Dive list: implement custom lessThan function

The dive list was sorted using the default-sorter of
QSortFilterProxy model. This is mighty inflexible as it
considers only one column. This has the funky effect that
for rows with identical elements, the sort order depends
on the previous sorting.

Implement a lessThan() function in the MultiFilterSortModel,
which simply hands the sorting down to the actual model.
This might be considered a layering violation, but it makes
things so much easier.

Sadly, it seems like the column-to-be-sorted is transported
in the provided indices. Therefore, the comparison is chosen
using a switch for *every* comparison. It would seem much
more logical to set a function pointer once and use that.
Further investigations are necessary.

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

1 files changed, 3 insertions, 0 deletions

diff --git a/qt-models/filtermodels.h b/qt-models/filtermodels.h
index f579df1a9..8830e99c3 100644
--- a/qt-models/filtermodels.h
+++ b/qt-models/filtermodels.h
@@ -11,6 +11,7 @@
 
 struct dive;
 struct dive_trip;
+class DiveTripModel;
 
 class FilterModelBase : public QAbstractListModel {
 	Q_OBJECT
@@ -127,6 +128,7 @@ public:
 	void divesDeleted(const QVector<dive *> &dives);
 	bool showDive(const struct dive *d) const;
 	int divesDisplayed;
+	bool lessThan(const QModelIndex &, const QModelIndex &) const override;
 public
 slots:
 	void myInvalidate();
@@ -142,6 +144,7 @@ private:
 	MultiFilterSortModel(QObject *parent = 0);
 	QList<FilterModelBase *> models;
 	struct dive_site *curr_dive_site;
+	DiveTripModel *model;
 };
 
 #endif