Undo: keep frontend informed of changes to dive site count

Add a new signal to DiveListNotifier. Send signal if dives are
added or removed and therefore the dive count of a dive site
changes. The dive sites are collected and the signal is sent
at the end of the command.

Add code to update the table view.

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

core/divesite.c

@@ -23,6 +23,7 @@ int get_divesite_idx(const struct dive_site *ds, struct dive_site_table *ds_tabl
 	return -1;
 }
 
+// TODO: keep table sorted by UUID and do a binary search?
 struct dive_site *get_dive_site_by_uuid(uint32_t uuid, struct dive_site_table *ds_table)
 {
 	int i;

core/subsurface-qt/DiveListNotifier.h

@@ -42,6 +42,9 @@ signals:
 	void divesDeselected(dive_trip *trip, const QVector<dive *> &dives);
 	void currentDiveChanged();
 	void selectionChanged();
+
+	// Dive site signals
+	void diveSiteDiveCountChanged(dive_site *ds);
 public:
 	// Desktop uses the QTreeView class to present the list of dives. The layout
 	// of this class gives us a very fundamental problem, as we can not easily

desktop-widgets/command_divelist.cpp

@@ -69,6 +69,8 @@ DiveToAdd DiveListBase::removeDive(struct dive *d, std::vector<OwningTripPtr> &t
 	// remove dive from trip and site - if this is the last dive in the trip
 	// remove the whole trip.
 	res.trip = unregister_dive_from_trip(d);
+	if (d->dive_site)
+		diveSiteCountChanged(d->dive_site);
 	res.site = unregister_dive_from_dive_site(d);
 	if (res.trip && res.trip->dives.nr == 0) {
 		unregister_trip(res.trip, &trip_table);	// Remove trip from backend
@@ -80,6 +82,12 @@ DiveToAdd DiveListBase::removeDive(struct dive *d, std::vector<OwningTripPtr> &t
 	return res;
 }
 
+void DiveListBase::diveSiteCountChanged(struct dive_site *ds)
+{
+	if (std::find(sitesCountChanged.begin(), sitesCountChanged.end(), ds) == sitesCountChanged.end())
+		sitesCountChanged.push_back(ds);
+}
+
 // This helper function adds a dive and returns ownership to the backend. It may also add a dive trip.
 // It is crucial that dives are added in reverse order of deletion (see comment above)!
 // Returns pointer to added dive (which is owned by the backend!)
@@ -87,8 +95,10 @@ dive *DiveListBase::addDive(DiveToAdd &d)
 {
 	if (d.trip)
 		add_dive_to_trip(d.dive.get(), d.trip);
-	if (d.site)
+	if (d.site) {
 		add_dive_to_dive_site(d.dive.get(), d.site);
+		diveSiteCountChanged(d.site);
+	}
 	dive *res = d.dive.release();		// Give up ownership of dive
 
 	// Set the filter flag according to current filter settings
@@ -370,6 +380,8 @@ void DiveListBase::finishWork()
 {
 	if (selectionChanged) // If the selection changed -> tell the frontend
 		emit diveListNotifier.selectionChanged();
+	for (dive_site *ds: sitesCountChanged)
+		emit diveListNotifier.diveSiteDiveCountChanged(ds);
 }
 
 // Set the current dive either from a list of selected dives,

desktop-widgets/command_divelist.h

@@ -66,6 +66,9 @@ protected:
 	DivesAndTripsToAdd removeDives(DivesAndSitesToRemove &divesAndSitesToDelete);
 	DivesAndSitesToRemove addDives(DivesAndTripsToAdd &toAdd);
 
+	// Register dive sites where counts changed so that we can signal the frontend later.
+	void diveSiteCountChanged(struct dive_site *ds);
+
 	// Set the selection to a given state. Set the selectionChanged flag if anything changed.
 	void restoreSelection(const std::vector<dive *> &selection, dive *currentDive);
 
@@ -74,9 +77,12 @@ protected:
 	// If this flag is set on first execution, a selectionChanged signal will
 	// be sent.
 	bool selectionChanged;
+
 private:
+	// Keep track of dive sites where the number of dives changed
+	std::vector<dive_site *> sitesCountChanged;
 	void initWork(); // reset selectionChanged flag
-	void finishWork(); // emit signal if selection changed
+	void finishWork(); // emit signals if selection or dive site counts changed
 	void undo() override;
 	void redo() override;
 	virtual void redoit() = 0;

qt-models/divelocationmodel.cpp

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 #include "core/units.h"
 #include "qt-models/divelocationmodel.h"
+#include "core/subsurface-qt/DiveListNotifier.h"
 #include "core/qthelper.h"
 #include "core/divesite.h"
 #include "core/metrics.h"
@@ -23,6 +24,7 @@ LocationInformationModel *LocationInformationModel::instance()
 
 LocationInformationModel::LocationInformationModel(QObject *obj) : QAbstractTableModel(obj)
 {
+	connect(&diveListNotifier, &DiveListNotifier::diveSiteDiveCountChanged, this, &LocationInformationModel::diveSiteDiveCountChanged);
 }
 
 int LocationInformationModel::columnCount(const QModelIndex &) const
@@ -154,6 +156,13 @@ bool LocationInformationModel::removeRows(int row, int, const QModelIndex&)
 	return true;
 }
 
+void LocationInformationModel::diveSiteDiveCountChanged(dive_site *ds)
+{
+	int idx = get_divesite_idx(ds, &dive_site_table);
+	if (idx >= 0)
+		dataChanged(createIndex(idx, NUM_DIVES), createIndex(idx, NUM_DIVES));
+}
+
 GeoReferencingOptionsModel *GeoReferencingOptionsModel::instance()
 {
 	static GeoReferencingOptionsModel *self = new GeoReferencingOptionsModel();

qt-models/divelocationmodel.h

@@ -9,6 +9,9 @@
 
 #define RECENTLY_ADDED_DIVESITE ((struct dive_site *)~0)
 
+struct dive;
+struct dive_trip;
+
 class LocationInformationModel : public QAbstractTableModel {
 Q_OBJECT
 public:
@@ -30,6 +33,7 @@ public:
 public slots:
 	void update();
 	QStringList allSiteNames() const;
+	void diveSiteDiveCountChanged(struct dive_site *ds);
 private:
 	QStringList locationNames;
 };