Updated strategy for removing cylinders

Change the strategy when to allow cylinder removal from a dive:
- Not remove when cylinder has gas switch events, in any other cases
  allow removal
- Remove this whole "cylinder with same gas" thing being a criteria
  for cylinder removal

When removing a cylinder which has corresponding pressure info in
samples, also remove this pressure info from the samples.

Signed-off-by: Stefan Fuchs <sfuchs@gmx.de>

5 files changed, 42 insertions, 37 deletions

diff --git a/core/dive.c b/core/dive.c
index 528cf9efa..c4a903eec 100644
--- a/core/dive.c
+++ b/core/dive.c
@@ -2072,7 +2072,7 @@ static void dc_cylinder_renumber(struct dive *dive, struct divecomputer *dc, int
 	if (mapping[0] > 0)
 		add_initial_gaschange(dive, dc);
 
-	/* Remap the sensor indexes */
+	/* Remap or delete the sensor indexes */
 	for (i = 0; i < dc->samples; i++) {
 		struct sample *s = dc->sample + i;
 		int j;
@@ -2081,8 +2081,18 @@ static void dc_cylinder_renumber(struct dive *dive, struct divecomputer *dc, int
 			int sensor;
 
 			sensor = mapping[s->sensor[j]];
-			if (sensor >= 0)
+			if (sensor == -1) {
+				// Remove sensor and gas pressure info
+				if (i == 0) {
+					s->sensor[j] = 0;
+					s->pressure[j].mbar = 0;
+				} else {
+					s->sensor[j] = s[-1].sensor[j];
+					s->pressure[j].mbar = s[-1].pressure[j].mbar;
+				}
+			} else {
 				s->sensor[j] = sensor;
+			}
 		}
 	}
 
diff --git a/core/dive.h b/core/dive.h
index b6f9c835f..b152d59e9 100644
--- a/core/dive.h
+++ b/core/dive.h
@@ -812,6 +812,7 @@ extern void free_events(struct event *ev);
 extern void copy_cylinders(struct dive *s, struct dive *d, bool used_only);
 extern void copy_samples(struct divecomputer *s, struct divecomputer *d);
 extern bool is_cylinder_used(struct dive *dive, int idx);
+extern bool is_cylinder_prot(struct dive *dive, int idx);
 extern void fill_default_cylinder(cylinder_t *cyl);
 extern void add_gas_switch_event(struct dive *dive, struct divecomputer *dc, int time, int idx);
 extern struct event *add_event(struct divecomputer *dc, unsigned int time, int type, int flags, int value, const char *name);
diff --git a/core/statistics.c b/core/statistics.c
index 678843b99..eed24505c 100644
--- a/core/statistics.c
+++ b/core/statistics.c
@@ -345,6 +345,19 @@ bool is_cylinder_used(struct dive *dive, int idx)
 	return false;
 }
 
+bool is_cylinder_prot(struct dive *dive, int idx)
+{
+	struct divecomputer *dc;
+	if (cylinder_none(&dive->cylinder[idx]))
+		return false;
+
+	for_each_dc(dive, dc) {
+		if (has_gaschange_event(dive, dc, idx))
+			return true;
+	}
+	return false;
+}
+
 void get_gas_used(struct dive *dive, volume_t gases[MAX_CYLINDERS])
 {
 	int idx;
diff --git a/qt-models/cylindermodel.cpp b/qt-models/cylindermodel.cpp
index 5bb25f505..a5b1b53c0 100644
--- a/qt-models/cylindermodel.cpp
+++ b/qt-models/cylindermodel.cpp
@@ -136,7 +136,6 @@ QVariant CylindersModel::data(const QModelIndex &index, int role) const
 	if (!index.isValid() || index.row() >= MAX_CYLINDERS)
 		return ret;
 
-	int same_gas = -1;
 	cylinder_t *cyl = &displayed_dive.cylinder[index.row()];
 
 	switch (role) {
@@ -231,10 +230,8 @@ QVariant CylindersModel::data(const QModelIndex &index, int role) const
 	case Qt::DecorationRole:
 	case Qt::SizeHintRole:
 		if (index.column() == REMOVE) {
-			same_gas = same_gasmix_cylinder(cyl, index.row(), &displayed_dive, false);
-
 			if ((in_planner() && DivePlannerPointsModel::instance()->tankInUse(index.row())) ||
-				(!in_planner() && is_cylinder_used(&displayed_dive, index.row()) && same_gas == -1)) {
+				(!in_planner() && is_cylinder_prot(&displayed_dive, index.row()))) {
 					ret = trashForbiddenIcon();
 			}
 			else ret = trashIcon();
@@ -244,10 +241,8 @@ QVariant CylindersModel::data(const QModelIndex &index, int role) const
 	case Qt::ToolTipRole:
 		switch (index.column()) {
 		case REMOVE:
-			same_gas = same_gasmix_cylinder(cyl, index.row(), &displayed_dive, false);
-
 			if ((in_planner() && DivePlannerPointsModel::instance()->tankInUse(index.row())) ||
-				(!in_planner() && is_cylinder_used(&displayed_dive, index.row()) && same_gas == -1)) {
+				(!in_planner() && is_cylinder_prot(&displayed_dive, index.row()))) {
 					ret = tr("This gas is in use. Only cylinders that are not used in the dive can be removed.");
 			}
 			else ret = tr("Clicking here will remove this cylinder.");
@@ -541,38 +536,22 @@ void CylindersModel::remove(const QModelIndex &index)
 	if (index.column() != REMOVE) {
 		return;
 	}
-	cylinder_t *cyl = &displayed_dive.cylinder[index.row()];
-	int same_gas = same_gasmix_cylinder(cyl, index.row(), &displayed_dive, false);
 
 	if ((in_planner() && DivePlannerPointsModel::instance()->tankInUse(index.row())) ||
-		(!in_planner() && is_cylinder_used(&displayed_dive, index.row()) && same_gas == -1))
+		(!in_planner() && is_cylinder_prot(&displayed_dive, index.row())))
 			return;
 
 	beginRemoveRows(QModelIndex(), index.row(), index.row()); // yah, know, ugly.
 	rows--;
-	// if we didn't find an identical gas, point same_gas at the index.row()
-	if (same_gas == -1)
-		same_gas = index.row();
-	if (index.row() == 0) {
-		// first gas - we need to make sure that the same gas ends up
-		// as first gas
-		memmove(cyl, &displayed_dive.cylinder[same_gas], sizeof(*cyl));
-		remove_cylinder(&displayed_dive, same_gas);
-		for (int i = 0; i < same_gas - 1; i++)
-			mapping[i] = i;
-		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--;
-		for (int i = 0; i < index.row(); i++)
-			mapping[i] = i;
-		mapping[index.row()] = same_gas;
-		for (int i = index.row() + 1; i < MAX_CYLINDERS; i++)
-			mapping[i] = i - 1;
-	}
+
+	remove_cylinder(&displayed_dive, index.row());
+	for (int i = 0; i < index.row(); i++)
+		mapping[i] = i;
+	// No mapping for removed gas, set to -1
+	mapping[index.row()] = -1;
+	for (int i = index.row() + 1; i < MAX_CYLINDERS; i++)
+		mapping[i] = i - 1;
+
 	cylinder_renumber(&displayed_dive, mapping);
 	if (in_planner())
 		DivePlannerPointsModel::instance()->cylinderRenumber(mapping);
diff --git a/qt-models/diveplannermodel.cpp b/qt-models/diveplannermodel.cpp
index 614f194aa..9af6833f0 100644
--- a/qt-models/diveplannermodel.cpp
+++ b/qt-models/diveplannermodel.cpp
@@ -346,8 +346,10 @@ void DivePlannerPointsModel::gasChange(const QModelIndex &index, int newcylinder
 
 void DivePlannerPointsModel::cylinderRenumber(int mapping[])
 {
-	for (int i = 0; i < rowCount(); i++)
-		divepoints[i].cylinderid = mapping[divepoints[i].cylinderid];
+	for (int i = 0; i < rowCount(); i++) {
+		if (mapping[divepoints[i].cylinderid] >= 0)
+			divepoints[i].cylinderid = mapping[divepoints[i].cylinderid];
+	}
 	emitDataChanged();
 }