Make FirebaseRecyclerAdapter use RecyclerView naming scheme and methods (#12)

Author: SUPERCILEX

app/src/main/java/com/firebase/uidemo/database/realtime/ChatActivity.java

@@ -22,7 +22,9 @@
 import android.support.v7.widget.LinearLayoutManager;
 import android.support.v7.widget.RecyclerView;
 import android.util.Log;
+import android.view.LayoutInflater;
 import android.view.View;
+import android.view.ViewGroup;
 import android.widget.Button;
 import android.widget.EditText;
 import android.widget.TextView;
@@ -142,18 +144,22 @@ public void onItemRangeInserted(int positionStart, int itemCount) {
     protected FirebaseRecyclerAdapter<Chat, ChatHolder> getAdapter() {
         Query lastFifty = mChatRef.limitToLast(50);
 
-        FirebaseRecyclerOptions<Chat, ChatHolder> options =
-                new FirebaseRecyclerOptions.Builder<Chat, ChatHolder>()
-                        .setViewHolder(R.layout.message, ChatHolder.class)
+        FirebaseRecyclerOptions<Chat> options =
+                new FirebaseRecyclerOptions.Builder<Chat>()
                         .setQuery(lastFifty, Chat.class)
                         .setLifecycleOwner(this)
                         .build();
 
         return new FirebaseRecyclerAdapter<Chat, ChatHolder>(options) {
+            @Override
+            public ChatHolder onCreateViewHolder(ViewGroup parent, int viewType) {
+                return new ChatHolder(LayoutInflater.from(parent.getContext())
+                        .inflate(R.layout.message, parent, false));
+            }
 
             @Override
-            public void populateViewHolder(ChatHolder holder, Chat chat, int position) {
-                holder.bind(chat);
+            protected void onBindViewHolder(ChatHolder holder, int position, Chat model) {
+                holder.bind(model);
             }
 
             @Override

app/src/main/java/com/firebase/uidemo/database/realtime/ChatIndexActivity.java

@@ -1,6 +1,8 @@
 package com.firebase.uidemo.database.realtime;
 
+import android.view.LayoutInflater;
 import android.view.View;
+import android.view.ViewGroup;
 
 import com.firebase.ui.database.FirebaseRecyclerAdapter;
 import com.firebase.ui.database.FirebaseRecyclerOptions;
@@ -33,17 +35,22 @@ protected FirebaseRecyclerAdapter<Chat, ChatHolder> getAdapter() {
                 .child("chatIndices")
                 .child(FirebaseAuth.getInstance().getCurrentUser().getUid());
 
-        FirebaseRecyclerOptions<Chat, ChatHolder> options =
-                new FirebaseRecyclerOptions.Builder<Chat, ChatHolder>()
+        FirebaseRecyclerOptions<Chat> options =
+                new FirebaseRecyclerOptions.Builder<Chat>()
                         .setIndexedQuery(mChatIndicesRef.limitToFirst(50), mChatRef, Chat.class)
-                        .setViewHolder(R.layout.message, ChatHolder.class)
                         .setLifecycleOwner(this)
                         .build();
 
         return new FirebaseRecyclerAdapter<Chat, ChatHolder>(options) {
             @Override
-            public void populateViewHolder(ChatHolder holder, Chat chat, int position) {
-                holder.bind(chat);
+            public ChatHolder onCreateViewHolder(ViewGroup parent, int viewType) {
+                return new ChatHolder(LayoutInflater.from(parent.getContext())
+                        .inflate(R.layout.message, parent, false));
+            }
+
+            @Override
+            protected void onBindViewHolder(ChatHolder holder, int position, Chat model) {
+                holder.bind(model);
             }
 
             @Override

database/src/main/java/com/firebase/ui/database/FirebaseRecyclerAdapter.java

@@ -5,18 +5,12 @@
 import android.arch.lifecycle.OnLifecycleEvent;
 import android.support.v7.widget.RecyclerView;
 import android.util.Log;
-import android.view.LayoutInflater;
-import android.view.View;
-import android.view.ViewGroup;
 
 import com.firebase.ui.common.ChangeEventType;
 import com.google.firebase.database.DataSnapshot;
 import com.google.firebase.database.DatabaseError;
 import com.google.firebase.database.DatabaseReference;
 
-import java.lang.reflect.Constructor;
-import java.lang.reflect.InvocationTargetException;
-
 /**
  * This class is a generic way of backing a {@link RecyclerView} with a Firebase location. It
  * handles all of the child events at the given Firebase location and marshals received data into
@@ -34,17 +28,13 @@ public abstract class FirebaseRecyclerAdapter<T, VH extends RecyclerView.ViewHol
     private static final String TAG = "FirebaseRecyclerAdapter";
 
     protected final ObservableSnapshotArray<T> mSnapshots;
-    protected final Class<VH> mViewHolderClass;
-    protected final int mModelLayout;
 
     /**
      * Initialize a {@link RecyclerView.Adapter} that listens to a Firebase query. See
      * {@link FirebaseRecyclerOptions} for configuration options.
      */
-    public FirebaseRecyclerAdapter(FirebaseRecyclerOptions<T, VH> options) {
+    public FirebaseRecyclerAdapter(FirebaseRecyclerOptions<T> options) {
         mSnapshots = options.getSnapshots();
-        mViewHolderClass = options.getViewHolderClass();
-        mModelLayout = options.getModelLayout();
 
         if (options.getOwner() != null) {
             options.getOwner().getLifecycle().addObserver(this);
@@ -123,44 +113,13 @@ public int getItemCount() {
     }
 
     @Override
-    public VH onCreateViewHolder(ViewGroup parent, int viewType) {
-        View view = LayoutInflater.from(parent.getContext()).inflate(viewType, parent, false);
-        try {
-            Constructor<VH> constructor = mViewHolderClass.getConstructor(View.class);
-            return constructor.newInstance(view);
-        } catch (NoSuchMethodException e) {
-            throw new RuntimeException(e);
-        } catch (InvocationTargetException e) {
-            throw new RuntimeException(e);
-        } catch (InstantiationException e) {
-            throw new RuntimeException(e);
-        } catch (IllegalAccessException e) {
-            throw new RuntimeException(e);
-        }
-    }
-
-    @Override
-    public int getItemViewType(int position) {
-        return mModelLayout;
-    }
-
-    @Override
-    public void onBindViewHolder(VH viewHolder, int position) {
-        T model = getItem(position);
-        populateViewHolder(viewHolder, model, position);
+    public void onBindViewHolder(VH holder, int position) {
+        onBindViewHolder(holder, position, getItem(position));
     }
 
     /**
-     * Each time the data at the given Firebase location changes, this method will be called for
-     * each item that needs to be displayed. The first two arguments correspond to the mLayout and
-     * mModelClass given to the constructor of this class. The third argument is the item's position
-     * in the list.
-     * <p>
-     * Your implementation should populate the view using the data contained in the model.
-     *
-     * @param viewHolder The view to populate
-     * @param model      The object containing the data used to populate the view
-     * @param position   The position in the list of the view being populated
+     * @param model the model object containing the data that should be used to populate the view.
+     * @see #onBindViewHolder(RecyclerView.ViewHolder, int)
      */
-    protected abstract void populateViewHolder(VH viewHolder, T model, int position);
+    protected abstract void onBindViewHolder(VH holder, int position, T model);
 }

database/src/main/java/com/firebase/ui/database/FirebaseRecyclerOptions.java

@@ -1,9 +1,7 @@
 package com.firebase.ui.database;
 
 import android.arch.lifecycle.LifecycleOwner;
-import android.support.annotation.LayoutRes;
 import android.support.annotation.Nullable;
-import android.support.v7.widget.RecyclerView;
 
 import com.google.firebase.database.DatabaseReference;
 import com.google.firebase.database.Query;
@@ -16,29 +14,19 @@
  *
  * @see Builder
  */
-public class FirebaseRecyclerOptions<T, VH extends RecyclerView.ViewHolder> {
+public class FirebaseRecyclerOptions<T> {
 
     private static final String ERR_SNAPSHOTS_SET = "Snapshot array already set. " +
             "Call only one of setSnapshotArray, setQuery, or setIndexedQuery.";
-
-    private static final String ERR_SNAPSHOTS_NULL =  "Snapshot array cannot be null. " +
+    private static final String ERR_SNAPSHOTS_NULL = "Snapshot array cannot be null. " +
             "Call one of setSnapshotArray, setQuery, or setIndexedQuery.";
 
-    private static final String ERR_VIEWHOLDER_NULL = "View holder class cannot be null. " +
-            "Call setViewHolder.";
-
     private final ObservableSnapshotArray<T> mSnapshots;
-    private final Class<VH> mViewHolderClass;
-    private final int mModelLayout;
     private final LifecycleOwner mOwner;
 
     private FirebaseRecyclerOptions(ObservableSnapshotArray<T> snapshots,
-                                    Class<VH> viewHolderClass,
-                                    @LayoutRes int modelLayout,
-                                    LifecycleOwner owner) {
+                                    @Nullable LifecycleOwner owner) {
         mSnapshots = snapshots;
-        mViewHolderClass = viewHolderClass;
-        mModelLayout = modelLayout;
         mOwner = owner;
     }
 
@@ -50,24 +38,8 @@ public ObservableSnapshotArray<T> getSnapshots() {
     }
 
     /**
-     * Get the class of the {@link android.support.v7.widget.RecyclerView.ViewHolder} for
-     * each RecyclerView item.
-     */
-    public Class<VH> getViewHolderClass() {
-        return mViewHolderClass;
-    }
-
-    /**
-     * Get the resource ID of the layout for each RecyclerView item.
-     */
-    @LayoutRes
-    public int getModelLayout() {
-        return mModelLayout;
-    }
-
-    /**
-     * Get the (optional) LifecycleOwner. Listening will start/stop after the appropriate
-     * lifecycle events.
+     * Get the (optional) LifecycleOwner. Listening will start/stop after the appropriate lifecycle
+     * events.
      */
     @Nullable
     public LifecycleOwner getOwner() {
@@ -78,109 +50,93 @@ public LifecycleOwner getOwner() {
      * Builder for a {@link FirebaseRecyclerOptions}.
      *
      * @param <T> the model class for the {@link FirebaseRecyclerAdapter}.
-     * @param <VH> the ViewHolder class for the {@link FirebaseRecyclerAdapter}.
      */
-    public static class Builder<T, VH extends RecyclerView.ViewHolder> {
+    public static class Builder<T> {
 
         private ObservableSnapshotArray<T> mSnapshots;
-        private Class<VH> mViewHolderClass;
-        private int mModelLayout;
         private LifecycleOwner mOwner;
 
         /**
          * Directly set the {@link ObservableSnapshotArray} to be listened to.
-         *
+         * <p>
          * Do not call this method after calling {@code setQuery}.
          */
-        public Builder<T, VH> setSnapshotArray(ObservableSnapshotArray<T> snapshots) {
+        public Builder<T> setSnapshotArray(ObservableSnapshotArray<T> snapshots) {
             assertNull(mSnapshots, ERR_SNAPSHOTS_SET);
 
             mSnapshots = snapshots;
             return this;
         }
 
         /**
-         * Set the Firebase query to listen to, along with a {@link SnapshotParser} to
-         * parse snapshots into model objects.
-         *
+         * Set the Firebase query to listen to, along with a {@link SnapshotParser} to parse
+         * snapshots into model objects.
+         * <p>
          * Do not call this method after calling {@link #setSnapshotArray(ObservableSnapshotArray)}.
          */
-        public Builder<T, VH> setQuery(Query query, SnapshotParser<T> snapshotParser) {
+        public Builder<T> setQuery(Query query, SnapshotParser<T> snapshotParser) {
             assertNull(mSnapshots, ERR_SNAPSHOTS_SET);
 
-            mSnapshots = new FirebaseArray<T>(query, snapshotParser);
+            mSnapshots = new FirebaseArray<>(query, snapshotParser);
             return this;
         }
 
         /**
-         * Set the Firebase query to listen to, along with a {@link Class} to which snapshots
-         * should be parsed.
-         *
+         * Set the Firebase query to listen to, along with a {@link Class} to which snapshots should
+         * be parsed.
+         * <p>
          * Do not call this method after calling {@link #setSnapshotArray(ObservableSnapshotArray)}.
          */
-        public Builder<T, VH> setQuery(Query query, Class<T> modelClass) {
-            return setQuery(query, new ClassSnapshotParser<T>(modelClass));
+        public Builder<T> setQuery(Query query, Class<T> modelClass) {
+            return setQuery(query, new ClassSnapshotParser<>(modelClass));
         }
 
 
         /**
-         * Set an indexed Firebase query to listen to, along with a {@link SnapshotParser} to
-         * parse snapshots into model objects. Keys are identified by the {@code keyQuery} and then
-         * data is fetched using those keys from the {@code dataRef}.
-         *
+         * Set an indexed Firebase query to listen to, along with a {@link SnapshotParser} to parse
+         * snapshots into model objects. Keys are identified by the {@code keyQuery} and then data
+         * is fetched using those keys from the {@code dataRef}.
+         * <p>
          * Do not call this method after calling {@link #setSnapshotArray(ObservableSnapshotArray)}.
          */
-        public Builder<T, VH> setIndexedQuery(Query keyQuery,
-                                              DatabaseReference dataRef,
-                                              SnapshotParser<T> snapshotParser) {
+        public Builder<T> setIndexedQuery(Query keyQuery,
+                                          DatabaseReference dataRef,
+                                          SnapshotParser<T> snapshotParser) {
             assertNull(mSnapshots, ERR_SNAPSHOTS_SET);
 
-            mSnapshots = new FirebaseIndexArray<T>(keyQuery, dataRef, snapshotParser);
+            mSnapshots = new FirebaseIndexArray<>(keyQuery, dataRef, snapshotParser);
             return this;
         }
 
         /**
-         * Set an indexed Firebase query to listen to, along with a {@link Class} to which
-         * snapshots should be parsed. Keys are identified by the {@code keyQuery} and then
-         * data is fetched using those keys from the {@code dataRef}.
-         *
+         * Set an indexed Firebase query to listen to, along with a {@link Class} to which snapshots
+         * should be parsed. Keys are identified by the {@code keyQuery} and then data is fetched
+         * using those keys from the {@code dataRef}.
+         * <p>
          * Do not call this method after calling {@link #setSnapshotArray(ObservableSnapshotArray)}.
          */
-        public Builder<T, VH> setIndexedQuery(Query keyQuery,
-                                              DatabaseReference dataRef,
-                                              Class<T> modelClass) {
-            return setIndexedQuery(keyQuery, dataRef, new ClassSnapshotParser<T>(modelClass));
-        }
-
-        /**
-         * Set the layout resource ID and class for the
-         * {@link android.support.v7.widget.RecyclerView.ViewHolder} for each RecyclerView item.
-         */
-        public Builder<T, VH> setViewHolder(@LayoutRes int modelLayout, Class<VH> viewHolderClass) {
-            mModelLayout = modelLayout;
-            mViewHolderClass = viewHolderClass;
-
-            return this;
+        public Builder<T> setIndexedQuery(Query keyQuery,
+                                          DatabaseReference dataRef,
+                                          Class<T> modelClass) {
+            return setIndexedQuery(keyQuery, dataRef, new ClassSnapshotParser<>(modelClass));
         }
 
         /**
          * Set the (optional) {@link LifecycleOwner}. Listens will start and stop after the
          * appropriate lifecycle events.
          */
-        public Builder<T, VH> setLifecycleOwner(LifecycleOwner owner) {
+        public Builder<T> setLifecycleOwner(LifecycleOwner owner) {
             mOwner = owner;
             return this;
         }
 
         /**
          * Build a {@link FirebaseRecyclerOptions} from the provided arguments.
          */
-        public FirebaseRecyclerOptions<T, VH> build() {
+        public FirebaseRecyclerOptions<T> build() {
             assertNonNull(mSnapshots, ERR_SNAPSHOTS_NULL);
-            assertNonNull(mViewHolderClass, ERR_VIEWHOLDER_NULL);
 
-            return new FirebaseRecyclerOptions<>(
-                    mSnapshots, mViewHolderClass, mModelLayout, mOwner);
+            return new FirebaseRecyclerOptions<>(mSnapshots, mOwner);
         }
     }
 

firestore/src/main/java/com/firebase/ui/firestore/FirestoreRecyclerAdapter.java

@@ -105,12 +105,8 @@ public void onBindViewHolder(VH holder, int position) {
     }
 
     /**
-     * Called when data has been added/changed and an item needs to be displayed.
-     *
-     * @param holder   the view to populate.
-     * @param position the position in the list of the view being populated.
-     * @param model    the model object containing the data that should be used to populate the
-     *                 view.
+     * @param model the model object containing the data that should be used to populate the view.
+     * @see #onBindViewHolder(RecyclerView.ViewHolder, int)
      */
     protected abstract void onBindViewHolder(VH holder, int position, T model);
 }