label_widget.hpp

// Copyright Take Vos 2020-2021.
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at https://www.boost.org/LICENSE_1_0.txt)
 
#pragma once
 
#include "widget.hpp"
#include "../GUI/draw_context.hpp"
#include "../stencils/label_stencil.hpp"
#include "../observable.hpp"
#include "../alignment.hpp"
#include <memory>
#include <string>
#include <array>
#include <optional>
#include <future>
 
namespace tt {
 
class label_widget final : public widget {
public:
    using super = widget;
 
    observable<label> label;
 
    template<typename Label>
    label_widget(
        gui_window &window,
        std::shared_ptr<abstract_container_widget> parent,
        alignment alignment,
        Label &&label) noexcept
        :
        super(window, parent),
        _alignment(alignment),
        label(std::forward<Label>(label))
    {
    }
 
    template<typename Label>
    label_widget(gui_window &window, std::shared_ptr<abstract_container_widget> parent, Label &&label) noexcept :
        super(window, parent), _alignment(alignment::top_right), label(std::forward<Label>(label))
    {
    }
 
    ~label_widget() {
    }
 
    void init() noexcept override {
        _label_callback = label.subscribe([this](auto...) {
            _request_reconstrain = true;
        });
    }
 
    [[nodiscard]] bool update_constraints(hires_utc_clock::time_point display_time_point, bool need_reconstrain) noexcept override
    {
        tt_axiom(gui_system_mutex.recurse_lock_count());
 
        if (super::update_constraints(display_time_point, need_reconstrain)) {
            _label_cell = stencil::make_unique(_alignment, *label, theme::global->labelStyle);
            _preferred_size = interval_vec2::make_minimum(_label_cell->preferred_extent());
            return true;
        } else {
            return false;
        }
    }
 
    [[nodiscard]] void update_layout(hires_utc_clock::time_point displayTimePoint, bool need_layout) noexcept override
    {
        tt_axiom(gui_system_mutex.recurse_lock_count());
 
        need_layout |= std::exchange(this->_request_relayout, false);
        if (need_layout) {
            _label_cell->set_layout_parameters(rectangle(), base_line());
        }
        super::update_layout(displayTimePoint, need_layout);
    }
 
    void draw(draw_context context, hires_utc_clock::time_point display_time_point) noexcept override {
        tt_axiom(gui_system_mutex.recurse_lock_count());
 
        if (overlaps(context, this->window_clipping_rectangle())) {
            if (*enabled) {
                context.line_color = theme::global->labelStyle.color;
            }
 
            _label_cell->draw(context, true);
        }
 
        super::draw(std::move(context), display_time_point);
    }
 
private:
    typename decltype(label)::callback_ptr_type _label_callback;
 
    std::unique_ptr<label_stencil> _label_cell;
    alignment _alignment;
};
 
}