Some cleanup

Change-Id: I278fe22606f979011409b37938092763358b4dac

Author: samtstern

app/src/main/java/com/firebase/uidemo/database/firestore/FirestoreChatActivity.java

@@ -7,7 +7,6 @@
 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;
@@ -16,10 +15,10 @@
 
 import com.firebase.ui.auth.util.ui.ImeHelper;
 import com.firebase.ui.firestore.ClassSnapshotParser;
-import com.firebase.ui.firestore.FirestoreInfiniteArray;
 import com.firebase.ui.firestore.FirestoreInfiniteScrollListener;
+import com.firebase.ui.firestore.FirestorePagingAdapter;
+import com.firebase.ui.firestore.FirestorePagingOptions;
 import com.firebase.ui.firestore.FirestoreRecyclerAdapter;
-import com.firebase.ui.firestore.FirestoreRecyclerOptions;
 import com.firebase.uidemo.R;
 import com.firebase.uidemo.database.ChatHolder;
 import com.firebase.uidemo.util.SignInResultNotifier;
@@ -51,7 +50,6 @@ public class FirestoreChatActivity extends AppCompatActivity
     private static final Query sChatQuery = sChatCollection.orderBy("timestamp").limit(50);
 
     private LinearLayoutManager mManager;
-    private FirestoreInfiniteArray<Chat> mArray;
 
     static {
         FirebaseFirestore.setLoggingEnabled(true);
@@ -75,11 +73,6 @@ protected void onCreate(Bundle savedInstanceState) {
         setContentView(R.layout.activity_chat);
         ButterKnife.bind(this);
 
-        mArray = new FirestoreInfiniteArray<>(
-                sChatCollection.orderBy("timestamp", Query.Direction.ASCENDING),
-                sChatCollection.orderBy("timestamp", Query.Direction.DESCENDING),
-                new ClassSnapshotParser<>(Chat.class));
-
         mManager = new LinearLayoutManager(this);
         mRecyclerView.setHasFixedSize(true);
         mRecyclerView.setLayoutManager(mManager);
@@ -95,7 +88,6 @@ public void onDonePressed() {
     @Override
     public void onStart() {
         super.onStart();
-        if (isSignedIn()) { attachRecyclerViewAdapter(); }
         FirebaseAuth.getInstance().addAuthStateListener(this);
     }
 
@@ -123,7 +115,7 @@ private boolean isSignedIn() {
     }
 
     private void attachRecyclerViewAdapter() {
-        final RecyclerView.Adapter adapter = newAdapter();
+        final FirestorePagingAdapter adapter = newAdapter();
 
         // Scroll to bottom on new messages
         // TODO
@@ -134,11 +126,9 @@ private void attachRecyclerViewAdapter() {
 //            }
 //        });
 
-        // TODO
-        mArray.setAdapter(adapter);
-
         // Scroll listener for infinite
-        mRecyclerView.addOnScrollListener(new FirestoreInfiniteScrollListener(mManager, mArray));
+        mRecyclerView.addOnScrollListener(
+                new FirestoreInfiniteScrollListener(mManager, adapter));
 
         mRecyclerView.setAdapter(adapter);
     }
@@ -153,14 +143,17 @@ public void onSendClick() {
         mMessageEdit.setText("");
     }
 
-    protected RecyclerView.Adapter newAdapter() {
-        FirestoreRecyclerOptions<Chat> options =
-                new FirestoreRecyclerOptions.Builder<Chat>()
-                        .setSnapshotArray(mArray)
-                        .setLifecycleOwner(this)
-                        .build();
+    protected FirestorePagingAdapter newAdapter() {
+        FirestorePagingOptions options = new FirestorePagingOptions.Builder()
+                .setLoadTriggerDistance(7)
+                .setMaxPages(3)
+                .build();
+
+        return new FirestorePagingAdapter<Chat, ChatHolder>(
+                new ClassSnapshotParser<>(Chat.class),
+                sChatCollection.orderBy("timestamp", Query.Direction.ASCENDING),
+                options) {
 
-        return new FirestoreRecyclerAdapter<Chat, ChatHolder>(options) {
             @Override
             public ChatHolder onCreateViewHolder(ViewGroup parent, int viewType) {
                 return new ChatHolder(LayoutInflater.from(parent.getContext())
@@ -171,12 +164,6 @@ public ChatHolder onCreateViewHolder(ViewGroup parent, int viewType) {
             protected void onBindViewHolder(@NonNull ChatHolder holder, int position, @NonNull Chat model) {
                 holder.bind(model);
             }
-
-            @Override
-            public void onDataChanged() {
-                // If there are no chat messages, show a view that invites the user to add a message.
-                mEmptyListMessage.setVisibility(getItemCount() == 0 ? View.VISIBLE : View.GONE);
-            }
         };
     }
 

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

@@ -6,16 +6,15 @@
 
 public class FirestoreInfiniteScrollListener extends RecyclerView.OnScrollListener {
 
-    private LinearLayoutManager mManager;
-    private FirestoreInfiniteArray mArray;
+    private final LinearLayoutManager mManager;
+    private final FirestorePagingAdapter mAdapter;
 
     private Handler mHandler = new Handler();
 
-    // TODO: This could take the same options as the Array
     public FirestoreInfiniteScrollListener(LinearLayoutManager manager,
-                                           FirestoreInfiniteArray array) {
+                                           FirestorePagingAdapter adapter) {
         mManager = manager;
-        mArray = array;
+        mAdapter = adapter;
     }
 
     @Override
@@ -30,44 +29,41 @@ public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
         int firstVisible = mManager.findFirstVisibleItemPosition();
         int lastVisible = mManager.findLastVisibleItemPosition();
 
-        int totalSize = mArray.size();
+        int totalSize = mAdapter.getItemCount();
 
-        // TODO: configurable "closeness" and number of pages to keep
         boolean movingDown = dy > 0;
         boolean movingUp = !movingDown;
-        boolean closeToTop = (firstVisible <= 5);
-        boolean closeToBottom = (totalSize - lastVisible) <= 5;
+        boolean closeToTop = (firstVisible <= mAdapter.getOptions().getLoadTriggerDistance());
+        boolean closeToBottom = (totalSize - lastVisible) <= mAdapter.getOptions().getLoadTriggerDistance();
 
         if (closeToBottom && movingDown) {
-
             mHandler.post(new Runnable() {
                 @Override
                 public void run() {
                     // Load one page down
-                    mArray.loadNextPage();
+                    mAdapter.loadNextPage();
 
                     // Unload top page.
-                    if (mArray.getPagesLoaded() >= 3 ) {
-                        mArray.unloadTopPage();
+                    // TODO: This should probably be inside the paging adapter
+                    if (mAdapter.getPagesLoaded() > mAdapter.getOptions().getMaxPages() ) {
+                        mAdapter.unloadTopPage();
                     }
                 }
             });
 
         } else if (closeToTop && movingUp) {
-
             mHandler.post(new Runnable() {
                 @Override
                 public void run() {
                     // Load one page up
-                    mArray.loadPrevPage();
+                    mAdapter.loadPrevPage();
 
                     // Unload bottom page
-                    if (mArray.getPagesLoaded() >= 3) {
-                        mArray.unloadBottomPage();
+                    if (mAdapter.getPagesLoaded() > mAdapter.getOptions().getMaxPages()) {
+                        mAdapter.unloadBottomPage();
                     }
                 }
             });
-
         }
     }