maplocationmodel: implement the clear() and add() methods

- add() will be used to add a MapLocation to the model with
beginInsertRows()...endInsertRows()
- clear() will be used to clear the model with beginRemoveRows()...
endRemoveRows()

NOTE: emiting dataChanged() does not seem to update the QML view for
this model so calling being<..>Rows() seems to be the "correct Qt
approach" to do this.

Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>

qt-models/maplocationmodel.cpp

@@ -30,7 +30,7 @@ MapLocationModel::MapLocationModel(QObject *parent) : QAbstractListModel(parent)
 
 MapLocationModel::~MapLocationModel()
 {
-	qDeleteAll(m_mapLocations);
+	clear();
 }
 
 QVariant MapLocationModel::data( const QModelIndex & index, int role ) const
@@ -63,3 +63,20 @@ MapLocation *MapLocationModel::get(int row)
 		return NULL;
 	return m_mapLocations.at(row);
 }
+
+void MapLocationModel::add(MapLocation *location)
+{
+	beginInsertRows(QModelIndex(), m_mapLocations.size(), m_mapLocations.size());
+	m_mapLocations.append(location);
+	endInsertRows();
+}
+
+void MapLocationModel::clear()
+{
+	if (!m_mapLocations.size())
+		return;
+	beginRemoveRows(QModelIndex(), 0, m_mapLocations.size() - 1);
+	qDeleteAll(m_mapLocations);
+	m_mapLocations.clear();
+	endRemoveRows();
+}

qt-models/maplocationmodel.h

@@ -44,6 +44,8 @@ public:
 	QVariant data(const QModelIndex &index, int role) const override;
 	int rowCount(const QModelIndex &parent) const override;
 	int count();
+	void add(MapLocation *);
+	void clear();
 
 protected:
 	QHash<int, QByteArray> roleNames() const;