QML SectionScroller and QList<QObject*> - qt

Question

I use QList<QObject*> as a model in my app. As there might be a lot of elements, I decided to use SectionScroller. When I try to scroll using the SectionScroller I'm getting a
Error: Unable to assign [undefined] to QString
What am I doing wrong?
My ListView is:
ListView
{
id: irrview
width: parent.width
model: irregulars.db // QList<QObject*>
anchors.top: caption.bottom
anchors.bottom: parent.bottom
clip: true
section.criteria: ViewSection.FirstCharacter
section.property: "form0"
section.delegate: Item {height: 10; width: parent.width; Text { text: section } } // for testing purposes
delegate: Rectangle
{
/**/
}
}
Thanks
EDIT: more code:
the irregulars header
class IrregularListWrapper : public QObject
{
Q_OBJECT
Q_PROPERTY(QList<QObject*> db READ getdb NOTIFY langChanged)
Q_ENUMS(Language)
public:
enum Language
{
English = 0,
German = 1
};
IrregularListWrapper() : db(0) { setLang(German); }
~IrregularListWrapper() { delete db; }
QList<QObject*> getdb() const { return *db; }
Q_INVOKABLE void changeLang(Language l) { delete db; setLang(l); }
signals:
void langChanged();
protected:
void setLang(Language);
QList<QObject*> * db;
};
and the body of a function
void IrregularListWrapper::setLang(Language l)
{
switch (l)
{
case English:
db = new english;
langName = "English";
break;
case German:
db = new german;
langName = "German";
break;
}
emit langChanged();
}
the classes german, english are like that
class german : public QList<QObject*>
{
public:
german();
};
german::german()
{
append(new IrregularVerb("anfangen", "fing an", "angefangen"));
/*more like that*/
}
and IrregularVerb:
class IrregularVerb : public QObject
{
Q_OBJECT
Q_PROPERTY(QString form0 READ getForm0 NOTIFY formChanged)
Q_PROPERTY(QString form1 READ getForm1 NOTIFY formChanged)
Q_PROPERTY(QString form2 READ getForm2 NOTIFY formChanged)
public:
QString forms[3];
QString getForm0() const { return getForm(0); }
QString getForm1() const { return getForm(1); }
QString getForm2() const { return getForm(2); }
IrregularVerb(QString a, QString b, QString c) { forms[0] = a; forms[1] = b; forms[2] = c; }
protected:
const QString& getForm(const int& ind) const { return forms[ind]; }
signals:
void formChanged();
};
Edit 2: this doesn't work
If I do
QVariantList getdb() const { return QVariant::fromValue(*db); }
IrregularListWrapper.h:24: error: could not convert 'QVariant::fromValue(const T&) [with T = QList<QObject*>; QVariant = QVariant]()' from 'QVariant' to 'QVariantList {aka QList<QVariant>}'
If I remove the star, the error is similar.
EDIT3:
I found out this http://ruedigergad.com/2011/08/22/qml-sectionscroller-vs-qabstractlistmodel/
And found out that irregulars.db.get is undefined
And changed german and english to
class german : public AbstractIrregularList
and
class AbstractIrregularList : public QObject, public QList<QObject*>
{
Q_OBJECT
public:
Q_INVOKABLE QObject* get(int index) {return at(index);}
};
But even now, irregulars.db.get(0) gives error (Result of expression 'irregulars.db.get' [undefined] is not a function.)
Why is happening like that, that the Q_INVOKABLE is not detected? The Q_OBJECT macro is there
/edit5: Even when using QVariant the errors are still there. It can be either treated as QList or as QObject*.

Answer 1

If I am not wrong, you should use QVariantList instead QList<SomeClass> to expose list of elements from C++ to QML.
It should solve problem.
Supported types in QML
Try making code to look like this (in irregulars header):
Q_PROPERTY(QVariantList db READ getdb NOTIFY langChanged)
//...
QVariantList getdb() const {/*convert db to QVariantList*/ return converted_db;}
Or if you want to code look like from links you gave:
Q_PROPERTY(QVariantList db READ getdb NOTIFY langChanged)
//...
QVariant getdb() const {return QVariant::fromValue(db);}