checkbox_widget.hpp

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// Copyright Take Vos 2021-2022.
// 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 "abstract_button_widget.hpp"
#include "../telemetry/telemetry.hpp"
#include "../macros.hpp"
 
namespace hi { inline namespace v1 {
 
class checkbox_widget final : public abstract_button_widget {
public:
    using super = abstract_button_widget;
    using delegate_type = typename super::delegate_type;
 
    checkbox_widget(
        widget *parent,
        std::shared_ptr<delegate_type> delegate,
        button_widget_attribute auto&&...attributes) noexcept :
        super(parent, std::move(delegate))
    {
        alignment = alignment::top_left();
        set_attributes<0>(hi_forward(attributes)...);
    }
 
    checkbox_widget(
        widget *parent,
        different_from<std::shared_ptr<delegate_type>> auto&& value,
        button_widget_attribute auto&&...attributes) noexcept requires requires
    {
        make_default_toggle_button_delegate(hi_forward(value));
    } : checkbox_widget(parent, make_default_toggle_button_delegate(hi_forward(value)), hi_forward(attributes)...) {}
 
    template<
        different_from<std::shared_ptr<delegate_type>> Value,
        forward_of<observer<observer_decay_t<Value>>> OnValue,
        button_widget_attribute... Attributes>
    checkbox_widget(widget *parent, Value&& value, OnValue&& on_value, Attributes&&...attributes) noexcept
        requires requires
    {
        make_default_toggle_button_delegate(hi_forward(value), hi_forward(on_value));
    } :
        checkbox_widget(
            parent,
            make_default_toggle_button_delegate(hi_forward(value), hi_forward(on_value)),
            hi_forward(attributes)...)
    {
    }
 
    template<
        different_from<std::shared_ptr<delegate_type>> Value,
        forward_of<observer<observer_decay_t<Value>>> OnValue,
        forward_of<observer<observer_decay_t<Value>>> OffValue,
        button_widget_attribute... Attributes>
    checkbox_widget(
        widget *parent,
        Value&& value,
        OnValue&& on_value,
        OffValue&& off_value,
        Attributes&&...attributes) noexcept requires requires
    {
        make_default_toggle_button_delegate(hi_forward(value), hi_forward(on_value), hi_forward(off_value));
    } :
        checkbox_widget(
            parent,
            make_default_toggle_button_delegate(hi_forward(value), hi_forward(on_value), hi_forward(off_value)),
            hi_forward(attributes)...)
    {
    }
 
    [[nodiscard]] box_constraints update_constraints() noexcept override
    {
        _label_constraints = super::update_constraints();
 
        _button_size = {theme().size(), theme().size()};
        hilet extra_size = extent2{theme().margin<float>() + _button_size.width(), 0};
 
        auto constraints = max(_label_constraints + extra_size, _button_size);
        constraints.margins = theme().margin();
        constraints.alignment = *alignment;
        return constraints;
    }
 
    void set_layout(widget_layout const& context) noexcept override
    {
        if (compare_store(_layout, context)) {
            auto alignment_ = os_settings::left_to_right() ? *alignment : mirror(*alignment);
 
            if (alignment_ == horizontal_alignment::left or alignment_ == horizontal_alignment::right) {
                _button_rectangle = align(context.rectangle(), _button_size, alignment_);
            } else {
                hi_not_implemented();
            }
 
            hilet label_width = context.width() - (_button_rectangle.width() + theme().margin<float>());
            if (alignment_ == horizontal_alignment::left) {
                hilet label_left = _button_rectangle.right() + theme().margin<float>();
                hilet label_rectangle = aarectangle{label_left, 0.0f, label_width, context.height()};
                _on_label_shape = _off_label_shape = _other_label_shape =
                    box_shape(_label_constraints, label_rectangle, theme().baseline_adjustment());
 
            } else if (alignment_ == horizontal_alignment::right) {
                hilet label_rectangle = aarectangle{0.0f, 0.0f, label_width, context.height()};
                _on_label_shape = _off_label_shape = _other_label_shape =
                    box_shape(_label_constraints, label_rectangle, theme().baseline_adjustment());
            } else {
                hi_not_implemented();
            }
 
            _check_glyph = find_glyph(elusive_icon::Ok);
            hilet check_glyph_bb = _check_glyph.get_metrics().bounding_rectangle * theme().icon_size();
            _check_glyph_rectangle = align(_button_rectangle, check_glyph_bb, alignment::middle_center());
 
            _minus_glyph = find_glyph(elusive_icon::Minus);
            hilet minus_glyph_bb = _minus_glyph.get_metrics().bounding_rectangle * theme().icon_size();
            _minus_glyph_rectangle = align(_button_rectangle, minus_glyph_bb, alignment::middle_center());
        }
        super::set_layout(context);
    }
 
    void draw(draw_context const& context) noexcept override
    {
        if (*mode > widget_mode::invisible and overlaps(context, layout())) {
            draw_check_box(context);
            draw_check_mark(context);
            draw_button(context);
        }
    }
private:
    box_constraints _label_constraints;
 
    extent2 _button_size;
    aarectangle _button_rectangle;
    font_book::font_glyph_type _check_glyph;
    aarectangle _check_glyph_rectangle;
    font_book::font_glyph_type _minus_glyph;
    aarectangle _minus_glyph_rectangle;
 
    void draw_check_box(draw_context const& context) noexcept
    {
        context.draw_box(
            layout(), _button_rectangle, background_color(), focus_color(), theme().border_width(), border_side::inside);
    }
 
    void draw_check_mark(draw_context const& context) noexcept
    {
        auto state_ = state();
 
        // Checkmark or tristate.
        if (state_ == hi::button_state::on) {
            context.draw_glyph(layout(), translate_z(0.1f) * _check_glyph_rectangle, _check_glyph, accent_color());
 
        } else if (state_ == hi::button_state::off) {
            ;
 
        } else {
            context.draw_glyph(layout(), translate_z(0.1f) * _minus_glyph_rectangle, _minus_glyph, accent_color());
        }
    }
};
 
}} // namespace hi::v1