Mobile: transform DiveObjectHelper into value-type

Instead of handing a reference-to-dive to QML, prerender all the needed
properties and store them as values in DiveObjectHelper. Exception:
 - date(): generated from timestamp
 - time(): generated from timestamp
 - cylinderList(): does not depend on dive anyway and should be made
   static.

This hopefully avoids the random mobile crashes that we are seeing.
Clearly, this code needs to be optimized, but it is a start.

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

1 files changed, 123 insertions, 203 deletions

diff --git a/core/subsurface-qt/DiveObjectHelper.cpp b/core/subsurface-qt/DiveObjectHelper.cpp
index f30ca0eab..ec62a9fec 100644
--- a/core/subsurface-qt/DiveObjectHelper.cpp
+++ b/core/subsurface-qt/DiveObjectHelper.cpp
@@ -12,9 +12,9 @@
 
 enum returnPressureSelector {START_PRESSURE, END_PRESSURE};
 
-static QString getFormattedWeight(struct dive *dive, unsigned int idx)
+static QString getFormattedWeight(const struct dive *dive, unsigned int idx)
 {
-	weightsystem_t *weight = &dive->weightsystems.weightsystems[idx];
+	const weightsystem_t *weight = &dive->weightsystems.weightsystems[idx];
 	if (!weight->description)
 		return QString();
 	QString fmt = QString(weight->description);
@@ -22,9 +22,9 @@ static QString getFormattedWeight(struct dive *dive, unsigned int idx)
 	return fmt;
 }
 
-static QString getFormattedCylinder(struct dive *dive, unsigned int idx)
+static QString getFormattedCylinder(const struct dive *dive, unsigned int idx)
 {
-	cylinder_t *cyl = &dive->cylinder[idx];
+	const cylinder_t *cyl = &dive->cylinder[idx];
 	const char *desc = cyl->type.description;
 	if (!desc && idx > 0)
 		return QString();
@@ -36,9 +36,9 @@ static QString getFormattedCylinder(struct dive *dive, unsigned int idx)
 	return fmt;
 }
 
-static QString getPressures(struct dive *dive, int i, enum returnPressureSelector ret)
+static QString getPressures(const struct dive *dive, int i, enum returnPressureSelector ret)
 {
-	cylinder_t *cyl = &dive->cylinder[i];
+	const cylinder_t *cyl = &dive->cylinder[i];
 	QString fmt;
 	if (ret == START_PRESSURE) {
 		if (cyl->start.mbar)
@@ -55,115 +55,20 @@ static QString getPressures(struct dive *dive, int i, enum returnPressureSelecto
 	return fmt;
 }
 
-// Qt's metatype system insists on generating a default constructed object,
-// even if that makes no sense. Usage of this object *will* crash.
-DiveObjectHelper::DiveObjectHelper() :
-	m_dive(nullptr)
-{
-}
-
-DiveObjectHelper::DiveObjectHelper(struct dive *d) :
-	m_dive(d)
-{
-}
-
-int DiveObjectHelper::number() const
-{
-	return m_dive->number;
-}
-
-int DiveObjectHelper::id() const
-{
-	return m_dive->id;
-}
-
-QString DiveObjectHelper::date() const
-{
-	QDateTime localTime = QDateTime::fromMSecsSinceEpoch(1000*m_dive->when, Qt::UTC);
-	localTime.setTimeSpec(Qt::UTC);
-	return localTime.date().toString(prefs.date_format_short);
-}
-
-timestamp_t DiveObjectHelper::timestamp() const
-{
-	return m_dive->when;
-}
-
-QString DiveObjectHelper::time() const
-{
-	QDateTime localTime = QDateTime::fromMSecsSinceEpoch(1000*m_dive->when, Qt::UTC);
-	localTime.setTimeSpec(Qt::UTC);
-	return localTime.time().toString(prefs.time_format);
-}
-
-QString DiveObjectHelper::location() const
-{
-	return get_dive_location(m_dive) ? QString::fromUtf8(get_dive_location(m_dive)) : QString();
-}
-
-QString DiveObjectHelper::gps() const
-{
-	struct dive_site *ds = m_dive->dive_site;
-	if (!ds)
-		return QString();
-	return printGPSCoords(&ds->location);
-}
-
-QString DiveObjectHelper::gps_decimal() const
+static QString format_gps_decimal(const dive *d)
 {
 	bool savep = prefs.coordinates_traditional;
-	QString val;
 
 	prefs.coordinates_traditional = false;
-	val = gps();
+	QString val = d->dive_site ? printGPSCoords(&d->dive_site->location) : QString();
 	prefs.coordinates_traditional = savep;
 	return val;
 }
 
-QVariant DiveObjectHelper::dive_site() const
-{
-	return QVariant::fromValue(m_dive->dive_site);
-}
-
-QString DiveObjectHelper::duration() const
+static QString formatNotes(const dive *d)
 {
-	return get_dive_duration_string(m_dive->duration.seconds, gettextFromC::tr("h"), gettextFromC::tr("min"));
-}
-
-bool DiveObjectHelper::noDive() const
-{
-	return m_dive->duration.seconds == 0 && m_dive->dc.duration.seconds == 0;
-}
-
-QString DiveObjectHelper::depth() const
-{
-	return get_depth_string(m_dive->dc.maxdepth.mm, true, true);
-}
-
-QString DiveObjectHelper::divemaster() const
-{
-	return m_dive->divemaster ? m_dive->divemaster : QString();
-}
-
-QString DiveObjectHelper::buddy() const
-{
-	return m_dive->buddy ? m_dive->buddy : QString();
-}
-
-QString DiveObjectHelper::airTemp() const
-{
-	return get_temperature_string(m_dive->airtemp, true);
-}
-
-QString DiveObjectHelper::waterTemp() const
-{
-	return get_temperature_string(m_dive->watertemp, true);
-}
-
-QString DiveObjectHelper::notes() const
-{
-	QString tmp = m_dive->notes ? QString::fromUtf8(m_dive->notes) : QString();
-	if (is_dc_planner(&m_dive->dc)) {
+	QString tmp = d->notes ? QString::fromUtf8(d->notes) : QString();
+	if (is_dc_planner(&d->dc)) {
 		QTextDocument notes;
 	#define _NOTES_BR "&#92n"
 		tmp.replace("<thead>", "<thead>" _NOTES_BR)
@@ -182,24 +87,19 @@ QString DiveObjectHelper::notes() const
 	return tmp;
 }
 
-QString DiveObjectHelper::tags() const
-{
-	return get_taglist_string(m_dive->tag_list);
-}
-
-QString DiveObjectHelper::gas() const
+static QString formatGas(const dive *d)
 {
 	/*WARNING: here should be the gastlist, returned
 	 * from the get_gas_string function or this is correct?
 	 */
 	QString gas, gases;
 	for (int i = 0; i < MAX_CYLINDERS; i++) {
-		if (!is_cylinder_used(m_dive, i))
+		if (!is_cylinder_used(d, i))
 			continue;
-		gas = m_dive->cylinder[i].type.description;
+		gas = d->cylinder[i].type.description;
 		if (!gas.isEmpty())
 			gas += QChar(' ');
-		gas += gasname(m_dive->cylinder[i].gasmix);
+		gas += gasname(d->cylinder[i].gasmix);
 		// if has a description and if such gas is not already present
 		if (!gas.isEmpty() && gases.indexOf(gas) == -1) {
 			if (!gases.isEmpty())
@@ -210,21 +110,21 @@ QString DiveObjectHelper::gas() const
 	return gases;
 }
 
-QString DiveObjectHelper::sac() const
+static QString formatSac(const dive *d)
 {
-	if (!m_dive->sac)
+	if (!d->sac)
 		return QString();
 	const char *unit;
 	int decimal;
-	double value = get_volume_units(m_dive->sac, &decimal, &unit);
+	double value = get_volume_units(d->sac, &decimal, &unit);
 	return QString::number(value, 'f', decimal).append(unit);
 }
 
-QString DiveObjectHelper::weightList() const
+static QString formatWeightList(const dive *d)
 {
 	QString weights;
-	for (int i = 0; i < m_dive->weightsystems.nr; i++) {
-		QString w = getFormattedWeight(m_dive, i);
+	for (int i = 0; i < d->weightsystems.nr; i++) {
+		QString w = getFormattedWeight(d, i);
 		if (w.isEmpty())
 			continue;
 		weights += w + "; ";
@@ -232,11 +132,11 @@ QString DiveObjectHelper::weightList() const
 	return weights;
 }
 
-QStringList DiveObjectHelper::weights() const
+static QStringList formatWeights(const dive *d)
 {
 	QStringList weights;
-	for (int i = 0; i < m_dive->weightsystems.nr; i++) {
-		QString w = getFormattedWeight(m_dive, i);
+	for (int i = 0; i < d->weightsystems.nr; i++) {
+		QString w = getFormattedWeight(d, i);
 		if (w.isEmpty())
 			continue;
 		weights << w;
@@ -244,47 +144,11 @@ QStringList DiveObjectHelper::weights() const
 	return weights;
 }
 
-bool DiveObjectHelper::singleWeight() const
-{
-	return m_dive->weightsystems.nr <= 1;
-}
-
-QString DiveObjectHelper::suit() const
-{
-	return m_dive->suit ? m_dive->suit : QString();
-}
-
-QStringList DiveObjectHelper::cylinderList() const
-{
-	QStringList cylinders;
-	struct dive *d;
-	int i = 0;
-	for_each_dive (i, d) {
-		for (int j = 0; j < MAX_CYLINDERS; j++) {
-			QString cyl = d->cylinder[j].type.description;
-			if (cyl.isEmpty())
-				continue;
-			cylinders << cyl;
-		}
-	}
-
-	for (unsigned long ti = 0; ti < MAX_TANK_INFO && tank_info[ti].name != NULL; ti++) {
-		QString cyl = tank_info[ti].name;
-		if (cyl.isEmpty())
-			continue;
-		cylinders << cyl;
-	}
-
-	cylinders.removeDuplicates();
-	cylinders.sort();
-	return cylinders;
-}
-
-QStringList DiveObjectHelper::cylinders() const
+static QStringList formatCylinders(const dive *d)
 {
 	QStringList cylinders;
 	for (int i = 0; i < MAX_CYLINDERS; i++) {
-		QString cyl = getFormattedCylinder(m_dive, i);
+		QString cyl = getFormattedCylinder(d, i);
 		if (cyl.isEmpty())
 			continue;
 		cylinders << cyl;
@@ -292,79 +156,135 @@ QStringList DiveObjectHelper::cylinders() const
 	return cylinders;
 }
 
-QVector<CylinderObjectHelper> DiveObjectHelper::cylinderObjects() const
+static QVector<CylinderObjectHelper> makeCylinderObjects(const dive *d)
 {
 	QVector<CylinderObjectHelper> res;
 	for (int i = 0; i < MAX_CYLINDERS; i++) {
 		//Don't add blank cylinders, only those that have been defined.
-		if (m_dive->cylinder[i].type.description)
-			res.append(CylinderObjectHelper(&m_dive->cylinder[i])); // no emplace for QVector. :(
+		if (d->cylinder[i].type.description)
+			res.append(CylinderObjectHelper(&d->cylinder[i])); // no emplace for QVector. :(
 	}
 	return res;
 }
 
-int DiveObjectHelper::maxcns() const
-{
-	return m_dive->maxcns;
-}
-
-int DiveObjectHelper::otu() const
-{
-	return m_dive->otu;
-}
-
-int DiveObjectHelper::rating() const
-{
-	return m_dive->rating;
-}
-
-int DiveObjectHelper::visibility() const
-{
-	return m_dive->visibility;
-}
-
-QString DiveObjectHelper::sumWeight() const
-{
-	weight_t sum = { total_weight(m_dive) };
-	return get_weight_string(sum, true);
-}
-
-QStringList DiveObjectHelper::getCylinder() const
+static QStringList formatGetCylinder(const dive *d)
 {
 	QStringList getCylinder; 
 	for (int i = 0; i < MAX_CYLINDERS; i++) {
-		if (is_cylinder_used(m_dive, i))
-			getCylinder << m_dive->cylinder[i].type.description;
+		if (is_cylinder_used(d, i))
+			getCylinder << d->cylinder[i].type.description;
 	}
 	return getCylinder;
 }
 
-QStringList DiveObjectHelper::startPressure() const
+static QStringList getStartPressure(const dive *d)
 {
 	QStringList startPressure;
 	for (int i = 0; i < MAX_CYLINDERS; i++) {
-		if (is_cylinder_used(m_dive, i))
-			startPressure << getPressures(m_dive, i, START_PRESSURE);
+		if (is_cylinder_used(d, i))
+			startPressure << getPressures(d, i, START_PRESSURE);
 	}
 	return startPressure;
 }
 
-QStringList DiveObjectHelper::endPressure() const
+static QStringList getEndPressure(const dive *d)
 {
 	QStringList endPressure;
 	for (int i = 0; i < MAX_CYLINDERS; i++) {
-		if (is_cylinder_used(m_dive, i))
-			endPressure << getPressures(m_dive, i, END_PRESSURE);
+		if (is_cylinder_used(d, i))
+			endPressure << getPressures(d, i, END_PRESSURE);
 	}
 	return endPressure;
 }
 
-QStringList DiveObjectHelper::firstGas() const
+static QStringList getFirstGas(const dive *d)
 {
 	QStringList gas;
 	for (int i = 0; i < MAX_CYLINDERS; i++) {
-		if (is_cylinder_used(m_dive, i))
-			gas << get_gas_string(m_dive->cylinder[i].gasmix);
+		if (is_cylinder_used(d, i))
+			gas << get_gas_string(d->cylinder[i].gasmix);
 	}
 	return gas;
 }
+
+// Qt's metatype system insists on generating a default constructed object, even if that makes no sense.
+DiveObjectHelper::DiveObjectHelper()
+{
+}
+
+DiveObjectHelper::DiveObjectHelper(const struct dive *d) :
+	number(d->number),
+	id(d->id),
+	rating(d->rating),
+	visibility(d->visibility),
+	timestamp(d->when),
+	location(get_dive_location(d) ? QString::fromUtf8(get_dive_location(d)) : QString()),
+	gps(d->dive_site ? printGPSCoords(&d->dive_site->location) : QString()),
+	gps_decimal(format_gps_decimal(d)),
+	dive_site(QVariant::fromValue(d->dive_site)),
+	duration(get_dive_duration_string(d->duration.seconds, gettextFromC::tr("h"), gettextFromC::tr("min"))),
+	noDive(d->duration.seconds == 0 && d->dc.duration.seconds == 0),
+	depth(get_depth_string(d->dc.maxdepth.mm, true, true)),
+	divemaster(d->divemaster ? d->divemaster : QString()),
+	buddy(d->buddy ? d->buddy : QString()),
+	airTemp(get_temperature_string(d->airtemp, true)),
+	waterTemp(get_temperature_string(d->watertemp, true)),
+	notes(formatNotes(d)),
+	tags(get_taglist_string(d->tag_list)),
+	gas(formatGas(d)),
+	sac(formatSac(d)),
+	weightList(formatWeightList(d)),
+	weights(formatWeights(d)),
+	singleWeight(d->weightsystems.nr <= 1),
+	suit(d->suit ? d->suit : QString()),
+	cylinders(formatCylinders(d)),
+	cylinderObjects(makeCylinderObjects(d)),
+	maxcns(d->maxcns),
+	otu(d->otu),
+	sumWeight(get_weight_string(weight_t { total_weight(d) }, true)),
+	getCylinder(formatGetCylinder(d)),
+	startPressure(getStartPressure(d)),
+	endPressure(getEndPressure(d)),
+	firstGas(getFirstGas(d))
+{
+}
+
+QString DiveObjectHelper::date() const
+{
+	QDateTime localTime = QDateTime::fromMSecsSinceEpoch(1000 * timestamp, Qt::UTC);
+	localTime.setTimeSpec(Qt::UTC);
+	return localTime.date().toString(prefs.date_format_short);
+}
+
+QString DiveObjectHelper::time() const
+{
+	QDateTime localTime = QDateTime::fromMSecsSinceEpoch(1000 * timestamp, Qt::UTC);
+	localTime.setTimeSpec(Qt::UTC);
+	return localTime.time().toString(prefs.time_format);
+}
+
+QStringList DiveObjectHelper::cylinderList() const
+{
+	QStringList cylinders;
+	int i = 0;
+	struct dive *d;
+	for_each_dive (i, d) {
+		for (int j = 0; j < MAX_CYLINDERS; j++) {
+			QString cyl = d->cylinder[j].type.description;
+			if (cyl.isEmpty())
+				continue;
+			cylinders << cyl;
+		}
+	}
+
+	for (int ti = 0; ti < MAX_TANK_INFO && tank_info[ti].name != NULL; ti++) {
+		QString cyl = tank_info[ti].name;
+		if (cyl.isEmpty())
+			continue;
+		cylinders << cyl;
+	}
+
+	cylinders.removeDuplicates();
+	cylinders.sort();
+	return cylinders;
+}