Add bounding box property for LocationsModel as well

Needed to property position the room map.

src/models/locationsmodel.h

@@ -5,6 +5,7 @@
 
 #include <QAbstractListModel>
 #include <QPointer>
+#include <QRectF>
 
 #include "neochatroom.h"
 
@@ -24,18 +25,23 @@ public:
     };
     Q_ENUM(Roles)
     Q_PROPERTY(NeoChatRoom *room READ room WRITE setRoom NOTIFY roomChanged)
+    /** Bounding box of all locations covered by this model. */
+    Q_PROPERTY(QRectF boundingBox READ boundingBox NOTIFY boundingBoxChanged)
 
     explicit LocationsModel(QObject *parent = nullptr);
 
     [[nodiscard]] NeoChatRoom *room() const;
     void setRoom(NeoChatRoom *room);
 
+    QRectF boundingBox() const;
+
     [[nodiscard]] QHash<int, QByteArray> roleNames() const override;
     [[nodiscard]] QVariant data(const QModelIndex &index, int roleName) const override;
-    [[nodiscard]] int rowCount(const QModelIndex &parent) const override;
+    [[nodiscard]] int rowCount(const QModelIndex &parent = {}) const override;
 
 Q_SIGNALS:
     void roomChanged();
+    void boundingBoxChanged();
 
 private:
     QPointer<NeoChatRoom> m_room;