crash fix: Don't cast to CylindersModel or CylindersModelFiltered

The tank-info-delegate cast its model to CylindersModelFiltered,
since this is what the equipment-tab uses since implementing the
filtering of unused cylinders. However, the planner users the same
delegate and still uses the unfiltered CylindersModel. This means
that the (dynamic) cast returns a null pointer and crashes.

One possibility would be to derive CylindersModelFiltered and
CylindersModel from the same class that defines virtual functions
and cast to that class.

This is a different attempt: don't cast (i.e. stay with a
QAbstractItemModel and play it via Qt's model-view system. Firstly,
replace the passInData function by a role to setData(). Secondly,
read the working-pressure and size via new columns using data().

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

desktop-widgets/modeldelegates.cpp

@@ -238,7 +238,7 @@ static struct RevertCylinderData {
 
 void TankInfoDelegate::setModelData(QWidget*, QAbstractItemModel*, const QModelIndex&) const
 {
-	CylindersModelFiltered *mymodel = qobject_cast<CylindersModelFiltered *>(currCombo.model);
+	QAbstractItemModel *mymodel = currCombo.model;
 	TankInfoModel *tanks = TankInfoModel::instance();
 	QModelIndexList matches = tanks->match(tanks->index(0, 0), Qt::DisplayRole, currCombo.activeText);
 	int row;
@@ -255,8 +255,8 @@ void TankInfoDelegate::setModelData(QWidget*, QAbstractItemModel*, const QModelI
 	int tankPressure = tanks->data(tanks->index(row, TankInfoModel::BAR)).toInt();
 
 	mymodel->setData(IDX(CylindersModel::TYPE), cylinderName, Qt::EditRole);
-	mymodel->passInData(IDX(CylindersModel::WORKINGPRESS), tankPressure);
+	mymodel->setData(IDX(CylindersModel::WORKINGPRESS), tankPressure, CylindersModel::PASS_IN_ROLE);
-	mymodel->passInData(IDX(CylindersModel::SIZE), tankSize);
+	mymodel->setData(IDX(CylindersModel::SIZE), tankSize, CylindersModel::PASS_IN_ROLE);
 }
 
 TankInfoDelegate::TankInfoDelegate(QObject *parent) : ComboBoxDelegate(TankInfoModel::instance(), parent, true)
@@ -277,10 +277,10 @@ void TankInfoDelegate::editorClosed(QWidget*, QAbstractItemDelegate::EndEditHint
 {
 	if (hint == QAbstractItemDelegate::NoHint ||
 	    hint == QAbstractItemDelegate::RevertModelCache) {
-		CylindersModelFiltered *mymodel = qobject_cast<CylindersModelFiltered *>(currCombo.model);
+		QAbstractItemModel *mymodel = currCombo.model;
 		mymodel->setData(IDX(CylindersModel::TYPE), currCylinderData.type, Qt::EditRole);
-		mymodel->passInData(IDX(CylindersModel::WORKINGPRESS), currCylinderData.pressure);
+		mymodel->setData(IDX(CylindersModel::WORKINGPRESS), currCylinderData.pressure, CylindersModel::PASS_IN_ROLE);
-		mymodel->passInData(IDX(CylindersModel::SIZE), currCylinderData.size);
+		mymodel->setData(IDX(CylindersModel::SIZE), currCylinderData.size, CylindersModel::PASS_IN_ROLE);
 	}
 }
 
@@ -289,11 +289,11 @@ QWidget *TankInfoDelegate::createEditor(QWidget *parent, const QStyleOptionViewI
 	// ncreate editor needs to be called before because it will populate a few
 	// things in the currCombo global var.
 	QWidget *delegate = ComboBoxDelegate::createEditor(parent, option, index);
-	CylindersModelFiltered *mymodel = qobject_cast<CylindersModelFiltered *>(currCombo.model);
+	QAbstractItemModel *model = currCombo.model;
-	cylinder_t *cyl = mymodel->cylinderAt(index);
+	int row = index.row();
-	currCylinderData.type = cyl->type.description;
+	currCylinderData.type = model->data(model->index(row, CylindersModel::TYPE)).value<QString>();
-	currCylinderData.pressure = cyl->type.workingpressure.mbar;
+	currCylinderData.pressure = model->data(model->index(row, CylindersModel::WORKINGPRESS_INT)).value<int>();
-	currCylinderData.size = cyl->type.size.mliter;
+	currCylinderData.size = model->data(model->index(row, CylindersModel::SIZE_INT)).value<int>();
 	MainWindow::instance()->graphics->setReplot(false);
 	return delegate;
 }

qt-models/cylindermodel.cpp

@@ -236,6 +236,10 @@ QVariant CylindersModel::data(const QModelIndex &index, int role) const
 			break;
 		case USE:
 			return gettextFromC::tr(cylinderuse_text[cyl->cylinder_use]);
+		case WORKINGPRESS_INT:
+			return static_cast<int>(cyl->type.workingpressure.mbar);
+		case SIZE_INT:
+			return static_cast<int>(cyl->type.size.mliter);
 		}
 		break;
 	case Qt::DecorationRole:
@@ -283,33 +287,35 @@ cylinder_t *CylindersModel::cylinderAt(const QModelIndex &index)
 	return get_cylinder(&displayed_dive, index.row());
 }
 
-// this is our magic 'pass data in' function that allows the delegate to get
-// the data here without silly unit conversions;
-// so we only implement the two columns we care about
-void CylindersModel::passInData(const QModelIndex &index, const QVariant &value)
-{
-	cylinder_t *cyl = cylinderAt(index);
-	switch (index.column()) {
-	case SIZE:
-		if (cyl->type.size.mliter != value.toInt()) {
-			cyl->type.size.mliter = value.toInt();
-			dataChanged(index, index);
-		}
-		break;
-	case WORKINGPRESS:
-		if (cyl->type.workingpressure.mbar != value.toInt()) {
-			cyl->type.workingpressure.mbar = value.toInt();
-			dataChanged(index, index);
-		}
-		break;
-	}
-}
-
 bool CylindersModel::setData(const QModelIndex &index, const QVariant &value, int role)
 {
 	QString vString;
 
 	cylinder_t *cyl = cylinderAt(index);
+	if (!cyl)
+		return false;
+
+	if (role == PASS_IN_ROLE) {
+		// this is our magic 'pass data in' function that allows the delegate to get
+		// the data here without silly unit conversions;
+		// so we only implement the two columns we care about
+		switch (index.column()) {
+		case SIZE:
+			if (cyl->type.size.mliter != value.toInt()) {
+				cyl->type.size.mliter = value.toInt();
+				dataChanged(index, index);
+			}
+			return true;
+		case WORKINGPRESS:
+			if (cyl->type.workingpressure.mbar != value.toInt()) {
+				cyl->type.workingpressure.mbar = value.toInt();
+				dataChanged(index, index);
+			}
+			return true;
+		}
+		return false;
+	}
+
 	switch (index.column()) {
 	case TYPE:
 		if (!value.isNull()) {
@@ -641,11 +647,6 @@ void CylindersModelFiltered::remove(QModelIndex index)
 	source.remove(mapToSource(index));
 }
 
-void CylindersModelFiltered::passInData(const QModelIndex &index, const QVariant &value)
-{
-	source.passInData(mapToSource(index), value);
-}
-
 cylinder_t *CylindersModelFiltered::cylinderAt(const QModelIndex &index)
 {
 	return source.cylinderAt(mapToSource(index));

qt-models/cylindermodel.h

@@ -25,16 +25,20 @@ public:
 		MOD,
 		MND,
 		USE,
+		WORKINGPRESS_INT,
+		SIZE_INT,
 		COLUMNS
 	};
 
+	enum Roles {
+		PASS_IN_ROLE = Qt::UserRole + 1 // For setting data: don't do any conversions
+	};
 	explicit CylindersModel(QObject *parent = 0);
 	QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const override;
 	int rowCount(const QModelIndex &parent = QModelIndex()) const override;
 	Qt::ItemFlags flags(const QModelIndex &index) const override;
 	bool setData(const QModelIndex &index, const QVariant &value, int role = Qt::EditRole) override;
 
-	void passInData(const QModelIndex &index, const QVariant &value);
 	void add();
 	void clear();
 	void updateDive();
@@ -67,7 +71,6 @@ public:
 	void add();
 	void updateDive();
 	cylinder_t *cylinderAt(const QModelIndex &index);
-	void passInData(const QModelIndex &index, const QVariant &value);
 public
 slots:
 	void remove(QModelIndex index);