DI components and modules

app/src/main/java/io/catter2/App.java

@@ -1,46 +1,25 @@
 package io.catter2;
 
 import android.app.Application;
+import android.content.Context;
+import android.util.Log;
 
-import io.catter2.cat_api.CacheTheCatAPI;
-import io.catter2.cat_api.RetrofitTheCatAPI;
-import io.catter2.cat_api.TheCatAPI;
-import io.catter2.favorites.FavoritesRepository;
-import io.catter2.favorites.SharedPrefFavoritesRepository;
+import io.catter2.di.AppDIComponent;
+import io.catter2.di.AppDIModule;
+import io.catter2.di.CachedRetrofitCatApiDIModule;
 
 public class App extends Application {
-    private static TheCatAPI theCatAPI;
-    private static FavoritesRepository favoritesRepository;
-
-    public static TheCatAPI getTheCatAPIService() {
-        return App.theCatAPI;
-    }
-
-    public static FavoritesRepository getFavoritesRepository() {
-        return App.favoritesRepository;
-    }
-
-
     @Override
     public void onCreate() {
         super.onCreate();
 
-        TheCatAPI theCatAPIService = new RetrofitTheCatAPI();
-        TheCatAPI theCatAPICache = new CacheTheCatAPI(theCatAPIService);
-        App.theCatAPI = theCatAPICache;
-    }
-
-    public void initializeFavoritesRepository(String userToken) {
-        if (App.favoritesRepository != null) {
-            throw new RuntimeException("FavoritesRepository already initialized.");
-        }
-        App.favoritesRepository = new SharedPrefFavoritesRepository(this, userToken);
-    }
-
-    public void destroyFavoritesRepository() {
-        if (App.favoritesRepository != null) {
-            App.favoritesRepository.clearChangeListener();
-            App.favoritesRepository = null;
-        }
+        Log.d("App", "Initialized");
+        AppDIModule appDIModule = new AppDIModule() {
+            @Override
+            public Context provideAppContext() {
+                return App.this;
+            }
+        };
+        AppDIComponent.initialize(appDIModule, new CachedRetrofitCatApiDIModule());
     }
 }

app/src/main/java/io/catter2/FavoritesActivity.java

@@ -13,6 +13,7 @@
 
 import java.util.List;
 
+import io.catter2.di.UserDIComponent;
 import io.catter2.favorites.GetFavoritesUseCase;
 
 public class FavoritesActivity extends AppCompatActivity {
@@ -50,7 +51,7 @@ public void onClick(View view) {
         rvAdapter = new ImagesRvAdapter(null);
         recyclerView.setAdapter(rvAdapter);
 
-        getFavoritesUseCase = new GetFavoritesUseCase(App.getFavoritesRepository());
+        getFavoritesUseCase = new GetFavoritesUseCase(UserDIComponent.get().getFavoritesRepository());
     }
 
     @Override

app/src/main/java/io/catter2/ListActivity.java

@@ -16,6 +16,7 @@
 import java.util.List;
 
 import io.catter2.cat_api.FetchCatImagesUseCase;
+import io.catter2.di.UserDIComponent;
 import io.catter2.favorites.AddFavoriteUseCase;
 
 public class ListActivity extends AppCompatActivity {
@@ -49,8 +50,8 @@ public void imageClicked(ImageView view, String url) {
         });
         recyclerView.setAdapter(adapter);
 
-        addFavoriteUseCase = new AddFavoriteUseCase(App.getFavoritesRepository());
-        fetchCatImagesUseCase = new FetchCatImagesUseCase(App.getTheCatAPIService());
+        addFavoriteUseCase = new AddFavoriteUseCase(UserDIComponent.get().getFavoritesRepository());
+        fetchCatImagesUseCase = new FetchCatImagesUseCase(UserDIComponent.get().getTheCatAPIService());
 
         fetchCatImagesUseCase.getImagesUrls(new FetchCatImagesUseCase.Callback() {
             @Override

app/src/main/java/io/catter2/LoginActivity.java

@@ -11,6 +11,9 @@
 import android.widget.EditText;
 import android.widget.TextView;
 
+import io.catter2.di.AppDIComponent;
+import io.catter2.di.SharedPrefFavoritesRepoDIModule;
+import io.catter2.di.UserDIComponent;
 import io.catter2.login.LoginUseCase;
 
 /**
@@ -51,7 +54,9 @@ public void onClick(View view) {
 
     @Override
     protected void onResume() {
-        ((App) getApplication()).destroyFavoritesRepository();
+        if (UserDIComponent.get() != null) {
+            UserDIComponent.get().close();
+        }
         super.onResume();
     }
 
@@ -64,7 +69,7 @@ private void attemptLogin() {
         String token = uc.login(username, password);
 
         if (token != null) {
-            ((App) getApplication()).initializeFavoritesRepository(token);
+            UserDIComponent.initialize(new SharedPrefFavoritesRepoDIModule(AppDIComponent.get(), token));
             FavoritesActivity.launch(this);
         } else {
             errorTv.setVisibility(View.VISIBLE);

app/src/main/java/io/catter2/di/AppDIComponent.java

@@ -0,0 +1,45 @@
+package io.catter2.di;
+
+import android.content.Context;
+
+import io.catter2.cat_api.TheCatAPI;
+
+public class AppDIComponent {
+    private static AppDIComponent instance;
+
+    public static AppDIComponent get() {
+        return AppDIComponent.instance;
+    }
+
+    public static void initialize(AppDIModule appDIModule, TheCatAPIDIModule theCatAPIDIModule) {
+        if (AppDIComponent.get() != null) {
+            throw new RuntimeException("AppDIComponent already initialized.");
+        }
+        AppDIComponent.instance = new AppDIComponent(appDIModule, theCatAPIDIModule);
+    }
+
+    private AppDIModule appDIModule;
+    private TheCatAPIDIModule theCatAPIDIModule;
+
+    private Context appContext;
+    private TheCatAPI theCatAPI;
+
+    public AppDIComponent(AppDIModule appDIModule, TheCatAPIDIModule theCatAPIDIModule) {
+        this.appDIModule = appDIModule;
+        this.theCatAPIDIModule = theCatAPIDIModule;
+    }
+
+    public Context getAppContext() {
+        if (appContext == null) {
+            appContext = appDIModule.provideAppContext();
+        }
+        return appContext;
+    }
+
+    public TheCatAPI getTheCatAPI() {
+        if (theCatAPI == null) {
+            theCatAPI = theCatAPIDIModule.provideTheCatAPI();
+        }
+        return theCatAPI;
+    }
+}

app/src/main/java/io/catter2/di/AppDIModule.java

@@ -0,0 +1,7 @@
+package io.catter2.di;
+
+import android.content.Context;
+
+public interface AppDIModule {
+    Context provideAppContext();
+}

app/src/main/java/io/catter2/di/CachedRetrofitCatApiDIModule.java

@@ -0,0 +1,20 @@
+package io.catter2.di;
+
+import io.catter2.cat_api.CacheTheCatAPI;
+import io.catter2.cat_api.RetrofitTheCatAPI;
+import io.catter2.cat_api.TheCatAPI;
+
+public class CachedRetrofitCatApiDIModule implements TheCatAPIDIModule {
+    @Override
+    public TheCatAPI provideTheCatAPI() {
+        return provideTheCatAPICached(provideTheCatAPIRetrofit());
+    }
+
+    public TheCatAPI provideTheCatAPIRetrofit() {
+        return new RetrofitTheCatAPI();
+    }
+
+    public TheCatAPI provideTheCatAPICached(TheCatAPI catAPI) {
+        return new CacheTheCatAPI(catAPI);
+    }
+}

app/src/main/java/io/catter2/di/FavoritesRepoDIModule.java

@@ -0,0 +1,9 @@
+package io.catter2.di;
+
+import io.catter2.favorites.FavoritesRepository;
+
+public interface FavoritesRepoDIModule {
+    AppDIComponent getAppDIComponent();
+
+    FavoritesRepository provideFavoritesRepository();
+}

app/src/main/java/io/catter2/di/SharedPrefFavoritesRepoDIModule.java

@@ -0,0 +1,28 @@
+package io.catter2.di;
+
+import io.catter2.favorites.FavoritesRepository;
+import io.catter2.favorites.SharedPrefFavoritesRepository;
+
+public class SharedPrefFavoritesRepoDIModule implements FavoritesRepoDIModule {
+    private AppDIComponent appDIComponent;
+    private String userToken;
+
+    public SharedPrefFavoritesRepoDIModule(AppDIComponent appDIComponent, String userToken) {
+        this.appDIComponent = appDIComponent;
+        this.userToken = userToken;
+    }
+
+    @Override
+    public AppDIComponent getAppDIComponent() {
+        return this.appDIComponent;
+    }
+
+    @Override
+    public FavoritesRepository provideFavoritesRepository() {
+        return new SharedPrefFavoritesRepository(appDIComponent.getAppContext(), provideUserToken());
+    }
+
+    public String provideUserToken() {
+        return this.userToken;
+    }
+}

app/src/main/java/io/catter2/di/TheCatAPIDIModule.java

@@ -0,0 +1,7 @@
+package io.catter2.di;
+
+import io.catter2.cat_api.TheCatAPI;
+
+public interface TheCatAPIDIModule {
+    TheCatAPI provideTheCatAPI();
+}

app/src/main/java/io/catter2/di/UserDIComponent.java

@@ -0,0 +1,43 @@
+package io.catter2.di;
+
+import io.catter2.cat_api.TheCatAPI;
+import io.catter2.favorites.FavoritesRepository;
+
+public class UserDIComponent {
+    private static UserDIComponent instance;
+
+    public static UserDIComponent get() {
+        return instance;
+    }
+
+    public static void initialize(FavoritesRepoDIModule module) {
+        if (UserDIComponent.get() != null) {
+            throw new RuntimeException("UserDIComponent already initialized.");
+        }
+        UserDIComponent.instance = new UserDIComponent(module);
+    }
+
+    private FavoritesRepoDIModule module;
+    private FavoritesRepository favoritesRepository;
+
+    private UserDIComponent(FavoritesRepoDIModule module) {
+        this.module = module;
+    }
+
+    public TheCatAPI getTheCatAPIService() {
+        return this.module.getAppDIComponent().getTheCatAPI();
+    }
+
+    public FavoritesRepository getFavoritesRepository() {
+        if (favoritesRepository == null) {
+            favoritesRepository = module.provideFavoritesRepository();
+        }
+        return favoritesRepository;
+    }
+
+    public void close() {
+        if (favoritesRepository != null) {
+            favoritesRepository.clearChangeListener();
+        }
+    }
+}