QML isn't updating nested C++ objects

mzimmers

Hi all -

I'm experimenting with nested C++ objects as follows:

class RepeatData {
    Q_GADGET
public:
    Q_PROPERTY(QVector<bool> weekDaysSelected MEMBER m_weekDaysSelected)
    QVector<bool> m_weekDaysSelected;
    bool operator ==(const RepeatData &rhs) const;
    bool operator !=(const RepeatData &rhs) const { return !operator==(rhs); }
    friend struct Schedule;
};

struct Schedule
{
    Q_GADGET
    QML_VALUE_TYPE(schedule)
    QML_STRUCTURED_VALUE // to allow this Q_GADGET to be instantiated in QML.
    Q_PROPERTY(RepeatData repeatData MEMBER m_repeatData)
public:
    RepeatData m_repeatData;
}

My QML seems to read the inner value(s) OK, but when I try to modify them, they don't change (no error messages). Here's an example of what's not working:

onButtonClicked: (index) => {
                     console.log("ScheduleRepeat.qml: weekDaysSelected is " + newSchedule.repeatData.weekDaysSelected)
                     newSchedule.repeatData.weekDaysSelected[index] = !(newSchedule.repeatData.weekDaysSelected[index])
                     console.log("ScheduleRepeat.qml: weekday button " + index + " clicked.")
                     console.log("ScheduleRepeat.qml: weekDaysSelected is " + newSchedule.repeatData.weekDaysSelected)
                 }

and the output:

qml: ScheduleRepeat.qml: weekDaysSelected is true,true,true,true,true,true,true
qml: ScheduleRepeat.qml: weekday button 2 clicked.
qml: ScheduleRepeat.qml: weekDaysSelected is true,true,true,true,true,true,true

This QML logic was working before I introduced the internal struct.

Any idea what I'm doing wrong here?

Thanks...

mzimmers

found the problem - my inner == operator had a bug which was causing it to always return true.

In debugging this, I noticed that my == operator gets called a lot more times than I'd expect. I only have 2 of these objects, and am creating a 3rd, but I must have hit a breaking point inside my comparison function 20 or more times. Does this suggest a design flaw on my part?

Thanks...