Use ListAdapter instead of RecyclerView.Adapter

app/src/main/java/dummydomain/yetanothercallblocker/BlacklistActivity.java

@@ -238,7 +238,7 @@ public class BlacklistActivity extends AppCompatActivity {
 
             @Override
             protected void onPostExecute(List<BlacklistItem> items) {
-                blacklistAdapter.setItems(items);
+                blacklistAdapter.submitList(items);
             }
         };
         loadBlacklistTask.execute();

app/src/main/java/dummydomain/yetanothercallblocker/BlacklistItemRecyclerViewAdapter.java

@@ -16,10 +16,10 @@ import androidx.core.util.ObjectsCompat;
 import androidx.recyclerview.selection.ItemDetailsLookup;
 import androidx.recyclerview.selection.ItemKeyProvider;
 import androidx.recyclerview.selection.SelectionTracker;
+import androidx.recyclerview.widget.DiffUtil;
 import androidx.recyclerview.widget.RecyclerView;
 
 import java.util.Date;
-import java.util.List;
 
 import dummydomain.yetanothercallblocker.data.db.BlacklistItem;
 
@@ -30,7 +30,7 @@ public class BlacklistItemRecyclerViewAdapter extends GenericRecyclerViewAdapter
 
     public BlacklistItemRecyclerViewAdapter(
             @Nullable ListInteractionListener<BlacklistItem> listener) {
-        super(listener);
+        super(new DiffUtilCallback(), listener);
     }
 
     public void setSelectionTracker(SelectionTracker<Long> selectionTracker) {
@@ -42,13 +42,13 @@ public class BlacklistItemRecyclerViewAdapter extends GenericRecyclerViewAdapter
             @Nullable
             @Override
             public Long getKey(int position) {
-                return items.get(position).getId();
+                return getItem(position).getId();
             }
 
             @Override
             public int getPosition(@NonNull Long key) {
-                for (int i = 0; i < items.size(); i++) {
+                for (int i = 0; i < getItemCount(); i++) {
-                    BlacklistItem item = items.get(i);
+                    BlacklistItem item = getItem(i);
                     if (key.equals(item.getId())) return i;
                 }
                 return RecyclerView.NO_POSITION;
@@ -81,12 +81,6 @@ public class BlacklistItemRecyclerViewAdapter extends GenericRecyclerViewAdapter
         return new BlacklistItemRecyclerViewAdapter.ViewHolder(view);
     }
 
-    @Override
-    protected DiffUtilCallback getDiffUtilCallback(
-            List<BlacklistItem> oldList, List<BlacklistItem> newList) {
-        return new DiffUtilCallback(oldList, newList);
-    }
-
     class ViewHolder extends GenericRecyclerViewAdapter
             <BlacklistItem, BlacklistItemRecyclerViewAdapter.ViewHolder>.GenericViewHolder {
 
@@ -148,7 +142,7 @@ public class BlacklistItemRecyclerViewAdapter extends GenericRecyclerViewAdapter
                     public Long getSelectionKey() {
                         int position = getAdapterPosition();
                         return position != RecyclerView.NO_POSITION
-                                ? items.get(position).getId() : null;
+                                ? getItem(position).getId() : null;
                     }
                 };
             }
@@ -162,15 +156,11 @@ public class BlacklistItemRecyclerViewAdapter extends GenericRecyclerViewAdapter
 
     }
 
-    static class DiffUtilCallback
+    static class DiffUtilCallback extends DiffUtil.ItemCallback<BlacklistItem> {
-            extends GenericRecyclerViewAdapter.GenericDiffUtilCallback<BlacklistItem> {
-
-        DiffUtilCallback(List<BlacklistItem> oldList, List<BlacklistItem> newList) {
-            super(oldList, newList);
-        }
 
         @Override
-        protected boolean areItemsTheSame(BlacklistItem oldItem, BlacklistItem newItem) {
+        public boolean areItemsTheSame(@NonNull BlacklistItem oldItem,
+                                       @NonNull BlacklistItem newItem) {
             if (oldItem.getId() != null || newItem.getId() != null) {
                 return ObjectsCompat.equals(oldItem.getId(), newItem.getId());
             }
@@ -179,7 +169,8 @@ public class BlacklistItemRecyclerViewAdapter extends GenericRecyclerViewAdapter
         }
 
         @Override
-        protected boolean areContentsTheSame(BlacklistItem oldItem, BlacklistItem newItem) {
+        public boolean areContentsTheSame(@NonNull BlacklistItem oldItem,
+                                          @NonNull BlacklistItem newItem) {
             return ObjectsCompat.equals(oldItem.getPattern(), newItem.getPattern())
                     && ObjectsCompat.equals(oldItem.getName(), newItem.getName())
                     && oldItem.getNumberOfCalls() == newItem.getNumberOfCalls()

app/src/main/java/dummydomain/yetanothercallblocker/CallLogItemRecyclerViewAdapter.java

@@ -11,6 +11,7 @@ import android.widget.TextView;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.appcompat.widget.AppCompatImageView;
+import androidx.recyclerview.widget.DiffUtil;
 
 import java.util.Iterator;
 import java.util.List;
@@ -23,7 +24,7 @@ public class CallLogItemRecyclerViewAdapter extends GenericRecyclerViewAdapter
         <CallLogItemGroup, CallLogItemRecyclerViewAdapter.ViewHolder> {
 
     public CallLogItemRecyclerViewAdapter(@Nullable ListInteractionListener<CallLogItemGroup> listener) {
-        super(listener);
+        super(new DiffUtilCallback(), listener);
     }
 
     @Override
@@ -34,12 +35,6 @@ public class CallLogItemRecyclerViewAdapter extends GenericRecyclerViewAdapter
         return new ViewHolder(view);
     }
 
-    @Override
-    protected DiffUtilCallback getDiffUtilCallback(
-            List<CallLogItemGroup> oldList, List<CallLogItemGroup> newList) {
-        return new DiffUtilCallback(oldList, newList);
-    }
-
     class ViewHolder extends GenericRecyclerViewAdapter<CallLogItemGroup, ViewHolder>.GenericViewHolder {
 
         final AppCompatImageView[] callTypeIcons;
@@ -174,15 +169,11 @@ public class CallLogItemRecyclerViewAdapter extends GenericRecyclerViewAdapter
         }
     }
 
-    static class DiffUtilCallback
+    static class DiffUtilCallback extends DiffUtil.ItemCallback<CallLogItemGroup> {
-            extends GenericRecyclerViewAdapter.GenericDiffUtilCallback<CallLogItemGroup> {
-
-        DiffUtilCallback(List<CallLogItemGroup> oldList, List<CallLogItemGroup> newList) {
-            super(oldList, newList);
-        }
 
         @Override
-        protected boolean areItemsTheSame(CallLogItemGroup oldGroup, CallLogItemGroup newGroup) {
+        public boolean areItemsTheSame(@NonNull CallLogItemGroup oldGroup,
+                                       @NonNull CallLogItemGroup newGroup) {
             if (oldGroup.getItems().size() != newGroup.getItems().size()) return false;
 
             for (Iterator<CallLogItem> it1 = oldGroup.getItems().iterator(),
@@ -201,7 +192,8 @@ public class CallLogItemRecyclerViewAdapter extends GenericRecyclerViewAdapter
         }
 
         @Override
-        public boolean areContentsTheSame(int oldItemPosition, int newItemPosition) {
+        public boolean areContentsTheSame(@NonNull CallLogItemGroup oldItem,
+                                          @NonNull CallLogItemGroup newItem) {
             return false; // time always updates
         }
 

app/src/main/java/dummydomain/yetanothercallblocker/GenericRecyclerViewAdapter.java

@@ -5,95 +5,40 @@ import android.view.View;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.recyclerview.widget.DiffUtil;
+import androidx.recyclerview.widget.ListAdapter;
 import androidx.recyclerview.widget.RecyclerView;
 
-import java.util.Collections;
-import java.util.List;
-
 public abstract class GenericRecyclerViewAdapter<T, V extends GenericRecyclerViewAdapter<T, V>.GenericViewHolder>
-        extends RecyclerView.Adapter<V> {
+        extends ListAdapter<T, V> {
 
     public interface ListInteractionListener<T> {
         void onListItemClicked(T item);
     }
 
-    protected @Nullable
+    protected @Nullable ListInteractionListener<T> listener;
-    ListInteractionListener<T> listener;
 
-    protected List<T> items = Collections.emptyList();
+    public GenericRecyclerViewAdapter(DiffUtil.ItemCallback<T> itemCallback,
-
+                                      @Nullable ListInteractionListener<T> listener) {
-    public GenericRecyclerViewAdapter(@Nullable ListInteractionListener<T> listener) {
+        super(itemCallback);
         this.listener = listener;
     }
 
     @Override
     public void onBindViewHolder(@NonNull V holder, int position) {
-        onBindViewHolder(holder, items.get(position));
+        onBindViewHolder(holder, getItem(position));
     }
 
     protected void onBindViewHolder(@NonNull V holder, T item) {
         holder.bind(item);
     }
 
-    @Override
-    public int getItemCount() {
-        return items.size();
-    }
-
-    public void setItems(List<T> items) {
-        DiffUtil.DiffResult diffResult = DiffUtil.calculateDiff(
-                getDiffUtilCallback(this.items, items));
-
-        this.items = items;
-
-        diffResult.dispatchUpdatesTo(this);
-    }
-
-    protected abstract GenericDiffUtilCallback<T> getDiffUtilCallback(
-            List<T> oldList, List<T> newList);
-
     protected void onClick(int index) {
         if (index != RecyclerView.NO_POSITION && listener != null) {
-            listener.onListItemClicked(items.get(index));
+            T item = getItem(index);
+            if (item != null) {
+                listener.onListItemClicked(item);
             }
         }
-
-    protected static class GenericDiffUtilCallback<T> extends DiffUtil.Callback {
-        protected List<T> oldList;
-        protected List<T> newList;
-
-        protected GenericDiffUtilCallback(List<T> oldList, List<T> newList) {
-            this.oldList = oldList;
-            this.newList = newList;
-        }
-
-        @Override
-        public int getOldListSize() {
-            return oldList.size();
-        }
-
-        @Override
-        public int getNewListSize() {
-            return newList.size();
-        }
-
-        @Override
-        public boolean areItemsTheSame(int oldItemPosition, int newItemPosition) {
-            return areItemsTheSame(oldList.get(oldItemPosition), newList.get(newItemPosition));
-        }
-
-        protected boolean areItemsTheSame(T oldItem, T newItem) {
-            return false;
-        }
-
-        @Override
-        public boolean areContentsTheSame(int oldItemPosition, int newItemPosition) {
-            return areContentsTheSame(oldList.get(oldItemPosition), newList.get(newItemPosition));
-        }
-
-        protected boolean areContentsTheSame(T oldItem, T newItem) {
-            return false;
-        }
     }
 
     protected abstract class GenericViewHolder extends RecyclerView.ViewHolder {

app/src/main/java/dummydomain/yetanothercallblocker/MainActivity.java

@@ -257,7 +257,7 @@ public class MainActivity extends AppCompatActivity {
                 // https://stackoverflow.com/a/44053550
                 @SuppressWarnings("ConstantConditions")
                 Parcelable recyclerViewState = recyclerView.getLayoutManager().onSaveInstanceState();
-                callLogAdapter.setItems(items);
+                callLogAdapter.submitList(items);
                 recyclerView.getLayoutManager().onRestoreInstanceState(recyclerViewState);
 
                 setCallLogVisibility(true);