[Qt-interest] Gestures

[Carl Snellman]

Thanks Luiz,

I got now a bit forward, now I see my gesture recognizer getting those events.

The documentation does not mention anything that the items need to
accept touchevents....

Thank you again,
Carl

On Mon, Aug 9, 2010 at 12:47 PM, Luiz Geovani Vier <lgvier at gmail.com> wrote:
> Hi Carl,
> Are you accepting touch events? You might want to check if you are receiving
> them properly.
> Also, in case you're using a QGraphicsScene, you also have to accept the
> Touch down event on the items to start receiving gestures.
> I sent a gestures-related question to this list yesterday; it contains a
> sample app that you could use, as it contains a custom Pan gesture
> recognizer.
> Hope that helps...
> -Geovani
> On Mon, Aug 9, 2010 at 3:28 PM, Carl Snellman <carl.snellman at gmail.com>
> wrote:
>>
>> Hey,
>>
>> sorry for repost, but I'm now blocked with the basic gesture
>> recognizer not working. If there is anyone out there having any
>> suggestions, I would be more than happy to hear...
>>
>> Thanks,
>> Carl
>>
>> ---------- Forwarded message ----------
>> From: Carl Snellman <carl.snellman at gmail.com>
>> Date: Fri, Aug 6, 2010 at 3:10 PM
>> Subject: Re: [Qt-interest] Gestures
>> To: qt-interest at trolltech.com
>>
>>
>> Hey Denis and others,
>>
>> (apologies for bringing such old thread back alive; I've been working
>> on other stuff, and now got back to this)
>>
>> I tried to implement my own gesture recognizer and bumped to a problem
>> right away.
>> I implemented the following recognizer:
>> >>>>>>>>>>>>>>>>>>>>>.
>> class MyTapGesture : public QTapGesture {
>> };
>>
>> class MyGestureRecognizer : public QGestureRecognizer {
>> public:
>>    virtual QGesture *create ( QObject * target ) {
>>        qDebug() << "MyGestureRecognizer::create";
>>        return new MyTapGesture;
>>    }
>>    virtual void reset ( QGesture * gesture ) {
>>        qDebug() << "MyGestureRecognizer::reset";
>>    }
>>
>>    virtual Result recognize(QGesture * gesture, QObject * watched,
>> QEvent * event) {
>>        qDebug() << "MyGestureRecognizer::recognize";
>>        return QGestureRecognizer::Ignore;
>>    }
>> };
>> <<<<<<<<<<<<<<<<<<<<<<<<<<<
>>
>> then I registered the recognizer:
>>
>> Qt::GestureType type = QGestureRecognizer::registerRecognizer(new
>> MyGestureRecognizer);
>> qDebug() << "Type:" << type;
>>
>>
>> The problem is that MyGestureRecognizer::recognize(..) never gets called!
>> I tried the app on Lenovo Ideapad S10-T3, and the imagegestures app
>> works fine otherwise, I get pan and pinch gestures.
>>
>> The MyGestureRecognizer::create(..) gets called once. I also disabled
>> grabbing all other gestures:
>> >>>>>>>>>>>
>> //! [enable gestures]
>> //    grabGesture(Qt::PanGesture);
>> //    grabGesture(Qt::PinchGesture);
>> //    grabGesture(Qt::SwipeGesture);
>>    grabGesture(Qt::CustomGesture);
>> //! [enable gestures]
>> <<<<<<<<<<<<<
>> No love, whatever I do. This all in the "imagestures" example app. The
>> whole project is avaiable at
>> http://www.4shared.com/file/NEetzicb/imagegestures.html
>>
>>
>> On Mon, Jun 7, 2010 at 3:20 AM, Denis Dzyubenko <shadone at gmail.com> wrote:
>> > single-touch device and touch are only sent as mouse events. Gestures
>> > that come with Qt are touch-based, implemented using QTouchEvents, so
>> > they wont work out of the box there.
>>
>> What I've understood is the MyGestureRecognizer should get a chance to
>> evaluate every input event, to recognize gestures from stream of
>> events. What is unclear to me is that what events are being passed to
>> gesture recognizers? QTouchEvents where mentioned above. Are mouse
>> events also passed to recognizers?
>> If not, it will be impossible to use gestures on say X11 systems, that
>> apparently provide only mouse events, and IMO this makes gestures
>> pretty much useless. (devices providing touch events are not that
>> common yet). Also, I dont see why we would not be able to recognize
>> all gestures (other than QPinchGesture) from mouse events? Why it
>> hasn't been implemented that way now? Definitely would be usefull if
>> gestures would work from mouse events out-of-the-box, if developer
>> wants to use them.
>>
>> Thanks,
>> Carl
>>
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