Asynchronously load messages to improve responsiveness

app/src/main/java/ch/dissem/apps/abit/MessageListFragment.java

@@ -39,12 +39,14 @@ import com.h6ah4i.android.widget.advrecyclerview.touchguard.RecyclerViewTouchAct
 import com.h6ah4i.android.widget.advrecyclerview.utils.WrapperAdapterUtils;
 
 import java.util.Collections;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.Objects;
 
 import ch.dissem.apps.abit.adapter.SwipeableMessageAdapter;
 import ch.dissem.apps.abit.listener.ActionBarListener;
 import ch.dissem.apps.abit.listener.ListSelectionListener;
+import ch.dissem.apps.abit.repository.AndroidMessageRepository;
 import ch.dissem.apps.abit.service.Singleton;
 import ch.dissem.bitmessage.entity.BitmessageAddress;
 import ch.dissem.bitmessage.entity.Plaintext;
@@ -77,7 +79,7 @@ public class MessageListFragment extends Fragment implements ListHolder {
 
     private Label currentLabel;
     private MenuItem emptyTrashMenuItem;
-    private MessageRepository messageRepo;
+    private AndroidMessageRepository messageRepo;
     private boolean activateOnItemClick;
 
     @Override
@@ -103,19 +105,15 @@ public class MessageListFragment extends Fragment implements ListHolder {
             return;
         }
 
-        if (!Objects.equals(currentLabel, label)) {
-            adapter.setData(label, Collections.<Plaintext>emptyList());
-            adapter.notifyDataSetChanged();
-        }
         doUpdateList(label);
     }
 
     private void doUpdateList(final Label label) {
+        adapter.clear(label);
         if (label == null) {
             if (getActivity() instanceof ActionBarListener) {
                 ((ActionBarListener) getActivity()).updateTitle(getString(R.string.app_name));
             }
-            adapter.setData(null, Collections.<Plaintext>emptyList());
             adapter.notifyDataSetChanged();
             return;
         }
@@ -131,18 +129,24 @@ public class MessageListFragment extends Fragment implements ListHolder {
                 actionBarListener.updateTitle(label.toString());
             }
         }
-        new AsyncTask<Void, Void, List<Plaintext>>() {
 
+        new AsyncTask<Void, Plaintext, Void>() {
             @Override
-            protected List<Plaintext> doInBackground(Void... params) {
+            protected Void doInBackground(Void... params) {
-                return messageRepo.findMessages(label);
+                List<Long> ids = messageRepo.findMessageIds(label);
+                for (Long id : ids) {
+                    Plaintext message = messageRepo.getMessage(id);
+                    publishProgress(message);
+                }
+                return null;
             }
 
             @Override
-            protected void onPostExecute(List<Plaintext> messages) {
+            protected void onProgressUpdate(Plaintext... values) {
                 if (adapter != null) {
-                    adapter.setData(label, messages);
+                    for (Plaintext message : values) {
-                    adapter.notifyDataSetChanged();
+                        adapter.add(message);
+                    }
                 }
             }
         }.execute();

app/src/main/java/ch/dissem/apps/abit/adapter/SwipeableMessageAdapter.java

@@ -37,6 +37,7 @@ import com.h6ah4i.android.widget.advrecyclerview.utils.AbstractSwipeableItemView
 import com.h6ah4i.android.widget.advrecyclerview.utils.RecyclerViewAdapterUtils;
 
 import java.util.Collections;
+import java.util.LinkedList;
 import java.util.List;
 
 import ch.dissem.apps.abit.Identicon;
@@ -59,7 +60,7 @@ public class SwipeableMessageAdapter
     extends RecyclerView.Adapter<SwipeableMessageAdapter.ViewHolder>
     implements SwipeableItemAdapter<SwipeableMessageAdapter.ViewHolder>, SwipeableItemConstants {
 
-    private List<Plaintext> data = Collections.emptyList();
+    private List<Plaintext> data = new LinkedList<>();
     private EventListener eventListener;
     private final View.OnClickListener itemViewOnClickListener;
     private final View.OnClickListener swipeableViewContainerOnClickListener;
@@ -124,9 +125,15 @@ public class SwipeableMessageAdapter
         setHasStableIds(true);
     }
 
-    public void setData(Label label, List<Plaintext> data) {
+    public void add(Plaintext item) {
-        this.label = label;
+        data.add(item);
-        this.data = data;
+        notifyDataSetChanged();
+    }
+
+    public void clear(Label newLabel) {
+        label = newLabel;
+        data.clear();
+        notifyDataSetChanged();
     }
 
     private void onItemViewClick(View v) {

app/src/main/java/ch/dissem/apps/abit/repository/AndroidMessageRepository.java

@@ -101,6 +101,15 @@ public class AndroidMessageRepository extends AbstractMessageRepository {
         }
     }
 
+    @NonNull
+    public List<Long> findMessageIds(Label label) {
+        if (label == LABEL_ARCHIVE) {
+            return findIds("id NOT IN (SELECT message_id FROM Message_Label)");
+        } else {
+            return findIds("id IN (SELECT message_id FROM Message_Label WHERE label_id=" + label.getId() + ")");
+        }
+    }
+
     @NonNull
     public List<Label> findLabels(String where) {
         List<Label> result = new LinkedList<>();
@@ -239,6 +248,31 @@ public class AndroidMessageRepository extends AbstractMessageRepository {
         db.update(PARENTS_TABLE_NAME, values, "conversation=?", whereArgs);
     }
 
+    @NonNull
+    protected List<Long> findIds(String where) {
+        List<Long> result = new LinkedList<>();
+
+        // Define a projection that specifies which columns from the database
+        // you will actually use after this query.
+        String[] projection = {
+            COLUMN_ID
+        };
+
+        SQLiteDatabase db = sql.getReadableDatabase();
+        try (Cursor c = db.query(
+            TABLE_NAME, projection,
+            where,
+            null, null, null,
+            COLUMN_RECEIVED + " DESC, " + COLUMN_SENT + " DESC"
+        )) {
+            while (c.moveToNext()) {
+                long id = c.getLong(c.getColumnIndex(COLUMN_ID));
+                result.add(id);
+            }
+        }
+        return result;
+    }
+
     @NonNull
     protected List<Plaintext> find(String where) {
         List<Plaintext> result = new LinkedList<>();
@@ -279,10 +313,14 @@ public class AndroidMessageRepository extends AbstractMessageRepository {
                 long id = c.getLong(c.getColumnIndex(COLUMN_ID));
                 builder.id(id);
                 builder.IV(InventoryVector.fromHash(iv));
-                builder.from(ctx.getAddressRepository().getAddress(c.getString(c.getColumnIndex
+                String sender = c.getString(c.getColumnIndex(COLUMN_SENDER));
-                    (COLUMN_SENDER))));
+                if (sender != null) {
-                builder.to(ctx.getAddressRepository().getAddress(c.getString(c.getColumnIndex
+                    builder.from(ctx.getAddressRepository().getAddress(sender));
-                    (COLUMN_RECIPIENT))));
+                }
+                String recipient = c.getString(c.getColumnIndex(COLUMN_RECIPIENT));
+                if (recipient != null) {
+                    builder.to(ctx.getAddressRepository().getAddress(recipient));
+                }
                 builder.ackData(c.getBlob(c.getColumnIndex(COLUMN_ACK_DATA)));
                 builder.sent(c.getLong(c.getColumnIndex(COLUMN_SENT)));
                 builder.received(c.getLong(c.getColumnIndex(COLUMN_RECEIVED)));