selection: add selection flag for trips

In analogy to dives add a selection flag for trips. The reason
being that search for a selected trip can be painfully slow when
we do it through Qt's proxy model.

Make sure to deselect trips when they are removed from the core.

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

commands/command_divelist.cpp

@@ -13,6 +13,14 @@
 
 namespace Command {
 
+// Helper function that takes care to unselect trips that are removed from the backend
+static void remove_trip_from_backend(dive_trip *trip)
+{
+	if (trip->selected)
+		deselect_trip(trip);
+	remove_trip(trip, &trip_table);	// Remove trip from backend
+}
+
 // This helper function removes a dive, takes ownership of the dive and adds it to a DiveToAdd structure.
 // If the trip the dive belongs to becomes empty, it is removed and added to the tripsToAdd vector.
 // It is crucial that dives are added in reverse order of deletion, so that the indices are correctly
@@ -32,7 +40,7 @@ DiveToAdd DiveListBase::removeDive(struct dive *d, std::vector<OwningTripPtr> &t
 		diveSiteCountChanged(d->dive_site);
 	res.site = unregister_dive_from_dive_site(d);
 	if (res.trip && res.trip->dives.nr == 0) {
-		remove_trip(res.trip, &trip_table);	// Remove trip from backend
+		remove_trip_from_backend(res.trip);	// Remove trip from backend
 		tripsToAdd.emplace_back(res.trip);	// Take ownership of trip
 	}
 
@@ -265,7 +273,7 @@ static OwningTripPtr moveDiveToTrip(DiveToTrip &diveToTrip)
 	// Remove dive from trip - if this is the last dive in the trip, remove the whole trip.
 	dive_trip *trip = unregister_dive_from_trip(diveToTrip.dive);
 	if (trip && trip->dives.nr == 0) {
-		remove_trip(trip, &trip_table);	// Remove trip from backend
+		remove_trip_from_backend(trip);	// Remove trip from backend
 		res.reset(trip);
 	}
 

core/selection.cpp

@@ -3,12 +3,13 @@
 
 #include "selection.h"
 #include "divelist.h"
-#include "display.h" // for amount_selected
+#include "trip.h"
 #include "subsurface-qt/divelistnotifier.h"
 
 #include <QVector>
 
 int amount_selected;
+static int amount_trips_selected;
 
 extern "C" void select_dive(struct dive *dive)
 {
@@ -155,6 +156,11 @@ void setSelection(const std::vector<dive *> &selection, dive *currentDive)
 	QVector<dive *> divesToSelect;
 	divesToSelect.reserve(selection.size());
 
+	// Since we select only dives, there are no selected trips!
+	amount_trips_selected = 0;
+	for (int i = 0; i < trip_table.nr; ++i)
+		trip_table.trips[i]->selected = false;
+
 	// TODO: We might want to keep track of selected dives in a more efficient way!
 	int i;
 	dive *d;
@@ -231,3 +237,19 @@ extern "C" void select_newest_visible_dive()
 	// No visible dive -> deselect all
 	select_single_dive(nullptr);
 }
+
+extern "C" void select_trip(struct dive_trip *trip)
+{
+	if (trip && !trip->selected) {
+		trip->selected = true;
+		amount_trips_selected++;
+	}
+}
+
+extern "C" void deselect_trip(struct dive_trip *trip)
+{
+	if (trip && trip->selected) {
+		trip->selected = false;
+		amount_trips_selected--;
+	}
+}

core/selection.h

@@ -21,6 +21,8 @@ extern struct dive *last_selected_dive(void);
 extern bool consecutive_selected(void);
 extern void select_newest_visible_dive();
 extern void select_single_dive(struct dive *d); // wrapper for setSelection() with a single dive. NULL clears the selection.
+extern void select_trip(struct dive_trip *trip);
+extern void deselect_trip(struct dive_trip *trip);
 
 #if DEBUG_SELECTION_TRACKING
 extern void dump_selection(void);

core/trip.h

@@ -17,6 +17,7 @@ typedef struct dive_trip
 	/* Used by the io-routines to mark trips that have already been written. */
 	bool saved;
 	bool autogen;
+	bool selected;
 } dive_trip_t;
 
 typedef struct trip_table {