text_field_widget.hpp

// Copyright Take Vos 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 "text_field_delegate.hpp"
#include "default_text_field_delegate.hpp"
#include "widget.hpp"
#include "../text/editable_text.hpp"
#include "../format.hpp"
#include "../label.hpp"
#include "../weak_or_unique_ptr.hpp"
#include <memory>
#include <string>
#include <array>
#include <optional>
#include <future>
 
namespace tt {
 
class text_field_widget final : public widget {
public:
    using delegate_type = text_field_delegate;
    using super = widget;
 
    observable<bool> continues = false;
 
    text_field_widget(gui_window &window, widget *parent, std::weak_ptr<delegate_type> delegate) noexcept;
 
    template<typename Value>
    text_field_widget(gui_window &window, widget *parent, Value &&value) noexcept
        requires(not std::is_convertible_v<Value, weak_or_unique_ptr<delegate_type>>) :
        text_field_widget(window, parent, make_unique_default_text_field_delegate(std::forward<Value>(value)))
    {
    }
 
    void init() noexcept override;
    void deinit() noexcept override;
    [[nodiscard]] bool constrain(hires_utc_clock::time_point display_time_point, bool need_reconstrain) noexcept override;
    void layout(hires_utc_clock::time_point display_time_point, bool need_layout) noexcept override;
    void draw(draw_context context, hires_utc_clock::time_point display_time_point) noexcept override;
    bool handle_event(command command) noexcept override;
    bool handle_event(mouse_event const &event) noexcept override;
    bool handle_event(keyboard_event const &event) noexcept override;
    hitbox hitbox_test(point2 position) const noexcept override;
    [[nodiscard]] bool accepts_keyboard_focus(keyboard_focus_group group) const noexcept override;
    [[nodiscard]] color focus_color() const noexcept override;
private:
    weak_or_unique_ptr<delegate_type> _delegate;
    typename delegate_type::callback_ptr_type _delegate_callback;
 
    bool _continues = false;
 
    std::optional<label>(_error);
 
    float _text_width = 0.0f;
    aarectangle _text_rectangle = {};
 
    aarectangle _text_field_rectangle;
    aarectangle _text_field_clipping_rectangle;
 
    editable_text _field;
    shaped_text _shaped_text;
    aarectangle _left_to_right_caret = {};
 
    float _drag_scroll_speed_x = 0.0f;
 
    int _drag_click_count = 0;
 
    point2 _drag_select_position = {};
 
    float _text_scroll_x = 0.0f;
 
    translate2 _text_translate;
    translate2 _text_inv_translate;
 
    static constexpr hires_utc_clock::duration _blink_interval = 500ms;
    hires_utc_clock::time_point _next_redraw_time_point;
    hires_utc_clock::time_point _last_update_time_point;
 
    text_field_widget(gui_window &window, widget *parent, weak_or_unique_ptr<delegate_type> delegate) noexcept;
    void revert(bool force) noexcept;
    void commit(bool force) noexcept;
    void drag_select() noexcept;
    void scroll_text() noexcept;
    void draw_background_box(draw_context context) const noexcept;
    void draw_selection_rectangles(draw_context context) const noexcept;
    void draw_partial_grapheme_caret(draw_context context) const noexcept;
    void draw_caret(draw_context context, hires_utc_clock::time_point display_time_point) noexcept;
    void draw_text(draw_context context) const noexcept;
};
 
} // namespace tt