bwidgets/inc/basic_widgets/w/base/widget.hpp

#ifndef BWIDGETS_WIDGET_HPP_
#define BWIDGETS_WIDGET_HPP_

#include <basic_widgets/core/renderer.hpp>
#include <basic_widgets/core/type/size.hpp>

union SDL_Event;

struct SDL_Renderer;

namespace bwidgets::widget
{
    class Widget
    {
    protected:
        core::Renderer* _renderer {nullptr};
        SDL_Rect        _viewport {0, 0, 0, 0};
        SDL_Rect        _widget_area {0, 0, 0, 0};

        virtual void _handle_geometry_change(const SDL_Rect&) noexcept = 0;
        virtual void _handle_renderer_change(core::Renderer* /*unused*/) {}
        virtual void _handle_rendering() = 0;

    public:
        Widget* parent;

        Widget(Widget* p = nullptr) : parent(p) {}

        virtual ~Widget() noexcept = default;
        virtual auto handle_event(const SDL_Event&) -> Widget*;

        [[nodiscard]] inline virtual auto size() const noexcept -> core::Size = 0;

        virtual auto render() -> Widget* final;

        virtual inline auto renderer(core::Renderer* r) -> Widget* final
        {
            _handle_renderer_change(r);
            _renderer = r;
            return this;
        }

        [[nodiscard]] virtual inline auto viewport() const noexcept
          -> const SDL_Rect& final
        {
            return _viewport;
        }
        virtual inline auto viewport(const SDL_Rect& vp) noexcept -> Widget* final
        {
            _handle_geometry_change(vp);
            _viewport = vp;
            return this;
        }
    };
}

#endif