mayhem-firmware/firmware/application/ui_handwrite.cpp

/*
 * Copyright (C) 2015 Jared Boone, ShareBrained Technology, Inc.
 * Copyright (C) 2016 Furrtek
 *
 * This file is part of PortaPack.
 *
 * This program 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 2, or (at your option)
 * any later version.
 *
 * This program 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 this program; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */

#include "ui_handwrite.hpp"

#include "portapack.hpp"
#include "hackrf_hal.hpp"
#include "portapack_shared_memory.hpp"

#include <algorithm>

using namespace portapack;

namespace ui {

void HandWriteView::paint(Painter& painter) {
    _painter = &painter;
}

HandWriteView::HandWriteView(
    NavigationView& nav,
    std::string* str,
    size_t max_length)
    : TextEntryView(nav, str, max_length) {
    size_t n;

    // Handwriting alphabet definition here
    handwriting = &handwriting_unistroke;

    add_children({&button_case});

    const auto button_fn = [this](Button& button) {
        this->on_button(button);
    };

    n = 0;
    for (auto& button : num_buttons) {
        add_child(&button);
        button.on_select = button_fn;
        button.set_parent_rect({static_cast<Coord>(n * 24),
                                static_cast<Coord>(236),
                                24, 28});
        const std::string label{
            (char)(n + '0')};
        button.set_text(label);
        button.id = n + '0';
        n++;
    }

    n = 0;
    for (auto& button : special_buttons) {
        add_child(&button);
        button.on_select = button_fn;
        button.set_parent_rect({static_cast<Coord>(50 + n * 24),
                                static_cast<Coord>(270),
                                24, 28});
        const std::string label{
            (char)(special_chars[n])};
        button.set_text(label);
        button.id = special_chars[n];
        n++;
    }

    button_case.on_select = [this, &nav](Button&) {
        if (_lowercase == true) {
            _lowercase = false;
            button_case.set_text("LC");
        } else {
            _lowercase = true;
            button_case.set_text("UC");
        }
    };

    button_ok.on_select = [this, &nav](Button&) {
        if (on_changed)
            on_changed(_str);
        nav.pop();
    };

    update_text();
}

bool HandWriteView::on_touch(const TouchEvent event) {
    if (event.type == ui::TouchEvent::Type::Start) {
        stroke_index = 0;
        move_wait = 3;
        tracing = true;
    }
    if (event.type == ui::TouchEvent::Type::End) {
        tracing = false;
        guess_letter();
    }
    if (event.type == ui::TouchEvent::Type::Move) {
        if (tracing)
            current_pos = event.point;
    }
    return true;
}

void HandWriteView::clear_zone(const Color color, const bool flash) {
    display.fill_rectangle(
        {{0, 32}, {240, 216}},
        color);
    if (flash) {
        flash_timer = 8;
    } else {
        // Draw grid
        _painter->draw_rectangle(
            {{0, 32}, {80, 216}},
            Color::grey());
        _painter->draw_rectangle(
            {{80, 32}, {80, 216}},
            Color::grey());
        _painter->draw_rectangle(
            {{160, 32}, {80, 216}},
            Color::grey());
        _painter->draw_rectangle(
            {{0, 104}, {240, 72}},
            Color::grey());
    }
}

void HandWriteView::guess_letter() {
    uint32_t symbol, match, count, stroke_idx, stroke_data;
    Condition cond;
    Direction dir;
    bool matched;

    // Letter guessing
    if (stroke_index) {
        for (symbol = 0; symbol < handwriting->letter_count; symbol++) {
            count = handwriting->letter[symbol].count;
            matched = false;
            if (count) {
                // We have a count match to do
                if ((count == 1) && (stroke_index == 1)) matched = true;
                if ((count == 2) && (stroke_index == 2)) matched = true;
                if ((count == 3) && (stroke_index > 2)) matched = true;
            } else {
                matched = true;
            }
            if (matched) {
                for (match = 0; match < 3; match++) {
                    cond = handwriting->letter[symbol].match[match].cond;
                    dir = handwriting->letter[symbol].match[match].dir;
                    if ((cond != cond_empty) && (dir != dir_empty)) {
                        if (cond == last) {
                            if (stroke_index)
                                stroke_idx = stroke_index - 1;
                            else
                                stroke_idx = 0;
                        } else if (cond == stroke_a)
                            stroke_idx = 0;
                        else if (cond == stroke_b)
                            stroke_idx = 1;
                        else if (cond == stroke_c)
                            stroke_idx = 2;
                        else
                            stroke_idx = 3;
                        if (stroke_idx >= stroke_index) break;
                        stroke_data = stroke_list[stroke_idx];
                        if ((dir & 0xF0) == 0xF0) {
                            if ((dir & 0x0F) != (stroke_data & 0x0F)) break;
                        } else if ((dir & 0x0F) == 0x0F) {
                            if ((dir & 0xF0) != (stroke_data & 0xF0)) break;
                        } else {
                            if (dir != (int32_t)stroke_data) break;
                        }
                    }
                }
                if (match == 3)
                    break;
                else
                    matched = false;
            }
        }
        if (matched) {
            if (symbol) {
                if (_lowercase)
                    char_add('a' + symbol - 1);
                else
                    char_add('A' + symbol - 1);
                clear_zone(Color::green(), true);  // Green flash
            } else {
                if (_cursor_pos) {
                    char_delete();
                    clear_zone(Color::yellow(), true);  // Yellow flash
                } else {
                    clear_zone(Color::red(), true);  // Red flash
                }
            }
        } else {
            clear_zone(Color::red(), true);  // Red flash
        }
    } else {
        // Short tap is space
        char_add(' ');
        clear_zone(Color::green(), true);  // Green flash
    }
    update_text();
    stroke_index = 0;
}

void HandWriteView::add_stroke(uint8_t dir) {
    if (stroke_index < 8) {
        stroke_list[stroke_index] = dir;
        stroke_index++;
    } else {
        guess_letter();
    }
}

void HandWriteView::sample_pen() {
    int16_t diff_x, diff_y;
    uint8_t dir, dir_ud, dir_lr, stroke_prev;

    draw_cursor();

    if (flash_timer) {
        if (flash_timer == 1) clear_zone(Color::black(), false);
        flash_timer--;
    }

    if (!(sample_skip & 1)) {
        if (tracing) {
            if (move_wait) {
                move_wait--;  // ~100ms delay to get rid of jitter from touch start
            } else {
                diff_x = current_pos.x() - last_pos.x();
                diff_y = current_pos.y() - last_pos.y();

                if (current_pos.y() <= 240) {
                    display.fill_rectangle(
                        {{current_pos.x(), current_pos.y()}, {4, 4}},
                        Color::grey());
                }

                dir = 0;  // UL by default
                if (abs(diff_x) > 7) {
                    if (diff_x > 0)
                        dir |= 0x01;  // R
                } else {
                    dir |= 0x02;  // ?
                }
                if (abs(diff_y) > 7) {
                    if (diff_y > 0)
                        dir |= 0x10;  // D
                } else {
                    dir |= 0x20;  // ?
                }

                // Need at least two identical directions to validate stroke
                if ((dir & 0x11) == (dir_prev & 0x11))
                    dir_cnt++;
                else
                    dir_cnt = 0;
                dir_prev = dir;

                if (dir_cnt > 1) {
                    dir_cnt = 0;
                    if (stroke_index) {
                        if ((stroke_list[stroke_index - 1] != dir) && (dir != 0x22)) {
                            // Register stroke if different from last one
                            dir_ud = (dir & 0xF0);
                            dir_lr = (dir & 0x0F);
                            stroke_prev = stroke_list[stroke_index - 1];
                            if (dir_ud == 0x20) {
                                // LR changed
                                if ((stroke_prev & 0x0F) != dir_lr) add_stroke(dir);
                            } else if (dir_lr == 0x02) {
                                // UD changed
                                if ((stroke_prev & 0xF0) != dir_ud) add_stroke(dir);
                            } else {
                                // Add direction
                                if (((stroke_prev & 0xF0) == 0x20) && (dir_ud != 0x20)) {
                                    // Add UD
                                    if ((stroke_prev & 0x0F) == dir_lr) {
                                        // Replace totally
                                        stroke_list[stroke_index - 1] = dir;
                                    } else if (dir_lr == 0x02) {
                                        // Merge UD
                                        stroke_list[stroke_index - 1] = dir_ud | (stroke_prev & 0x0F);
                                    } else {
                                        add_stroke(dir);
                                    }
                                } else if (((stroke_prev & 0x0F) == 0x02) && (dir_lr != 0x02)) {
                                    // Add LR
                                    if ((stroke_prev & 0xF0) == dir_ud) {
                                        // Replace totally
                                        stroke_list[stroke_index - 1] = dir;
                                    } else if (dir_ud == 0x20) {
                                        // Merge LR
                                        stroke_list[stroke_index - 1] = dir_lr | (stroke_prev & 0xF0);
                                    } else {
                                        add_stroke(dir);
                                    }
                                } else {
                                    add_stroke(dir);
                                }
                            }
                        }
                    } else {
                        // Register first stroke
                        if (dir != 0x22) add_stroke(dir);
                    }
                }
            }

            last_pos = current_pos;
        }
    }

    sample_skip++;
}

void HandWriteView::on_show() {
    clear_zone(Color::black(), false);
}

void HandWriteView::on_button(Button& button) {
    char_add(button.id);
    update_text();
}

}  // namespace ui