Qt embedded, multitouch and tslib with multitouch support

[webquinty]

Hello,

I am interesting in qt embedded with gestures.
At this moment, I use qt 4.8.4 with tslib using a multitouch screen configurate as single touch an it works fine.

Now I replace my old tslib library with a new one that it has a multitouch support.
Using ts_test with debug, library detect all points with your ID and position.

But now, I dont known how use this in Qt.
All touch examples only use one finger. If I use two fingers, only one touch is active.

Has anybody any experience using multitouch with Qt embedded??

Bestregards

[webquinty]

Hello again,

After read several pages, My conclusion is that TSLIB is not the correct plugin to handle multi touch points.

bool QWSTslibMouseHandlerPrivate::get_sample(struct ts_sample *sample)
    {
        if (!calibrated)
            return (ts_read_raw(dev, sample, 1) == 1);
 
        return (ts_read(dev, sample, 1) == 1);
    }
 
    int StackCnt;
    void QWSTslibMouseHandlerPrivate::readMouseData()
    {
        if (!qt_screen)
            return;
 
        for(;;) {
            struct ts_sample sample = lastSample;
            bool pressed = wasPressed;
 
            // Fast return if there's no events.
            if (!get_sample(&sample))
                return;
 
            pressed = (sample.pressure > 0);
 
            // Only return last sample unless there's a press/release event.
            while (pressed == wasPressed) {
                if (!get_sample(&sample))
                    break;
                pressed = (sample.pressure > 0);
            }
 
            // work around missing coordinates on mouse release in raw mode
            if (!calibrated && !pressed && sample.x == 0 && sample.y == 0) {
                sample.x = lastSample.x;
                sample.y = lastSample.y;
            }
 
            int dx = sample.x - lastSample.x;
            int dy = sample.y - lastSample.y;
 
            // Remove small movements in oppsite direction
            if (dx * lastdx < 0 && qAbs(dx) < jitter_limit) {
                sample.x = lastSample.x;
                dx = 0;
            }
            if (dy * lastdy < 0 && qAbs(dy) < jitter_limit) {
                sample.y = lastSample.y;
                dy = 0;
            }
 
            if (wasPressed == pressed && dx == 0 && dy == 0)
                return;
 
    #ifdef TSLIBMOUSEHANDLER_DEBUG
            qDebug() << "last" << QPoint(lastSample.x, lastSample.y)
                     << "curr" << QPoint(sample.x, sample.y)
                     << "dx,dy" << QPoint(dx, dy)
                     << "ddx,ddy" << QPoint(dx*lastdx, dy*lastdy)
                     << "pressed" << wasPressed << pressed;
    #endif
 
            lastSample = sample;
            wasPressed = pressed;
            if (dx != 0)
                lastdx = dx;
            if (dy != 0)
                lastdy = dy;
 
            const QPoint p(sample.x, sample.y);
            if (calibrated) {
                // tslib should do all the translation and filtering, so we send a
                // "raw" mouse event
                handler->QWSMouseHandler::mouseChanged(p, pressed);
            } else {
                handler->sendFiltered(p, pressed);
            }
        }
    }

bool QWSTslibMouseHandlerPrivate::get_sample(struct ts_sample *sample)
    {
        if (!calibrated)
            return (ts_read_raw(dev, sample, 1) == 1);
     
        return (ts_read(dev, sample, 1) == 1);
    }
     
    int StackCnt;
    void QWSTslibMouseHandlerPrivate::readMouseData()
    {
        if (!qt_screen)
            return;
     
        for(;;) {
            struct ts_sample sample = lastSample;
            bool pressed = wasPressed;
     
            // Fast return if there's no events.
            if (!get_sample(&sample))
                return;
     
            pressed = (sample.pressure > 0);
     
            // Only return last sample unless there's a press/release event.
            while (pressed == wasPressed) {
                if (!get_sample(&sample))
                    break;
                pressed = (sample.pressure > 0);
            }
     
            // work around missing coordinates on mouse release in raw mode
            if (!calibrated && !pressed && sample.x == 0 && sample.y == 0) {
                sample.x = lastSample.x;
                sample.y = lastSample.y;
            }
     
            int dx = sample.x - lastSample.x;
            int dy = sample.y - lastSample.y;
     
            // Remove small movements in oppsite direction
            if (dx * lastdx < 0 && qAbs(dx) < jitter_limit) {
                sample.x = lastSample.x;
                dx = 0;
            }
            if (dy * lastdy < 0 && qAbs(dy) < jitter_limit) {
                sample.y = lastSample.y;
                dy = 0;
            }
     
            if (wasPressed == pressed && dx == 0 && dy == 0)
                return;
     
    #ifdef TSLIBMOUSEHANDLER_DEBUG
            qDebug() << "last" << QPoint(lastSample.x, lastSample.y)
                     << "curr" << QPoint(sample.x, sample.y)
                     << "dx,dy" << QPoint(dx, dy)
                     << "ddx,ddy" << QPoint(dx*lastdx, dy*lastdy)
                     << "pressed" << wasPressed << pressed;
    #endif
     
            lastSample = sample;
            wasPressed = pressed;
            if (dx != 0)
                lastdx = dx;
            if (dy != 0)
                lastdy = dy;
     
            const QPoint p(sample.x, sample.y);
            if (calibrated) {
                // tslib should do all the translation and filtering, so we send a
                // "raw" mouse event
                handler->QWSMouseHandler::mouseChanged(p, pressed);
            } else {
                handler->sendFiltered(p, pressed);
            }
        }
    }

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I could read only one sample and it can not handle slots and trancking_id, then, in my opinion, it is impossible to handle a multitouch events with this code.
If I want to touch two buttons, I think I need to handle MT_SLOT and MT_TRACKING_ID to determinate how many fingers are pressed touch screen.

Finally, i am going to create my own mouse handler plugin but I only have a bit problem.
I dont known how to send a touchevevnt from plugin. somebody knowns?

qt_translateRawTouchEvent(QWidget *window, QTouchEvent::DeviceType deviceType, const QList<QTouchEvent::TouchPoint> &touchPoints);

qt_translateRawTouchEvent(QWidget *window, QTouchEvent::DeviceType deviceType, const QList<QTouchEvent::TouchPoint> &touchPoints);

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I have found this function but it need pointer to widget, but in my new mouse plugin I dont known the pointer to widget.

Is it possible to setup widget as NULL and qt_translateRawTouchEvent send touch events to upper layer???
I have tried with some examples but it doesnt receive any touch events.

Best regards.