QML UI: implement undelete

This code is very similar to the undo code in the desktop UI, but
untangling that from the desktop seemed massive overkill; we don't have
lists of dives to delete and undelete here - so this is actually much
simpler and easier to maintain (I hope).

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

qt-mobile/qml/DiveDetails.qml

@@ -63,11 +63,12 @@ MobileComponents.Page {
 			text: "Delete dive"
 			iconName: "trash-empty"
 			onTriggered: {
-				manager.deleteDive(diveDetailsListView.currentItem.modelData.dive.id)
+				var deletedId = diveDetailsListView.currentItem.modelData.dive.id
+				manager.deleteDive(deletedId)
 				var notification = notificationComponent.createObject(contentItem.parent);
 				notification.showNotification("Dive deleted", 3000, "Undo",
 							      function() {
-								      print("now I need to undo!")
+								      manager.undoDelete(deletedId)
 							      });
 				contextDrawer.close()
 				stackView.pop()

qt-mobile/qmlmanager.cpp

@@ -43,7 +43,9 @@ extern "C" int gitProgressCB(int percent)
 QMLManager::QMLManager() : m_locationServiceEnabled(false),
 	m_verboseEnabled(false),
 	m_credentialStatus(UNKNOWN),
-	reply(0)
+	reply(0),
+	deletedDive(0),
+	deletedTrip(0)
 {
 	m_instance = this;
 	appendTextToLog(getUserAgent());
@@ -610,6 +612,34 @@ void QMLManager::saveChanges()
 	mark_divelist_changed(false);
 }
 
+void QMLManager::undoDelete(int id)
+{
+	if (!deletedDive || deletedDive->id != id) {
+		qDebug() << "can't find the deleted dive";
+		return;
+	}
+	if (deletedTrip)
+		insert_trip(&deletedTrip);
+	if (deletedDive->divetrip) {
+		struct dive_trip *trip = deletedDive->divetrip;
+		tripflag_t tripflag = deletedDive->tripflag; // this gets overwritten in add_dive_to_trip()
+		deletedDive->divetrip = NULL;
+		deletedDive->next = NULL;
+		deletedDive->pprev = NULL;
+		add_dive_to_trip(deletedDive, trip);
+		deletedDive->tripflag = tripflag;
+	}
+	record_dive(deletedDive);
+	DiveListModel::instance()->addDive(deletedDive);
+	prefs.cloud_background_sync = false;
+	prefs.git_local_only = true;
+	saveChanges();
+	prefs.cloud_background_sync = true;
+	prefs.git_local_only = false;
+	deletedDive = NULL;
+	deletedTrip = NULL;
+}
+
 void QMLManager::deleteDive(int id)
 {
 	struct dive *d = get_dive_by_uniq_id(id);
@@ -617,6 +647,28 @@ void QMLManager::deleteDive(int id)
 		qDebug() << "oops, trying to delete non-existing dive";
 		return;
 	}
+	// clean up (or create) the storage for the deleted dive and trip (if applicable)
+	if (!deletedDive)
+		deletedDive = alloc_dive();
+	else
+		clear_dive(deletedDive);
+	copy_dive(d, deletedDive);
+	if (!deletedTrip) {
+		deletedTrip = (struct dive_trip *)calloc(1, sizeof(struct dive_trip));
+	} else {
+		free(deletedTrip->location);
+		free(deletedTrip->notes);
+		memset(deletedTrip, 0, sizeof(struct dive_trip));
+	}
+	// if this is the last dive in that trip, remember the trip as well
+	if (d->divetrip && d->divetrip->nrdives == 1) {
+		deletedTrip = (struct dive_trip *)calloc(1, sizeof(struct dive_trip));
+		*deletedTrip = *d->divetrip;
+		deletedTrip->location = copy_string(d->divetrip->location);
+		deletedTrip->notes = copy_string(d->divetrip->notes);
+		deletedTrip->nrdives = 0;
+		deletedDive->divetrip = deletedTrip;
+	}
 	DiveListModel::instance()->removeDiveById(id);
 	delete_single_dive(get_idx_by_uniq_id(id));
 	prefs.cloud_background_sync = false;

qt-mobile/qmlmanager.h

@@ -92,6 +92,7 @@ public slots:
 
 	void saveChanges();
 	void deleteDive(int id);
+	void undoDelete(int id);
 	QString addDive();
 	void addDiveAborted(int id);
 	void applyGpsData();
@@ -125,6 +126,8 @@ private:
 	static QMLManager *m_instance;
 	QNetworkReply *reply;
 	QNetworkRequest request;
+	struct dive *deletedDive;
+	struct dive_trip *deletedTrip;
 
 	credentialStatus_t m_credentialStatus;