When deleting a cylinder, adapt gas changes

When we delete a cylinder the gas changes in that dive may have to be
adjusted. We didn't do this at all in the past. With this commit we should
be doing this right for a single dive that is being edited.

This does NOT handle multiple dives being edited at the same time (or more
specifically - if you have multiple dives selected and delete a cylinder,
the dives that had the same set of cylinders (other than the displayed
dive) will get that particular cylinder deleted, but won't have their gas
change events (and sensor data in the samples) adapted.

Possibly we should simply prohibit deleting cylinders when more than one
dive are selected.

See #834

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

2 files changed, 25 insertions, 0 deletions

diff --git a/qt-ui/maintab.cpp b/qt-ui/maintab.cpp
index a75b80722..314626c5d 100644
--- a/qt-ui/maintab.cpp
+++ b/qt-ui/maintab.cpp
@@ -813,6 +813,16 @@ void MainTab::acceptChanges()
 				cd->cylinder[i] = displayed_dive.cylinder[i];
 				cd->cylinder[i].type.description = copy_string(displayed_dive.cylinder[i].type.description);
 			}
+			/* if cylinders changed we may have changed gas change events
+			 * - so far this is ONLY supported for a single selected dive */
+			struct divecomputer *tdc = &current_dive->dc;
+			struct divecomputer *sdc = &displayed_dive.dc;
+			while(tdc && sdc) {
+				free_events(tdc->events);
+				copy_events(sdc, tdc);
+				tdc = tdc->next;
+				sdc = sdc->next;
+			}
 			do_replot = true;
 		}
 
diff --git a/qt-ui/models.cpp b/qt-ui/models.cpp
index 6376bb82a..d6b425b52 100644
--- a/qt-ui/models.cpp
+++ b/qt-ui/models.cpp
@@ -388,6 +388,7 @@ Qt::ItemFlags CylindersModel::flags(const QModelIndex &index) const
 
 void CylindersModel::remove(const QModelIndex &index)
 {
+	int mapping[MAX_CYLINDERS];
 	if (index.column() != REMOVE) {
 		return;
 	}
@@ -395,6 +396,7 @@ void CylindersModel::remove(const QModelIndex &index)
 	cylinder_t *cyl = &displayed_dive.cylinder[index.row()];
 	struct gasmix *mygas = &cyl->gasmix;
 	for (int i = 0; i < MAX_CYLINDERS; i++) {
+		mapping[i] = i;
 		if (i == index.row() || cylinder_none(&displayed_dive.cylinder[i]))
 			continue;
 		struct gasmix *gas2 = &displayed_dive.cylinder[i].gasmix;
@@ -419,11 +421,24 @@ void CylindersModel::remove(const QModelIndex &index)
 		// as first gas
 		memmove(cyl, &displayed_dive.cylinder[same_gas], sizeof(*cyl));
 		remove_cylinder(&displayed_dive, same_gas);
+		mapping[same_gas] = 0;
+		for (int i = same_gas + 1; i < MAX_CYLINDERS; i++)
+			mapping[i] = i - 1;
 	} else {
 		remove_cylinder(&displayed_dive, index.row());
+		if (same_gas > index.row())
+			same_gas--;
+		mapping[index.row()] = same_gas;
+		for (int i = index.row() + 1; i < MAX_CYLINDERS; i++)
+			mapping[i] = i - 1;
 	}
 	changed = true;
 	endRemoveRows();
+	struct divecomputer *dc = &displayed_dive.dc;
+	while (dc) {
+		dc_cylinder_renumber(&displayed_dive, dc, mapping);
+		dc = dc->next;
+	}
 }
 
 WeightModel::WeightModel(QObject *parent) : CleanerTableModel(parent),