source: trunk/src/gui/embedded/qmouseqnx_qws.cpp@ 965

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#include "qplatformdefs.h"
#include "qmouseqnx_qws.h"

#include "qsocketnotifier.h"
#include "qdebug.h"

#include <sys/dcmd_input.h>

#include <errno.h>

QT_BEGIN_NAMESPACE

/*!
    \class QQnxMouseHandler
    \preliminary
    \ingroup qws
    \internal
    \since 4.6

    \brief The QQnxMouseHandler class implements a mouse driver
    for the QNX \c{devi-hid} input manager.

    To be able to compile this mouse handler, \l{Qt for Embedded Linux}
    must be configured with the \c -qt-mouse-qnx option, see the
    \l{Qt for Embedded Linux Pointer Handling}{Pointer Handling} documentation for details.

    In order to use this mouse handler, the \c{devi-hid} input manager
    must be set up and run with the resource manager interface (option \c{-r}).
    Also, Photon must not be running.

    Example invocation from command line: \c{/usr/photon/bin/devi-hid -Pr kbd mouse}
    Note that after running \c{devi-hid}, you will not be able to use the local
    shell anymore. It is suggested to run the command in a shell scrip, that launches
    a Qt application after invocation of \c{devi-hid}.

    To make \l{Qt for Embedded Linux} explicitly choose the qnx mouse
    handler, set the QWS_MOUSE_PROTO environment variable to \c{qnx}. By default,
    the first mouse device (\c{/dev/devi/mouse0}) is used. To override, pass a device
    name as the first and only parameter, for example
    \c{QWS_MOUSE_PROTO=qnx:/dev/devi/mouse1; export QWS_MOUSE_PROTO}.

    \sa {Qt for Embedded Linux Pointer Handling}{Pointer Handling}, {Qt for Embedded Linux}
*/

/*!
    Constructs a mouse handler for the specified \a device, defaulting to \c{/dev/devi/mouse0}.
    The \a driver parameter must be \c{"qnx"}.

    Note that you should never instanciate this class, instead let QMouseDriverFactory
    handle the mouse handlers.

    \sa QMouseDriverFactory
 */
QQnxMouseHandler::QQnxMouseHandler(const QString & /*driver*/, const QString &device)
{
    // open the mouse device with O_NONBLOCK so reading won't block when there's no data
    mouseFD = QT_OPEN(device.isEmpty() ? "/dev/devi/mouse0" : device.toLatin1().constData(),
                          QT_OPEN_RDONLY | O_NONBLOCK);
    if (mouseFD == -1) {
        qErrnoWarning(errno, "QQnxMouseHandler: Unable to open mouse device");
        return;
    }

    // register a socket notifier on the file descriptor so we'll wake up whenever
    // there's a mouse move waiting for us.
    mouseNotifier = new QSocketNotifier(mouseFD, QSocketNotifier::Read, this);
    connect(mouseNotifier, SIGNAL(activated(int)), SLOT(socketActivated()));

    qDebug() << "QQnxMouseHandler: connected.";
}

/*!
    Destroys this mouse handler and closes the connection to the mouse device.
 */
QQnxMouseHandler::~QQnxMouseHandler()
{
    QT_CLOSE(mouseFD);
}

/*! \reimp */
void QQnxMouseHandler::resume()
{
    if (mouseNotifier)
        mouseNotifier->setEnabled(true);
}

/*! \reimp */
void QQnxMouseHandler::suspend()
{
    if (mouseNotifier)
        mouseNotifier->setEnabled(false);
}

/*! \internal

  This function is called whenever there is activity on the mouse device.
  By default, it reads up to 10 mouse move packets and calls mouseChanged()
  for each of them.
*/
void QQnxMouseHandler::socketActivated()
{
    // _mouse_packet is a QNX structure. devi-hid is nice enough to translate
    // the raw byte data from mouse devices into generic format for us.
    _mouse_packet packet;

    int iteration = 0;

    // read mouse events in batches of 10. Since we're getting quite a lot
    // of mouse events, it's better to do them in batches than to return to the
    // event loop every time.
    do {
        int bytesRead = QT_READ(mouseFD, &packet, sizeof(packet));
        if (bytesRead == -1) {
            // EAGAIN means that there are no more mouse events to read
            if (errno != EAGAIN)
                qErrnoWarning(errno, "QQnxMouseHandler: Unable to read from socket");
            return;
        }

        // bytes read should always be equal to the size of a packet.
        Q_ASSERT(bytesRead == sizeof(packet));

        // translate the coordinates from the QNX data structure to Qt coordinates
        // note the swapped y axis
        QPoint pos = mousePos;
        pos += QPoint(packet.dx, -packet.dy);

        // QNX only tells us relative mouse movements, not absolute ones, so limit the
        // cursor position manually to the screen
        limitToScreen(pos);

        // translate the QNX mouse button bitmask to Qt buttons
        int buttons = Qt::NoButton;

        if (packet.hdr.buttons & _POINTER_BUTTON_LEFT)
            buttons |= Qt::LeftButton;
        if (packet.hdr.buttons & _POINTER_BUTTON_MIDDLE)
            buttons |= Qt::MidButton;
        if (packet.hdr.buttons & _POINTER_BUTTON_RIGHT)
            buttons |= Qt::RightButton;

        // call mouseChanged() - this does all the magic to actually move the on-screen
        // mouse cursor.
        mouseChanged(pos, buttons, 0);
    } while (++iteration < 11);
}

QT_END_NAMESPACE