ui.cpp

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#include <planet/sdl/renderer.hpp>
#include <planet/sdl/ui/text.hpp>
#include <planet/ui/baseplate.hpp>

planet::sdl::ui::text

 
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planet::sdl::ui::text::text(renderer &rr, sdl::font &f, std::string_view const s)
: reflowable{"planet::sdl::ui::text"},
  r{rr},
  font{f},
  space{font.measure(" ")} {
    auto const words = identify_words(s);
    for (auto const &w : words) {
        std::string word{w};
        elements.emplace_back(constrained_type{font.measure(word.c_str())});
        elements.back().value.word = std::move(word);
    }
}


auto planet::sdl::ui::text::do_reflow(
        reflow_parameters const &,
        constrained_type const &within) -> constrained_type {
    if (not elements.laid_out_in
        or not elements.laid_out_in->is_at_least_as_constrained_as(within)) {
        elements.laid_out_in = within;
        auto const fit_into = within.extents();
        float top{}, left{}, width{};
        for (auto &element : elements) {
            auto const ex = element.constraints.extents();
            if (left and left + ex.width > fit_into.width) {
                width = std::max(width, left);
                left = {};
                top += space.height;
            }
            element.position = {{left, top}, ex};
            left += space.width + ex.width;
        }
        width = std::max(width, left);
        elements.extents = {width, width ? top + space.height : 0};
    }

TODO Return a smarter set of constraints

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    return constrained_type{elements.extents.value()};
}


void planet::sdl::ui::text::draw() {
    auto const &pos = position();
    for (auto &element : elements) {
        if (not element.value.texture) {
            element.value.texture = {
                    r, font.render(element.value.word.c_str())};
        }
        if (element.position) {
            auto const p = element.position->top_left + pos.top_left;
            r.copy(*element.value.texture, static_cast<int>(p.x()),
                   static_cast<int>(p.y()));
        }
    }
}


std::vector<std::string_view>
        planet::sdl::ui::text::identify_words(std::string_view const t) {
    constexpr std::string_view whitespace{" \n\t"};
    if (t.empty()) { return {}; }
    std::vector<std::string_view> words;
    for (std::size_t start{t.find_first_not_of(whitespace)};
         start != std::string_view::npos;
         start = t.find_first_not_of(whitespace, start)) {
        auto const end = t.find_first_of(whitespace, start);
        if (end == std::string_view::npos) {
            words.push_back(t.substr(start));
            return words;
        } else {
            words.push_back(t.substr(start, end - start));
            start = end + 1;
        }
    }
    return words;
}