cleanup: create common QDateTime -> timestamp conversion function

In analogy to the timestamp -> QDateTime conversion, create a
common function.
1) For symmetry with the opposite conversion.
2) To remove numerous inconsistencies.
3) To remove use of the deprecated QDateTime::toTime_t() function.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

core/gpslocation.cpp

@@ -169,7 +169,7 @@ void GpsLocation::newPosition(QGeoPositionInfo pos)
 	// if we are waiting for a position update or
 	// if we have no record stored or if at least the configured minimum
 	// time has passed or we moved at least the configured minimum distance
-	int64_t delta = (int64_t)pos.timestamp().toTime_t() + gettimezoneoffset() - lastTime;
+	int64_t delta = dateTimeToTimestamp(pos.timestamp()) + gettimezoneoffset() - lastTime;
 	if (!nr || waitingForPosition || delta > prefs.time_threshold ||
 	    lastCoord.distanceTo(pos.coordinate()) > prefs.distance_threshold) {
 		QString msg = QStringLiteral("received new position %1 after delta %2 threshold %3 (now %4 last %5)");
@@ -177,7 +177,7 @@ void GpsLocation::newPosition(QGeoPositionInfo pos)
 		waitingForPosition = false;
 		acquiredPosition();
 		gpsTracker gt;
-		gt.when = pos.timestamp().toTime_t();
+		gt.when = dateTimeToTimestamp(pos.timestamp());
 		gt.when += gettimezoneoffset(gt.when);
 		gt.location = create_location(pos.coordinate().latitude(), pos.coordinate().longitude());
 		addFixToStorage(gt);

core/metadata.cpp

@@ -271,7 +271,7 @@ static bool parseDate(const QString &s_in, timestamp_t &timestamp)
 	if (datetime.isValid()) {
 		// Not knowing any better, we suppose that time is give in UTC
 		datetime.setTimeSpec(Qt::UTC);
-		timestamp = datetime.toMSecsSinceEpoch() / 1000;
+		timestamp = dateTimeToTimestamp(datetime);
 		return true;
 	}
 
@@ -312,7 +312,7 @@ static bool parseDate(const QString &s_in, timestamp_t &timestamp)
 	// Not knowing any better, we suppose that time is give in UTC
 	datetime = QDateTime(date, time, Qt::UTC);
 	if (datetime.isValid()) {
-		timestamp = datetime.toMSecsSinceEpoch() / 1000;
+		timestamp = dateTimeToTimestamp(datetime);
 		return true;
 	}
 
@@ -542,9 +542,9 @@ extern "C" mediatype_t get_metadata(const char *filename_in, metadata *data)
 	// have a standard way of storing this datum), use the file creation date of the file.
 	if (data->timestamp == 0)
 #if QT_VERSION >= QT_VERSION_CHECK(5, 10, 0)
-		data->timestamp = QFileInfo(filename).birthTime().toMSecsSinceEpoch() / 1000;
+		data->timestamp = dateTimeToTimestamp(QFileInfo(filename).birthTime());
 #else
-		data->timestamp = QFileInfo(filename).created().toMSecsSinceEpoch() / 1000;
+		data->timestamp = dateTimeToTimestamp(QFileInfo(filename).created());
 #endif
 	return res;
 }

core/qthelper.cpp

@@ -709,6 +709,11 @@ QDateTime timestampToDateTime(timestamp_t when)
 	return QDateTime::fromMSecsSinceEpoch(1000 * when, Qt::UTC);
 }
 
+timestamp_t dateTimeToTimestamp(const QDateTime &t)
+{
+	return t.toSecsSinceEpoch();
+}
+
 QString render_seconds_to_string(int seconds)
 {
 	if (seconds % 60 == 0)

core/qthelper.h

@@ -63,6 +63,7 @@ QString getPrintingTemplatePathUser();
 QString getPrintingTemplatePathBundle();
 int gettimezoneoffset(timestamp_t when = 0);
 QDateTime timestampToDateTime(timestamp_t when);
+timestamp_t dateTimeToTimestamp(const QDateTime &t);
 int parseDurationToSeconds(const QString &text);
 int parseLengthToMm(const QString &text);
 int parseTemperatureToMkelvin(const QString &text);

desktop-widgets/simplewidgets.cpp

@@ -279,7 +279,7 @@ void ShiftImageTimesDialog::dcDateTimeChanged(const QDateTime &newDateTime)
 	if (!dcImageEpoch)
 		return;
 	newtime.setTimeSpec(Qt::UTC);
-	setOffset(newtime.toTime_t() - dcImageEpoch);
+	setOffset(dateTimeToTimestamp(newtime) - dcImageEpoch);
 }
 
 void ShiftImageTimesDialog::matchAllImagesToggled(bool state)

desktop-widgets/tab-widgets/maintab.cpp

@@ -598,7 +598,7 @@ void MainTab::on_depth_editingFinished()
 // all dives are shifted by an offset.
 static void shiftTime(QDateTime &dateTime)
 {
-	timestamp_t when = dateTime.toTime_t();
+	timestamp_t when = dateTimeToTimestamp(dateTime);
 	if (current_dive && current_dive->when != when) {
 		timestamp_t offset = when - current_dive->when;
 		Command::shiftTime(getDiveSelection(), (int)offset);

mobile-widgets/qmlmanager.cpp

@@ -908,7 +908,7 @@ parsed:
 			// add a hundred years.
 			if (newDate.addYears(100) < QDateTime::currentDateTime().addYears(1))
 				newDate = newDate.addYears(100);
-			d->dc.when = d->when = newDate.toMSecsSinceEpoch() / 1000;
+			d->dc.when = d->when = dateTimeToTimestamp(newDate);
 			return true;
 		}
 		appendTextToLog("none of our parsing attempts worked for the date string");

qt-models/diveplannermodel.cpp

@@ -85,7 +85,7 @@ void DivePlannerPointsModel::setupStartTime()
 	if (dive_table.nr) {
 		struct dive *d = get_dive(dive_table.nr - 1);
 		time_t ends = dive_endtime(d);
-		time_t diff = ends - startTime.toTime_t();
+		time_t diff = ends - dateTimeToTimestamp(startTime);
 		if (diff > 0) {
 			startTime = startTime.addSecs(diff + 3600);
 		}
@@ -700,7 +700,7 @@ void DivePlannerPointsModel::setSurfaceSegment(int duration)
 void DivePlannerPointsModel::setStartDate(const QDate &date)
 {
 	startTime.setDate(date);
-	diveplan.when = startTime.toTime_t();
+	diveplan.when = dateTimeToTimestamp(startTime);
 	displayed_dive.when = diveplan.when;
 	emitDataChanged();
 }
@@ -708,7 +708,7 @@ void DivePlannerPointsModel::setStartDate(const QDate &date)
 void DivePlannerPointsModel::setStartTime(const QTime &t)
 {
 	startTime.setTime(t);
-		diveplan.when = startTime.toTime_t();
+		diveplan.when = dateTimeToTimestamp(startTime);
 	displayed_dive.when = diveplan.when;
 	emitDataChanged();
 }

qt-models/divesummarymodel.cpp

@@ -263,7 +263,7 @@ void DiveSummaryModel::calc(int column, int period)
 	if (startTime == currentTime)
 		start = 0;
 	else
-		start = startTime.toMSecsSinceEpoch() / 1000L + gettimezoneoffset();
+		start = dateTimeToTimestamp(startTime) + gettimezoneoffset();
 
 	// Loop over all dives and sum up data
 	Stats stats = loopDives(start);