fix offline preparations to actually happen in background

src/org/fox/ttrss/offline/OfflineDownloadService.java

@@ -198,7 +198,9 @@ public class OfflineDownloadService extends Service {
 		
 		ApiRequest req = new ApiRequest(getApplicationContext()) {
 			@Override
-			protected void onPostExecute(JsonElement content) {
+			protected JsonElement doInBackground(HashMap<String, String>... params) {
+				JsonElement content = super.doInBackground(params);
+
 				if (content != null) {
 
 					try {
@@ -226,18 +228,24 @@ public class OfflineDownloadService extends Service {
 						m_articleOffset = 0;
 						
 						getWritableDb().execSQL("DELETE FROM articles;");
-						
-						if (m_canProceed) { 
-							downloadArticles();
-						} else {
-							downloadFailed();
-						}
 					} catch (Exception e) {
 						e.printStackTrace();
 						updateNotification(R.string.offline_switch_error);
 						downloadFailed();
 					}
+				}
 				
+				return content;
+			}
+			
+			@Override
+			protected void onPostExecute(JsonElement content) {
+				if (content != null) {
+					if (m_canProceed) { 
+						downloadArticles();
+					} else {
+						downloadFailed();
+					}
 				} else {
 					updateNotification(getErrorMessage());
 					downloadFailed();
@@ -266,10 +274,10 @@ public class OfflineDownloadService extends Service {
 		getWritableDb().execSQL("DELETE FROM categories;");
 		
 		ApiRequest req = new ApiRequest(getApplicationContext()) {
-			@Override
+			protected JsonElement doInBackground(HashMap<String, String>... params) {
-			protected void onPostExecute(JsonElement content) {
+				JsonElement content = super.doInBackground(params);
-				if (content != null) {
 				
+				if (content != null) {
 					try {
 						Type listType = new TypeToken<List<FeedCategory>>() {}.getType();
 						List<FeedCategory> cats = new Gson().fromJson(content, listType);
@@ -289,17 +297,23 @@ public class OfflineDownloadService extends Service {
 
 						Log.d(TAG, "offline: done downloading categories");
 						
-						if (m_canProceed) { 
-							downloadFeeds();
-						} else {
-							downloadFailed();
-						}
 					} catch (Exception e) {
 						e.printStackTrace();
 						updateNotification(R.string.offline_switch_error);
 						downloadFailed();
 					}
+				}
 			
+				return content;
+			}
+			@Override
+			protected void onPostExecute(JsonElement content) {
+				if (content != null) {
+					if (m_canProceed) { 
+						downloadFeeds();
+					} else {
+						downloadFailed();
+					}
 				} else {
 					updateNotification(getErrorMessage());
 					downloadFailed();
@@ -335,22 +349,27 @@ public class OfflineDownloadService extends Service {
 	}
 
 	public class OfflineArticlesRequest extends ApiRequest {
+		List<Article> m_articles;
+		
 		public OfflineArticlesRequest(Context context) {
 			super(context);
 		}
 
 		@Override
-		protected void onPostExecute(JsonElement content) {
+		protected JsonElement doInBackground(HashMap<String, String>... params) {
+			JsonElement content = super.doInBackground(params);
+			
 			if (content != null) {
+
 				try {
 					Type listType = new TypeToken<List<Article>>() {}.getType();
-					List<Article> articles = new Gson().fromJson(content, listType);
+					m_articles = new Gson().fromJson(content, listType);
 	
 					SQLiteStatement stmtInsert = getWritableDb().compileStatement("INSERT INTO articles " +
 							"("+BaseColumns._ID+", unread, marked, published, updated, is_updated, title, link, feed_id, tags, content) " +
 					"VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?);");
 	
-					for (Article article : articles) {
+					for (Article article : m_articles) {
 	
 						String tagsString = "";
 						
@@ -402,25 +421,12 @@ public class OfflineDownloadService extends Service {
 	
 					}
 
+					m_articleOffset += m_articles.size();
+
+					Log.d(TAG, "offline: received " + m_articles.size() + " articles; canProc=" + m_canProceed);
+
 					stmtInsert.close();
 
-					//m_canGetMoreArticles = articles.size() == 30;
-					m_articleOffset += articles.size();
-	
-					Log.d(TAG, "offline: received " + articles.size() + " articles; canProc=" + m_canProceed);
-					
-					if (m_canProceed) {
-						if (articles.size() == OFFLINE_SYNC_SEQ && m_articleOffset < m_syncMax) {
-							downloadArticles();
-						} else {
-							downloadComplete();
-						}
-					} else {
-						downloadFailed();
-					}
-					
-					return;
-					
 				} catch (Exception e) {
 					updateNotification(R.string.offline_switch_error);
 					Log.d(TAG, "offline: failed: exception when loading articles");
@@ -428,6 +434,25 @@ public class OfflineDownloadService extends Service {
 					downloadFailed();
 				}
 				
+			}
+			
+			return content;
+		}
+		
+		@Override
+		protected void onPostExecute(JsonElement content) {
+			if (content != null) {
+				
+				if (m_canProceed && m_articles != null) {
+					if (m_articles.size() == OFFLINE_SYNC_SEQ && m_articleOffset < m_syncMax) {
+						downloadArticles();
+					} else {
+						downloadComplete();
+					}
+				} else {
+					downloadFailed();
+				}
+
 			} else {
 				Log.d(TAG, "offline: failed: " + getErrorMessage());
 				updateNotification(getErrorMessage());