Cleanup: unify idiosyncratic singletons

The way we handle singletons in QML, QML insists on allocating the
objects. This leads to a very idiosyncratic way of handling
singletons: The global instance pointer is set in the constructor.

Unify all these by implementing a "SillySingleton" template. All
of the weird singleton-classes can derive from this template and
don't have to bother with reimplementing the instance() function
with all the safety-checks, etc.

This serves firstly as documentation but also improves debugging
as we will now see wanted and unwanted creation and destruction
of these weird singletons.

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

1 files changed, 2 insertions, 4 deletions

diff --git a/qt-models/divelistmodel.h b/qt-models/divelistmodel.h
index d6eb07463..cccece51d 100644
--- a/qt-models/divelistmodel.h
+++ b/qt-models/divelistmodel.h
@@ -6,6 +6,7 @@
 #include <QSortFilterProxyModel>
 
 #include "core/subsurface-qt/DiveObjectHelper.h"
+#include "core/singleton.h"
 
 class DiveListSortModel : public QSortFilterProxyModel
 {
@@ -28,7 +29,7 @@ private:
 	void updateFilterState();
 };
 
-class DiveListModel : public QAbstractListModel
+class DiveListModel : public QAbstractListModel, public SillySingleton<DiveListModel>
 {
 	Q_OBJECT
 public:
@@ -45,7 +46,6 @@ public:
 		DepthDurationRole,
 	};
 
-	static DiveListModel *instance();
 	DiveListModel(QObject *parent = 0);
 	void addDive(const QList<dive *> &listOfDives);
 	void addAllDives();
@@ -63,8 +63,6 @@ public:
 	QString startAddDive();
 	void resetInternalData();
 	Q_INVOKABLE DiveObjectHelper at(int i);
-private:
-	static DiveListModel *m_instance;
 };
 
 #endif // DIVELISTMODEL_H