WidgetInit.h

#pragma once
class QWidget;
namespace NDEVR
{
    class DockItem;
    class QCustomDockWidget;
    class WidgetInit
    {
    public:
        WidgetInit(std::function<QWidget*()> init)
            : m_create_widget(init)
        {}

        WidgetInit(QWidget* widget)
            : m_widget(widget)
        {}

        virtual QWidget* getWidget()
        {
            if (m_widget == nullptr)
                m_widget = m_create_widget();
            return m_widget;
        }
    protected:
        const std::function<QWidget*()> m_create_widget;    
        QWidget* m_widget = nullptr;                        
    };

    class DockInit
    {
    public:
        DockInit(std::function<QCustomDockWidget*()> init)
            : m_create_dock(init)
        {}

        DockInit(QCustomDockWidget* init)
            : m_dock_item(init)
        {}

        bool isInit() const
        {
            return m_dock_item != nullptr;
        }

        virtual QCustomDockWidget* getDock()
        {
            if (m_dock_item == nullptr)
                m_dock_item = m_create_dock();
            return m_dock_item;
        }
    protected:
        const std::function<QCustomDockWidget*()> m_create_dock;    
        QCustomDockWidget* m_dock_item = nullptr;                   
    };
}