divetripmodel: introduce CURRENT_ROLE

Use this role to test whether a dive is the currently displayed dive.
This will be needed to transport changes of the current dive to
the mobile list models.

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

qt-models/divetripmodel.cpp

@@ -255,6 +255,8 @@ QVariant DiveTripModelBase::diveData(const struct dive *d, int column, int role)
 		return get_divenr(d);
 	case SELECTED_ROLE:
 		return d->selected;
+	case CURRENT_ROLE:
+		return d == current_dive;
 	}
 	return QVariant();
 }

qt-models/divetripmodel.h

@@ -49,7 +49,8 @@ public:
 		DIVE_ROLE,
 		TRIP_ROLE,
 		DIVE_IDX,
-		SELECTED_ROLE
+		SELECTED_ROLE,
+		CURRENT_ROLE
 	};
 	enum Layout {
 		TREE,