usbmonitor.cpp

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/*
 * 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 3 of the License, 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; if not, see <http://www.gnu.org/licenses/>
 *
 * Additional note on redistribution: The copyright and license notices above
 * must be maintained in each individual source file that is a derivative work
 * of this source file; otherwise redistribution is prohibited.
 */

#include "usbmonitor.h"
#include <QDebug>

#include "rawhid.h"

//#define USB_MON_DEBUG
#ifdef USB_MON_DEBUG
#define USB_MON_QXTLOG_DEBUG(...) qDebug() << __VA_ARGS__
#else // USB_MON_DEBUG
#define USB_MON_QXTLOG_DEBUG(...)
#endif // USB_MON_DEBUG

#define printf USB_MON_QXTLOG_DEBUG

USBMonitor *USBMonitor::m_instance = nullptr;

USBMonitor::USBMonitor(QObject *parent)
    : QObject(parent)
{
    m_instance = this;

    qRegisterMetaType<USBPortInfo>();

    hid_init();

    connect(&periodicTimer, &QTimer::timeout, this, &USBMonitor::periodic);
    periodicTimer.setSingleShot(true);
    periodicTimer.start(150);

    enumerating = false;
    prevDevList = NULL;
}

USBMonitor::~USBMonitor()
{
    hid_free_enumeration(prevDevList);
}

void USBMonitor::periodic()
{
    // This is here to catch recursion, from the process_pending_events in
    // hidapi on OS X.
    if (enumerating) {
        return;
    }

    enumerating = true;

    struct hid_device_info *hidDevList = hid_enumerate(0, 0, prevDevList);

    QList<USBPortInfo> unseenDevices = knowndevices;
    QList<USBPortInfo> newDevices;

    bool didAnything = false;

    for (struct hid_device_info *hidDev = hidDevList; hidDev != NULL; hidDev = hidDev->next) {
        USBPortInfo info;

        info.vendorID = hidDev->vendor_id;
        info.productID = hidDev->product_id;
        info.bcdDevice = hidDev->release_number;
        info.serialNumber = QString::fromWCharArray(hidDev->serial_number);
        info.product = QString::fromWCharArray(hidDev->product_string);
        info.manufacturer = QString::fromWCharArray(hidDev->manufacturer_string);
        info.path = QString::fromLatin1(hidDev->path);

        if (!unseenDevices.removeOne(info)) {
            newDevices.append(info);
        }
    }

    prevDevList = hidDevList;

    enumerating = false;

    foreach (USBPortInfo item, unseenDevices) {
        didAnything = true;

        qDebug() << "Removing " << item.vendorID << item.productID << item.bcdDevice
                 << item.serialNumber << item.product << item.manufacturer;

        knowndevices.removeOne(item);

        emit deviceRemoved(item);
    }

    foreach (USBPortInfo item, newDevices) {
        if (!knowndevices.contains(item)) {
            didAnything = true;

            qDebug() << "Adding " << item.vendorID << item.productID << item.bcdDevice
                     << item.serialNumber << item.product << item.manufacturer;

            knowndevices.append(item);

            emit deviceDiscovered(item);
        }
    }

    if (didAnything) {
        qDebug() << "usbmonitor detection cycle complete.";
    }

    /* Ensure our signals are spaced out.  Also limit our CPU consumption */
    periodicTimer.start(150);
}

QList<USBPortInfo> USBMonitor::availableDevices()
{
    periodic();
    return knowndevices;
}

QList<USBPortInfo> USBMonitor::availableDevices(int vid, int pid, int bcdDeviceMSB,
                                                int bcdDeviceLSB)
{
    periodic();

    QList<USBPortInfo> thePortsWeWant;

    foreach (USBPortInfo port, knowndevices) {
        if ((port.vendorID == vid || vid == -1) && (port.productID == pid || pid == -1)
            && ((port.bcdDevice >> 8) == bcdDeviceMSB || bcdDeviceMSB == -1)
            && ((port.bcdDevice & 0x00ff) == bcdDeviceLSB || bcdDeviceLSB == -1))
            thePortsWeWant.append(port);
    }

    return thePortsWeWant;
}

USBMonitor *USBMonitor::instance()
{
    return m_instance;
}