Connect changes in the tanks with the dive that is being added

- you can no longer delete a tank when its gas is in use
- therefore you can no longer delete the last tank
- when you change the gas mix of a tank, the corresponding segments in the
  dive change as well
- when changing gas for a segment the correct available gases are offered

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

qt-ui/diveplanner.cpp

@@ -1263,6 +1263,64 @@ DivePlannerPointsModel::Mode DivePlannerPointsModel::currentMode() const
 	return mode;
 }
 
+QList<QPair<int, int> > DivePlannerPointsModel::collectGases(struct dive *d)
+{
+	QList<QPair<int, int> > l;
+	for (int i = 0; i < MAX_CYLINDERS; i++) {
+		cylinder_t *cyl = &d->cylinder[i];
+		if (!cylinder_nodata(cyl))
+			l.push_back(QPair<int, int>(cyl->gasmix.o2.permille, cyl->gasmix.he.permille));
+	}
+	return l;
+}
+void DivePlannerPointsModel::rememberTanks()
+{
+	oldGases = collectGases(stagingDive);
+}
+
+bool DivePlannerPointsModel::tankInUse(int o2, int he)
+{
+	for (int j = 0; j < rowCount(); j++) {
+		divedatapoint& p = divepoints[j];
+		if (p.time == 0) // special entries that hold the available gases
+			continue;
+		if ((p.o2 == o2 && p.he == he) ||
+		    (is_air(p.o2, p.he) && is_air(o2, he)))
+			return true;
+	}
+	return false;
+}
+
+void DivePlannerPointsModel::tanksUpdated()
+{
+	if (mode == ADD) {
+		// we don't know exactly what changed - what we care about is
+		// "did a gas change on us". So we look through the diveplan to
+		// see if there is a gas that is now missing and if there is, we
+		// replace it with the matching new gas.
+		QList<QPair<int,int> > gases = collectGases(stagingDive);
+		if (gases.length() == oldGases.length()) {
+			// either nothing relevant changed, or exactly ONE gasmix changed
+			for (int i = 0; i < gases.length(); i++) {
+				if (gases.at(i) != oldGases.at(i)) {
+					for (int j = 0; j < rowCount(); j++) {
+						divedatapoint& p = divepoints[j];
+						int o2 = oldGases.at(i).first;
+						int he = oldGases.at(i).second;
+						if (p.o2 == o2 && p.he == he ||
+						    (is_air(p.o2, p.he) && (is_air(o2, he) || (o2 == 0 && he == 0)))) {
+							p.o2 = gases.at(i).first;
+							p.he = gases.at(i).second;
+						}
+					}
+					break;
+				}
+			}
+		}
+		emit dataChanged(createIndex(0, 0), createIndex(rowCount()-1, COLUMNS-1));
+	}
+}
+
 void DivePlannerPointsModel::clear()
 {
 	if (mode == ADD) {
@@ -1312,8 +1370,8 @@ void DivePlannerPointsModel::createTemporaryPlan()
 #endif
 	plan(&diveplan, &cache, &tempDive, isPlanner(), &errorString);
 	if (mode == ADD) {
+		// copy the samples and events, but don't overwrite the cylinders
 		copy_samples(tempDive, current_dive);
-		copy_cylinders(tempDive, current_dive);
 		copy_events(tempDive, current_dive);
 	}
 #if DEBUG_PLAN

qt-ui/diveplanner.h

@@ -34,6 +34,9 @@ public:
 	void createSimpleDive();
 	void clear();
 	Mode currentMode() const;
+	void tanksUpdated();
+	void rememberTanks();
+	bool tankInUse(int o2, int he);
 	/**
 	 * @return the row number.
 	 */
@@ -42,6 +45,8 @@ public:
 	int size();
 	struct diveplan getDiveplan();
 	QStringList &getGasList();
+	QList<QPair<int, int> > collectGases(dive *d);
+
 public slots:
 	int addStop(int meters = 0, int minutes = 0, int o2 = 0, int he = 0, int ccpoint = 0 );
 	void addCylinder_clicked();
@@ -73,6 +78,7 @@ private:
 	void deleteTemporaryPlan(struct divedatapoint *dp);
 	QVector<sample> backupSamples; // For editing added dives.
 	struct dive *stagingDive;
+	QList<QPair<int, int> > oldGases;
 };
 
 class Button : public QObject, public QGraphicsRectItem {

qt-ui/models.cpp

@@ -5,6 +5,8 @@
  *
  */
 #include "models.h"
+#include "diveplanner.h"
+#include "mainwindow.h"
 #include "../helpers.h"
 #include "../dive.h"
 #include "../device.h"
@@ -17,6 +19,7 @@
 #include <QBrush>
 #include <QFont>
 #include <QIcon>
+#include <QMessageBox>
 
 QFont defaultModelFont()
 {
@@ -196,6 +199,10 @@ void CylindersModel::passInData(const QModelIndex& index, const QVariant& value)
 
 bool CylindersModel::setData(const QModelIndex& index, const QVariant& value, int role)
 {
+	bool addDiveMode = DivePlannerPointsModel::instance()->currentMode() != DivePlannerPointsModel::NOTHING;
+	if (addDiveMode)
+		DivePlannerPointsModel::instance()->rememberTanks();
+
 	cylinder_t *cyl = cylinderAt(index);
 	switch(index.column()) {
 	case TYPE:
@@ -296,6 +303,8 @@ bool CylindersModel::setData(const QModelIndex& index, const QVariant& value, in
 		}
 	}
 	dataChanged(index, index);
+	if (addDiveMode)
+		DivePlannerPointsModel::instance()->tanksUpdated();
 	return true;
 }
 
@@ -311,7 +320,7 @@ void CylindersModel::add()
 	}
 
 	int row = rows;
-
+	fill_default_cylinder(&current->cylinder[row]);
 	beginInsertRows(QModelIndex(), row, row);
 	rows++;
 	changed = true;
@@ -366,6 +375,14 @@ void CylindersModel::remove(const QModelIndex& index)
 	if (index.column() != REMOVE) {
 		return;
 	}
+	cylinder_t *cyl = &current->cylinder[index.row()];
+	if (DivePlannerPointsModel::instance()->tankInUse(cyl->gasmix.o2.permille, cyl->gasmix.he.permille)) {
+		QMessageBox::warning(mainWindow(),
+				     tr("Cylinder cannot be removed"),
+				     tr("This gas in use. Only cylinders that are not used in the dive can be removed."),
+				     QMessageBox::Ok);
+		return;
+	}
 	beginRemoveRows(QModelIndex(), index.row(), index.row()); // yah, know, ugly.
 	rows--;
 	remove_cylinder(current, index.row());