X-Git-Url: https://git.ktnx.net/?a=blobdiff_plain;f=app%2Fsrc%2Fmain%2Fjava%2Fnet%2Fktnx%2Fmobileledger%2Futils%2FMLDB.java;h=6aaa62c6df099cf28fa4c65d971182dac926acc7;hb=4097e258df29d671bb72f89483489388dd5f4aa8;hp=07aea52b34b91a2e425ffda643c77d2a94f57e5f;hpb=64d69a2f7f729949b9236489ab7c4ce9f9aaea86;p=mobile-ledger.git

diff --git a/app/src/main/java/net/ktnx/mobileledger/utils/MLDB.java b/app/src/main/java/net/ktnx/mobileledger/utils/MLDB.java
index 07aea52b..6aaa62c6 100644
--- a/app/src/main/java/net/ktnx/mobileledger/utils/MLDB.java
+++ b/app/src/main/java/net/ktnx/mobileledger/utils/MLDB.java
@@ -191,7 +191,47 @@ public final class MLDB {
 
         if (callback != null) view.setOnItemClickListener((parent, itemView, position, id) -> {
             callback.descriptionSelected(String.valueOf(view.getText()));
+    }
+    public static void queryInBackground(@NonNull String statement, @NonNull String[] params,
+                                         @NonNull CallbackHelper callbackHelper) {
+        /* All callbacks are called in the new (asynchronous) thread! */
+        Thread t = new Thread(() -> {
+            callbackHelper.onStart();
+            try {
+                SQLiteDatabase db = App.getDatabase();
+
+                try (Cursor cursor = db.rawQuery(statement, params)) {
+                    boolean gotRow = false;
+                    while (cursor.moveToNext()) {
+                        gotRow = true;
+                        if (!callbackHelper.onRow(cursor))
+                            break;
+                    }
+                    if (!gotRow) {
+                        callbackHelper.onNoRows();
+                    }
+                }
+            }
+            catch (Exception e) {
+                callbackHelper.onException(e);
+            }
+            finally {
+                callbackHelper.onDone();
+            }
         });
+
+        t.start();
+    }
+    /* MLDB.CallbackHelper -- Abstract class for asynchronous SQL query callbacks */
+    @SuppressWarnings("WeakerAccess")
+    abstract public static class CallbackHelper {
+        public void onStart() {}
+        public abstract boolean onRow(@NonNull Cursor cursor);
+        public void onNoRows() {}
+        public void onException(Exception exception) {
+            Logger.debug("MLDB", "Exception in asynchronous SQL", exception);
+        }
+        public void onDone() {}
     }
 }