unleashed-firmware/applications/plugins/usbkeyboard/views/usb_hid_keyboard.c

#include "usb_hid_keyboard.h"
#include <furi.h>
#include <furi_hal_usb_hid.h>
#include <gui/elements.h>
#include <gui/icon_i.h>
#include <USB_Keyboard_icons.h>

struct UsbHidKeyboard {
    View* view;
};

typedef struct {
    bool shift;
    bool alt;
    bool ctrl;
    bool gui;
    uint8_t x;
    uint8_t y;
    uint8_t last_key_code;
    uint16_t modifier_code;
    bool ok_pressed;
    bool back_pressed;
    bool connected;
    char key_string[5];
} UsbHidKeyboardModel;

typedef struct {
    uint8_t width;
    char* key;
    const Icon* icon;
    char* shift_key;
    uint8_t value;
} UsbHidKeyboardKey;

typedef struct {
    int8_t x;
    int8_t y;
} UsbHidKeyboardPoint;

// 4 BY 12
#define MARGIN_TOP 0
#define MARGIN_LEFT 4
#define KEY_WIDTH 9
#define KEY_HEIGHT 12
#define KEY_PADDING 1
#define ROW_COUNT 7
#define COLUMN_COUNT 12

// 0 width items are not drawn, but there value is used
const UsbHidKeyboardKey usb_hid_keyboard_keyset[ROW_COUNT][COLUMN_COUNT] = {
    {
        {.width = 1, .icon = NULL, .key = "1", .shift_key = "!", .value = HID_KEYBOARD_1},
        {.width = 1, .icon = NULL, .key = "2", .shift_key = "@", .value = HID_KEYBOARD_2},
        {.width = 1, .icon = NULL, .key = "3", .shift_key = "#", .value = HID_KEYBOARD_3},
        {.width = 1, .icon = NULL, .key = "4", .shift_key = "$", .value = HID_KEYBOARD_4},
        {.width = 1, .icon = NULL, .key = "5", .shift_key = "%", .value = HID_KEYBOARD_5},
        {.width = 1, .icon = NULL, .key = "6", .shift_key = "^", .value = HID_KEYBOARD_6},
        {.width = 1, .icon = NULL, .key = "7", .shift_key = "&", .value = HID_KEYBOARD_7},
        {.width = 1, .icon = NULL, .key = "8", .shift_key = "*", .value = HID_KEYBOARD_8},
        {.width = 1, .icon = NULL, .key = "9", .shift_key = "(", .value = HID_KEYBOARD_9},
        {.width = 1, .icon = NULL, .key = "0", .shift_key = ")", .value = HID_KEYBOARD_0},
        {.width = 2, .icon = &I_Pin_arrow_left_9x7, .value = HID_KEYBOARD_DELETE},
        {.width = 0, .value = HID_KEYBOARD_DELETE},
    },
    {
        {.width = 1, .icon = NULL, .key = "q", .shift_key = "Q", .value = HID_KEYBOARD_Q},
        {.width = 1, .icon = NULL, .key = "w", .shift_key = "W", .value = HID_KEYBOARD_W},
        {.width = 1, .icon = NULL, .key = "e", .shift_key = "E", .value = HID_KEYBOARD_E},
        {.width = 1, .icon = NULL, .key = "r", .shift_key = "R", .value = HID_KEYBOARD_R},
        {.width = 1, .icon = NULL, .key = "t", .shift_key = "T", .value = HID_KEYBOARD_T},
        {.width = 1, .icon = NULL, .key = "y", .shift_key = "Y", .value = HID_KEYBOARD_Y},
        {.width = 1, .icon = NULL, .key = "u", .shift_key = "U", .value = HID_KEYBOARD_U},
        {.width = 1, .icon = NULL, .key = "i", .shift_key = "I", .value = HID_KEYBOARD_I},
        {.width = 1, .icon = NULL, .key = "o", .shift_key = "O", .value = HID_KEYBOARD_O},
        {.width = 1, .icon = NULL, .key = "p", .shift_key = "P", .value = HID_KEYBOARD_P},
        {.width = 1, .icon = NULL, .key = "[", .shift_key = "{", .value = HID_KEYBOARD_OPEN_BRACKET},
        {.width = 1,
         .icon = NULL,
         .key = "]",
         .shift_key = "}",
         .value = HID_KEYBOARD_CLOSE_BRACKET},
    },
    {
        {.width = 1, .icon = NULL, .key = "a", .shift_key = "A", .value = HID_KEYBOARD_A},
        {.width = 1, .icon = NULL, .key = "s", .shift_key = "S", .value = HID_KEYBOARD_S},
        {.width = 1, .icon = NULL, .key = "d", .shift_key = "D", .value = HID_KEYBOARD_D},
        {.width = 1, .icon = NULL, .key = "f", .shift_key = "F", .value = HID_KEYBOARD_F},
        {.width = 1, .icon = NULL, .key = "g", .shift_key = "G", .value = HID_KEYBOARD_G},
        {.width = 1, .icon = NULL, .key = "h", .shift_key = "H", .value = HID_KEYBOARD_H},
        {.width = 1, .icon = NULL, .key = "j", .shift_key = "J", .value = HID_KEYBOARD_J},
        {.width = 1, .icon = NULL, .key = "k", .shift_key = "K", .value = HID_KEYBOARD_K},
        {.width = 1, .icon = NULL, .key = "l", .shift_key = "L", .value = HID_KEYBOARD_L},
        {.width = 1, .icon = NULL, .key = ";", .shift_key = ":", .value = HID_KEYBOARD_SEMICOLON},
        {.width = 2, .icon = &I_Pin_arrow_right_9x7, .value = HID_KEYBOARD_RETURN},
        {.width = 0, .value = HID_KEYBOARD_RETURN},
    },
    {
        {.width = 1, .icon = NULL, .key = "z", .shift_key = "Z", .value = HID_KEYBOARD_Z},
        {.width = 1, .icon = NULL, .key = "x", .shift_key = "X", .value = HID_KEYBOARD_X},
        {.width = 1, .icon = NULL, .key = "c", .shift_key = "C", .value = HID_KEYBOARD_C},
        {.width = 1, .icon = NULL, .key = "v", .shift_key = "V", .value = HID_KEYBOARD_V},
        {.width = 1, .icon = NULL, .key = "b", .shift_key = "B", .value = HID_KEYBOARD_B},
        {.width = 1, .icon = NULL, .key = "n", .shift_key = "N", .value = HID_KEYBOARD_N},
        {.width = 1, .icon = NULL, .key = "m", .shift_key = "M", .value = HID_KEYBOARD_M},
        {.width = 1, .icon = NULL, .key = "/", .shift_key = "?", .value = HID_KEYBOARD_SLASH},
        {.width = 1, .icon = NULL, .key = "\\", .shift_key = "|", .value = HID_KEYBOARD_BACKSLASH},
        {.width = 1, .icon = NULL, .key = "`", .shift_key = "~", .value = HID_KEYBOARD_GRAVE_ACCENT},
        {.width = 1, .icon = &I_ButtonUp_7x4, .value = HID_KEYBOARD_UP_ARROW},
        {.width = 1, .icon = NULL, .key = "-", .shift_key = "_", .value = HID_KEYBOARD_MINUS},
    },
    {
        {.width = 1, .icon = &I_Pin_arrow_up_7x9, .value = HID_KEYBOARD_L_SHIFT},
        {.width = 1, .icon = NULL, .key = ",", .shift_key = "<", .value = HID_KEYPAD_COMMA},
        {.width = 1, .icon = NULL, .key = ".", .shift_key = ">", .value = HID_KEYBOARD_DOT},
        {.width = 4, .icon = NULL, .key = " ", .value = HID_KEYBOARD_SPACEBAR},
        {.width = 0, .value = HID_KEYBOARD_SPACEBAR},
        {.width = 0, .value = HID_KEYBOARD_SPACEBAR},
        {.width = 0, .value = HID_KEYBOARD_SPACEBAR},
        {.width = 1, .icon = NULL, .key = "'", .shift_key = "\"", .value = HID_KEYBOARD_APOSTROPHE},
        {.width = 1, .icon = NULL, .key = "=", .shift_key = "+", .value = HID_KEYBOARD_EQUAL_SIGN},
        {.width = 1, .icon = &I_ButtonLeft_4x7, .value = HID_KEYBOARD_LEFT_ARROW},
        {.width = 1, .icon = &I_ButtonDown_7x4, .value = HID_KEYBOARD_DOWN_ARROW},
        {.width = 1, .icon = &I_ButtonRight_4x7, .value = HID_KEYBOARD_RIGHT_ARROW},
    },
    {
        {.width = 2, .icon = NULL, .key = "Ctl", .value = HID_KEYBOARD_L_CTRL},
        {.width = 0, .icon = NULL, .value = HID_KEYBOARD_L_CTRL},
        {.width = 2, .icon = NULL, .key = "Alt", .value = HID_KEYBOARD_L_ALT},
        {.width = 0, .icon = NULL, .value = HID_KEYBOARD_L_ALT},
        {.width = 2, .icon = NULL, .key = "Cmd", .value = HID_KEYBOARD_L_GUI},
        {.width = 0, .icon = NULL, .value = HID_KEYBOARD_L_GUI},
        {.width = 2, .icon = NULL, .key = "Tab", .value = HID_KEYBOARD_TAB},
        {.width = 0, .icon = NULL, .value = HID_KEYBOARD_TAB},
        {.width = 2, .icon = NULL, .key = "Esc", .value = HID_KEYBOARD_ESCAPE},
        {.width = 0, .icon = NULL, .value = HID_KEYBOARD_ESCAPE},
        {.width = 2, .icon = NULL, .key = "Del", .value = HID_KEYBOARD_DELETE_FORWARD},
        {.width = 0, .icon = NULL, .value = HID_KEYBOARD_DELETE_FORWARD},
    },
    {
        {.width = 1, .icon = NULL, .key = "1", .shift_key = "1", .value = HID_KEYBOARD_F1},
        {.width = 1, .icon = NULL, .key = "2", .shift_key = "2", .value = HID_KEYBOARD_F2},
        {.width = 1, .icon = NULL, .key = "3", .shift_key = "3", .value = HID_KEYBOARD_F3},
        {.width = 1, .icon = NULL, .key = "4", .shift_key = "4", .value = HID_KEYBOARD_F4},
        {.width = 1, .icon = NULL, .key = "5", .shift_key = "5", .value = HID_KEYBOARD_F5},
        {.width = 1, .icon = NULL, .key = "6", .shift_key = "6", .value = HID_KEYBOARD_F6},
        {.width = 1, .icon = NULL, .key = "7", .shift_key = "7", .value = HID_KEYBOARD_F7},
        {.width = 1, .icon = NULL, .key = "8", .shift_key = "8", .value = HID_KEYBOARD_F8},
        {.width = 1, .icon = NULL, .key = "9", .shift_key = "9", .value = HID_KEYBOARD_F9},
        {.width = 1, .icon = NULL, .key = "0", .shift_key = "0", .value = HID_KEYBOARD_F10},
        {.width = 1, .icon = NULL, .key = "1", .shift_key = "1", .value = HID_KEYBOARD_F11},
        {.width = 1, .icon = NULL, .key = "2", .shift_key = "2", .value = HID_KEYBOARD_F12},
    }};

static void usb_hid_keyboard_to_upper(char* str) {
    while(*str) {
        *str = toupper((unsigned char)*str);
        str++;
    }
}

static void usb_hid_keyboard_draw_key(
    Canvas* canvas,
    UsbHidKeyboardModel* model,
    uint8_t x,
    uint8_t y,
    UsbHidKeyboardKey key,
    bool selected) {
    if(!key.width) return;

    canvas_set_color(canvas, ColorBlack);
    uint8_t keyWidth = KEY_WIDTH * key.width + KEY_PADDING * (key.width - 1);
    if(selected) {
        // Draw a filled box
        elements_slightly_rounded_box(
            canvas,
            MARGIN_LEFT + x * (KEY_WIDTH + KEY_PADDING),
            MARGIN_TOP + y * (KEY_HEIGHT + KEY_PADDING),
            keyWidth,
            KEY_HEIGHT);
        canvas_set_color(canvas, ColorWhite);
    } else {
        // Draw a framed box
        elements_slightly_rounded_frame(
            canvas,
            MARGIN_LEFT + x * (KEY_WIDTH + KEY_PADDING),
            MARGIN_TOP + y * (KEY_HEIGHT + KEY_PADDING),
            keyWidth,
            KEY_HEIGHT);
    }
    if(key.icon != NULL) {
        // Draw the icon centered on the button
        canvas_draw_icon(
            canvas,
            MARGIN_LEFT + x * (KEY_WIDTH + KEY_PADDING) + keyWidth / 2 - key.icon->width / 2,
            MARGIN_TOP + y * (KEY_HEIGHT + KEY_PADDING) + KEY_HEIGHT / 2 - key.icon->height / 2,
            key.icon);
    } else {
        // If shift is toggled use the shift key when available
        strcpy(model->key_string, (model->shift && key.shift_key != 0) ? key.shift_key : key.key);
        // Upper case if ctrl or alt was toggled true
        if((model->ctrl && key.value == HID_KEYBOARD_L_CTRL) ||
           (model->alt && key.value == HID_KEYBOARD_L_ALT) ||
           (model->gui && key.value == HID_KEYBOARD_L_GUI)) {
            usb_hid_keyboard_to_upper(model->key_string);
        }
        canvas_draw_str_aligned(
            canvas,
            MARGIN_LEFT + x * (KEY_WIDTH + KEY_PADDING) + keyWidth / 2 + 1,
            MARGIN_TOP + y * (KEY_HEIGHT + KEY_PADDING) + KEY_HEIGHT / 2,
            AlignCenter,
            AlignCenter,
            model->key_string);
    }
}

static void usb_hid_keyboard_draw_callback(Canvas* canvas, void* context) {
    furi_assert(context);
    UsbHidKeyboardModel* model = context;

    canvas_set_font(canvas, FontKeyboard);
    // Start shifting the all keys up if on the next row (Scrolling)
    uint8_t initY = model->y - 4 > 0 ? model->y - 4 : 0;
    for(uint8_t y = initY; y < ROW_COUNT; y++) {
        const UsbHidKeyboardKey* keyboardKeyRow = usb_hid_keyboard_keyset[y];
        uint8_t x = 0;
        for(uint8_t i = 0; i < COLUMN_COUNT; i++) {
            UsbHidKeyboardKey key = keyboardKeyRow[i];
            // Select when the button is hovered
            // Select if the button is hovered within its width
            // Select if back is clicked and its the backspace key
            // Deselect when the button clicked or not hovered
            bool keySelected = (x <= model->x && model->x < (x + key.width)) && y == model->y;
            // Revert selection for function keys
            keySelected = y == ROW_COUNT - 1 ? !keySelected : keySelected;
            bool backSelected = model->back_pressed && key.value == HID_KEYBOARD_DELETE;
            usb_hid_keyboard_draw_key(
                canvas,
                model,
                x,
                y - initY,
                key,
                (!model->ok_pressed && keySelected) || backSelected);
            x += key.width;
        }
    }
}

static uint8_t usb_hid_keyboard_get_selected_key(UsbHidKeyboardModel* model) {
    UsbHidKeyboardKey key = usb_hid_keyboard_keyset[model->y][model->x];
    // Use upper case if shift is toggled
    bool useUppercase = model->shift;
    // Check if the key has an upper case version
    bool hasUppercase = key.shift_key != 0;
    if(useUppercase && hasUppercase)
        return key.value;
    else
        return key.value;
}

static void
    usb_hid_keyboard_get_select_key(UsbHidKeyboardModel* model, UsbHidKeyboardPoint delta) {
    // Keep going until a valid spot is found, this allows for nulls and zero width keys in the map
    do {
        if(((int8_t)model->y) + delta.y < 0)
            model->y = ROW_COUNT - 1;
        else
            model->y = (model->y + delta.y) % ROW_COUNT;
    } while(delta.y != 0 && usb_hid_keyboard_keyset[model->y][model->x].value == 0);

    do {
        if(((int8_t)model->x) + delta.x < 0)
            model->x = COLUMN_COUNT - 1;
        else
            model->x = (model->x + delta.x) % COLUMN_COUNT;
    } while(delta.x != 0 && usb_hid_keyboard_keyset[model->y][model->x].width ==
                                0); // Skip zero width keys, pretend they are one key
}

static void usb_hid_keyboard_process(UsbHidKeyboard* usb_hid_keyboard, InputEvent* event) {
    with_view_model(
        usb_hid_keyboard->view,
        UsbHidKeyboardModel * model,
        {
            if(event->key == InputKeyOk) {
                if(event->type == InputTypePress) {
                    model->ok_pressed = true;
                } else if(event->type == InputTypeLong || event->type == InputTypeShort) {
                    model->last_key_code = usb_hid_keyboard_get_selected_key(model);

                    // Toggle the modifier key when clicked, and click the key
                    if(model->last_key_code == HID_KEYBOARD_L_SHIFT) {
                        model->shift = !model->shift;
                        if(model->shift)
                            model->modifier_code |= KEY_MOD_LEFT_SHIFT;
                        else
                            model->modifier_code &= ~KEY_MOD_LEFT_SHIFT;
                    } else if(model->last_key_code == HID_KEYBOARD_L_ALT) {
                        model->alt = !model->alt;
                        if(model->alt)
                            model->modifier_code |= KEY_MOD_LEFT_ALT;
                        else
                            model->modifier_code &= ~KEY_MOD_LEFT_ALT;
                    } else if(model->last_key_code == HID_KEYBOARD_L_CTRL) {
                        model->ctrl = !model->ctrl;
                        if(model->ctrl)
                            model->modifier_code |= KEY_MOD_LEFT_CTRL;
                        else
                            model->modifier_code &= ~KEY_MOD_LEFT_CTRL;
                    } else if(model->last_key_code == HID_KEYBOARD_L_GUI) {
                        model->gui = !model->gui;
                        if(model->gui)
                            model->modifier_code |= KEY_MOD_LEFT_GUI;
                        else
                            model->modifier_code &= ~KEY_MOD_LEFT_GUI;
                    }
                    furi_hal_hid_kb_press(model->modifier_code | model->last_key_code);
                } else if(event->type == InputTypeRelease) {
                    // Release happens after short and long presses
                    furi_hal_hid_kb_release(model->modifier_code | model->last_key_code);
                    model->ok_pressed = false;
                }
            } else if(event->key == InputKeyBack) {
                // If back is pressed for a short time, backspace
                if(event->type == InputTypePress) {
                    model->back_pressed = true;
                } else if(event->type == InputTypeShort) {
                    furi_hal_hid_kb_press(HID_KEYBOARD_DELETE);
                    furi_hal_hid_kb_release(HID_KEYBOARD_DELETE);
                } else if(event->type == InputTypeRelease) {
                    model->back_pressed = false;
                }
            } else if(event->type == InputTypePress || event->type == InputTypeRepeat) {
                // Cycle the selected keys
                if(event->key == InputKeyUp) {
                    usb_hid_keyboard_get_select_key(model, (UsbHidKeyboardPoint){.x = 0, .y = -1});
                } else if(event->key == InputKeyDown) {
                    usb_hid_keyboard_get_select_key(model, (UsbHidKeyboardPoint){.x = 0, .y = 1});
                } else if(event->key == InputKeyLeft) {
                    usb_hid_keyboard_get_select_key(model, (UsbHidKeyboardPoint){.x = -1, .y = 0});
                } else if(event->key == InputKeyRight) {
                    usb_hid_keyboard_get_select_key(model, (UsbHidKeyboardPoint){.x = 1, .y = 0});
                }
            }
        },
        true);
}

static bool usb_hid_keyboard_input_callback(InputEvent* event, void* context) {
    furi_assert(context);
    UsbHidKeyboard* usb_hid_keyboard = context;
    bool consumed = false;

    if(event->type == InputTypeLong && event->key == InputKeyBack) {
        furi_hal_hid_kb_release_all();
    } else {
        usb_hid_keyboard_process(usb_hid_keyboard, event);
        consumed = true;
    }

    return consumed;
}

UsbHidKeyboard* usb_hid_keyboard_alloc() {
    UsbHidKeyboard* usb_hid_keyboard = malloc(sizeof(UsbHidKeyboard));

    usb_hid_keyboard->view = view_alloc();
    view_set_context(usb_hid_keyboard->view, usb_hid_keyboard);
    view_allocate_model(usb_hid_keyboard->view, ViewModelTypeLocking, sizeof(UsbHidKeyboardModel));
    view_set_draw_callback(usb_hid_keyboard->view, usb_hid_keyboard_draw_callback);
    view_set_input_callback(usb_hid_keyboard->view, usb_hid_keyboard_input_callback);

    with_view_model(
        usb_hid_keyboard->view, UsbHidKeyboardModel * model, { model->connected = true; }, true);

    return usb_hid_keyboard;
}

void usb_hid_keyboard_free(UsbHidKeyboard* usb_hid_keyboard) {
    furi_assert(usb_hid_keyboard);
    view_free(usb_hid_keyboard->view);
    free(usb_hid_keyboard);
}

View* usb_hid_keyboard_get_view(UsbHidKeyboard* usb_hid_keyboard) {
    furi_assert(usb_hid_keyboard);
    return usb_hid_keyboard->view;
}