stringfield.hpp

/*
    KTech, Kaup's C++ 2D terminal game engine library.
    Copyright (C) 2023-2025 Ethan Kaufman (AKA Kaup)
 
    This file is part of KTech.
 
    KTech is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    any later version.
 
    KTech is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
    along with KTech. If not, see <https://www.gnu.org/licenses/>.
*/
 
#pragma once
 
#include "../ktech.hpp"
 
class StringField : public KTech::Widget
{
public:
    static constexpr std::pair<char, char> charRange_lower{'a', 'z'}; 
    static constexpr std::pair<char, char> charRange_upper{'A', 'Z'}; 
    static constexpr std::pair<char, char> charRange_numbers{'0', '9'}; 
    static constexpr std::pair<char, char> charRange_all{' ', '~'}; 
 
    std::string m_string; 
 
    std::function<void()> m_OnInsert; 
 
    StringField(KTech::Engine& engine,
        KTech::ID<KTech::UI> ui,
        std::function<void()> OnInsert = nullptr,
        const std::vector<std::pair<char, char>>& allowedCharacters = {charRange_all},
        KTech::Point position = { 0, 0 },
        const std::string& text = "Value = ",
        unsigned int maxChars = 8,
        const std::string& defaultString = "String",
        bool withFrame = false,
        KTech::RGBA unselected = KTech::RGBAColors::gray,
        KTech::RGBA selected = KTech::RGBAColors::white)
        : Widget(engine, ui, position), m_OnInsert(std::move(OnInsert)), m_maxChars(maxChars), m_unselectedRGBA(unselected), m_selectedRGBA(selected), m_string(defaultString)
    {
        // Textures
        SetText(text, withFrame);
        SetValue(defaultString);
        // Input handlers
        for (const std::pair<char, char>& charRange : allowedCharacters)
        {
            m_callbackGroup.RegisterRangedCallback(charRange.first, charRange.second, [this]() -> bool { return this->Insert(); });
        }
        m_callbackGroup.RegisterCallback(KTech::Keys::delete_, [this]() -> bool { return this->Insert(); });
        m_callbackGroup.RegisterCallback(KTech::Keys::backspace, [this]() -> bool { return this->Insert(); });
    }
 
    void SetText(const std::string& text, bool withFrame)
    {
        KTech::RGBA tempRGBA = (m_selected ? m_selectedRGBA : m_unselectedRGBA);
        if (withFrame)
        {
            m_textures.resize(TEXTURES_SIZE_FRAMED);
            m_textures[ti_topLeftCorner].Simple(KTech::UPoint(1, 1), KTech::CellA('#', tempRGBA), KTech::Point(0, 0));
            m_textures[ti_topRightCorner].Simple(KTech::UPoint(1, 1), KTech::CellA('#', tempRGBA), KTech::Point(1 + text.length() + m_maxChars, 0));
            m_textures[ti_bottomLeftCorner].Simple(KTech::UPoint(1, 1), KTech::CellA('#', tempRGBA), KTech::Point(0, 2));
            m_textures[ti_bottomRightCorner].Simple(KTech::UPoint(1, 1), KTech::CellA('#', tempRGBA), KTech::Point(1 + text.length() + m_maxChars, 2));
            m_textures[ti_topFrame].Simple(KTech::UPoint(text.length() + m_maxChars, 1), KTech::CellA('-', tempRGBA), KTech::Point(1, 0));
            m_textures[ti_leftFrame].Simple(KTech::UPoint(1, 1), KTech::CellA('|', tempRGBA), KTech::Point(0, 1));
            m_textures[ti_bottomFrame].Simple(KTech::UPoint(text.length() + m_maxChars, 1), KTech::CellA('-', tempRGBA), KTech::Point(1, 2));
            m_textures[ti_rightFrame].Simple(KTech::UPoint(1, 1), KTech::CellA('|', tempRGBA), KTech::Point(1 + text.length() + m_maxChars, 1));
        }
        else
        {
            m_textures.resize(TEXTURES_SIZE_FRAMELESS);
        }
        // input position
        m_textures[ti_input].m_rPos = KTech::Point(1 + text.length(), 1);
        // text
        m_textures[ti_text].Write({text}, tempRGBA, KTech::RGBA(0, 0, 0, 0), KTech::Point(1, 1));
    }
 
    void SetValue(const std::string& value)
    {
        m_string = value.substr(0, (m_string.size() > m_maxChars ? m_maxChars : m_string.size()));
        m_textures[ti_input].Write({m_string}, (m_selected ? m_selectedRGBA : m_unselectedRGBA), KTech::RGBAColors::transparent);
        m_currentChar = m_string.length();
    }
 
private:
    enum TextureIndex : size_t
    {
        ti_input,
        ti_text,
        TEXTURES_SIZE_FRAMELESS,
        ti_topLeftCorner = TEXTURES_SIZE_FRAMELESS,
        ti_topRightCorner,
        ti_bottomLeftCorner,
        ti_bottomRightCorner,
        ti_topFrame,
        ti_leftFrame,
        ti_bottomFrame,
        ti_rightFrame,
        TEXTURES_SIZE_FRAMED
    };
 
    KTech::RGBA m_unselectedRGBA, m_selectedRGBA;
    uint16_t m_currentChar = 0;
    uint16_t m_maxChars;
 
    void OnSelect() override
    {
        RenderSelected();
    }
 
    void OnDeselect() override
    {
        RenderUnselected();
    }
 
    auto Insert() -> bool
    {
        if (engine.input.Is(KTech::Keys::backspace) || engine.input.Is(KTech::Keys::delete_))
        {
            if (m_currentChar == 0)
            {
                return false;
            }
 
            m_currentChar--;
            m_string.pop_back();
 
            m_textures[ti_input](m_currentChar, 0).c = ' ';
        }
        else if (m_currentChar == m_maxChars)
        {
            return false;
        }
        else
        {
            m_textures[ti_input](m_currentChar, 0).c = engine.input.input.at(0);
            m_string.push_back(engine.input.input.at(0));
            m_currentChar++;
        }
        if (m_OnInsert)
        {
            m_OnInsert();
        }
        return true;
    }
 
    void RenderSelected()
    {
        for (KTech::Texture& texture : m_textures)
        {
            texture.Transform([&](KTech::CellA& cell){ cell.f = m_selectedRGBA; });
        }
    }
 
    void RenderUnselected()
    {
        for (KTech::Texture& texture : m_textures)
        {
            texture.Transform([&](KTech::CellA& cell){ cell.f = m_unselectedRGBA; });
        }
    }
};