[Development] QtQuick: Drag pixmap

[Alan Alpert]

On Wed, Jan 22, 2014 at 10:42 AM, Mark Gaiser <markg85 at gmail.com> wrote:
> On Wed, Jan 22, 2014 at 12:11 AM, Fabien Castan <fabcastan at gmail.com> wrote:
>> Hi,
>>
>> Qt 5.2 adds the possibility to use drag&drop from/to external applications.
>> To allows to drag an item from QML to an external application, we can't
>> simply set a target item, because we want to see this item ouside of the qml
>> window.
>> In Qt, we could set a pixmap on drag events:
>> http://qt-project.org/doc/qt-4.8/qdrag.html#setPixmap
>>
>> I don't see something like that in QtQuick (Qt 5.2):
>> http://qt-project.org/doc/qt-5/qml-qtquick-drag.html
>>
>> Is there a solution to do such thing in pure QML?
>>
>> Regards,
>> Fabien
>
> While browsing through the code (qquickdrag.cpp) i found these two
> commented lines:
>     // TODO: how to handle drag image?
>     // drag->setPixmap(iconPixmap);
>
> Along with that no more function for "setPixmap" that is exposed to QML.
> That makes me fear that the setPixmap property is not there anymore.
>
> Odd, since it would be an API break which i can't really imagine from Qt.
>
> I hope someone else more knowledgeable in this area can chime in?

Use of direct QPixmaps in QML is discouraged, because there's no real
way to manage the memory of the pointer. If there were a QObject or
QJSValue wrapper around QPixmap then a setPixmap could be added,
similar to the setPixmap in QDrag (although not actually accepting a
QPixmap type).

So without a good solution handy, that part has been left "for later".

--
Alan Alpert