Using QAbstractItemModel as a Q_PROPERTY inside c++ with READ WRITE - qt

Question

I'm trying to achieve a filter model that has a source model inside QML. Both of my models are c++ based and registered as modules.
Assuming I have:
ListView {
id: autocomplete
anchors.top: field.bottom
model: MyTreeModelCompleter {
separator: "."
model: MyTreeModel{}
}
}
The c++ of MyTreeModelCompleter:
class TreeModelCompleter : public QCompleter
{
Q_OBJECT
Q_PROPERTY(QString separator READ separator WRITE setSeparator)
Q_PROPERTY(QAbstractItemModel* model READ model WRITE setModel)
public:
explicit TreeModelCompleter(QObject *parent = Q_NULLPTR);
explicit TreeModelCompleter(QAbstractItemModel *model, QObject *parent = Q_NULLPTR);
QString separator() const;
QAbstractItemModel* model();
public slots:
void setSeparator(const QString&);
void setModel(QAbstractItemModel*);
protected:
QStringList splitPath(const QString &path) const override;
QString pathFromIndex(const QModelIndex &index) const override;
private:
QString m_sep;
QAbstractItemModel *m_model;
};
MyTreeModel c++:
class MyTreeModel : public QAbstractItemModel
{
Q_OBJECT
...
};
MyTreeModel QML:
MyTreeElement {
property bool check
property string name: "name1"
property string description: "desc of name1"
MyTreeElement {
property bool check
property string name: "name2"
property string description: "desc of name2"
}
MyTreeElement {
property bool check
property string name: "name3"
property string description: "desc of name3"
MyTreeElement {
property bool check
property string name: "name 4"
property string description: "desc of name4"
MyTreeElement {
property bool check
property string name: "name 5"
property string description: "desc of name5"
}
}
}
}
MyTreeelement:
class MyTreeNode : public QObject
{
Q_OBJECT
public:
Q_PROPERTY(QQmlListProperty<MyTreeNode> nodes READ nodes)
Q_CLASSINFO("DefaultProperty", "nodes")
MyTreeNode(QObject *parent = Q_NULLPTR);
void setParentNode(MyTreeNode *parent);
Q_INVOKABLE MyTreeNode *parentNode() const;
bool insertNode(MyTreeNode *node, int pos = (-1));
QQmlListProperty<MyTreeNode> nodes();
MyTreeNode *childNode(int index) const;
void clear();
Q_INVOKABLE int pos() const;
Q_INVOKABLE int count() const;
private:
QList<MyTreeNode *> m_nodes;
MyTreeNode *m_parentNode;
};
My main issue is including MyTreeModel inside the completer model MyTreeModelCompleter. The issue is generated when I try to bind them, the compiler complains that the values don't match in types as 1 is QAbstractItemModel* and the other is QAbstractItemModel.
Is there a way to get this model binding to work?
This is by no means a working code, because I think the issue is in the embedding of the Models in one another and not in the actual code.
The error:
Cannot assign object of type "MyTreeModel" to property of type
"QAbstractItemModel*" as the former is neither the same as the latter
nor a sub-class of it.

Answer 1

A way to handle the problem is to use QObject * instead of QAbstractItemModel * for the model property. Here is an example :
class TreeModelCompleter : public QCompleter
{
Q_OBJECT
Q_PROPERTY(QString separator READ separator WRITE setSeparator)
Q_PROPERTY(QObject* model READ model WRITE setModel)
public:
explicit TreeModelCompleter(QObject *parent = Q_NULLPTR);
explicit TreeModelCompleter(QAbstractItemModel *model, QObject *parent = Q_NULLPTR);
QString separator() const;
QObject* model();
public slots:
void setSeparator(const QString&);
void setModel(QObject*);
protected:
QStringList splitPath(const QString &path) const override;
QString pathFromIndex(const QModelIndex &index) const override;
private:
QString m_sep;
QAbstractItemModel *m_model;
};