How to promote a custom widget in QT Creator

Question

In qt 5.2.1 I've created some custom widgets, like a button. Traditionally there's two ways of doing this. You can either promote an existing widget. And change/add functionality. Or create a custom widget from scratch. I've used the latter.

However, in some cases I would like to use my custom widget, but change some of it's functionality by promoting. The usual way to do this would be to add a widget, and promote it. However, when creating a new kind of promoted widget, a base class has to be picked. And in the dialog where this can be done, only the default widgets are listed.

Is it possible to add a custom widget to this list?

Regards,

Lauris

Edit:

I've played around with it a lot. And now all of a sudden a custom widget is been added to the list of base classes. Yet I still don't know how I've added it. And why this is the only custom widget showing on the list.

Answer 1

This seems to be a bug in Qt Creator. A workaround, oddly enough is to add widgets twice to the list of widgets a widget library exports:

IOSwidgets::IOSwidgets(QObject *parent)
    : QObject(parent)
{

    m_widgets.append(new aircraftAttitudePlugin(this));
    m_widgets.append(m_widgets.last());
    m_widgets.append(new alfabeticKeypadPlugin(this));
    m_widgets.append(m_widgets.last());
    m_widgets.append(new arrowedFramePlugin(this));
    m_widgets.append(m_widgets.last());
    m_widgets.append(new buttonWidgetPlugin(this));
    m_widgets.append(m_widgets.last());
    m_widgets.append(new dataButtonPlugin(this));
    m_widgets.append(m_widgets.last());
    m_widgets.append(new frameWidgetPlugin(this));
    m_widgets.append(m_widgets.last());
    m_widgets.append(new headingDialPlugin(this));
    m_widgets.append(m_widgets.last());
    m_widgets.append(new imageWidgetPlugin(this));
    m_widgets.append(m_widgets.last());
    m_widgets.append(new labelWidgetPlugin(this));
    m_widgets.append(m_widgets.last());
    m_widgets.append(new linkedButtonWidgetPlugin(this));
    m_widgets.append(m_widgets.last());
    m_widgets.append(new linkedLabelWidgetPlugin(this));
    m_widgets.append(m_widgets.last());
    m_widgets.append(new linkedSliderWidgetPlugin(this));
    m_widgets.append(m_widgets.last());
    m_widgets.append(new NavButtonPlugin(this));
    m_widgets.append(m_widgets.last());
    m_widgets.append(new numericKeypadPlugin(this));
    m_widgets.append(m_widgets.last());
    m_widgets.append(new repositionWidgetPlugin(this));
    m_widgets.append(m_widgets.last());
    m_widgets.append(new runwayInformationPlugin(this));
    m_widgets.append(m_widgets.last());
    m_widgets.append(new slewWidgetPlugin(this));
    m_widgets.append(m_widgets.last());
    m_widgets.append(new sliderWidgetPlugin(this));
    m_widgets.append(m_widgets.last());
    m_widgets.append(new WeightBalancePlugin(this));
    m_widgets.append(m_widgets.last());
    m_widgets.append(new WindshearMicroburstLateralPlugin(this));
    m_widgets.append(m_widgets.last());
}

Hope this saves the next person who runs into this problem, the painstaking effort and the huge amount of time it took me to find this out:).