Add new method for updating songs based on song ID

Show status updating database.

Fixes #750

src/collection/collectiontask.cpp

@@ -0,0 +1,35 @@
+/*
+ * Strawberry Music Player
+ * Copyright 2021, Jonas Kvinge <jonas@jkvinge.net>
+ *
+ * Strawberry is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Strawberry 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 for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <QString>
+
+#include "core/taskmanager.h"
+#include "collectiontask.h"
+
+CollectionTask::CollectionTask(TaskManager *task_manager, const QString &message) : task_manager_(task_manager), task_id_(-1) {
+
+  if (task_manager_) task_id_ = task_manager_->StartTask(message);
+
+}
+
+CollectionTask::~CollectionTask() {
+
+  if (task_manager_) task_manager_->SetTaskFinished(task_id_);
+
+}