Merge pull request #807 from psh/java-8-retrolambda

Java 8 & Retrolambda

app/build.gradle

@@ -1,4 +1,5 @@
 apply plugin: 'com.android.application'
+apply plugin: 'me.tatarka.retrolambda'
 apply plugin: 'jacoco-android'
 apply from: 'quality.gradle'
 apply plugin: 'com.getkeepsafe.dexcount'
@@ -75,6 +76,11 @@ android {
         abortOnError false
     }
 
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
+
     //FIXME: Temporary fix for https://github.com/commons-app/apps-android-commons/issues/709
     configurations.all {
         resolutionStrategy.force 'com.android.support:support-annotations:25.2.0'

app/src/main/java/fr/free/nrw/commons/CommonsApplication.java

@@ -197,8 +197,8 @@ public class CommonsApplication extends Application {
 
         AccountManager accountManager = AccountManager.get(this);
         Account[] allAccounts = accountManager.getAccountsByType(AccountUtil.accountType());
-        for (int index = 0; index < allAccounts.length; index++) {
+        for (Account allAccount : allAccounts) {
-            accountManager.removeAccount(allAccounts[index], null, null);
+            accountManager.removeAccount(allAccount, null, null);
         }
 
         //TODO: fix preference manager 

app/src/main/java/fr/free/nrw/commons/WelcomeActivity.java

@@ -27,12 +27,7 @@ public class WelcomeActivity extends BaseActivity {
 
         pager.setAdapter(adapter);
         indicator.setViewPager(pager);
-        adapter.setCallback(new WelcomePagerAdapter.Callback() {
+        adapter.setCallback(this::finish);
-            @Override
-            public void onYesClicked() {
-                finish();
-            }
-        });
     }
 
     @Override

app/src/main/java/fr/free/nrw/commons/auth/LoginActivity.java

@@ -26,6 +26,9 @@ import fr.free.nrw.commons.PageTitle;
 import fr.free.nrw.commons.contributions.ContributionsActivity;
 import timber.log.Timber;
 
+import static android.view.KeyEvent.KEYCODE_ENTER;
+import static android.view.inputmethod.EditorInfo.IME_ACTION_DONE;
+
 
 public class LoginActivity extends AccountAuthenticatorActivity {
 
@@ -63,18 +66,8 @@ public class LoginActivity extends AccountAuthenticatorActivity {
         twoFactorEdit.addTextChangedListener(textWatcher);
         passwordEdit.setOnEditorActionListener(newLoginInputActionListener());
 
-        loginButton.setOnClickListener(new View.OnClickListener() {
+        loginButton.setOnClickListener(this::performLogin);
-            @Override
+        signupButton.setOnClickListener(this::signUp);
-            public void onClick(View v) {
-                performLogin();
-            }
-        });
-        signupButton.setOnClickListener(new View.OnClickListener() {
-            @Override
-            public void onClick(View v) {
-                signUp(v);
-            }
-        });
     }
 
     private class LoginTextWatcher implements TextWatcher {
@@ -98,20 +91,17 @@ public class LoginActivity extends AccountAuthenticatorActivity {
     }
 
     private TextView.OnEditorActionListener newLoginInputActionListener() {
-        return new TextView.OnEditorActionListener() {
+        return (textView, actionId, keyEvent) -> {
-            @Override
-            public boolean onEditorAction(TextView textView, int actionId, KeyEvent keyEvent) {
             if (loginButton.isEnabled()) {
-                    if (actionId == EditorInfo.IME_ACTION_DONE) {
+                if (actionId == IME_ACTION_DONE) {
-                        performLogin();
+                    performLogin(textView);
                     return true;
-                    } else if ((keyEvent != null) && keyEvent.getKeyCode() == KeyEvent.KEYCODE_ENTER) {
+                } else if ((keyEvent != null) && keyEvent.getKeyCode() == KEYCODE_ENTER) {
-                        performLogin();
+                    performLogin(textView);
                     return true;
                 }
             }
             return false;
-            }
         };
     }
 
@@ -142,7 +132,7 @@ public class LoginActivity extends AccountAuthenticatorActivity {
         super.onDestroy();
     }
 
-    private void performLogin() {
+    private void performLogin(View view) {
         Timber.d("Login to start!");
         LoginTask task = getLoginTask();
         task.execute();

app/src/main/java/fr/free/nrw/commons/category/CategorizationFragment.java

@@ -409,12 +409,9 @@ public class CategorizationFragment extends Fragment {
         categoriesNotFoundView = (TextView) rootView.findViewById(R.id.categoriesNotFound);
         categoriesSkip = (TextView) rootView.findViewById(R.id.categoriesExplanation);
 
-        categoriesSkip.setOnClickListener(new View.OnClickListener() {
+        categoriesSkip.setOnClickListener(view -> {
-            @Override
-            public void onClick(View view) {
             getActivity().onBackPressed();
             getActivity().finish();
-            }
         });
 
         ArrayList<CategoryItem> items;
@@ -429,9 +426,7 @@ public class CategorizationFragment extends Fragment {
         categoriesAdapter = new CategoriesAdapter(getActivity(), items);
         categoriesList.setAdapter(categoriesAdapter);
 
-        categoriesList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
+        categoriesList.setOnItemClickListener((adapterView, view, index, id) -> {
-            @Override
-            public void onItemClick(AdapterView<?> adapterView, View view, int index, long id) {
             CheckedTextView checkedView = (CheckedTextView) view;
             CategoryItem item = (CategoryItem) adapterView.getAdapter().getItem(index);
             item.selected = !item.selected;
@@ -439,7 +434,6 @@ public class CategorizationFragment extends Fragment {
             if (item.selected) {
                 updateCategoryCount(item.name);
             }
-            }
         });
 
         categoriesFilter.addTextChangedListener(textWatcher);
@@ -463,15 +457,12 @@ public class CategorizationFragment extends Fragment {
         if (rootView != null) {
             rootView.setFocusableInTouchMode(true);
             rootView.requestFocus();
-            rootView.setOnKeyListener(new View.OnKeyListener() {
+            rootView.setOnKeyListener((v, keyCode, event) -> {
-                @Override
-                public boolean onKey(View v, int keyCode, KeyEvent event) {
                 if (event.getAction() == KeyEvent.ACTION_UP && keyCode == KeyEvent.KEYCODE_BACK) {
                     backButtonDialog();
                     return true;
                 }
                 return false;
-                }
             });
         }
     }
@@ -487,18 +478,10 @@ public class CategorizationFragment extends Fragment {
 
         builder.setMessage("Are you sure you want to go back? The image will not have any categories saved.")
                 .setTitle("Warning");
-        builder.setPositiveButton("No", new DialogInterface.OnClickListener() {
+        builder.setPositiveButton("No", (dialog, id) -> {
-            @Override
-            public void onClick(DialogInterface dialog, int id) {
             //No need to do anything, user remains on categorization screen
-            }
-        });
-        builder.setNegativeButton("Yes", new DialogInterface.OnClickListener() {
-            @Override
-            public void onClick(DialogInterface dialog, int id) {
-                getActivity().finish();
-            }
         });
+        builder.setNegativeButton("Yes", (dialog, id) -> getActivity().finish());
 
         AlertDialog dialog = builder.create();
         dialog.show();
@@ -537,20 +520,12 @@ public class CategorizationFragment extends Fragment {
 
                     builder.setMessage("Images without categories are rarely usable. Are you sure you want to submit without selecting categories?")
                             .setTitle("No Categories Selected");
-                    builder.setPositiveButton("No, go back", new DialogInterface.OnClickListener() {
+                    builder.setPositiveButton("No, go back", (dialog, id) -> {
-                        @Override
-                        public void onClick(DialogInterface dialog, int id) {
                         //Exit menuItem so user can select their categories
-                            return;
-                        }
                     });
-                    builder.setNegativeButton("Yes, submit", new DialogInterface.OnClickListener() {
+                    builder.setNegativeButton("Yes, submit", (dialog, id) -> {
-                        @Override
-                        public void onClick(DialogInterface dialog, int id) {
                         //Proceed to submission
                         onCategoriesSaveHandler.onCategoriesSave(selectedCategories);
-                            return;
-                        }
                     });
 
                     AlertDialog dialog = builder.create();

app/src/main/java/fr/free/nrw/commons/concurrency/BackgroundPoolExceptionHandler.java

@@ -9,11 +9,8 @@ public class BackgroundPoolExceptionHandler implements ExceptionHandler {
     public void onException(@NonNull final Throwable t) {
         //Crash for debug build
         if (BuildConfig.DEBUG) {
-            Thread thread = new Thread(new Runnable() {
+            Thread thread = new Thread(() -> {
-                @Override
-                public void run() {
                 throw new RuntimeException(t);
-                }
             });
             thread.start();
         }

app/src/main/java/fr/free/nrw/commons/concurrency/ThreadFactoryMaker.java

@@ -11,17 +11,13 @@ class ThreadFactoryMaker {
             private int count = 0;
 
             @Override
-            public Thread newThread(final Runnable runnable) {
+            public Thread newThread(@NonNull final Runnable runnable) {
                 count++;
-                Runnable wrapperRunnable = new Runnable() {
+                Runnable wrapperRunnable = () -> {
-                    @Override
-                    public void run() {
                     Process.setThreadPriority(priority);
                     runnable.run();
-                    }
                 };
-                Thread t = new Thread(wrapperRunnable, String.format("%s-%s", name, count));
+                return new Thread(wrapperRunnable, String.format("%s-%s", name, count));
-                return t;
             }
         };
     }

app/src/main/java/fr/free/nrw/commons/contributions/ContributionsListFragment.java

@@ -29,6 +29,7 @@ import fr.free.nrw.commons.R;
 import fr.free.nrw.commons.nearby.NearbyActivity;
 import timber.log.Timber;
 
+import static android.Manifest.permission.READ_EXTERNAL_STORAGE;
 import static android.app.Activity.RESULT_OK;
 
 public class ContributionsListFragment extends Fragment {
@@ -110,11 +111,11 @@ public class ContributionsListFragment extends Fragment {
 
                     // Here, thisActivity is the current activity
                     if (ContextCompat.checkSelfPermission(getActivity(),
-                            Manifest.permission.READ_EXTERNAL_STORAGE)
+                            READ_EXTERNAL_STORAGE)
                             != PackageManager.PERMISSION_GRANTED) {
 
                         // Should we show an explanation?
-                        if (shouldShowRequestPermissionRationale(Manifest.permission.READ_EXTERNAL_STORAGE)) {
+                        if (shouldShowRequestPermissionRationale(READ_EXTERNAL_STORAGE)) {
 
                             // Show an explanation to the user *asynchronously* -- don't block
                             // this thread waiting for the user's response! After the user
@@ -122,15 +123,9 @@ public class ContributionsListFragment extends Fragment {
 
                             new AlertDialog.Builder(getActivity())
                                     .setMessage(getString(R.string.storage_permission_rationale))
-                                    .setPositiveButton("OK", new DialogInterface.OnClickListener() {
+                                    .setPositiveButton("OK", (dialog, which) -> {
-                                        @Override
+                                        requestPermissions(new String[]{READ_EXTERNAL_STORAGE}, 1);
-                                        public void onClick(DialogInterface dialog, int which) {
-
-                                            requestPermissions(
-                                                    new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},
-                                                    1);
                                         dialog.dismiss();
-                                        }
                                     })
                                     .setNegativeButton("Cancel", null)
                                     .create()
@@ -140,7 +135,7 @@ public class ContributionsListFragment extends Fragment {
 
                             // No explanation needed, we can request the permission.
 
-                            requestPermissions(new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},
+                            requestPermissions(new String[]{READ_EXTERNAL_STORAGE},
                                     1);
 
                             // MY_PERMISSIONS_REQUEST_READ_CONTACTS is an

app/src/main/java/fr/free/nrw/commons/contributions/UploadCountClient.java

@@ -14,10 +14,10 @@ import fr.free.nrw.commons.concurrency.BackgroundPoolExceptionHandler;
 import fr.free.nrw.commons.concurrency.ThreadPoolExecutorService;
 import timber.log.Timber;
 
-public class UploadCountClient {
+class UploadCountClient {
     private ThreadPoolExecutorService threadPoolExecutor;
 
-    public UploadCountClient() {
+    UploadCountClient() {
         threadPoolExecutor = new ThreadPoolExecutorService.Builder("bg-pool")
                 .setPoolSize(Runtime.getRuntime().availableProcessors())
                 .setExceptionHandler(new BackgroundPoolExceptionHandler())
@@ -27,11 +27,9 @@ public class UploadCountClient {
     private static final String UPLOAD_COUNT_URL_TEMPLATE =
             "https://tools.wmflabs.org/urbanecmbot/uploadsbyuser/uploadsbyuser.py?user=%s";
 
-    public ListenableFuture<Integer> getUploadCount(final String userName) {
+    ListenableFuture<Integer> getUploadCount(final String userName) {
         final SettableFuture<Integer> future = SettableFuture.create();
-        threadPoolExecutor.schedule(new Runnable() {
+        threadPoolExecutor.schedule(() -> {
-            @Override
-            public void run() {
             URL url;
             try {
                 url = new URL(String.format(Locale.ENGLISH, UPLOAD_COUNT_URL_TEMPLATE,
@@ -50,7 +48,6 @@ public class UploadCountClient {
                 Timber.e("Error getting upload count Error", e);
                 future.setException(e);
             }
-            }
         });
         return future;
     }

app/src/main/java/fr/free/nrw/commons/media/MediaDetailFragment.java

@@ -119,12 +119,7 @@ public class MediaDetailFragment extends Fragment {
         licenseList = new LicenseList(getActivity());
 
         // Progressively darken the image in the background when we scroll detail pane up
-        scrollListener = new ViewTreeObserver.OnScrollChangedListener() {
+        scrollListener = this::updateTheDarkness;
-            @Override
-            public void onScrollChanged() {
-                updateTheDarkness();
-            }
-        };
         view.getViewTreeObserver().addOnScrollChangedListener(scrollListener);
 
         // Layout layoutListener to size the spacer item relative to the available space.
@@ -280,15 +275,12 @@ public class MediaDetailFragment extends Fragment {
 
         textView.setText(catName);
         if (categoriesLoaded && categoriesPresent) {
-            textView.setOnClickListener(new View.OnClickListener() {
+            textView.setOnClickListener(view -> {
-                @Override
-                public void onClick(View view) {
                 String selectedCategoryTitle = "Category:" + catName;
                 Intent viewIntent = new Intent();
                 viewIntent.setAction(Intent.ACTION_VIEW);
                 viewIntent.setData(new PageTitle(selectedCategoryTitle).getCanonicalUri());
                 startActivity(viewIntent);
-                }
             });
         }
         return item;

app/src/main/java/fr/free/nrw/commons/media/MediaDetailPagerFragment.java

@@ -72,12 +72,7 @@ public class MediaDetailPagerFragment extends Fragment implements ViewPager.OnPa
         public Fragment getItem(int i) {
             if (i == 0) {
                 // See bug https://code.google.com/p/android/issues/detail?id=27526
-                pager.postDelayed(new Runnable() {
+                pager.postDelayed(() -> getActivity().supportInvalidateOptionsMenu(), 5);
-                    @Override
-                    public void run() {
-                        getActivity().supportInvalidateOptionsMenu();
-                    }
-                }, 5);
             }
             return MediaDetailFragment.forMedia(i, editable);
         }
@@ -100,14 +95,11 @@ public class MediaDetailPagerFragment extends Fragment implements ViewPager.OnPa
             final int pageNumber = savedInstanceState.getInt("current-page");
             // Adapter doesn't seem to be loading immediately.
             // Dear God, please forgive us for our sins
-            view.postDelayed(new Runnable() {
+            view.postDelayed(() -> {
-                @Override
-                public void run() {
                 pager.setAdapter(adapter);
                 pager.setCurrentItem(pageNumber, false);
                 getActivity().supportInvalidateOptionsMenu();
                 adapter.notifyDataSetChanged();
-                }
             }, 100);
         } else {
             pager.setAdapter(adapter);
@@ -196,13 +188,8 @@ public class MediaDetailPagerFragment extends Fragment implements ViewPager.OnPa
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && !(ContextCompat.checkSelfPermission(getContext(), Manifest.permission.READ_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED)) {
             Snackbar.make(getView(), R.string.storage_permission_rationale,
                     Snackbar.LENGTH_INDEFINITE)
-                    .setAction(R.string.ok, new View.OnClickListener() {
+                    .setAction(R.string.ok, view -> ActivityCompat.requestPermissions(getActivity(),
-                        @Override
+                            new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, 1)).show();
-                        public void onClick(View view) {
-                            ActivityCompat.requestPermissions(getActivity(),
-                                    new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, 1);
-                        }
-                    }).show();
         } else {
             final DownloadManager manager = (DownloadManager)getActivity().getSystemService(Context.DOWNLOAD_SERVICE);
             manager.enqueue(req);

app/src/main/java/fr/free/nrw/commons/mwapi/ApacheHttpClientMediaWikiApi.java

@@ -351,12 +351,7 @@ public class ApacheHttpClientMediaWikiApi implements MediaWikiApi {
     @Override
     @NonNull
     public UploadResult uploadFile(String filename, InputStream file, long dataLength, String pageContents, String editSummary, final ProgressListener progressListener) throws IOException {
-        ApiResult result = api.upload(filename, file, dataLength, pageContents, editSummary, new in.yuvi.http.fluent.ProgressListener() {
+        ApiResult result = api.upload(filename, file, dataLength, pageContents, editSummary, progressListener::onProgress);
-            @Override
-            public void onProgress(long transferred, long total) {
-                progressListener.onProgress(transferred, total);
-            }
-        });
 
         Log.e("WTF", "Result: "+result.toString());
 

app/src/main/java/fr/free/nrw/commons/nearby/NearbyActivity.java

@@ -2,7 +2,6 @@ package fr.free.nrw.commons.nearby;
 
 import android.Manifest;
 import android.content.Context;
-import android.content.DialogInterface;
 import android.content.Intent;
 import android.content.pm.PackageManager;
 import android.location.LocationManager;
@@ -41,7 +40,8 @@ import timber.log.Timber;
 
 public class NearbyActivity extends NavigationBaseActivity {
 
-    @BindView(R.id.progressBar) ProgressBar progressBar;
+    @BindView(R.id.progressBar)
+    ProgressBar progressBar;
     private boolean isMapViewActive = false;
     private static final int LOCATION_REQUEST = 1;
 
@@ -115,15 +115,11 @@ public class NearbyActivity extends NavigationBaseActivity {
 
                         new AlertDialog.Builder(this)
                                 .setMessage(getString(R.string.location_permission_rationale))
-                                .setPositiveButton("OK", new DialogInterface.OnClickListener() {
+                                .setPositiveButton("OK", (dialog, which) -> {
-                                    @Override
-                                    public void onClick(DialogInterface dialog, int which) {
-
                                     ActivityCompat.requestPermissions(NearbyActivity.this,
                                             new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
                                             LOCATION_REQUEST);
                                     dialog.dismiss();
-                                    }
                                 })
                                 .setNegativeButton("Cancel", null)
                                 .create()
@@ -175,26 +171,19 @@ public class NearbyActivity extends NavigationBaseActivity {
         LocationManager manager = (LocationManager) getSystemService(LOCATION_SERVICE);
         if (!manager.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
             Timber.d("GPS is not enabled");
-            AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(this);
+            new AlertDialog.Builder(this)
-            alertDialogBuilder.setMessage(R.string.gps_disabled)
+                    .setMessage(R.string.gps_disabled)
                     .setCancelable(false)
                     .setPositiveButton(R.string.enable_gps,
-                            new DialogInterface.OnClickListener() {
+                            (dialog, id) -> {
-                                public void onClick(DialogInterface dialog, int id) {
                                 Intent callGPSSettingIntent = new Intent(
                                         android.provider.Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                                 Timber.d("Loaded settings page");
                                 startActivityForResult(callGPSSettingIntent, 1);
-                                }
+                            })
-                            });
+                    .setNegativeButton(R.string.menu_cancel_upload, (dialog, id) -> dialog.cancel())
-            alertDialogBuilder.setNegativeButton(R.string.menu_cancel_upload,
+                    .create()
-                    new DialogInterface.OnClickListener() {
+                    .show();
-                        public void onClick(DialogInterface dialog, int id) {
-                            dialog.cancel();
-                        }
-                    });
-            AlertDialog alert = alertDialogBuilder.create();
-            alert.show();
         } else {
             Timber.d("GPS is enabled");
         }
@@ -257,7 +246,7 @@ public class NearbyActivity extends NavigationBaseActivity {
 
         private final Context mContext;
 
-        private NearbyAsyncTask (Context context) {
+        private NearbyAsyncTask(Context context) {
             mContext = context;
         }
 

app/src/main/java/fr/free/nrw/commons/nearby/NearbyAdapterFactory.java

@@ -1,5 +1,7 @@
 package fr.free.nrw.commons.nearby;
 
+import android.support.annotation.NonNull;
+
 import com.pedrogomez.renderers.ListAdapteeCollection;
 import com.pedrogomez.renderers.RVRendererAdapter;
 import com.pedrogomez.renderers.RendererBuilder;
@@ -10,7 +12,7 @@ import java.util.List;
 class NearbyAdapterFactory {
     private PlaceRenderer.PlaceClickedListener listener;
 
-    NearbyAdapterFactory(PlaceRenderer.PlaceClickedListener listener) {
+    NearbyAdapterFactory(@NonNull PlaceRenderer.PlaceClickedListener listener) {
         this.listener = listener;
     }
 

app/src/main/java/fr/free/nrw/commons/nearby/NearbyController.java

@@ -52,14 +52,11 @@ public class NearbyController {
                 distances.put(place, computeDistanceBetween(place.location, curLatLng));
             }
             Collections.sort(places,
-                    new Comparator<Place>() {
+                    (lhs, rhs) -> {
-                        @Override
-                        public int compare(Place lhs, Place rhs) {
                         double lhsDistance = distances.get(lhs);
                         double rhsDistance = distances.get(rhs);
                         return (int) (lhsDistance - rhsDistance);
                     }
-                    }
             );
         }
         return places;

app/src/main/java/fr/free/nrw/commons/nearby/NearbyInfoDialog.java

@@ -63,15 +63,10 @@ public class NearbyInfoDialog extends OverlayDialog {
 
         overflowButton.setVisibility(showMenu() ? View.VISIBLE : View.GONE);
 
-        overflowButton.setOnClickListener(new View.OnClickListener() {
+        overflowButton.setOnClickListener(this::popupMenuListener);
-            @Override
-            public void onClick(View v) {
-                popupMenuListener();
-            }
-        });
     }
 
-    private void popupMenuListener() {
+    private void popupMenuListener(View v) {
         PopupMenu popupMenu = new PopupMenu(getActivity(), overflowButton);
         popupMenu.inflate(R.menu.nearby_info_dialog_options);
 

app/src/main/java/fr/free/nrw/commons/nearby/NearbyListFragment.java

@@ -48,12 +48,7 @@ public class NearbyListFragment extends Fragment {
         View view = inflater.inflate(R.layout.fragment_nearby, container, false);
         recyclerView = (RecyclerView) view.findViewById(R.id.listView);
         recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
-        adapterFactory = new NearbyAdapterFactory(new PlaceRenderer.PlaceClickedListener() {
+        adapterFactory = new NearbyAdapterFactory(place -> NearbyInfoDialog.showYourself(getActivity(), place));
-            @Override
-            public void placeClicked(Place place) {
-                NearbyInfoDialog.showYourself(getActivity(), place);
-            }
-        });
         return view;
     }
 

app/src/main/java/fr/free/nrw/commons/nearby/NearbyMapFragment.java

@@ -88,25 +88,19 @@ public class NearbyMapFragment extends android.support.v4.app.Fragment {
         // create map
         mapView = new MapView(getActivity(), options);
         mapView.onCreate(savedInstanceState);
-        mapView.getMapAsync(new OnMapReadyCallback() {
+        mapView.getMapAsync(mapboxMap -> {
-            @Override
-            public void onMapReady(MapboxMap mapboxMap) {
             mapboxMap.addMarkers(baseMarkerOptions);
 
-                mapboxMap.setOnMarkerClickListener(new MapboxMap.OnMarkerClickListener() {
+            mapboxMap.setOnMarkerClickListener(marker -> {
-                    @Override
-                    public boolean onMarkerClick(@NonNull Marker marker) {
                 if (marker instanceof NearbyMarker) {
                     NearbyMarker nearbyMarker = (NearbyMarker) marker;
                     Place place = nearbyMarker.getNearbyBaseMarker().getPlace();
                     NearbyInfoDialog.showYourself(getActivity(), place);
                 }
                 return false;
-                    }
             });
 
             addCurrentLocationMarker(mapboxMap);
-            }
         });
         if (PreferenceManager.getDefaultSharedPreferences(getActivity()).getBoolean("theme",true)) {
             mapView.setStyleUrl(getResources().getString(R.string.map_theme_dark));

app/src/main/java/fr/free/nrw/commons/nearby/PlaceRenderer.java

@@ -1,5 +1,6 @@
 package fr.free.nrw.commons.nearby;
 
+import android.support.annotation.NonNull;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
@@ -19,7 +20,7 @@ class PlaceRenderer extends Renderer<Place> {
     @BindView(R.id.icon) ImageView icon;
     private final PlaceClickedListener listener;
 
-    PlaceRenderer(PlaceClickedListener listener) {
+    PlaceRenderer(@NonNull PlaceClickedListener listener) {
         this.listener = listener;
     }
 
@@ -35,14 +36,7 @@ class PlaceRenderer extends Renderer<Place> {
 
     @Override
     protected void hookListeners(View view) {
-        view.setOnClickListener(new View.OnClickListener() {
+        view.setOnClickListener(v -> listener.placeClicked(getContent()));
-            @Override
-            public void onClick(View v) {
-                if (listener != null) {
-                    listener.placeClicked(getContent());
-                }
-            }
-        });
     }
 
     @Override

app/src/main/java/fr/free/nrw/commons/settings/SettingsFragment.java

@@ -28,21 +28,15 @@ public class SettingsFragment extends PreferenceFragment {
         licensePreference.setSummary(getString(Utils.licenseNameFor(licensePreference.getValue())));
 
         // Keep summary updated when changing value
-        licensePreference.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
+        licensePreference.setOnPreferenceChangeListener((preference, newValue) -> {
-            @Override
-            public boolean onPreferenceChange(Preference preference, Object newValue) {
             preference.setSummary(getString(Utils.licenseNameFor((String) newValue)));
             return true;
-            }
         });
 
         CheckBoxPreference themePreference = (CheckBoxPreference) findPreference("theme");
-        themePreference.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
+        themePreference.setOnPreferenceChangeListener((preference, newValue) -> {
-            @Override
-            public boolean onPreferenceChange(Preference preference, Object newValue) {
             getActivity().recreate();
             return true;
-            }
         });
 
         final EditTextPreference uploadLimit = (EditTextPreference) findPreference("uploads");
@@ -51,21 +45,14 @@ public class SettingsFragment extends PreferenceFragment {
         int uploads = sharedPref.getInt(Prefs.UPLOADS_SHOWING, 100);
         uploadLimit.setText(uploads + "");
         uploadLimit.setSummary(uploads + "");
-        uploadLimit.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
+        uploadLimit.setOnPreferenceChangeListener((preference, newValue) -> {
-
-            @Override
-            public boolean onPreferenceChange(Preference preference, Object newValue) {
             int value = Integer.parseInt(newValue.toString());
             final SharedPreferences.Editor editor = sharedPref.edit();
             if (value > 500) {
                 new AlertDialog.Builder(getActivity())
                         .setTitle(R.string.maximum_limit)
                         .setMessage(R.string.maximum_limit_alert)
-                            .setPositiveButton(android.R.string.yes,
+                        .setPositiveButton(android.R.string.yes, (dialog, which) -> {})
-                                    new DialogInterface.OnClickListener() {
-                                        public void onClick(DialogInterface dialog, int which) {
-                                        }
-                                    })
                         .setIcon(android.R.drawable.ic_dialog_alert)
                         .show();
                 editor.putInt(Prefs.UPLOADS_SHOWING, 500);
@@ -79,8 +66,6 @@ public class SettingsFragment extends PreferenceFragment {
             }
             editor.apply();
             return true;
-            }
-
         });
 
 

app/src/main/java/fr/free/nrw/commons/theme/NavigationBaseActivity.java

@@ -55,12 +55,7 @@ public class NavigationBaseActivity extends BaseActivity
     public void initBackButton() {
         int backStackEntryCount = getSupportFragmentManager().getBackStackEntryCount();
         toggle.setDrawerIndicatorEnabled(backStackEntryCount == 0);
-        toggle.setToolbarNavigationClickListener(new View.OnClickListener() {
+        toggle.setToolbarNavigationClickListener(v -> onBackPressed());
-            @Override
-            public void onClick(View v) {
-                onBackPressed();
-            }
-        });
     }
 
     public void initBack() {
@@ -118,9 +113,7 @@ public class NavigationBaseActivity extends BaseActivity
                 new AlertDialog.Builder(this)
                         .setMessage(R.string.logout_verification)
                         .setCancelable(false)
-                        .setPositiveButton(R.string.yes, new DialogInterface.OnClickListener() {
+                        .setPositiveButton(R.string.yes, (dialog, which) -> {
-                            @Override
-                            public void onClick(DialogInterface dialog, int which) {
                             ((CommonsApplication) getApplicationContext())
                                     .clearApplicationData(NavigationBaseActivity.this);
                             Intent nearbyIntent = new Intent(
@@ -129,14 +122,8 @@ public class NavigationBaseActivity extends BaseActivity
                             nearbyIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                             startActivity(nearbyIntent);
                             finish();
-                            }
-                        })
-                        .setNegativeButton(R.string.no, new DialogInterface.OnClickListener() {
-                            @Override
-                            public void onClick(DialogInterface dialog, int which) {
-                                dialog.cancel();
-                            }
                         })
+                        .setNegativeButton(R.string.no, (dialog, which) -> dialog.cancel())
                         .show();
                 return true;
             default:

app/src/main/java/fr/free/nrw/commons/upload/ExistingFileAsync.java

@@ -72,21 +72,13 @@ public class ExistingFileAsync extends AsyncTask<Void, Void, Boolean> {
             AlertDialog.Builder builder = new AlertDialog.Builder(context);
             builder.setMessage(R.string.file_exists)
                     .setTitle(R.string.warning);
-            builder.setPositiveButton(R.string.no, new DialogInterface.OnClickListener() {
+            builder.setPositiveButton(R.string.no, (dialog, id) -> {
-                @Override
-                public void onClick(DialogInterface dialog, int id) {
                 //Go back to ContributionsActivity
                 Intent intent = new Intent(context, ContributionsActivity.class);
                 context.startActivity(intent);
                 callback.onResult(Result.DUPLICATE_CANCELLED);
-                }
-            });
-            builder.setNegativeButton(R.string.yes, new DialogInterface.OnClickListener() {
-                @Override
-                public void onClick(DialogInterface dialog, int id) {
-                    callback.onResult(Result.DUPLICATE_PROCEED);
-                }
             });
+            builder.setNegativeButton(R.string.yes, (dialog, id) -> callback.onResult(Result.DUPLICATE_PROCEED));
 
             AlertDialog dialog = builder.create();
             dialog.show();

app/src/main/java/fr/free/nrw/commons/upload/MultipleShareActivity.java

@@ -125,11 +125,9 @@ public  class       MultipleShareActivity
             Contribution up = photosList.get(i);
             final int uploadCount = i + 1; // Goddamn Java
 
-            uploadController.startUpload(up, new UploadController.ContributionUploadProgress() {
+            uploadController.startUpload(up, contribution -> {
-                @Override
-                public void onUploadStarted(Contribution contribution) {
                 dialog.setProgress(uploadCount);
-                    if(uploadCount == photosList.size()) {
+                if (uploadCount == photosList.size()) {
                     dialog.dismiss();
                     Toast startingToast = Toast.makeText(
                             CommonsApplication.getInstance(),
@@ -138,7 +136,6 @@ public  class       MultipleShareActivity
                     );
                     startingToast.show();
                 }
-                }
             });
         }
 

app/src/main/java/fr/free/nrw/commons/upload/MwVolleyApi.java

@@ -57,7 +57,7 @@ public class MwVolleyApi {
         Timber.d("URL: %s", apiUrl);
 
         JsonRequest<QueryResponse> request = new QueryRequest(apiUrl,
-                new LogResponseListener<QueryResponse>(), new LogResponseErrorListener());
+                new LogResponseListener<>(), new LogResponseErrorListener());
         getQueue().add(request);
     }
 

app/src/main/java/fr/free/nrw/commons/upload/ShareActivity.java

@@ -44,6 +44,9 @@ import fr.free.nrw.commons.modifications.TemplateRemoveModifier;
 import fr.free.nrw.commons.mwapi.EventLog;
 import timber.log.Timber;
 
+import static fr.free.nrw.commons.upload.ExistingFileAsync.Result.DUPLICATE_PROCEED;
+import static fr.free.nrw.commons.upload.ExistingFileAsync.Result.NO_DUPLICATE;
+
 /**
  * Activity for the title/desc screen after image is selected. Also starts processing image
  * GPS coordinates or user location (if enabled in Settings) for category suggestions.
@@ -133,12 +136,9 @@ public  class       ShareActivity
             Timber.d("Cache the categories found");
         }
 
-        uploadController.startUpload(title, mediaUri, description, mimeType, source, decimalCoords, new UploadController.ContributionUploadProgress() {
+        uploadController.startUpload(title, mediaUri, description, mimeType, source, decimalCoords, c -> {
-            @Override
+            ShareActivity.this.contribution = c;
-            public void onUploadStarted(Contribution contribution) {
-                ShareActivity.this.contribution = contribution;
             showPostUpload();
-            }
         });
     }
 
@@ -379,14 +379,10 @@ public  class       ShareActivity
                     Timber.d("File SHA1 is: %s", fileSHA1);
 
                     ExistingFileAsync fileAsyncTask =
-                            new ExistingFileAsync(fileSHA1, this, new ExistingFileAsync.Callback() {
+                            new ExistingFileAsync(fileSHA1, this, result -> {
-                                @Override
-                                public void onResult(ExistingFileAsync.Result result) {
                                 Timber.d("%s duplicate check: %s", mediaUri.toString(), result);
-                                    duplicateCheckPassed =
+                                duplicateCheckPassed = (result == DUPLICATE_PROCEED
-                                            result == ExistingFileAsync.Result.DUPLICATE_PROCEED
+                                        || result == NO_DUPLICATE);
-                                                    || result == ExistingFileAsync.Result.NO_DUPLICATE;
-                                }
                             });
                     fileAsyncTask.execute();
                 } catch (IOException e) {
@@ -401,17 +397,12 @@ public  class       ShareActivity
         }
     }
 
-    private Snackbar requestPermissionUsingSnackBar(
+    private Snackbar requestPermissionUsingSnackBar(String rationale,
-            String rationale, final String[] perms, final int code) {
+                                                    final String[] perms,
+                                                    final int code) {
         Snackbar snackbar = Snackbar.make(findViewById(android.R.id.content), rationale,
-                Snackbar.LENGTH_INDEFINITE)
+                Snackbar.LENGTH_INDEFINITE).setAction(R.string.ok,
-                .setAction(R.string.ok, new View.OnClickListener() {
+                view -> ActivityCompat.requestPermissions(ShareActivity.this, perms, code));
-                    @Override
-                    public void onClick(View view) {
-                        ActivityCompat.requestPermissions(ShareActivity.this,
-                                perms, code);
-                    }
-                });
         snackbar.show();
         return snackbar;
     }

app/src/main/java/fr/free/nrw/commons/utils/ExecutorUtils.java

@@ -7,15 +7,12 @@ import java.util.concurrent.Executor;
 
 public class ExecutorUtils {
 
-    private static final Executor uiExecutor = new Executor() {
+    private static final Executor uiExecutor = command -> {
-        @Override
-        public void execute(Runnable command) {
         if (Looper.myLooper() == Looper.getMainLooper()) {
             command.run();
         } else {
             new Handler(Looper.getMainLooper()).post(command);
         }
-        }
     };
 
     public static Executor uiExecutor () { return uiExecutor;}

app/src/main/java/fr/free/nrw/commons/utils/FileUtils.java

@@ -42,8 +42,8 @@ public class FileUtils {
         if (file != null) {
             if (file.isDirectory()) {
                 String[] children = file.list();
-                for (int i = 0; i < children.length; i++) {
+                for (String child : children) {
-                    deletedAll = deleteFile(new File(file, children[i])) && deletedAll;
+                    deletedAll = deleteFile(new File(file, child)) && deletedAll;
                 }
             } else {
                 deletedAll = file.delete();

app/src/test/java/fr/free/nrw/commons/nearby/NearbyAdapterFactoryTest.java

@@ -113,14 +113,6 @@ public class NearbyAdapterFactoryTest {
         assertEquals(PLACE, clickedPlace);
     }
 
-    @Test
-    public void clickViewHandlesMisconfiguredListener() {
-        NearbyAdapterFactory testObject = new NearbyAdapterFactory(null);
-        RVRendererAdapter<Place> result = testObject.create(Collections.singletonList(PLACE));
-        RendererViewHolder viewHolder = renderComponent(result);
-        viewHolder.itemView.performClick();
-    }
-
     @NonNull
     private RendererViewHolder renderComponent(RVRendererAdapter<Place> result) {
         FrameLayout viewGroup = new FrameLayout(RuntimeEnvironment.application);

build.gradle

@@ -8,6 +8,7 @@ buildscript {
         classpath "com.android.tools.build:gradle:${project.gradleVersion}"
         classpath 'com.dicedmelon.gradle:jacoco-android:0.1.1'
         classpath 'com.getkeepsafe.dexcount:dexcount-gradle-plugin:0.7.1'
+        classpath 'me.tatarka:gradle-retrolambda:3.6.1'
     }
 }