GroupBox.h

#pragma once
 
#include "Panel.h"
 
namespace sw
{
    class GroupBox : public Panel
    {
    private:
        using TBase = Panel;
 
        SIZE _textSize;
 
        std::unique_ptr<LayoutHost> _defaultLayout;
 
    public:
        GroupBox();
 
    protected:
        virtual LayoutHost *GetDefaultLayout() override;
 
        virtual void OnDrawBorder(HDC hdc, RECT &rect) override;
 
        virtual void OnTextChanged() override;
 
        virtual void FontChanged(HFONT hfont) override;
 
        virtual void OnSetBackColor(Color color, bool redraw) override;
 
        virtual void OnSetTextColor(Color color, bool redraw) override;
 
    public:
        template <typename TLayout>
        auto SetLayout()
            -> typename std::enable_if<std::is_base_of<LayoutHost, TLayout>::value>::type
        {
            auto layout = std::make_unique<TLayout>();
            layout->Associate(this);
            _defaultLayout = std::move(layout);
            InvalidateMeasure();
        }
 
        template <std::nullptr_t>
        void SetLayout()
        {
            _defaultLayout.reset(nullptr);
            InvalidateMeasure();
        }
 
    private:
        void _UpdateTextSize();
    };
}