[GSoC] Added Pagination to Leaderboard

app/build.gradle

@@ -42,6 +42,7 @@ dependencies {
     implementation 'com.dinuscxj:circleprogressbar:1.1.1'
     implementation 'com.karumi:dexter:5.0.0'
     implementation "com.jakewharton:butterknife:$BUTTERKNIFE_VERSION"
+    implementation 'androidx.lifecycle:lifecycle-extensions:2.2.0'
 
     kapt "com.jakewharton:butterknife-compiler:$BUTTERKNIFE_VERSION"
     implementation "com.hannesdorfmann:adapterdelegates4-kotlin-dsl-layoutcontainer:$ADAPTER_DELEGATES_VERSION"
@@ -210,8 +211,8 @@ android {
 
     configurations.all {
         resolutionStrategy.force 'androidx.annotation:annotation:1.0.2'
+        exclude module: 'okhttp-ws'
     }
-
     flavorDimensions 'tier'
     productFlavors {
         prod {

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

@@ -3,14 +3,14 @@
 import android.text.TextUtils;
 import androidx.annotation.NonNull;
 import com.google.gson.Gson;
-import fr.free.nrw.commons.profile.achievements.FeaturedImages;
-import fr.free.nrw.commons.profile.achievements.FeedbackResponse;
 import fr.free.nrw.commons.campaigns.CampaignResponseDTO;
 import fr.free.nrw.commons.explore.depictions.DepictsClient;
 import fr.free.nrw.commons.location.LatLng;
 import fr.free.nrw.commons.nearby.Place;
 import fr.free.nrw.commons.nearby.model.NearbyResponse;
 import fr.free.nrw.commons.nearby.model.NearbyResultItem;
+import fr.free.nrw.commons.profile.achievements.FeaturedImages;
+import fr.free.nrw.commons.profile.achievements.FeedbackResponse;
 import fr.free.nrw.commons.profile.leaderboard.LeaderboardResponse;
 import fr.free.nrw.commons.upload.FileUtils;
 import fr.free.nrw.commons.upload.structure.depictions.DepictedItem;
@@ -65,32 +65,32 @@ public OkHttpJsonApiClient(OkHttpClient okHttpClient,
   }
 
   @NonNull
-  public Single<LeaderboardResponse> getLeaderboard(String userName, String duration, String category, String limit, String offset) {
+  public Observable<LeaderboardResponse> getLeaderboard(String userName, String duration, String category, String limit, String offset) {
     final String fetchLeaderboardUrlTemplate = wikiMediaTestToolforgeUrl
         + "/leaderboard.py";
-    return Single.fromCallable(() -> {
-      String url = String.format(Locale.ENGLISH,
-          fetchLeaderboardUrlTemplate,
-          userName,
-          duration,
-          category,
-          limit,
-          offset);
-      HttpUrl.Builder urlBuilder = HttpUrl.parse(url).newBuilder();
-      urlBuilder.addQueryParameter("user", userName);
-      urlBuilder.addQueryParameter("duration", duration);
-      urlBuilder.addQueryParameter("category", category);
-      urlBuilder.addQueryParameter("limit", limit);
-      urlBuilder.addQueryParameter("offset", offset);
-      Timber.i("Url %s", urlBuilder.toString());
-      Request request = new Request.Builder()
-          .url(urlBuilder.toString())
-          .build();
+    String url = String.format(Locale.ENGLISH,
+        fetchLeaderboardUrlTemplate,
+        userName,
+        duration,
+        category,
+        limit,
+        offset);
+    HttpUrl.Builder urlBuilder = HttpUrl.parse(url).newBuilder();
+    urlBuilder.addQueryParameter("user", userName);
+    urlBuilder.addQueryParameter("duration", duration);
+    urlBuilder.addQueryParameter("category", category);
+    urlBuilder.addQueryParameter("limit", limit);
+    urlBuilder.addQueryParameter("offset", offset);
+    Timber.i("Url %s", urlBuilder.toString());
+    Request request = new Request.Builder()
+        .url(urlBuilder.toString())
+        .build();
+    return Observable.fromCallable(() -> {
       Response response = okHttpClient.newCall(request).execute();
       if (response != null && response.body() != null && response.isSuccessful()) {
         String json = response.body().string();
         if (json == null) {
-          return null;
+          return new LeaderboardResponse();
         }
         Timber.d("Response for leaderboard is %s", json);
         try {
@@ -99,7 +99,7 @@ public Single<LeaderboardResponse> getLeaderboard(String userName, String durati
           return new LeaderboardResponse();
         }
       }
-      return null;
+      return new LeaderboardResponse();
     });
   }
 
@@ -188,7 +188,6 @@ public Single<FeedbackResponse> getAchievements(String userName) {
           userName);
       HttpUrl.Builder urlBuilder = HttpUrl.parse(url).newBuilder();
       urlBuilder.addQueryParameter("user", userName);
-      Timber.i("Url %s", urlBuilder.toString());
       Request request = new Request.Builder()
           .url(urlBuilder.toString())
           .build();

app/src/main/java/fr/free/nrw/commons/profile/leaderboard/DataSourceClass.java

@@ -0,0 +1,88 @@
+package fr.free.nrw.commons.profile.leaderboard;
+
+import static fr.free.nrw.commons.profile.leaderboard.LeaderboardConstants.LOADED;
+import static fr.free.nrw.commons.profile.leaderboard.LeaderboardConstants.LOADING;
+import static fr.free.nrw.commons.profile.leaderboard.LeaderboardConstants.PAGE_SIZE;
+import static fr.free.nrw.commons.profile.leaderboard.LeaderboardConstants.START_OFFSET;
+
+import androidx.annotation.NonNull;
+import androidx.lifecycle.MutableLiveData;
+import androidx.paging.PageKeyedDataSource;
+import fr.free.nrw.commons.auth.SessionManager;
+import fr.free.nrw.commons.mwapi.OkHttpJsonApiClient;
+import io.reactivex.disposables.CompositeDisposable;
+import java.util.Objects;
+import timber.log.Timber;
+
+public class DataSourceClass extends PageKeyedDataSource<Integer, LeaderboardList> {
+
+    private OkHttpJsonApiClient okHttpJsonApiClient;
+    private SessionManager sessionManager;
+    private MutableLiveData<String> progressLiveStatus;
+    private CompositeDisposable compositeDisposable = new CompositeDisposable();
+
+    public DataSourceClass(OkHttpJsonApiClient okHttpJsonApiClient,SessionManager sessionManager) {
+        this.okHttpJsonApiClient = okHttpJsonApiClient;
+        this.sessionManager = sessionManager;
+        progressLiveStatus = new MutableLiveData<>();
+    }
+
+
+    public MutableLiveData<String> getProgressLiveStatus() {
+        return progressLiveStatus;
+    }
+
+    @Override
+    public void loadInitial(@NonNull LoadInitialParams<Integer> params,
+        @NonNull LoadInitialCallback<Integer, LeaderboardList> callback) {
+
+        compositeDisposable.add(okHttpJsonApiClient
+                .getLeaderboard(Objects.requireNonNull(sessionManager.getCurrentAccount()).name,
+                    "all_time", "upload", String.valueOf(PAGE_SIZE), String.valueOf(START_OFFSET))
+                .doOnSubscribe(disposable -> {
+                    compositeDisposable.add(disposable);
+                    progressLiveStatus.postValue(LOADING);
+                }).subscribe(
+                response -> {
+                    if (response != null && response.getStatus() == 200) {
+                        progressLiveStatus.postValue(LOADED);
+                        callback.onResult(response.getLeaderboardList(), null, response.getLimit());
+                    }
+                },
+                t -> {
+                    Timber.e(t, "Fetching leaderboard statistics failed");
+                    progressLiveStatus.postValue(LOADING);
+                }
+            ));
+
+    }
+
+    @Override
+    public void loadBefore(@NonNull LoadParams<Integer> params,
+        @NonNull LoadCallback<Integer, LeaderboardList> callback) {
+
+    }
+
+    @Override
+    public void loadAfter(@NonNull LoadParams<Integer> params,
+        @NonNull LoadCallback<Integer, LeaderboardList> callback) {
+        compositeDisposable.add(okHttpJsonApiClient
+            .getLeaderboard(Objects.requireNonNull(sessionManager.getCurrentAccount()).name,
+                "all_time", "upload", String.valueOf(PAGE_SIZE), String.valueOf(params.key))
+            .doOnSubscribe(disposable -> {
+                compositeDisposable.add(disposable);
+                progressLiveStatus.postValue(LOADING);
+            }).subscribe(
+                response -> {
+                    if (response != null && response.getStatus() == 200) {
+                        progressLiveStatus.postValue(LOADED);
+                        callback.onResult(response.getLeaderboardList(), params.key + PAGE_SIZE);
+                    }
+                },
+                t -> {
+                    Timber.e(t, "Fetching leaderboard statistics failed");
+                    progressLiveStatus.postValue(LOADING);
+                }
+            ));
+    }
+}

app/src/main/java/fr/free/nrw/commons/profile/leaderboard/DataSourceFactory.java

@@ -0,0 +1,34 @@
+package fr.free.nrw.commons.profile.leaderboard;
+
+import androidx.lifecycle.MutableLiveData;
+import androidx.paging.DataSource;
+import fr.free.nrw.commons.auth.SessionManager;
+import fr.free.nrw.commons.mwapi.OkHttpJsonApiClient;
+import io.reactivex.disposables.CompositeDisposable;
+
+public class DataSourceFactory extends DataSource.Factory<Integer, LeaderboardList> {
+
+    private MutableLiveData<DataSourceClass> liveData;
+    private OkHttpJsonApiClient okHttpJsonApiClient;
+    private CompositeDisposable compositeDisposable;
+    private SessionManager sessionManager;
+
+    public DataSourceFactory(OkHttpJsonApiClient okHttpJsonApiClient, CompositeDisposable compositeDisposable,
+        SessionManager sessionManager) {
+        this.okHttpJsonApiClient = okHttpJsonApiClient;
+        this.compositeDisposable = compositeDisposable;
+        this.sessionManager = sessionManager;
+        liveData = new MutableLiveData<>();
+    }
+
+    public MutableLiveData<DataSourceClass> getMutableLiveData() {
+        return liveData;
+    }
+
+    @Override
+    public DataSource<Integer, LeaderboardList> create() {
+        DataSourceClass dataSourceClass = new DataSourceClass(okHttpJsonApiClient, sessionManager);
+        liveData.postValue(dataSourceClass);
+        return dataSourceClass;
+    }
+}

app/src/main/java/fr/free/nrw/commons/profile/leaderboard/LeaderboardConstants.java

@@ -0,0 +1,15 @@
+package fr.free.nrw.commons.profile.leaderboard;
+
+public class LeaderboardConstants {
+
+    public static final int PAGE_SIZE = 10;
+
+    public static final int START_OFFSET = 0;
+
+    public static final String AVATAR_SOURCE_URL = "https://upload.wikimedia.org/wikipedia/commons/thumb/0/0a/%s/1024px-%s.png";
+
+    public final static String LOADING = "Loading";
+
+    public final static String LOADED = "Loaded";
+
+}

app/src/main/java/fr/free/nrw/commons/profile/leaderboard/LeaderboardFragment.java

@@ -1,18 +1,20 @@
 package fr.free.nrw.commons.profile.leaderboard;
 
+import static fr.free.nrw.commons.profile.leaderboard.LeaderboardConstants.LOADED;
+import static fr.free.nrw.commons.profile.leaderboard.LeaderboardConstants.LOADING;
+
 import android.accounts.Account;
-import android.net.Uri;
 import android.os.Bundle;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.ProgressBar;
-import android.widget.TextView;
+import androidx.lifecycle.ViewModelProvider;
 import androidx.recyclerview.widget.LinearLayoutManager;
+import androidx.recyclerview.widget.MergeAdapter;
 import androidx.recyclerview.widget.RecyclerView;
 import butterknife.BindView;
 import butterknife.ButterKnife;
-import com.facebook.drawee.view.SimpleDraweeView;
 import fr.free.nrw.commons.R;
 import fr.free.nrw.commons.auth.SessionManager;
 import fr.free.nrw.commons.di.CommonsDaggerSupportFragment;
@@ -21,25 +23,12 @@
 import io.reactivex.android.schedulers.AndroidSchedulers;
 import io.reactivex.disposables.CompositeDisposable;
 import io.reactivex.schedulers.Schedulers;
-import java.util.List;
 import java.util.Objects;
 import javax.inject.Inject;
 import timber.log.Timber;
 
 public class LeaderboardFragment extends CommonsDaggerSupportFragment {
 
-    @BindView(R.id.avatar)
-    SimpleDraweeView avatar;
-
-    @BindView(R.id.username)
-    TextView username;
-
-    @BindView(R.id.rank)
-    TextView rank;
-
-    @BindView(R.id.count)
-    TextView count;
-
     @BindView(R.id.leaderboard_list)
     RecyclerView leaderboardListRecyclerView;
 
@@ -52,7 +41,10 @@ public class LeaderboardFragment extends CommonsDaggerSupportFragment {
     @Inject
     OkHttpJsonApiClient okHttpJsonApiClient;
 
-    private String avatarSourceURL = "https://upload.wikimedia.org/wikipedia/commons/thumb/0/0a/%s/1024px-%s.png";
+    @Inject
+    ViewModelFactory viewModelFactory;
+
+    LeaderboardListViewModel viewModel;
 
     private CompositeDisposable compositeDisposable = new CompositeDisposable();
 
@@ -67,12 +59,12 @@ public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle sa
     }
 
     /**
-     * To call the API to get results in form Single<JSONObject>
-     * which then calls parseJson when results are fetched
+     * To call the API to get results
+     * which then sets the views using setLeaderboardUser method
      */
     private void setLeaderboard() {
         if (checkAccount()) {
-            try{
+            try {
                 compositeDisposable.add(okHttpJsonApiClient
                     .getLeaderboard(Objects.requireNonNull(sessionManager.getCurrentAccount()).name,
                         "all_time", "upload", null, null)
@@ -81,8 +73,7 @@ private void setLeaderboard() {
                     .subscribe(
                         response -> {
                             if (response != null && response.getStatus() == 200) {
-                                setLeaderboardUser(response);
-                                setLeaderboardList(response.getLeaderboardList());
+                                setViews(response);
                             }
                         },
                         t -> {
@@ -101,20 +92,23 @@ private void setLeaderboard() {
      * Set the views
      * @param response Leaderboard Response Object
      */
-    private void setLeaderboardUser(LeaderboardResponse response) {
-        hideProgressBar();
-        avatar.setImageURI(
-            Uri.parse(String.format(avatarSourceURL, response.getAvatar(), response.getAvatar())));
-        username.setText(response.getUsername());
-        rank.setText(String.format("%s %d", getString(R.string.rank_prefix), response.getRank()));
-        count.setText(String.format("%s %d", getString(R.string.count_prefix), response.getCategoryCount()));
-    }
-
-    private void setLeaderboardList(List<LeaderboardList> leaderboardList) {
-        LeaderboardListAdapter leaderboardListAdapter = new LeaderboardListAdapter(leaderboardList);
+    private void setViews(LeaderboardResponse response) {
+        viewModel = new ViewModelProvider(this, viewModelFactory).get(LeaderboardListViewModel.class);
+        LeaderboardListAdapter leaderboardListAdapter = new LeaderboardListAdapter();
+        UserDetailAdapter userDetailAdapter= new UserDetailAdapter(response);
+        MergeAdapter mergeAdapter = new MergeAdapter(userDetailAdapter, leaderboardListAdapter);
         LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getContext());
         leaderboardListRecyclerView.setLayoutManager(linearLayoutManager);
-        leaderboardListRecyclerView.setAdapter(leaderboardListAdapter);
+        leaderboardListRecyclerView.setAdapter(mergeAdapter);
+
+        viewModel.getListLiveData().observe(getViewLifecycleOwner(), leaderboardListAdapter::submitList);
+        viewModel.getProgressLoadStatus().observe(getViewLifecycleOwner(), status -> {
+                if (Objects.requireNonNull(status).equalsIgnoreCase(LOADING)) {
+                    showProgressBar();
+                } else if (status.equalsIgnoreCase(LOADED)) {
+                    hideProgressBar();
+                }
+        });
     }
 
     /**
@@ -123,20 +117,23 @@ private void setLeaderboardList(List<LeaderboardList> leaderboardList) {
     private void hideProgressBar() {
         if (progressBar != null) {
             progressBar.setVisibility(View.GONE);
-            avatar.setVisibility(View.VISIBLE);
-            username.setVisibility(View.VISIBLE);
-            rank.setVisibility(View.VISIBLE);
             leaderboardListRecyclerView.setVisibility(View.VISIBLE);
         }
     }
 
+    /**
+     * to show progressbar
+     */
+    private void showProgressBar() {
+        if (progressBar != null) {
+            progressBar.setVisibility(View.VISIBLE);
+        }
+    }
+
     /**
      * used to hide the layouts while fetching results from api
      */
     private void hideLayouts(){
-        avatar.setVisibility(View.INVISIBLE);
-        username.setVisibility(View.INVISIBLE);
-        rank.setVisibility(View.INVISIBLE);
         leaderboardListRecyclerView.setVisibility(View.INVISIBLE);
     }