Added empty state text to updates/installed apps.

Both of these reuse the text that was used in 0.102.

app/src/main/java/org/fdroid/fdroid/views/installed/InstalledAppsActivity.java

@@ -32,6 +32,7 @@ import android.support.v7.widget.RecyclerView;
 import android.support.v7.widget.Toolbar;
 import android.view.View;
 import android.view.ViewGroup;
+import android.widget.TextView;
 
 import org.fdroid.fdroid.FDroidApp;
 import org.fdroid.fdroid.R;
@@ -43,6 +44,8 @@ import org.fdroid.fdroid.views.apps.AppListItemController;
 public class InstalledAppsActivity extends AppCompatActivity implements LoaderManager.LoaderCallbacks<Cursor> {
 
     private InstalledAppListAdapter adapter;
+    private RecyclerView appList;
+    private TextView emptyState;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -59,10 +62,12 @@ public class InstalledAppsActivity extends AppCompatActivity implements LoaderMa
 
         adapter = new InstalledAppListAdapter(this);
 
-        RecyclerView appList = (RecyclerView) findViewById(R.id.app_list);
+        appList = (RecyclerView) findViewById(R.id.app_list);
         appList.setHasFixedSize(true);
         appList.setLayoutManager(new LinearLayoutManager(this));
         appList.setAdapter(adapter);
+
+        emptyState = (TextView) findViewById(R.id.empty_state);
     }
 
     @Override
@@ -85,6 +90,14 @@ public class InstalledAppsActivity extends AppCompatActivity implements LoaderMa
     @Override
     public void onLoadFinished(Loader<Cursor> loader, Cursor cursor) {
         adapter.setApps(cursor);
+
+        if (adapter.getItemCount() == 0) {
+            appList.setVisibility(View.GONE);
+            emptyState.setVisibility(View.VISIBLE);
+        } else {
+            appList.setVisibility(View.VISIBLE);
+            emptyState.setVisibility(View.GONE);
+        }
     }
 
     @Override

app/src/main/java/org/fdroid/fdroid/views/updates/UpdatesViewBinder.java

@@ -5,22 +5,28 @@ import android.support.v7.widget.LinearLayoutManager;
 import android.support.v7.widget.RecyclerView;
 import android.view.View;
 import android.widget.FrameLayout;
+import android.widget.TextView;
 
 import org.fdroid.fdroid.R;
 
 public class UpdatesViewBinder {
 
     private final UpdatesAdapter adapter;
+    private final RecyclerView list;
+    private final TextView emptyState;
 
     public UpdatesViewBinder(AppCompatActivity activity, FrameLayout parent) {
         View view = activity.getLayoutInflater().inflate(R.layout.main_tab_updates, parent, true);
 
         adapter = new UpdatesAdapter(activity);
+        adapter.registerAdapterDataObserver(adapterChangeListener);
 
-        RecyclerView list = (RecyclerView) view.findViewById(R.id.list);
+        list = (RecyclerView) view.findViewById(R.id.list);
         list.setHasFixedSize(true);
         list.setLayoutManager(new LinearLayoutManager(activity));
         list.setAdapter(adapter);
+
+        emptyState = (TextView) view.findViewById(R.id.empty_state);
     }
 
     public void bind() {
@@ -30,4 +36,32 @@ public class UpdatesViewBinder {
     public void unbind() {
         adapter.stopListeningForStatusUpdates();
     }
+
+    private void updateEmptyState() {
+        if (adapter.getItemCount() == 0) {
+            list.setVisibility(View.GONE);
+            emptyState.setVisibility(View.VISIBLE);
+        } else {
+            list.setVisibility(View.VISIBLE);
+            emptyState.setVisibility(View.GONE);
+        }
+    }
+
+    @SuppressWarnings("FieldCanBeLocal")
+    private final RecyclerView.AdapterDataObserver adapterChangeListener = new RecyclerView.AdapterDataObserver() {
+        @Override
+        public void onChanged() {
+            updateEmptyState();
+        }
+
+        @Override
+        public void onItemRangeInserted(int positionStart, int itemCount) {
+            updateEmptyState();
+        }
+
+        @Override
+        public void onItemRangeRemoved(int positionStart, int itemCount) {
+            updateEmptyState();
+        }
+    };
 }

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

@@ -16,6 +16,18 @@
         app:theme="?attr/actionBarTheme"
         app:popupTheme="?attr/actionBarPopupTheme" />
 
+    <TextView
+        android:id="@+id/empty_state"
+        android:layout_width="0dp"
+        android:layout_height="0dp"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/toolbar"
+        style="@style/AppListEmptyText"
+        android:visibility="gone"
+        android:text="@string/empty_installed_app_list" />
+
     <android.support.v7.widget.RecyclerView
         android:id="@+id/app_list"
         android:layout_width="0dp"

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

@@ -5,6 +5,14 @@
     android:layout_width="match_parent"
     android:layout_height="match_parent">
 
+    <TextView
+        android:id="@+id/empty_state"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        style="@style/AppListEmptyText"
+        android:visibility="gone"
+        android:text="@string/empty_can_update_app_list" />
+
     <android.support.v7.widget.RecyclerView
         android:id="@+id/list"
         tools:listitem="@layout/app_list_item"