Extending a Control when creating Custom Control in c++

Question

I'm trying to create a custom control but with limited c++ knowledge I'm struggling a bit.

I've taken a look at the header file RadioGroup.h as I'm trying to build something with similar functionality.

Here are my 2 files:

CompanyRadioGroup.h

#ifndef COMPANYRADIOGROUP_H_
#define COMPANYRADIOGROUP_H_

#include <bb/cascades/Control>
#include <bb/cascades/Container>
#include <bb/cascades/Option>

using namespace bb::cascades;

class CompanyRadioGroup : public Control {
private:
Q_OBJECT
QDeclarativeListProperty<Option> options();

public:
CompanyRadioGroup(Container * parent = 0);
virtual ~CompanyRadioGroup();

template <typename BuilderType, typename BuiltType>
class TBuilder : public BaseClass::TBuilder<BuilderType, BuiltType>
        {
        protected:
            TBuilder(BuiltType* node) : BaseClass::TBuilder<BuilderType, BuiltType>(node)
            {
            }
        public:

            /*!
             * @copydoc bb::cascades::RadioGroup::setDividersVisible(bool)
             *
             * @since BlackBerry 10.0.0
             */
            BuilderType& dividers(bool dividersVisible)
            {
                this->instance().setDividersVisible(dividersVisible);
                return this->builder();
            }

            BuilderType& add(Option* option)
            {
                this->instance().add(option);
                return this->builder();
            }

            BuilderType& add(const QString &optionText, const QVariant &value = QVariant(), bool selected = false)
            {
                this->instance().add(Option::create().text(optionText).value(value).selected(selected));
                return this->builder();
            }
        };

        class Builder : public TBuilder<Builder, CompanyRadioGroup>
        {
        public:
            explicit Builder() : TBuilder<Builder, CompanyRadioGroup>(new CompanyRadioGroup())
            {
            }
        };

        static Builder create()
        {
            return Builder();
        }
};

#endif

CompanyRadioGroup.cpp

#include "CompanyRadioGroup.h"

#include <bb/cascades/Control>

CompanyRadioGroup::CompanyRadioGroup(Container * parent) : Control(parent){


}

CompanyRadioGroup::~CompanyRadioGroup() {
// TODO Auto-generated destructor stub
}

On compiling I am getting an error

CompanyRadioGroup.cpp:12:72: error: no matching function for call to 'bb::cascades::Control::Control(bb::cascades::Container*&)'

It appears that the contructor for Control requires 2 parameters, however I cannot find any documentation on the first parameter or an example.

According to the Control.h file it has the following:

Control(ControlPrivate &_d_ptr, Control* parent = 0);

Can anyone advise how I pass _d_ptr or how I can overcome this issue?

Answer 1

If you do not need the first parameter _d_ptr anywhere in your code create a dummy abject instance that indicates "no-object" and pass that as the first parameter. References can't be null in c++ so you can't pass a null argument. Just create a dummy contrilPrivate object and pass a reference to it to the constructor.