a_group_impl.cpp

#include <nana/gui.hpp>
#include <nana/gui/place.hpp>
#include <nana/gui/widgets/button.hpp>
#include <nana/gui/widgets/panel.hpp>
#include <nana/gui/widgets/form.hpp>
#include <nana/gui/widgets/label.hpp>
#include <nana/gui/drawing.hpp>

using namespace nana;
namespace dm
{
    class group
            : public panel<true>
    {
    public:
            template<typename T, typename ...Args>
            T* create_widget(Args&&... args)
            {
                    widgets_.emplace_back(new T(*this, std::forward<Args>(args)...)); // warning C4800: 'const wchar_t *': forcing value to bool 'true' or 'false'  

                    plc_["abc"] << widgets_.back()->handle();
                    plc_.collocate();
                    return static_cast<T*>(widgets_.back().get());
            }
    private:
            void _m_complete_creation() override
            {
                    //define an etiquete
                    plc_.bind(*this);
                    plc_.div("abc vert gap=5 margin=3");

                    //draw a simple border.
                    drawing dw(*this);
                    dw.draw([](paint::graphics& graph)
                    {
                            graph.rectangle(false, colors::gray_border);
                    });
            }
    private:
            place plc_;
            std::vector<std::unique_ptr<widget>> widgets_;
    };

    class group1: public panel<true>
    {
    public:
        place           plc   {*this};
        label           titel/*  {*this}*/;
        std::string     fmt;

        group1 ( widget &owner, 
                 std::string titel_={}, 
                 bool format=false, 
                 unsigned gap=2, 
                 rectangle r={})
        : panel (owner, r),
          titel (*this, titel_)
        {
            titel.format(format);
            nana::size sz = titel.measure(1000);
            std::stringstream ft;

            ft << "vertical margin=[0," << gap << "," << gap << "," << gap << "]"
               << " <weight=" << sz.height << " <weight=5> <titel weight=" << sz.width+1 << "> >";
            fmt = ft.str();

            plc["titel"] << titel;

            color obg = owner.bgcolor();
            titel.bgcolor(obg.blend(colors::black, 0.025) );
            color bg=obg.blend(colors::black, 0.050 );
            bgcolor(bg);

            drawing dw(*this);
                    dw.draw([gap,sz,bg,obg](paint::graphics& graph)
                    {
                            graph.rectangle(true, obg);
                graph.round_rectangle(rectangle(       point ( gap-1,   sz.height/2), 
                                                 nana::size  (graph.width()-2*(gap-1),   graph.height()-sz.height/2-(gap-1))),
                                      3,3, colors::gray_border,     true, bg);
           });

           plc.div(fmt.c_str());
        }
    };

}

int main()
{

        form fm;
    fm.bgcolor(colors::mint_cream );
    place plc(fm);


        dm::group grp;
        grp.create(fm );
    grp.create_widget<label>("Group:");

    plc["left_field"] << grp;

    dm::group1 grp_1(fm, "A new <bold=true, color=0xff0000, font=\"Consolas\">Group:</>", true );
    label lab{grp_1, "A label "};
    button b1{grp_1, "add button"};
    button b2{grp_1, "button2"};
    button b3{grp_1, "button3"};
    grp_1.fmt += "<vertical margin=2 gap= 2 <lab> | 70% < <left_field> | 70% <right_field>> >";
    grp_1.plc["lab"] << lab.text_align(align::right)  ;
    grp_1.plc["left_field"] << b1  ;
    grp_1.plc["right_field"] << b2 << b3;
    grp_1.plc.div(grp_1.fmt.c_str());
    //grp1.plc.collocate();    // problem !!!!!!!!!!!!!!

    plc["right_field"] << grp_1;
    plc.div("horizontal gap=3 margin=30  < <left_field> | 70% <right_field>> ");
    plc.collocate();
    grp_1.plc.collocate();    // OK

        b1.events().click([&grp]
        {
                auto p = grp.create_widget<button>();
                p->caption("Button");
        });

        fm.show();

        ::nana::exec(

#ifdef NANA_AUTOMATIC_GUI_TESTING
                1, 1, [&b1, &b2]()
        {
                click(b1);
                click(b2);
        }
#endif

        );
}