spk_layout.hpp

#pragma once
 
#include "structure/design_pattern/spk_cached_data.hpp"
#include "structure/graphics/spk_extend_2d.hpp"
#include "structure/math/spk_vector2.hpp"
#include "structure/widget/spk_resizable_element.hpp"
 
#include <any>
#include <limits>
#include <vector>
 
namespace spk
{
    class Layout : public ResizableElement
    {
    public:
        struct SizePolicy
        {
            enum Value
            {
                Desired,  // Take the "Desired" size of the element, forcing it.
                Extend,   // Take as much space as possible, while lower or equal to the maximal size hint.
                Standard, // Take as much space as possible, but after the extended widget have taken position.
                Minimum,  // Take up the minimal space requested by the element, with no resize.
            };

            Value horizontal;
            Value vertical;
        };
 
    private:
        spk::Vector2UInt _padding{};
 
    protected:
        struct Element
        {
            ResizableElement *element;
            SizePolicy sizePolicy;
            std::any extraData;
        };

        using ElementContainer = std::vector<Element>;

        ElementContainer _elementContainer;

        const ElementContainer &_elements() const;
 
    public:
        Layout() = default;

        void setPadding(const spk::Vector2UInt &p_padding);
        const spk::Vector2UInt &padding() const;

        void clear();

        template <typename TExtra>
        void addElement(ResizableElement *p_element, const SizePolicy &p_sizePolicy, TExtra &&p_extra)
        {
            if (p_element == nullptr)
            {
                throw std::runtime_error("Can't add a nullptr to a layout");
            }
            _elementContainer.push_back(Element{p_element, p_sizePolicy, std::forward<TExtra>(p_extra)});
            sizeHint().release();
        }

        void addElement(ResizableElement *p_element, const SizePolicy &p_sizePolicy);
    };
 
    std::string toString(const Layout::SizePolicy::Value &p_value);
    std::wstring toWstring(const Layout::SizePolicy::Value &p_value);
    std::string toString(const Layout::SizePolicy &p_sizePolicy);
    std::wstring toWstring(const Layout::SizePolicy &p_sizePolicy);
 
    std::ostream &operator<<(std::ostream &p_stream, const Layout::SizePolicy::Value &p_value);
    std::wostream &operator<<(std::wostream &p_stream, const Layout::SizePolicy::Value &p_value);
    std::ostream &operator<<(std::ostream &p_stream, const Layout::SizePolicy &p_sizePolicy);
    std::wostream &operator<<(std::wostream &p_stream, const Layout::SizePolicy &p_sizePolicy);
}