Display a MaterialLoadingProgressBar instead of a ProgressBar when loading posts. Correctly handle the visibility of the MaterialLoadingProgressBar when loading posts.

app/build.gradle

@@ -71,4 +71,5 @@ dependencies {
     implementation 'com.github.santalu:aspect-ratio-imageview:1.0.6'
     implementation 'com.felipecsl:gifimageview:2.2.0'
     implementation "android.arch.paging:runtime:1.0.1"
+    implementation "com.lsjwzh:materialloadingprogressbar:0.5.8-RELEASE"
 }

app/src/main/java/ml/docilealligator/infinityforreddit/PostDataSource.java

@@ -41,11 +41,11 @@ class PostDataSource extends PageKeyedDataSource<String, Post> {
         initialLoading = new MutableLiveData();
     }
 
-    public MutableLiveData getNetworkState() {
+    MutableLiveData getNetworkState() {
         return networkState;
     }
 
-    public MutableLiveData getInitialLoading() {
+    MutableLiveData getInitialLoading() {
         return initialLoading;
     }
 

app/src/main/java/ml/docilealligator/infinityforreddit/PostDataSourceFactory.java

@@ -2,7 +2,6 @@ package ml.docilealligator.infinityforreddit;
 
 import android.arch.lifecycle.MutableLiveData;
 import android.arch.paging.DataSource;
-import android.arch.paging.PageKeyedDataSource;
 
 import java.util.Locale;
 
@@ -15,7 +14,7 @@ class PostDataSourceFactory extends DataSource.Factory {
     private boolean isBestPost;
     private String subredditName;
 
-    private MutableLiveData<PageKeyedDataSource<String, Post>> mutableLiveData;
+    private MutableLiveData<PostDataSource> mutableLiveData;
 
     PostDataSourceFactory(Retrofit retrofit, String accessToken, Locale locale, boolean isBestPost) {
         this.retrofit = retrofit;
@@ -45,7 +44,7 @@ class PostDataSourceFactory extends DataSource.Factory {
         return postDataSource;
     }
 
-    public MutableLiveData<PageKeyedDataSource<String, Post>> getMutableLiveData() {
+    public MutableLiveData<PostDataSource> getMutableLiveData() {
         return mutableLiveData;
     }
 }

app/src/main/java/ml/docilealligator/infinityforreddit/PostFragment.java

@@ -7,6 +7,7 @@ import android.content.SharedPreferences;
 import android.os.Bundle;
 import android.support.annotation.NonNull;
 import android.support.design.widget.CoordinatorLayout;
+import android.support.design.widget.Snackbar;
 import android.support.v4.app.Fragment;
 import android.support.v7.widget.LinearLayoutManager;
 import android.support.v7.widget.RecyclerView;
@@ -15,7 +16,9 @@ import android.view.View;
 import android.view.ViewGroup;
 import android.widget.ImageView;
 import android.widget.LinearLayout;
-import android.widget.ProgressBar;
+
+import com.bumptech.glide.Glide;
+import com.lsjwzh.widget.materialloadingprogressbar.CircleProgressBar;
 
 import javax.inject.Inject;
 import javax.inject.Named;
@@ -31,15 +34,10 @@ public class PostFragment extends Fragment implements FragmentCommunicator {
     static final String SUBREDDIT_NAME_KEY = "SNK";
     static final String IS_BEST_POST_KEY = "IBPK";
 
-    private static final String LAST_ITEM_STATE = "LIS";
-    private static final String LOADING_STATE_STATE = "LSS";
-    private static final String LOAD_SUCCESS_STATE = "LOSS";
-    private static final String IS_REFRESH_STATE = "IRS";
-
     private CoordinatorLayout mCoordinatorLayout;
     private RecyclerView mPostRecyclerView;
     private LinearLayoutManager mLinearLayoutManager;
-    private ProgressBar mProgressBar;
+    private CircleProgressBar mProgressBar;
     private LinearLayout mFetchPostErrorLinearLayout;
     private ImageView mFetchPostErrorImageView;
 
@@ -134,6 +132,15 @@ public class PostFragment extends Fragment implements FragmentCommunicator {
         }
         mPostViewModel = ViewModelProviders.of(this, factory).get(PostViewModel.class);
         mPostViewModel.getPosts().observe(this, posts -> mAdapter.submitList(posts));
+        mPostViewModel.getInitialLoadingState().observe(this, networkState -> {
+            if(networkState.getStatus().equals(NetworkState.Status.SUCCESS)) {
+                mProgressBar.setVisibility(View.GONE);
+            } else if(networkState.getStatus().equals(NetworkState.Status.FAILED)) {
+                showErrorView();
+            } else {
+                mProgressBar.setVisibility(View.VISIBLE);
+            }
+        });
 
         return rootView;
     }
@@ -143,7 +150,6 @@ public class PostFragment extends Fragment implements FragmentCommunicator {
 
     }
 
-    /*
     private void showErrorView() {
         mProgressBar.setVisibility(View.GONE);
         if(mIsBestPost) {
@@ -156,14 +162,14 @@ public class PostFragment extends Fragment implements FragmentCommunicator {
             snackbar.setAction(R.string.retry, new View.OnClickListener() {
                 @Override
                 public void onClick(View view) {
-                    if (mIsBestPost) {
+                    /*if (mIsBestPost) {
                         fetchBestPost();
                     } else {
                         fetchPost();
-                    }
+                    }*/
                 }
             });
             snackbar.show();
         }
-    }*/
+    }
 }

app/src/main/java/ml/docilealligator/infinityforreddit/PostViewModel.java

@@ -1,10 +1,10 @@
 package ml.docilealligator.infinityforreddit;
 
 import android.arch.lifecycle.LiveData;
+import android.arch.lifecycle.Transformations;
 import android.arch.lifecycle.ViewModel;
 import android.arch.lifecycle.ViewModelProvider;
 import android.arch.paging.LivePagedListBuilder;
-import android.arch.paging.PageKeyedDataSource;
 import android.arch.paging.PagedList;
 import android.support.annotation.NonNull;
 
@@ -15,18 +15,19 @@ import retrofit2.Retrofit;
 
 public class PostViewModel extends ViewModel {
     private Executor executor;
-    LiveData<NetworkState> networkState;
+    private LiveData<NetworkState> networkState;
-    LiveData<PagedList<Post>> posts;
+    private LiveData<NetworkState> initialLoadingState;
-    LiveData<PageKeyedDataSource<String, Post>> liveDataSource;
+    private LiveData<PagedList<Post>> posts;
 
     public PostViewModel(Retrofit retrofit, String accessToken, Locale locale, boolean isBestPost) {
         //executor = Executors.newFixedThreadPool(5);
 
         PostDataSourceFactory postDataSourceFactory = new PostDataSourceFactory(retrofit, accessToken, locale, isBestPost);
-        /*networkState = Transformations.switchMap(postDataSourceFactory.getMutableLiveData(),
-                (Function<PostDataSource, LiveData<NetworkState>>) PostDataSource::getNetworkState);*/
-        liveDataSource = postDataSourceFactory.getMutableLiveData();
 
+        initialLoadingState = Transformations.switchMap(postDataSourceFactory.getMutableLiveData(),
+                dataSource -> dataSource.getInitialLoading());
+        networkState = Transformations.switchMap(postDataSourceFactory.getMutableLiveData(),
+                dataSource -> dataSource.getNetworkState());
         PagedList.Config pagedListConfig =
                 (new PagedList.Config.Builder())
                         .setEnablePlaceholders(false)
@@ -40,9 +41,11 @@ public class PostViewModel extends ViewModel {
         //executor = Executors.newFixedThreadPool(5);
 
         PostDataSourceFactory postDataSourceFactory = new PostDataSourceFactory(retrofit, locale, isBestPost, subredditName);
-        /*networkState = Transformations.switchMap(postDataSourceFactory.getMutableLiveData(),
+
-                (Function<PostDataSource, LiveData<NetworkState>>) PostDataSource::getNetworkState);*/
+        initialLoadingState = Transformations.switchMap(postDataSourceFactory.getMutableLiveData(),
-        liveDataSource = postDataSourceFactory.getMutableLiveData();
+                dataSource -> dataSource.getInitialLoading());
+        networkState = Transformations.switchMap(postDataSourceFactory.getMutableLiveData(),
+                dataSource -> dataSource.getNetworkState());
 
         PagedList.Config pagedListConfig =
                 (new PagedList.Config.Builder())
@@ -57,9 +60,13 @@ public class PostViewModel extends ViewModel {
         return posts;
     }
 
-    /*public LiveData<NetworkState> getNetworkState() {
+    LiveData<NetworkState> getNetworkState() {
         return networkState;
-    }*/
+    }
+
+    public LiveData<NetworkState> getInitialLoadingState() {
+        return initialLoadingState;
+    }
 
     public static class Factory extends ViewModelProvider.NewInstanceFactory {
         private Retrofit retrofit;

app/src/main/java/ml/docilealligator/infinityforreddit/ViewPostDetailActivity.java

@@ -31,6 +31,7 @@ import com.bumptech.glide.load.engine.GlideException;
 import com.bumptech.glide.request.RequestListener;
 import com.bumptech.glide.request.RequestOptions;
 import com.bumptech.glide.request.target.Target;
+import com.lsjwzh.widget.materialloadingprogressbar.CircleProgressBar;
 import com.multilevelview.MultiLevelRecyclerView;
 import com.santalu.aspectratioimageview.AspectRatioImageView;
 
@@ -83,7 +84,7 @@ public class ViewPostDetailActivity extends AppCompatActivity {
     @BindView(R.id.minus_button_view_post_detail) ImageView mDownvoteButton;
     @BindView(R.id.share_button_view_post_detail) ImageView mShareButton;
 
-    @BindView(R.id.comment_progress_bar_view_post_detail) ProgressBar mCommentProgressbar;
+    @BindView(R.id.comment_progress_bar_view_post_detail) CircleProgressBar mCommentProgressbar;
     @BindView(R.id.comment_card_view_view_post_detail) CardView mCommentCardView;
     @BindView(R.id.recycler_view_view_post_detail) MultiLevelRecyclerView mRecyclerView;
 

app/src/main/res/layout/activity_view_post_detail.xml

@@ -258,13 +258,15 @@
 
             </android.support.v7.widget.CardView>
 
-            <ProgressBar
+            <com.lsjwzh.widget.materialloadingprogressbar.CircleProgressBar
                 android:id="@+id/comment_progress_bar_view_post_detail"
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
-                android:layout_gravity="center"
+                android:layout_marginTop="16dp"
-                android:layout_margin="16dp"
+                android:layout_marginBottom="16dp"
-                android:visibility="gone"/>
+                app:mlpb_progress_stoke_width="3dp"
+                app:mlpb_progress_color="@color/colorAccent"
+                android:layout_gravity="center_horizontal"/>
 
             <android.support.v7.widget.CardView
                 android:id="@+id/comment_card_view_view_post_detail"

app/src/main/res/layout/fragment_post.xml

@@ -6,13 +6,15 @@
     android:id="@+id/coordinator_layout_post_fragment"
     tools:context="ml.docilealligator.infinityforreddit.PostFragment">
 
-    <ProgressBar
+    <com.lsjwzh.widget.materialloadingprogressbar.CircleProgressBar
         android:id="@+id/progress_bar_post_fragment"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_marginTop="16dp"
         android:layout_marginBottom="16dp"
-        android:layout_gravity="center" />
+        app:mlpb_progress_stoke_width="3dp"
+        app:mlpb_progress_color="@color/colorAccent"
+        android:layout_gravity="center_horizontal"/>
 
     <android.support.v7.widget.RecyclerView
         android:id="@+id/recycler_view_post_fragment"