[Qt-interest] QTouchEvent/QGestureEvent propagation

[Wathek LOUED]

I see Sean thank you so much I had found an other way but it doesn't work
very well. I thought that since I'm using QGraphicsView/QGrahicsScene and
QGraphicsObject I could try to cast the "object" in
QGestreRecognizer::recognize(QGesture *state, QObject *object, QEvent
*event)

I try to do a static_cast<QGraphicsObject *>(object) and see if the item
inherits QGraphicsObject if so I get its scene and then I call the
QGraphicsScene::itemAt function with the QTouchPoint position and I check if
it's the same item as the casted object or not.

And If the object doesn't inherits QGraphicsObject that means that it's
probably the scene or the view.

But it seems that there's some fix to do cause it doesn't really work well.


On Mon, Apr 11, 2011 at 3:47 AM, Sean Hayes <sean.t.hayes at vanderbilt.edu>wrote:

> I agree, the order the events are received in within the QGraphicsView is
> counter intuitive.
>
> I had a problem similar to this a while ago and I think I solved it by
> adding a custom property to all my QGraphicsObjects (something link
> receiveNextGesture). Then within the items I only handled the gesture if
> that property was true. The property was set through my implementation of
> QGraphicsView::sceneEvent(). The pseudocode for the sceneEvent() function
> is:
>
> if the event is a QGestureEvent
>
> if the gesture has a hotspot
>
>  itemList = list of all items at the hotspot (see
> http://doc.qt.nokia.com/latest/qgraphicsview.html#items-2)
> if itemList.size() >= 1
>
>  itemList[0]->receiveNextGesture = true
>
> for all the rest of the items in the list
>
>  itemList[iter]->receiveNextGesture = false
>
>
> On Sun, Apr 10, 2011 at 3:33 PM, Wathek LOUED <wathek at gmail.com> wrote:
>
>> Hi all,
>>
>> I've noticed that the Events in Qt using the
>> QGraphicsView/QGraphicsScene/QGraphicsItem are spread from the QGraphicsView
>> then to the QGraphicsScene and the to the item that got the lowest Z-Index
>> to the most top item.
>>
>> I think that that's a bit weird cause generally when using QTouchEvent and
>> QGesture we look at the most top element so imagine that you programmed a
>> gesture and that that gesture occured at position (x, y) and in that
>> position there's 4 items that are grabbing the same gesture, so it'll be
>> grabbed by all the item and not the top element won't it ?
>>
>> I'm trying to find a way to make it grabbed by only the most top element
>> at the position (x, y) any one could help me for that please ?
>>
>> Thank you so much
>>
>> Sincerely
>> W.L
>>
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>>
>>
>
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