ClassifyFragment: onCreateLoader(): Slight refactoring.

Reorganize this so we could have multiple loaders.
murraycu · Mar 16, 2017 · e018a84 · e018a84
1 parent ab6e3c8
commit e018a84
Showing 1 changed file with 15 additions and 8 deletions.
diff --git a/app/src/main/java/com/murrayc/galaxyzoo/app/ClassifyFragment.java b/app/src/main/java/com/murrayc/galaxyzoo/app/ClassifyFragment.java
@@ -48,7 +48,8 @@
  */
 public class ClassifyFragment extends ItemFragment implements LoaderManager.LoaderCallbacks<Cursor> {
 
-    private static final int URL_LOADER = 0;
+    private static final int LOADER_ID_NEXT_ID = 0;
+
     // We have to hard-code the indices - we can't use getColumnIndex because the Cursor
     // (actually a SQliteDatabase cursor returned
     // from our ContentProvider) only knows about the underlying SQLite database column names,
@@ -274,7 +275,7 @@ public void update() {
 
         if (TextUtils.equals(getItemId(), ItemsContentProvider.URI_PART_ITEM_ID_NEXT)) {
             /*
-             * Initializes the CursorLoader. The URL_LOADER value is eventually passed
+             * Initializes the CursorLoader. The LOADER_ID_NEXT_ID value is eventually passed
              * to onCreateLoader().
              * We use restartLoader(), instead of initLoader(),
              * so we can refresh this fragment to show a different subject,
@@ -295,7 +296,7 @@ public void update() {
                 }
 
                 //Get the actual ID and other details:
-                getLoaderManager().restartLoader(URL_LOADER, null, this);
+                getLoaderManager().restartLoader(LOADER_ID_NEXT_ID, null, this);
             }
         } else {
             //Add, or update, the child fragments already, because we know the Item IDs:
@@ -374,13 +375,19 @@ private void updateFromCursor() {
         addOrUpdateChildFragments();
     }
 
-    //We only bother using this when we have asked for the "next" item,
-    //because we want to know its ID.
     @Override
     public Loader<Cursor> onCreateLoader(final int loaderId, final Bundle bundle) {
-        if (loaderId != URL_LOADER) {
-            return null;
+        //We only bother using this when we have asked for the "next" item,
+        //because we want to know its ID.
+        if (loaderId == LOADER_ID_NEXT_ID) {
+            return onCreateLoaderGetNextId();
         }
+
+        return null;
+    }
+
+    @Nullable
+    private Loader<Cursor> onCreateLoaderGetNextId() {
         final String itemId = getItemId();
         if (TextUtils.isEmpty(itemId)) {
             return null;
@@ -417,7 +424,7 @@ public void onLoadFinished(final Loader<Cursor> cursorLoader, final Cursor curso
         // another item:
         // See http://stackoverflow.com/questions/14719814/onloadfinished-called-twice
         // and https://code.google.com/p/android/issues/detail?id=63179
-        getLoaderManager().destroyLoader(URL_LOADER);
+        getLoaderManager().destroyLoader(LOADER_ID_NEXT_ID);
     }
 
     @Override