widgetfactory.h

#ifndef WIDGETFACTORY_H
#define WIDGETFACTORY_H

#include <opencv2/core.hpp>
#include <map>
#include <memory>
#include <functional>
#include "layout.h"
#include "canvascv/themes/themerepository.h"

namespace canvascv
{

class Widget;
class Layout;

class WidgetFactory
{
public:
    static std::shared_ptr<Widget> newWidget(std::string type, Layout &layoutVal, const cv::Point &pos);

protected:
    typedef std::function<Widget*(const cv::Point &)> Allocator;
    static void addWidget(std::string name, Allocator a);

private:
    template <class T> friend class WidgetFactoryT;

    typedef std::map<std::string,Allocator> AllocatorsMap;
    static AllocatorsMap *allocators;
};

template <class T>
class WidgetFactoryT : public WidgetFactory
{
public:
    static bool addType(std::string name);

    static std::shared_ptr<T> newWidget(Layout &layoutVal, const cv::Point &pos = cv::Point(0,0));
};

template <class T>
bool WidgetFactoryT<T>::addType(std::string name)
{
    static bool doneOnce;
    if (! doneOnce)
    {
        addWidget(name, [](const cv::Point& pos)->Widget*{return new T(pos);});
        doneOnce = true;
    }
    return true;
}

template <class T>
std::shared_ptr<T> WidgetFactoryT<T>::newWidget(Layout &layoutVal, const cv::Point &pos)
{
    std::shared_ptr<T> widget(new T(pos));
    ThemeRepository::applyCurrentTheme(widget.get());
    layoutVal.addWidget(widget);
    return widget;
}

}

#define CCV_REGISTER_WIDGET(X) static bool regWidget##X = canvascv::WidgetFactoryT<X>::addType(#X)


#endif // WIDGETFACTORY_H