USBHIDKeyboard.cpp

/*
  Keyboard.cpp

  Copyright (c) 2015, Arduino LLC
  Original code (pre-library): Copyright (c) 2011, Peter Barrett

  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.

  This library 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
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/
#include "USBHID.h"
#if SOC_USB_OTG_SUPPORTED

#if CONFIG_TINYUSB_HID_ENABLED

#include "USBHIDKeyboard.h"

ESP_EVENT_DEFINE_BASE(ARDUINO_USB_HID_KEYBOARD_EVENTS);
esp_err_t arduino_usb_event_post(esp_event_base_t event_base, int32_t event_id, void *event_data, size_t event_data_size, TickType_t ticks_to_wait);
esp_err_t arduino_usb_event_handler_register_with(esp_event_base_t event_base, int32_t event_id, esp_event_handler_t event_handler, void *event_handler_arg);

static const uint8_t report_descriptor[] = {
    TUD_HID_REPORT_DESC_KEYBOARD(HID_REPORT_ID(HID_REPORT_ID_KEYBOARD))
};

USBHIDKeyboard::USBHIDKeyboard(): hid(HID_ITF_PROTOCOL_KEYBOARD), shiftKeyReports(true){
    static bool initialized = false;
    if(!initialized){
        initialized = true;
        memset(&_keyReport, 0, sizeof(KeyReport));
        hid.addDevice(this, sizeof(report_descriptor));
    }
}

uint16_t USBHIDKeyboard::_onGetDescriptor(uint8_t* dst){
    memcpy(dst, report_descriptor, sizeof(report_descriptor));
    return sizeof(report_descriptor);
}

void USBHIDKeyboard::begin(){
    hid.begin();
}

void USBHIDKeyboard::end(){
}

void USBHIDKeyboard::onEvent(esp_event_handler_t callback){
    onEvent(ARDUINO_USB_HID_KEYBOARD_ANY_EVENT, callback);
}
void USBHIDKeyboard::onEvent(arduino_usb_hid_keyboard_event_t event, esp_event_handler_t callback){
    arduino_usb_event_handler_register_with(ARDUINO_USB_HID_KEYBOARD_EVENTS, event, callback, this);
}

void USBHIDKeyboard::_onOutput(uint8_t report_id, const uint8_t* buffer, uint16_t len){
    if(report_id == HID_REPORT_ID_KEYBOARD){
        arduino_usb_hid_keyboard_event_data_t p;
        p.leds = buffer[0];
        arduino_usb_event_post(ARDUINO_USB_HID_KEYBOARD_EVENTS, ARDUINO_USB_HID_KEYBOARD_LED_EVENT, &p, sizeof(arduino_usb_hid_keyboard_event_data_t), portMAX_DELAY);
    }
}

void USBHIDKeyboard::sendReport(KeyReport* keys)
{
    hid_keyboard_report_t report;
    report.reserved = 0;
    report.modifier = keys->modifiers;
    memcpy(report.keycode, keys->keys, 6);
    hid.SendReport(HID_REPORT_ID_KEYBOARD, &report, sizeof(report));
}

void USBHIDKeyboard::setShiftKeyReports(bool set)
{
    shiftKeyReports = set;
}

#define SHIFT 0x80
const uint8_t _asciimap[128] =
{
    0x00,          // NUL
    0x00,          // SOH
    0x00,          // STX
    0x00,          // ETX
    0x00,          // EOT
    0x00,          // ENQ
    0x00,          // ACK  
    0x00,          // BEL
    0x2a,          // BS   Backspace
    0x2b,          // TAB  Tab
    0x28,          // LF   Enter
    0x00,          // VT 
    0x00,          // FF 
    0x00,          // CR 
    0x00,          // SO 
    0x00,          // SI 
    0x00,          // DEL
    0x00,          // DC1
    0x00,          // DC2
    0x00,          // DC3
    0x00,          // DC4
    0x00,          // NAK
    0x00,          // SYN
    0x00,          // ETB
    0x00,          // CAN
    0x00,          // EM 
    0x00,          // SUB
    0x00,          // ESC
    0x00,          // FS 
    0x00,          // GS 
    0x00,          // RS 
    0x00,          // US 

    0x2c,          //  ' '
    0x1e|SHIFT,    // !
    0x34|SHIFT,    // "
    0x20|SHIFT,    // #
    0x21|SHIFT,    // $
    0x22|SHIFT,    // %
    0x24|SHIFT,    // &
    0x34,          // '
    0x26|SHIFT,    // (
    0x27|SHIFT,    // )
    0x25|SHIFT,    // *
    0x2e|SHIFT,    // +
    0x36,          // ,
    0x2d,          // -
    0x37,          // .
    0x38,          // /
    0x27,          // 0
    0x1e,          // 1
    0x1f,          // 2
    0x20,          // 3
    0x21,          // 4
    0x22,          // 5
    0x23,          // 6
    0x24,          // 7
    0x25,          // 8
    0x26,          // 9
    0x33|SHIFT,    // :
    0x33,          // ;
    0x36|SHIFT,    // <
    0x2e,          // =
    0x37|SHIFT,    // >
    0x38|SHIFT,    // ?
    0x1f|SHIFT,    // @
    0x04|SHIFT,    // A
    0x05|SHIFT,    // B
    0x06|SHIFT,    // C
    0x07|SHIFT,    // D
    0x08|SHIFT,    // E
    0x09|SHIFT,    // F
    0x0a|SHIFT,    // G
    0x0b|SHIFT,    // H
    0x0c|SHIFT,    // I
    0x0d|SHIFT,    // J
    0x0e|SHIFT,    // K
    0x0f|SHIFT,    // L
    0x10|SHIFT,    // M
    0x11|SHIFT,    // N
    0x12|SHIFT,    // O
    0x13|SHIFT,    // P
    0x14|SHIFT,    // Q
    0x15|SHIFT,    // R
    0x16|SHIFT,    // S
    0x17|SHIFT,    // T
    0x18|SHIFT,    // U
    0x19|SHIFT,    // V
    0x1a|SHIFT,    // W
    0x1b|SHIFT,    // X
    0x1c|SHIFT,    // Y
    0x1d|SHIFT,    // Z
    0x2f,          // [
    0x31,          // bslash
    0x30,          // ]
    0x23|SHIFT,    // ^
    0x2d|SHIFT,    // _
    0x35,          // `
    0x04,          // a
    0x05,          // b
    0x06,          // c
    0x07,          // d
    0x08,          // e
    0x09,          // f
    0x0a,          // g
    0x0b,          // h
    0x0c,          // i
    0x0d,          // j
    0x0e,          // k
    0x0f,          // l
    0x10,          // m
    0x11,          // n
    0x12,          // o
    0x13,          // p
    0x14,          // q
    0x15,          // r
    0x16,          // s
    0x17,          // t
    0x18,          // u
    0x19,          // v
    0x1a,          // w
    0x1b,          // x
    0x1c,          // y
    0x1d,          // z
    0x2f|SHIFT,    // {
    0x31|SHIFT,    // |
    0x30|SHIFT,    // }
    0x35|SHIFT,    // ~
    0              // DEL
};

size_t USBHIDKeyboard::pressRaw(uint8_t k) 
{
    uint8_t i;
    if (k >= 0xE0 && k < 0xE8) {
        // it's a modifier key
        _keyReport.modifiers |= (1<<(k-0x80));
    } else if (k && k < 0xA5) {
        // Add k to the key report only if it's not already present
        // and if there is an empty slot.
        if (_keyReport.keys[0] != k && _keyReport.keys[1] != k && 
            _keyReport.keys[2] != k && _keyReport.keys[3] != k &&
            _keyReport.keys[4] != k && _keyReport.keys[5] != k) {
            
            for (i=0; i<6; i++) {
                if (_keyReport.keys[i] == 0x00) {
                    _keyReport.keys[i] = k;
                    break;
                }
            }
            if (i == 6) {
                return 0;
            }   
        }
    } else {
        //not a modifier and not a key
        return 0;
    }
    sendReport(&_keyReport);
    return 1;
}

size_t USBHIDKeyboard::releaseRaw(uint8_t k) 
{
    uint8_t i;
    if (k >= 0xE0 && k < 0xE8) {
        // it's a modifier key
        _keyReport.modifiers &= ~(1<<(k-0x80));
    } else if (k && k < 0xA5) {
        // Test the key report to see if k is present.  Clear it if it exists.
        // Check all positions in case the key is present more than once (which it shouldn't be)
        for (i=0; i<6; i++) {
            if (0 != k && _keyReport.keys[i] == k) {
                _keyReport.keys[i] = 0x00;
            }
        }
    } else {
        //not a modifier and not a key
        return 0;
    }

    sendReport(&_keyReport);
    return 1;
}

// press() adds the specified key (printing, non-printing, or modifier)
// to the persistent key report and sends the report.  Because of the way 
// USB HID works, the host acts like the key remains pressed until we 
// call release(), releaseAll(), or otherwise clear the report and resend.
size_t USBHIDKeyboard::press(uint8_t k) 
{
    if (k >= 0x88) {         // it's a non-printing key (not a modifier)
        k = k - 0x88;
    } else if (k >= 0x80) {  // it's a modifier key
        _keyReport.modifiers |= (1<<(k-0x80));
        k = 0;
    } else {                // it's a printing key
        k = _asciimap[k];
        if (!k) {
            return 0;
        }
        if (k & 0x80) {                     // it's a capital letter or other character reached with shift
            // At boot, some PCs need a separate report with the shift key down like a real keyboard.
            if (shiftKeyReports) {
                pressRaw(HID_KEY_SHIFT_LEFT);
            } else {
                _keyReport.modifiers |= 0x02;   // the left shift modifier
            }
            k &= 0x7F;
        }
    }
    return pressRaw(k);
}

// release() takes the specified key out of the persistent key report and
// sends the report.  This tells the OS the key is no longer pressed and that
// it shouldn't be repeated any more.
size_t USBHIDKeyboard::release(uint8_t k) 
{
    if (k >= 0x88) {         // it's a non-printing key (not a modifier)
        k = k - 0x88;
    } else if (k >= 0x80) {  // it's a modifier key
        _keyReport.modifiers &= ~(1<<(k-0x80));
        k = 0;
    } else {                // it's a printing key
        k = _asciimap[k];
        if (!k) {
            return 0;
        }
        if (k & 0x80) {                         // it's a capital letter or other character reached with shift
            if (shiftKeyReports) {
                releaseRaw(k & 0x7F);           // Release key without shift modifier
                k = HID_KEY_SHIFT_LEFT;         // Below, release shift modifier
            } else {
                _keyReport.modifiers &= ~(0x02);    // the left shift modifier
                k &= 0x7F;
            }
        }
    }
    return releaseRaw(k);
}

void USBHIDKeyboard::releaseAll(void)
{
    _keyReport.keys[0] = 0;
    _keyReport.keys[1] = 0; 
    _keyReport.keys[2] = 0;
    _keyReport.keys[3] = 0; 
    _keyReport.keys[4] = 0;
    _keyReport.keys[5] = 0; 
    _keyReport.modifiers = 0;
    sendReport(&_keyReport);
}

size_t USBHIDKeyboard::write(uint8_t c)
{
    uint8_t p = press(c);  // Keydown
    release(c);            // Keyup
    return p;              // just return the result of press() since release() almost always returns 1
}

size_t USBHIDKeyboard::write(const uint8_t *buffer, size_t size) {
    size_t n = 0;
    while (size--) {
        if (*buffer != '\r') {
            if (write(*buffer)) {
              n++;
            } else {
              break;
            }
        }
        buffer++;
    }
    return n;
}

#endif /* CONFIG_TINYUSB_HID_ENABLED */
#endif /* SOC_USB_OTG_SUPPORTED */