DiveObjectHelper: Turn DiveObjectHelper into Q_GADGET based object

DiveObjectHelper is a tiny wrapper around dive * to allow access
to dive data from QML and grantlee. It doesn't have to be a
full-fledged QObject with support for signals, etc. Therefore,
turn it into a Q_GADGET based object. This allows us passing the
object around as object, not as pointer to DiveObjectHelper.
This makes memory-management distinctly easier.

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

5 files changed, 101 insertions, 20 deletions

diff --git a/core/subsurface-qt/DiveObjectHelper.cpp b/core/subsurface-qt/DiveObjectHelper.cpp
index e4945f007..c19c03eb4 100644
--- a/core/subsurface-qt/DiveObjectHelper.cpp
+++ b/core/subsurface-qt/DiveObjectHelper.cpp
@@ -55,6 +55,13 @@ 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)
 {
diff --git a/core/subsurface-qt/DiveObjectHelper.h b/core/subsurface-qt/DiveObjectHelper.h
index 397bc4d36..7071c1580 100644
--- a/core/subsurface-qt/DiveObjectHelper.h
+++ b/core/subsurface-qt/DiveObjectHelper.h
@@ -9,8 +9,8 @@
 #include <QVector>
 #include <QVariant>
 
-class DiveObjectHelper : public QObject {
-	Q_OBJECT
+class DiveObjectHelper {
+	Q_GADGET
 	Q_PROPERTY(int number READ number CONSTANT)
 	Q_PROPERTY(int id READ id CONSTANT)
 	Q_PROPERTY(int rating READ rating CONSTANT)
@@ -48,6 +48,7 @@ class DiveObjectHelper : public QObject {
 	Q_PROPERTY(QStringList endPressure READ endPressure CONSTANT)
 	Q_PROPERTY(QStringList firstGas READ firstGas CONSTANT)
 public:
+	DiveObjectHelper(); // This is only to be used by Qt's metatype system!
 	DiveObjectHelper(struct dive *dive);
 	int number() const;
 	int id() const;
@@ -92,6 +93,6 @@ public:
 private:
 	struct dive *m_dive;
 };
-	Q_DECLARE_METATYPE(DiveObjectHelper *)
+	Q_DECLARE_METATYPE(DiveObjectHelper)
 
 #endif
diff --git a/desktop-widgets/templatelayout.cpp b/desktop-widgets/templatelayout.cpp
index 99deeef97..bdcdfbbe9 100644
--- a/desktop-widgets/templatelayout.cpp
+++ b/desktop-widgets/templatelayout.cpp
@@ -134,19 +134,13 @@ QString TemplateLayout::generate()
 	Grantlee::registerMetaType<template_options>();
 	Grantlee::registerMetaType<print_options>();
 	Grantlee::registerMetaType<CylinderObjectHelper>(); // TODO: Remove when grantlee supports Q_GADGET
+	Grantlee::registerMetaType<DiveObjectHelper>(); // TODO: Remove when grantlee supports Q_GADGET
 
-	// Note: Currently, this should not be transformed into a QVector<> or std::vector<>,
-	// as diveList contains pointers to elements in this list. But vectors might relocate
-	// and thus invalidate the pointers! std::list<> is used here, because the new elements
-	// can be directly constructed in the list with the emplace_back() call.
-	// Ultimately, the memory management should be fixed.
-	std::list<DiveObjectHelper> diveObjectList;
 	QVariantList diveList;
 
 	struct dive *dive;
 	if (in_planner()) {
-		diveObjectList.emplace_back(&displayed_dive);
-		diveList.append(QVariant::fromValue(&diveObjectList.back()));
+		diveList.append(QVariant::fromValue(DiveObjectHelper(&displayed_dive)));
 		emit progressUpdated(100.0);
 	} else {
 		int i;
@@ -154,8 +148,7 @@ QString TemplateLayout::generate()
 			//TODO check for exporting selected dives only
 			if (!dive->selected && printOptions->print_selected)
 				continue;
-			diveObjectList.emplace_back(dive);
-			diveList.append(QVariant::fromValue(&diveObjectList.back()));
+			diveList.append(QVariant::fromValue(DiveObjectHelper(dive)));
 			progress++;
 			emit progressUpdated(lrint(progress * 100.0 / totalWork));
 		}
@@ -198,6 +191,7 @@ QString TemplateLayout::generateStatistics()
 	Grantlee::registerMetaType<template_options>();
 	Grantlee::registerMetaType<print_options>();
 	Grantlee::registerMetaType<CylinderObjectHelper>(); // TODO: Remove when grantlee supports Q_GADGET
+	Grantlee::registerMetaType<DiveObjectHelper>(); // TODO: Remove when grantlee supports Q_GADGET
 
 	QVariantList years;
 
diff --git a/desktop-widgets/templatelayout.h b/desktop-widgets/templatelayout.h
index 10c5e96cc..aea44b2b8 100644
--- a/desktop-widgets/templatelayout.h
+++ b/desktop-widgets/templatelayout.h
@@ -139,4 +139,83 @@ if (property == "description") {
 	return object.gasMix;
 }
 GRANTLEE_END_LOOKUP
+
+// TODO: This is currently needed because our grantlee version
+// doesn't support Q_GADGET based classes. A patch to fix this
+// exists. Remove in due course.
+GRANTLEE_BEGIN_LOOKUP(DiveObjectHelper)
+if (property == "number") {
+	return object.number();
+} else if (property == "id") {
+	return object.id();
+} else if (property == "rating") {
+	return object.rating();
+} else if (property == "visibility") {
+	return object.visibility();
+} else if (property == "date") {
+	return object.date();
+} else if (property == "time") {
+	return object.time();
+} else if (property == "timestamp") {
+	return QVariant::fromValue(object.timestamp());
+} else if (property == "location") {
+	return object.location();
+} else if (property == "gps") {
+	return object.gps();
+} else if (property == "gps_decimal") {
+	return object.gps_decimal();
+} else if (property == "dive_site") {
+	return object.dive_site();
+} else if (property == "duration") {
+	return object.duration();
+} else if (property == "noDive") {
+	return object.noDive();
+} else if (property == "depth") {
+	return object.depth();
+} else if (property == "divemaster") {
+	return object.divemaster();
+} else if (property == "buddy") {
+	return object.buddy();
+} else if (property == "airTemp") {
+	return object.airTemp();
+} else if (property == "waterTemp") {
+	return object.waterTemp();
+} else if (property == "notes") {
+	return object.notes();
+} else if (property == "tags") {
+	return object.tags();
+} else if (property == "gas") {
+	return object.gas();
+} else if (property == "sac") {
+	return object.sac();
+} else if (property == "weightList") {
+	return object.weightList();
+} else if (property == "weights") {
+	return object.weights();
+} else if (property == "singleWeight") {
+	return object.singleWeight();
+} else if (property == "suit") {
+	return object.suit();
+} else if (property == "cylinderList") {
+	return object.cylinderList();
+} else if (property == "cylinders") {
+	return object.cylinders();
+} else if (property == "cylinderObjects") {
+	return QVariant::fromValue(object.cylinderObjects());
+} else if (property == "maxcns") {
+	return object.maxcns();
+} else if (property == "otu") {
+	return object.otu();
+} else if (property == "sumWeight") {
+	return object.sumWeight();
+} else if (property == "getCylinder") {
+	return object.getCylinder();
+} else if (property == "startPressure") {
+	return object.startPressure();
+} else if (property == "endPressure") {
+	return object.endPressure();
+} else if (property == "firstGas") {
+	return object.firstGas();
+}
+GRANTLEE_END_LOOKUP
 #endif
diff --git a/qt-models/divelistmodel.cpp b/qt-models/divelistmodel.cpp
index 9c67ced8d..028bd3600 100644
--- a/qt-models/divelistmodel.cpp
+++ b/qt-models/divelistmodel.cpp
@@ -64,8 +64,8 @@ int DiveListSortModel::getIdxForId(int id)
 {
 	for (int i = 0; i < rowCount(); i++) {
 		QVariant v = data(index(i, 0), DiveListModel::DiveRole);
-		DiveObjectHelper *d = v.value<DiveObjectHelper *>();
-		if (d->id() == id)
+		DiveObjectHelper d = v.value<DiveObjectHelper>();
+		if (d.id() == id)
 			return i;
 	}
 	return -1;
@@ -239,13 +239,13 @@ QVariant DiveListModel::data(const QModelIndex &index, int role) const
 	if(index.row() < 0 || index.row() >= m_dives.count())
 		return QVariant();
 
-	DiveObjectHelper *curr_dive = m_dives[index.row()];
-	const dive *d = curr_dive->getDive();
+	DiveObjectHelper &curr_dive = *m_dives[index.row()];
+	const dive *d = curr_dive.getDive();
 	if (!d)
 		return QVariant();
 	switch(role) {
-	case DiveRole: return QVariant::fromValue<QObject*>(curr_dive);
-	case DiveDateRole: return (qlonglong)curr_dive->timestamp();
+	case DiveRole: return QVariant::fromValue<DiveObjectHelper>(curr_dive);
+	case DiveDateRole: return (qlonglong)d->when;
 	case TripIdRole: return d->divetrip ? QString::number((quint64)d->divetrip, 16) : QString();
 	case TripNrDivesRole: return d->divetrip ? d->divetrip->dives.nr : 0;
 	case DateTimeRole: {
@@ -305,7 +305,7 @@ DiveListModel *DiveListModel::instance()
 	return m_instance;
 }
 
-DiveObjectHelper* DiveListModel::at(int i)
+DiveObjectHelper *DiveListModel::at(int i)
 {
 	return m_dives.at(i);
 }