First refactor to use dagger on presentation layer.

data/src/main/java/com/fernandocejas/android10/sample/data/cache/serializer/JsonSerializer.java

@@ -6,14 +6,18 @@ package com.fernandocejas.android10.sample.data.cache.serializer;
 
 import com.fernandocejas.android10.sample.data.entity.UserEntity;
 import com.google.gson.Gson;
+import javax.inject.Inject;
+import javax.inject.Singleton;
 
 /**
  * Class user as Serializer/Deserializer for user entities.
  */
+@Singleton
 public class JsonSerializer {
 
   private final Gson gson = new Gson();
 
+  @Inject
   public JsonSerializer() {
     //empty
   }

data/src/main/java/com/fernandocejas/android10/sample/data/entity/mapper/UserEntityDataMapper.java

@@ -9,13 +9,17 @@ import com.fernandocejas.android10.sample.domain.User;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
+import javax.inject.Inject;
+import javax.inject.Singleton;
 
 /**
  * Mapper class used to transform {@link UserEntity} (in the data layer) to {@link User} in the
  * domain layer.
  */
+@Singleton
 public class UserEntityDataMapper {
 
+  @Inject
   public UserEntityDataMapper() {
     //empty
   }

data/src/main/java/com/fernandocejas/android10/sample/data/repository/datasource/UserDataStoreFactory.java

@@ -9,6 +9,7 @@ import com.fernandocejas.android10.sample.data.cache.UserCache;
 import com.fernandocejas.android10.sample.data.entity.mapper.UserEntityJsonMapper;
 import com.fernandocejas.android10.sample.data.net.RestApi;
 import com.fernandocejas.android10.sample.data.net.RestApiImpl;
+import javax.inject.Inject;
 
 /**
  * Factory that creates different implementations of {@link UserDataStore}.
@@ -18,6 +19,7 @@ public class UserDataStoreFactory {
   private final Context context;
   private final UserCache userCache;
 
+  @Inject
   public UserDataStoreFactory(Context context, UserCache userCache) {
     if (context == null || userCache == null) {
       throw new IllegalArgumentException("Constructor parameters cannot be null!!!");

presentation/src/main/java/com/fernandocejas/android10/sample/presentation/AndroidApplication.java

@@ -9,6 +9,8 @@ import com.fernandocejas.android10.sample.presentation.internal.di.components.Ap
 import com.fernandocejas.android10.sample.presentation.internal.di.components.Dagger_ApplicationComponent;
 import com.fernandocejas.android10.sample.presentation.internal.di.modules.ApplicationModule;
 import com.fernandocejas.android10.sample.presentation.view.activity.BaseActivity;
+import com.fernandocejas.android10.sample.presentation.view.fragment.UserDetailsFragment;
+import com.fernandocejas.android10.sample.presentation.view.fragment.UserListFragment;
 
 /**
  * Android Main Application
@@ -32,4 +34,12 @@ public class AndroidApplication extends Application {
   public void inject(BaseActivity baseActivity) {
     this.applicationComponent.inject(baseActivity);
   }
+
+  public void inject(UserListFragment userListFragment) {
+    this.applicationComponent.inject(userListFragment);
+  }
+
+  public void inject(UserDetailsFragment userDetailsFragment) {
+    this.applicationComponent.inject(userDetailsFragment);
+  }
 }

presentation/src/main/java/com/fernandocejas/android10/sample/presentation/internal/di/components/ApplicationComponent.java

@@ -7,13 +7,18 @@ package com.fernandocejas.android10.sample.presentation.internal.di.components;
 import com.fernandocejas.android10.sample.presentation.AndroidApplication;
 import com.fernandocejas.android10.sample.presentation.internal.di.modules.ActivityModule;
 import com.fernandocejas.android10.sample.presentation.internal.di.modules.ApplicationModule;
+import com.fernandocejas.android10.sample.presentation.internal.di.modules.UserModule;
 import com.fernandocejas.android10.sample.presentation.view.activity.BaseActivity;
+import com.fernandocejas.android10.sample.presentation.view.fragment.UserDetailsFragment;
+import com.fernandocejas.android10.sample.presentation.view.fragment.UserListFragment;
 import dagger.Component;
 import javax.inject.Singleton;
 
 @Singleton
-@Component(modules = {ApplicationModule.class, ActivityModule.class})
+@Component(modules = {ApplicationModule.class, ActivityModule.class, UserModule.class})
 public interface ApplicationComponent {
   void inject(AndroidApplication androidApplication);
   void inject(BaseActivity activity);
+  void inject(UserListFragment userListFragment);
+  void inject(UserDetailsFragment userDetailsFragment);
 }

presentation/src/main/java/com/fernandocejas/android10/sample/presentation/internal/di/modules/UserModule.java

@@ -0,0 +1,91 @@
+/**
+ * Copyright (C) 2015 android10.org. All rights reserved.
+ * @author Fernando Cejas (the android10 coder)
+ */
+package com.fernandocejas.android10.sample.presentation.internal.di.modules;
+
+import android.content.Context;
+import com.fernandocejas.android10.sample.data.cache.FileManager;
+import com.fernandocejas.android10.sample.data.cache.UserCache;
+import com.fernandocejas.android10.sample.data.cache.UserCacheImpl;
+import com.fernandocejas.android10.sample.data.cache.serializer.JsonSerializer;
+import com.fernandocejas.android10.sample.data.entity.mapper.UserEntityDataMapper;
+import com.fernandocejas.android10.sample.data.executor.JobExecutor;
+import com.fernandocejas.android10.sample.data.repository.UserDataRepository;
+import com.fernandocejas.android10.sample.data.repository.datasource.UserDataStoreFactory;
+import com.fernandocejas.android10.sample.domain.executor.PostExecutionThread;
+import com.fernandocejas.android10.sample.domain.executor.ThreadExecutor;
+import com.fernandocejas.android10.sample.domain.interactor.GetUserDetailsUseCase;
+import com.fernandocejas.android10.sample.domain.interactor.GetUserDetailsUseCaseImpl;
+import com.fernandocejas.android10.sample.domain.interactor.GetUserListUseCase;
+import com.fernandocejas.android10.sample.domain.interactor.GetUserListUseCaseImpl;
+import com.fernandocejas.android10.sample.domain.repository.UserRepository;
+import com.fernandocejas.android10.sample.presentation.UIThread;
+import com.fernandocejas.android10.sample.presentation.mapper.UserModelDataMapper;
+import com.fernandocejas.android10.sample.presentation.presenter.UserDetailsPresenter;
+import com.fernandocejas.android10.sample.presentation.presenter.UserListPresenter;
+import dagger.Module;
+import dagger.Provides;
+
+@Module
+public class UserModule {
+
+  @Provides ThreadExecutor provideThreadExecutor() {
+    return JobExecutor.getInstance();
+  }
+
+  @Provides PostExecutionThread providePostExecutionThread() {
+    return UIThread.getInstance();
+  }
+
+  @Provides JsonSerializer provideJsonSerializer() {
+    return new JsonSerializer();
+  }
+
+  @Provides FileManager provideFileManager() {
+    return FileManager.getInstance();
+  }
+
+  @Provides UserCache provideUserCache(Context context, JsonSerializer jsonSerializer,
+      FileManager fileManager, ThreadExecutor threadExecutor) {
+    return UserCacheImpl.getInstance(context, jsonSerializer, fileManager, threadExecutor);
+  }
+
+  @Provides UserDataStoreFactory provideUserDataStoreFactory(Context context, UserCache userCache) {
+    return new UserDataStoreFactory(context, userCache);
+  }
+
+  @Provides UserEntityDataMapper provideUserEntityDataMapper() {
+    return new UserEntityDataMapper();
+  }
+
+  @Provides UserRepository provideUserRepository(UserDataStoreFactory userDataStoreFactory,
+      UserEntityDataMapper userEntityDataMapper) {
+    return UserDataRepository.getInstance(userDataStoreFactory, userEntityDataMapper);
+  }
+
+  @Provides GetUserListUseCase provideGetUserListUseCase(UserRepository userRepository,
+      ThreadExecutor threadExecutor, PostExecutionThread postExecutionThread) {
+    return new GetUserListUseCaseImpl(userRepository, threadExecutor, postExecutionThread);
+  }
+
+  @Provides UserModelDataMapper provideUserModelDataMapper() {
+    return new UserModelDataMapper();
+  }
+
+  @Provides UserListPresenter provideUserListPresenter(GetUserListUseCase userListUseCase,
+      UserModelDataMapper userModelDataMapper) {
+    return new UserListPresenter(userListUseCase, userModelDataMapper);
+  }
+
+  @Provides GetUserDetailsUseCase provideGetUserDetailsUseCase(UserRepository userRepository,
+      ThreadExecutor threadExecutor, PostExecutionThread postExecutionThread) {
+    return  new GetUserDetailsUseCaseImpl(userRepository,
+        threadExecutor, postExecutionThread);
+  }
+
+  @Provides UserDetailsPresenter provideUserDetailsPresenter(GetUserDetailsUseCase getUserDetailsUseCase,
+      UserModelDataMapper userModelDataMapper) {
+    return new UserDetailsPresenter(getUserDetailsUseCase, userModelDataMapper);
+  }
+}

presentation/src/main/java/com/fernandocejas/android10/sample/presentation/mapper/UserModelDataMapper.java

@@ -9,13 +9,17 @@ import com.fernandocejas.android10.sample.presentation.model.UserModel;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
+import javax.inject.Inject;
+import javax.inject.Singleton;
 
 /**
  * Mapper class used to transform {@link User} (in the domain layer) to {@link UserModel} in the
  * presentation layer.
  */
+@Singleton
 public class UserModelDataMapper {
 
+  @Inject
   public UserModelDataMapper() {
     //empty
   }

presentation/src/main/java/com/fernandocejas/android10/sample/presentation/presenter/UserDetailsPresenter.java

@@ -4,6 +4,7 @@
  */
 package com.fernandocejas.android10.sample.presentation.presenter;
 
+import android.support.annotation.NonNull;
 import com.fernandocejas.android10.sample.domain.User;
 import com.fernandocejas.android10.sample.domain.exception.ErrorBundle;
 import com.fernandocejas.android10.sample.domain.interactor.GetUserDetailsUseCase;
@@ -21,20 +22,21 @@ public class UserDetailsPresenter implements Presenter {
   /** id used to retrieve user details */
   private int userId;
 
-  private final UserDetailsView viewDetailsView;
+  private UserDetailsView viewDetailsView;
+
   private final GetUserDetailsUseCase getUserDetailsUseCase;
   private final UserModelDataMapper userModelDataMapper;
 
-  public UserDetailsPresenter(UserDetailsView userDetailsView,
-      GetUserDetailsUseCase getUserDetailsUseCase, UserModelDataMapper userModelDataMapper) {
-    if (userDetailsView == null || getUserDetailsUseCase == null || userModelDataMapper == null) {
-      throw new IllegalArgumentException("Constructor parameters cannot be null!!!");
-    }
-    this.viewDetailsView = userDetailsView;
+  public UserDetailsPresenter(GetUserDetailsUseCase getUserDetailsUseCase,
+      UserModelDataMapper userModelDataMapper) {
     this.getUserDetailsUseCase = getUserDetailsUseCase;
     this.userModelDataMapper = userModelDataMapper;
   }
 
+  public void setView(@NonNull UserDetailsView view) {
+    this.viewDetailsView = view;
+  }
+
   @Override public void resume() {}
 
   @Override public void pause() {}

presentation/src/main/java/com/fernandocejas/android10/sample/presentation/presenter/UserListPresenter.java

@@ -4,6 +4,7 @@
  */
 package com.fernandocejas.android10.sample.presentation.presenter;
 
+import android.support.annotation.NonNull;
 import com.fernandocejas.android10.sample.domain.User;
 import com.fernandocejas.android10.sample.domain.exception.ErrorBundle;
 import com.fernandocejas.android10.sample.domain.interactor.GetUserListUseCase;
@@ -12,27 +13,32 @@ import com.fernandocejas.android10.sample.presentation.mapper.UserModelDataMappe
 import com.fernandocejas.android10.sample.presentation.model.UserModel;
 import com.fernandocejas.android10.sample.presentation.view.UserListView;
 import java.util.Collection;
+import javax.inject.Inject;
+import javax.inject.Singleton;
 
 /**
  * {@link Presenter} that controls communication between views and models of the presentation
  * layer.
  */
+@Singleton
 public class UserListPresenter implements Presenter {
 
-  private final UserListView viewListView;
+  private UserListView viewListView;
+
   private final GetUserListUseCase getUserListUseCase;
   private final UserModelDataMapper userModelDataMapper;
 
-  public UserListPresenter(UserListView userListView, GetUserListUseCase getUserListUserCase,
+  @Inject
+  public UserListPresenter(GetUserListUseCase getUserListUserCase,
       UserModelDataMapper userModelDataMapper) {
-    if (userListView == null || getUserListUserCase == null || userModelDataMapper == null) {
-      throw new IllegalArgumentException("Constructor parameters cannot be null!!!");
-    }
-    this.viewListView = userListView;
     this.getUserListUseCase = getUserListUserCase;
     this.userModelDataMapper = userModelDataMapper;
   }
 
+  public void setView(@NonNull UserListView view) {
+    this.viewListView = view;
+  }
+
   @Override public void resume() {}
 
   @Override public void pause() {}

presentation/src/main/java/com/fernandocejas/android10/sample/presentation/view/fragment/BaseFragment.java

@@ -7,6 +7,7 @@ package com.fernandocejas.android10.sample.presentation.view.fragment;
 import android.app.Fragment;
 import android.os.Bundle;
 import android.widget.Toast;
+import com.fernandocejas.android10.sample.presentation.AndroidApplication;
 
 /**
  * Base {@link android.app.Fragment} class for every fragment in this application.
@@ -16,15 +17,8 @@ public abstract class BaseFragment extends Fragment {
   @Override public void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     setRetainInstance(true);
-    initializePresenter();
   }
 
-  /**
-   * Initializes the {@link com.fernandocejas.android10.sample.presentation.presenter.Presenter}
-   * for this fragment in a MVP pattern used to architect the application presentation layer.
-   */
-  abstract void initializePresenter();
-
   /**
    * Shows a {@link android.widget.Toast} message.
    *
@@ -33,4 +27,13 @@ public abstract class BaseFragment extends Fragment {
   protected void showToastMessage(String message) {
     Toast.makeText(getActivity(), message, Toast.LENGTH_SHORT).show();
   }
+
+  /**
+   * Get the Android Main Application.
+   *
+   * @return singleton {@link com.fernandocejas.android10.sample.presentation.AndroidApplication}
+   */
+  protected AndroidApplication getApplication() {
+    return (AndroidApplication)getActivity().getApplication();
+  }
 }

presentation/src/main/java/com/fernandocejas/android10/sample/presentation/view/fragment/UserDetailsFragment.java

@@ -15,26 +15,12 @@ import android.widget.TextView;
 import butterknife.ButterKnife;
 import butterknife.InjectView;
 import butterknife.OnClick;
-import com.fernandocejas.android10.sample.data.cache.FileManager;
-import com.fernandocejas.android10.sample.data.cache.UserCache;
-import com.fernandocejas.android10.sample.data.cache.UserCacheImpl;
-import com.fernandocejas.android10.sample.data.cache.serializer.JsonSerializer;
-import com.fernandocejas.android10.sample.data.entity.mapper.UserEntityDataMapper;
-import com.fernandocejas.android10.sample.data.executor.JobExecutor;
-import com.fernandocejas.android10.sample.data.repository.UserDataRepository;
-import com.fernandocejas.android10.sample.data.repository.datasource.UserDataStoreFactory;
-import com.fernandocejas.android10.sample.domain.executor.PostExecutionThread;
-import com.fernandocejas.android10.sample.domain.executor.ThreadExecutor;
-import com.fernandocejas.android10.sample.domain.interactor.GetUserDetailsUseCase;
-import com.fernandocejas.android10.sample.domain.interactor.GetUserDetailsUseCaseImpl;
-import com.fernandocejas.android10.sample.domain.repository.UserRepository;
 import com.fernandocejas.android10.sample.presentation.R;
-import com.fernandocejas.android10.sample.presentation.UIThread;
-import com.fernandocejas.android10.sample.presentation.mapper.UserModelDataMapper;
 import com.fernandocejas.android10.sample.presentation.model.UserModel;
 import com.fernandocejas.android10.sample.presentation.presenter.UserDetailsPresenter;
 import com.fernandocejas.android10.sample.presentation.view.UserDetailsView;
 import com.fernandocejas.android10.sample.presentation.view.component.AutoLoadImageView;
+import javax.inject.Inject;
 
 /**
  * Fragment that shows details of a certain user.
@@ -44,7 +30,8 @@ public class UserDetailsFragment extends BaseFragment implements UserDetailsView
   private static final String ARGUMENT_KEY_USER_ID = "org.android10.ARGUMENT_USER_ID";
 
   private int userId;
-  private UserDetailsPresenter userDetailsPresenter;
+
+  @Inject UserDetailsPresenter userDetailsPresenter;
 
   @InjectView(R.id.iv_cover) AutoLoadImageView iv_cover;
   @InjectView(R.id.tv_fullname) TextView tv_fullname;
@@ -69,6 +56,7 @@ public class UserDetailsFragment extends BaseFragment implements UserDetailsView
 
   @Override public void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
+    this.getApplication().inject(this);
     this.initialize();
   }
 
@@ -96,28 +84,9 @@ public class UserDetailsFragment extends BaseFragment implements UserDetailsView
     this.userDetailsPresenter.pause();
   }
 
-  @Override void initializePresenter() {
-    // All these dependency initialization could have been avoided using a
-    // dependency injection framework. But in this case are used this way for
-    // LEARNING EXAMPLE PURPOSE.
-    ThreadExecutor threadExecutor = JobExecutor.getInstance();
-    PostExecutionThread postExecutionThread = UIThread.getInstance();
-
-    JsonSerializer userCacheSerializer = new JsonSerializer();
-    UserCache userCache = UserCacheImpl.getInstance(getActivity(), userCacheSerializer,
-        FileManager.getInstance(), threadExecutor);
-    UserDataStoreFactory userDataStoreFactory =
-        new UserDataStoreFactory(this.getContext(), userCache);
-    UserEntityDataMapper userEntityDataMapper = new UserEntityDataMapper();
-    UserRepository userRepository = UserDataRepository.getInstance(userDataStoreFactory,
-        userEntityDataMapper);
-
-    GetUserDetailsUseCase getUserDetailsUseCase = new GetUserDetailsUseCaseImpl(userRepository,
-        threadExecutor, postExecutionThread);
-    UserModelDataMapper userModelDataMapper = new UserModelDataMapper();
-
-    this.userDetailsPresenter =
-        new UserDetailsPresenter(this, getUserDetailsUseCase, userModelDataMapper);
+  private void initialize() {
+    this.userDetailsPresenter.setView(this);
+    this.userId = getArguments().getInt(ARGUMENT_KEY_USER_ID);
   }
 
   @Override public void renderUser(UserModel user) {
@@ -156,13 +125,6 @@ public class UserDetailsFragment extends BaseFragment implements UserDetailsView
     return getActivity().getApplicationContext();
   }
 
-  /**
-   * Initializes fragment's private members.
-   */
-  private void initialize() {
-    this.userId = getArguments().getInt(ARGUMENT_KEY_USER_ID);
-  }
-
   /**
    * Loads all users.
    */

presentation/src/main/java/com/fernandocejas/android10/sample/presentation/view/fragment/UserListFragment.java

@@ -16,28 +16,14 @@ import android.widget.RelativeLayout;
 import butterknife.ButterKnife;
 import butterknife.InjectView;
 import butterknife.OnClick;
-import com.fernandocejas.android10.sample.data.cache.FileManager;
-import com.fernandocejas.android10.sample.data.cache.UserCache;
-import com.fernandocejas.android10.sample.data.cache.UserCacheImpl;
-import com.fernandocejas.android10.sample.data.cache.serializer.JsonSerializer;
-import com.fernandocejas.android10.sample.data.entity.mapper.UserEntityDataMapper;
-import com.fernandocejas.android10.sample.data.executor.JobExecutor;
-import com.fernandocejas.android10.sample.data.repository.UserDataRepository;
-import com.fernandocejas.android10.sample.data.repository.datasource.UserDataStoreFactory;
-import com.fernandocejas.android10.sample.domain.executor.PostExecutionThread;
-import com.fernandocejas.android10.sample.domain.executor.ThreadExecutor;
-import com.fernandocejas.android10.sample.domain.interactor.GetUserListUseCase;
-import com.fernandocejas.android10.sample.domain.interactor.GetUserListUseCaseImpl;
-import com.fernandocejas.android10.sample.domain.repository.UserRepository;
 import com.fernandocejas.android10.sample.presentation.R;
-import com.fernandocejas.android10.sample.presentation.UIThread;
-import com.fernandocejas.android10.sample.presentation.mapper.UserModelDataMapper;
 import com.fernandocejas.android10.sample.presentation.model.UserModel;
 import com.fernandocejas.android10.sample.presentation.presenter.UserListPresenter;
 import com.fernandocejas.android10.sample.presentation.view.UserListView;
 import com.fernandocejas.android10.sample.presentation.view.adapter.UsersAdapter;
 import com.fernandocejas.android10.sample.presentation.view.adapter.UsersLayoutManager;
 import java.util.Collection;
+import javax.inject.Inject;
 
 /**
  * Fragment that shows a list of Users.
@@ -51,7 +37,7 @@ public class UserListFragment extends BaseFragment implements UserListView {
     void onUserClicked(final UserModel userModel);
   }
 
-  private UserListPresenter userListPresenter;
+  @Inject UserListPresenter userListPresenter;
 
   @InjectView(R.id.rv_users) RecyclerView rv_users;
   @InjectView(R.id.rl_progress) RelativeLayout rl_progress;
@@ -72,6 +58,12 @@ public class UserListFragment extends BaseFragment implements UserListView {
     }
   }
 
+  @Override public void onCreate(Bundle savedInstanceState) {
+    super.onCreate(savedInstanceState);
+    this.getApplication().inject(this);
+    this.initialize();
+  }
+
   @Override public View onCreateView(LayoutInflater inflater, ViewGroup container,
       Bundle savedInstanceState) {
 
@@ -97,27 +89,8 @@ public class UserListFragment extends BaseFragment implements UserListView {
     this.userListPresenter.pause();
   }
 
-  @Override protected void initializePresenter() {
-    // All these dependency initialization could have been avoided using a
-    // dependency injection framework. But in this case are used this way for
-    // LEARNING EXAMPLE PURPOSE.
-    ThreadExecutor threadExecutor = JobExecutor.getInstance();
-    PostExecutionThread postExecutionThread = UIThread.getInstance();
-
-    JsonSerializer userCacheSerializer = new JsonSerializer();
-    UserCache userCache = UserCacheImpl.getInstance(getActivity(), userCacheSerializer,
-        FileManager.getInstance(), threadExecutor);
-    UserDataStoreFactory userDataStoreFactory =
-        new UserDataStoreFactory(this.getContext(), userCache);
-    UserEntityDataMapper userEntityDataMapper = new UserEntityDataMapper();
-    UserRepository userRepository = UserDataRepository.getInstance(userDataStoreFactory,
-        userEntityDataMapper);
-
-    GetUserListUseCase getUserListUseCase = new GetUserListUseCaseImpl(userRepository,
-        threadExecutor, postExecutionThread);
-    UserModelDataMapper userModelDataMapper = new UserModelDataMapper();
-
-    this.userListPresenter = new UserListPresenter(this, getUserListUseCase, userModelDataMapper);
+  private void initialize() {
+    this.userListPresenter.setView(this);
   }
 
   private void setupUI() {