menu_button_widget.hpp

Go to the documentation of this file.

// 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"
 
namespace hi { inline namespace v1 {
 
template<fixed_string Name = "">
class menu_button_widget final : public abstract_button_widget<Name / "menu-button"> {
public:
    using super = abstract_button_widget<Name / "menu-button">;
    using delegate_type = typename super::delegate_type;
    using super::prefix;
 
    menu_button_widget(
        widget *parent,
        std::shared_ptr<delegate_type> delegate,
        button_widget_attribute auto&&...attributes) noexcept :
        super(parent, std::move(delegate))
    {
        this->alignment = alignment::middle_flush();
        this->set_attributes<0>(hi_forward(attributes)...);
    }
 
    template<
        different_from<std::shared_ptr<delegate_type>> Value,
        forward_of<observer<observer_decay_t<Value>>> OnValue,
        button_widget_attribute... Attributes>
    menu_button_widget(widget *parent, Value&& value, OnValue&& on_value, Attributes&&...attributes) noexcept
        requires requires { make_default_radio_button_delegate(hi_forward(value), hi_forward(on_value)); }
        :
        menu_button_widget(
            parent,
            make_default_radio_button_delegate(hi_forward(value), hi_forward(on_value)),
            hi_forward(attributes)...)
    {
    }
 
    [[nodiscard]] box_constraints update_constraints() noexcept override
    {
        _label_constraints = super::update_constraints();
 
        // Make room for button and margin.
        _short_cut_size = _check_size =
            extent2i{theme<prefix>.line_height(this), theme<prefix>.line_height(this)};
 
        // On left side a check mark, on right side short-cut. Around the label extra margin.
        hilet extra_size = extent2i{
            theme<prefix>.margin_left(this) + _check_size.width() + theme<prefix>.spacing_horizontal(this) +
                theme<prefix>.spacing_horizontal(this) + _short_cut_size.width() + theme<prefix>.margin_right(this),
            theme<prefix>.margin_top(this) + theme<prefix>.margin_bottom(this)};
 
        auto constraints = _label_constraints + extra_size;
        constraints.margins = 0;
        return constraints;
    }
 
    void set_layout(widget_layout const& context) noexcept override
    {
        if (compare_store(this->layout, context)) {
            hilet spacing = theme<prefix>.spacing_horizontal(this);
            hilet cap_height = theme<prefix>.cap_height(this);
 
            hilet inside_rectangle = context.rectangle() - spacing;
 
            if (os_settings::left_to_right()) {
                _check_rectangle = align(inside_rectangle, _check_size, alignment::middle_left());
                _short_cut_rectangle = align(inside_rectangle, _short_cut_size, alignment::middle_right());
                hilet label_rectangle = aarectanglei{
                    point2i{_check_rectangle.right() + spacing, 0},
                    point2i{_short_cut_rectangle.left() - spacing, context.height()}};
                this->_on_label_shape = this->_off_label_shape = this->_other_label_shape =
                    box_shape{_label_constraints, label_rectangle, cap_height};
 
            } else {
                _short_cut_rectangle = align(inside_rectangle, _short_cut_size, alignment::middle_left());
                _check_rectangle = align(inside_rectangle, _check_size, alignment::middle_right());
                hilet label_rectangle = aarectanglei{
                    point2i{_short_cut_rectangle.right() + spacing, 0},
                    point2i{_check_rectangle.left() - spacing, context.height()}};
                this->_on_label_shape = this->_off_label_shape = this->_other_label_shape =
                    box_shape{_label_constraints, label_rectangle, cap_height};
            }
 
            _check_glyph = find_glyph(elusive_icon::Ok);
            hilet check_glyph_bb =
                narrow_cast<aarectanglei>(_check_glyph.get_bounding_rectangle() * theme<prefix>.line_height(this));
            _check_glyph_rectangle = align(_check_rectangle, check_glyph_bb, alignment::middle_center());
        }
 
        super::set_layout(context);
    }
 
    void draw(widget_draw_context& context) noexcept override
    {
        if (*this->mode > widget_mode::invisible and overlaps(context, this->layout)) {
            draw_menu_button(context);
            draw_check_mark(context);
            this->draw_button(context);
        }
    }
 
    [[nodiscard]] bool accepts_keyboard_focus(keyboard_focus_group group) const noexcept override
    {
        return *this->mode >= widget_mode::partial and to_bool(group & hi::keyboard_focus_group::menu);
    }
 
    bool handle_event(gui_event const& event) noexcept override
    {
        using enum gui_event_type;
 
        switch (event.type()) {
        case gui_menu_next:
            if (*this->mode >= widget_mode::partial and not this->is_last(keyboard_focus_group::menu)) {
                this->process_event(gui_event::window_set_keyboard_target(
                    nullptr, keyboard_focus_group::menu, keyboard_focus_direction::forward));
                return true;
            }
            break;
 
        case gui_menu_prev:
            if (*this->mode >= widget_mode::partial and not this->is_first(keyboard_focus_group::menu)) {
                this->process_event(gui_event::window_set_keyboard_target(
                    nullptr, keyboard_focus_group::menu, keyboard_focus_direction::backward));
                return true;
            }
            break;
 
        case gui_activate:
            if (*this->mode >= widget_mode::partial) {
                this->activate();
                this->process_event(gui_event::window_set_keyboard_target(
                    nullptr, keyboard_focus_group::normal, keyboard_focus_direction::forward));
                this->process_event(gui_event::window_set_keyboard_target(
                    nullptr, keyboard_focus_group::normal, keyboard_focus_direction::backward));
                return true;
            }
            break;
 
        default:;
        }
 
        return super::handle_event(event);
    }
private:
    box_constraints _label_constraints;
 
    font_book::font_glyph_type _check_glyph;
    extent2i _check_size;
    aarectanglei _check_rectangle;
    aarectanglei _check_glyph_rectangle;
    extent2i _short_cut_size;
    aarectanglei _short_cut_rectangle;
 
    void draw_menu_button(widget_draw_context& context) noexcept
    {
        context.draw_box(
            this->layout,
            this->layout.rectangle(),
            theme<prefix>.background_color(this),
            theme<prefix>.border_color(this),
            theme<prefix>.border_width(this),
            border_side::inside);
    }
 
    void draw_check_mark(widget_draw_context& context) noexcept
    {
        // Checkmark or tristate.
        if (*this->state != hi::widget_state::off) {
            context.draw_glyph(
                this->layout,
                translate_z(0.1f) * narrow_cast<aarectangle>(_check_glyph_rectangle),
                _check_glyph,
                theme<prefix>.fill_color(this));
        }
    }
};
 
}} // namespace hi::v1