My question is, that how can I specify a custom object as a role in a model derived from QAbstractListModel so when visualizing it within a ListView I can access its member variables. To have an example here is some simple code example:
This is my class representing my custom object:
class MyCustomObject {
public:
MyCustomObject(Qstring name, Qstring type);
QString getName();
QString getType();
private:
QString name;
QString type;
};
This is how the overridden data() function looks like now (but it is not working) of my MyModel derived from QAbsractListModel:
QVariant MyModel::data(const QModelIndex &index, int role) const {
if (index.row() < 0 || index.row() > m_atoms.count()) {
//if (!index.isValid()) {
return QVariant();
}
const MyData &data = m_data[index.row()];
if(role == SomeRole) {
return data.someString()
}
else if (role == MyCustomRole) {
return data.myCustomObject; // How can I do this?
}
return QVariant();
}
Here I specify the role names in MyModel:
QHash<int, QByteArray> AtomModel::roleNames() const {
QHash<int, QByteArray> roles;
roles[SomeRole] = "someRole";
roles[MyCustomRole] = "myCustomRole";
return roles;
}
and this is how my ListView looks like in QML code with an example how I would like to access MyCustomObject member variables in the delegate:
ListView {
width: 400
height: 400
model: myModel
delegate: Text {
text: "Type: " + myCustomRole.getType() + ", Name: " + myCustomRole.getName() + ", some string: " someRole
}
}
EDIT1: => fix needed copy constructor
When I am adding Q_DECLARE_METATYPE under my MyCustomObject I receive the following error:
call to implicitly-deleted copy constructor of `MyCustomObject`
in instantiation of member function 'QtMetaTypePrivate::QMetaTypeFunctionHelper<MyCustomObject, true>::Construct' requested here
in instantiation of function template specialization 'qRegisterNormalizedMetaType<MyCustomObject>' requested here QtMetaTypePrivate::QMetaTypeFunctionHelper<T>::Construct,
return qRegisterNormalizedMetaType<T>(normalizedTypeName, dummy, defined);
in instantiation of function template specialization 'qRegisterMetaType<MyCustomObject>' requested here
Q_DECLARE_METATYPE(MyCustomObject)
expanded from macro 'Q_DECLARE_METATYPE'
#define Q_DECLARE_METATYPE(TYPE) Q_DECLARE_METATYPE_IMPL(TYPE)
expanded from macro 'Q_DECLARE_METATYPE_IMPL'
const int newId = qRegisterMetaType< TYPE >(#TYPE,
copy constructor of 'MyCustomObject' is implicitly deleted because base class 'QObject' has a deleted copy constructor
class MyCustomObject : public QObject
'QObject' has been explicitly marked deleted here Q_DISABLE_COPY(QObject)
expanded from macro 'Q_DISABLE_COPY'
Class(const Class &) Q_DECL_EQ_DELETE;\
EDIT2:
So I have added all the necessary functions what @Evgeny has suggested. My code now compiles without errors, but I get a qml error on run time saying:
TypeError: Property 'getType' of object QVariant(MyCustomObject) is not a function
I have added Q_INVOKABLE in front of the getType() method and I also deriving MyCustomObject class from public QObject. I have added Q_DECLARE_METATYPE at the bottom of my MyCustomObject header file. In the constructor of MyCustomObject I call qRegisterMetaType<MyCustomObject>("MyCustomObject") and in my main I register the class also like this qmlRegisterType<MyCustomObject>("com.test.mycustomobject", 1, 0, "MyCustomObject")
This is how MyCustomObject class looks like now:
class MyCustomObject : public QObject {
public:
MyCustomObject();
MyCustomObject(Qstring name, Qstring type);
MyCustomObject(const MyCustomObject& obj);
~MyCustomObject();
Q_INVOKABLE QString getName();
Q_INVOKABLE QString getType();
private:
QString name;
QString type;
};
Q_DECLARE_METATYPE(MyCustomObject)
This is how the overridden data() function looks like now of my MyModel derived from QAbsractListModel:
QVariant MyModel::data(const QModelIndex &index, int role) const {
if (index.row() < 0 || index.row() > m_atoms.count()) {
//if (!index.isValid()) {
return QVariant();
}
const MyData &data = m_data[index.row()];
if(role == SomeRole) {
return data.someString()
}
else if (role == MyCustomRole) {
QVariant var; // this is the part, which has changed
var.setValue(data.myCustomObject);
return var;
}
return QVariant();
}
All other functions which I have posted originally are the same.