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/****************************************************************************
**
** usb input device hot plug function
** by sn02241 
**
****************************************************************************/
 
#include "qdevicediscovery_hotplug_p.h"
 
#include <QCoreApplication>
#include <QObject>
#include <QHash>
#include <QDir>
#include <QLoggingCategory>
#include <QtCore/private/qcore_unix_p.h>
 
#include <linux/input.h>
#include <fcntl.h>
 
/* android (and perhaps some other linux-derived stuff) don't define everything
 * in linux/input.h, so we'll need to do that ourselves.
 */
#ifndef KEY_CNT
#define KEY_CNT                 (KEY_MAX+1)
#endif
#ifndef REL_CNT
#define REL_CNT                 (REL_MAX+1)
#endif
#ifndef ABS_CNT
#define ABS_CNT                 (ABS_MAX+1)
#endif
 
#define LONG_BITS (sizeof(long) * 8 )
#define LONG_FIELD_SIZE(bits) ((bits / LONG_BITS) + 1)
 
static bool testBit(long bit, const long *field)
{
    return (field[bit / LONG_BITS] >> bit % LONG_BITS) & 1;
}
 
QT_BEGIN_NAMESPACE
 
Q_LOGGING_CATEGORY(lcDD, "qt.qpa.input")
 
QDeviceDiscovery *QDeviceDiscovery::create(QDeviceTypes types, QObject *parent)
{
    return new QDeviceDiscoveryHotPlug(types, parent);
}
 
QDeviceDiscoveryHotPlug::QDeviceDiscoveryHotPlug(QDeviceTypes types, QObject *parent)
    : QDeviceDiscovery(types, parent),m_fileWatcher(0)
{
    // 初始化文件监听器
    m_fileWatcher = new QFileSystemWatcher(this);
    m_fileWatcher->addPath(QString::fromLatin1(QT_EVDEV_DEVICE_PATH));// "dev/input/"
    connect(m_fileWatcher, SIGNAL(directoryChanged(QString)), this, SLOT(handleHotPlugWatch(QString)));
 
    qCDebug(lcDD) << "hotplug device discovery for type" << types;
}
 
QStringList QDeviceDiscoveryHotPlug::scanConnectedDevices()
{
    m_devices.clear();
    QDir dir;
    dir.setFilter(QDir::System);
 
    // check for input devices
    if (m_types & Device_InputMask) {
        dir.setPath(QString::fromLatin1(QT_EVDEV_DEVICE_PATH));
        foreach (const QString &deviceFile, dir.entryList()) {
            QString absoluteFilePath = dir.absolutePath() + QString::fromLatin1("/") + deviceFile;
            if (checkDeviceType(absoluteFilePath))
                m_devices << absoluteFilePath;
        }
    }
 
    // check for drm devices
    if (m_types & Device_VideoMask) {
        dir.setPath(QString::fromLatin1(QT_DRM_DEVICE_PATH));
        foreach (const QString &deviceFile, dir.entryList()) {
            QString absoluteFilePath = dir.absolutePath() + QString::fromLatin1("/") + deviceFile;
            if (checkDeviceType(absoluteFilePath))
                m_devices << absoluteFilePath;
        }
    }
 
    qCDebug(lcDD) << "Found matching devices" << m_devices;
 
    return m_devices;
}
 
bool QDeviceDiscoveryHotPlug::checkDeviceType(const QString &device)
{
    bool ret = false;
    int fd = QT_OPEN(device.toLocal8Bit().constData(), O_RDONLY | O_NDELAY, 0);
    if (!fd) {
        qWarning() << "Device discovery cannot open device" << device;
        return false;
    }
 
    long bitsKey[LONG_FIELD_SIZE(KEY_CNT)];
    if (ioctl(fd, EVIOCGBIT(EV_KEY, sizeof(bitsKey)), bitsKey) >= 0 ) {
        if (!ret && (m_types & Device_Keyboard)) {
            if (testBit(KEY_Q, bitsKey)) {
                qCDebug(lcDD) << "Found keyboard at" << device;
                ret = true;
            }
        }
 
        if (!ret && (m_types & Device_Mouse)) {
            long bitsRel[LONG_FIELD_SIZE(REL_CNT)];
            if (ioctl(fd, EVIOCGBIT(EV_REL, sizeof(bitsRel)), bitsRel) >= 0 ) {
                if (testBit(REL_X, bitsRel) && testBit(REL_Y, bitsRel) && testBit(BTN_MOUSE, bitsKey)) {
                    qCDebug(lcDD) << "Found mouse at" << device;
                    ret = true;
                }
            }
        }
 
        if (!ret && (m_types & (Device_Touchpad | Device_Touchscreen))) {
            long bitsAbs[LONG_FIELD_SIZE(ABS_CNT)];
            if (ioctl(fd, EVIOCGBIT(EV_ABS, sizeof(bitsAbs)), bitsAbs) >= 0 ) {
                if (testBit(ABS_X, bitsAbs) && testBit(ABS_Y, bitsAbs)) {
                    if ((m_types & Device_Touchpad) && testBit(BTN_TOOL_FINGER, bitsKey)) {
                        qCDebug(lcDD) << "Found touchpad at" << device;
                        ret = true;
                    } else if ((m_types & Device_Touchscreen) && testBit(BTN_TOUCH, bitsKey)) {
                        qCDebug(lcDD) << "Found touchscreen at" << device;
                        ret = true;
                    } else if ((m_types & Device_Tablet) && (testBit(BTN_STYLUS, bitsKey) || testBit(BTN_TOOL_PEN, bitsKey))) {
                        qCDebug(lcDD) << "Found tablet at" << device;
                        ret = true;
                    }
                }
            }
        }
 
        if (!ret && (m_types & Device_Joystick)) {
            long bitsAbs[LONG_FIELD_SIZE(ABS_CNT)];
            if (ioctl(fd, EVIOCGBIT(EV_ABS, sizeof(bitsAbs)), bitsAbs) >= 0 ) {
                if ((m_types & Device_Joystick)
                    && (testBit(BTN_A, bitsKey) || testBit(BTN_TRIGGER, bitsKey) || testBit(ABS_RX, bitsAbs))) {
                    qCDebug(lcDD) << "Found joystick/gamepad at" << device;
                    ret = true;
                }
            }
        }
    }
 
    if (!ret && (m_types & Device_DRM) && device.contains(QString::fromLatin1(QT_DRM_DEVICE_PREFIX)))
        ret = true;
 
    QT_CLOSE(fd);
    return ret;
}
 
void QDeviceDiscoveryHotPlug::handleHotPlugWatch(const QString &path)
{
	if(path.compare(QString::fromLatin1(QT_EVDEV_DEVICE_PATH)))
	{
		return;
	}
 
	QStringList devices;
 
	// 先移除原来的设备
    foreach (const QString &device, m_devices)
        deviceRemoved(device);
 
	// 获取现在的设备
	// 注，这里获取的设备已经经过过滤，原因是在对该类进行实例化的时候
	// 已经传进了筛选参数，如：QDeviceDiscovery::Device_Keyboard
	devices = this->scanConnectedDevices();
 
	// 重新添加设备
    foreach (const QString &device, devices)
        deviceDetected(device);
}
 
QT_END_NAMESPACE

/****************************************************************************
**
** usb input device hot plug function
** by sn02241
**
****************************************************************************/
 
#ifndef QDEVICEDISCOVERY_HOTPLUG_H
#define QDEVICEDISCOVERY_HOTPLUG_H
 
//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists purely as an
// implementation detail.  This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//
 
#include "qdevicediscovery_p.h"
#include <QFileSystemWatcher>
#include <QStringList>
 
QT_BEGIN_NAMESPACE
 
class QDeviceDiscoveryHotPlug : public QDeviceDiscovery
{
    Q_OBJECT
 
public:
    QDeviceDiscoveryHotPlug(QDeviceTypes types, QObject *parent = 0);
    QStringList scanConnectedDevices() Q_DECL_OVERRIDE;
 
private slots:
    void handleHotPlugWatch(const QString &path);
 
private:
    bool checkDeviceType(const QString &device);
 
    // 用于检测鼠标键盘热插拔
    QFileSystemWatcher *m_fileWatcher;
 
	// 原有的设备列表
    QStringList m_devices;
};
 
QT_END_NAMESPACE
 
#endif // QDEVICEDISCOVERY_HOTPLUG_H