new: go to a date from transaction list

[mobile-ledger-staging.git] / app / src / main / java / net / ktnx / mobileledger / async / TransactionDateFinder.java

diff --git a/app/src/main/java/net/ktnx/mobileledger/async/TransactionDateFinder.java b/app/src/main/java/net/ktnx/mobileledger/async/TransactionDateFinder.java
new file mode 100644 (file)
index 0000000..c15e599
--- /dev/null
+++ b/app/src/main/java/net/ktnx/mobileledger/async/TransactionDateFinder.java
@@ -0,0 +1,81 @@
+/*
+ * Copyright © 2020 Damyan Ivanov.
+ * This file is part of MoLe.
+ * MoLe is free software: you can distribute it and/or modify it
+ * under the term of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your opinion), any later version.
+ *
+ * MoLe is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License terms for details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with MoLe. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package net.ktnx.mobileledger.async;
+
+import android.os.AsyncTask;
+
+import net.ktnx.mobileledger.model.Data;
+import net.ktnx.mobileledger.model.TransactionListItem;
+import net.ktnx.mobileledger.utils.LockHolder;
+import net.ktnx.mobileledger.utils.Logger;
+import net.ktnx.mobileledger.utils.SimpleDate;
+
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.List;
+import java.util.Locale;
+
+public class TransactionDateFinder extends AsyncTask<SimpleDate, Void, Integer> {
+    @Override
+    protected void onPostExecute(Integer pos) {
+        Data.foundTransactionItemIndex.setValue(pos);
+    }
+    @Override
+    protected Integer doInBackground(SimpleDate... simpleDates) {
+        SimpleDate date = simpleDates[0];
+        Logger.debug("go-to-date",
+                String.format(Locale.US, "Looking for date %04d-%02d-%02d", date.year, date.month,
+                        date.day));
+        Logger.debug("go-to-date", String.format(Locale.US, "List contains %d transactions",
+                Data.transactions.size()));
+
+        try (LockHolder locker = Data.transactions.lockForWriting()) {
+            List<TransactionListItem> transactions = Data.transactions.getList();
+            TransactionListItem target = new TransactionListItem(date, true);
+            int found = Collections.binarySearch(transactions, target,
+                    new TransactionListItemComparator());
+            if (found >= 0)
+                return found;
+            else
+                return 1 - found;
+        }
+    }
+    static class TransactionListItemComparator implements Comparator<TransactionListItem> {
+        @Override
+        public int compare(TransactionListItem a, TransactionListItem b) {
+            final SimpleDate aDate = a.getDate();
+            final SimpleDate bDate = b.getDate();
+            int res = aDate.compareTo(bDate);
+            if (res != 0)
+                return -res;    // transactions are reverse sorted by date
+
+            if (a.getType() == TransactionListItem.Type.DELIMITER) {
+                if (b.getType() == TransactionListItem.Type.DELIMITER)
+                    return 0;
+                else
+                    return -1;
+            }
+            else {
+                if (b.getType() == TransactionListItem.Type.DELIMITER)
+                    return +1;
+                else
+                    return 0;
+            }
+        }
+    }
+}