = (EditText) this.findViewById(R.id.et_login_username);
editPass = (EditText) this.findViewById(R.id.et_login_password);
btnLogin = (Button) this.findViewById(R.id.btn_login_login);
btnClear = (Button) this.findViewById(R.id.btn_login_clear);
progressBar = (ProgressBar) this.findViewById(R.id.progress_login);
//set listener
btnLogin.setOnClickListener(this);
btnClear.setOnClickListener(this);
//init
loginPresenter = new LoginPresenterCompl(this);
loginPresenter.setProgressBarVisiblity(View.INVISIBLE);
}
@Override
public void onClick(View v) {
switch (v.getId()){
case R.id.btn_login_clear:
loginPresenter.clear();
break;
case R.id.btn_login_login:
loginPresenter.setProgressBarVisiblity(View.VISIBLE);
btnLogin.setEnabled(false);
btnClear.setEnabled(false);
loginPresenter.doLogin(editUser.getText().toString(), editPass.getText().toString());
break;
}
}
@Override
public void onClearText() {
editUser.setText("");
editPass.setText("");
}
@Override
public void onLoginResult(Boolean result, int code) {
loginPresenter.setProgressBarVisiblity(View.INVISIBLE);
btnLogin.setEnabled(true);
btnClear.setEnabled(true);
if (result){
Toast.makeText(this,"Login Success",Toast.LENGTH_SHORT).show();
}
else
Toast.makeText(this,"Login Fail, code = " + code,Toast.LENGTH_SHORT).show();
}
@Override
protected void onDestroy() {
super.onDestroy();
}
@Override
public void onSetProgressBarVisibility(int visibility) {
progressBar.setVisibility(visibility);
}
}
Creating an ILoginView Interface
Create an ILoginView interface for update info from Presenter under view folder as follows:
public interface ILoginView {
public void onClearText();
public void onLoginResult(Boolean result, int code);
public void onSetProgressBarVisibility(int visibility);
}
Creating an ILoginPresenter Interface
Create an ILoginPresenter interface in order to communicate with LoginActivity (Views) and create the LoginPresenterCompl class for handling login functionality and reporting back to the Activity. The LoginPresenterCompl class implements the ILoginPresenter interface:
ILoginPresenter.class
public interface ILoginPresenter {
void clear();
void doLogin(String name, String passwd);
void setProgressBarVisiblity(int visiblity);
}
LoginPresenterCompl.class
public class LoginPresenterCompl implements ILoginPresenter {
ILoginView iLoginView;
IUser user;
Handler handler;
public LoginPresenterCompl(ILoginView iLoginView) {
this.iLoginView = iLoginView;
initUser();
handler = new Handler(Looper.getMainLooper());
}
@Override
public void clear() {
iLoginView.onClearText();
}
@Override
public void doLogin(String name, String passwd) {
Boolean isLoginSuccess = true;
final int code = user.checkUserValidity(name,passwd);
if (code!=0) isLoginSuccess = false;
final Boolean result = isLoginSuccess;
handler.postDelayed(new Runnable() {
@Override
public void run() {
iLoginView.onLoginResult(result, code);
}
}, 5000);
}
@Override
public void setProgressBarVisiblity(int visiblity){
iLoginView.onSetProgressBarVisibility(visiblity);
}
private void initUser(){
user = new UserModel("mvp","mvp");
}
}
Creating a UserModel
Create a UserModel which is like a Pojo class for LoginActivity. Create an IUser interface for Pojo validations:
UserModel.class
public class UserModel implements IUser {
String name;
String passwd;
public UserModel(String name, String passwd) {
this.name = name;
this.passwd = passwd;
}
@Override
public String getName() {
return name;
}
@Override
public String getPasswd() {
return passwd;
}
@Override
public int checkUserValidity(String name, String passwd){
if (name==null||passwd==null||!name.equals(getName())||!passwd.equals(getPasswd())){
return -1;
}
return 0;
}
IUser.class
public interface IUser {
String getName();
String getPasswd();
int checkUserValidity(String name, String passwd);
}
MVP
A Model-view-presenter (MVP) is a derivation of the model–view–controller (MVC) architectural pattern. It is used mostly for building user interfaces and offers the following benefits:
- Views are more separated from Models. The Presenter is the mediator between Model and View.
- It is easier to create unit tests.
- Generally, there is a one-to-one mapping between View and Presenter, with the possibility to use multiple Presenters for complex Views.
