QGraphicsScene drag and drop
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Reimplementing virtual methods is always tricky. I think your problem is, is that your Scene implementation doesn't call the base class implementation of the virtual methods you reimplemented. This way, you disabled Qt's own event propagation mechanisms that are implemented in the base classes.
Unless you're sure you should not, always call the base class implementation in your reimplementation of a virtual class. It may do actual work you were not aware of.
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Thanks for the answer I thought that to.
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[quote author="Andre" date="1294921290"]
[quote author="Olorin5800" date="1294919561"]Thanks for the answer I thought that to.[/quote]
But...? That doesn't solve your issue?[/quote]
Can't test right now but looking through the qt source code not calling the base implementation seems to be the problem in the qgraphicsscene implementation of the drag move event is where the forwarding is taking place my code overrides the event and never calls the parent.
[quote author="Volker" date="1294920632"]What is the error on //here?
Is the method called at all?
Is it called but you do not get into accepting the event?[/quote]No error the method where t i put the comment is not called in the item class if overriding the scene implementation of drag enter, drag move and drop events.
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gnarf ... of course it does not call the dragEnterEvent method of your item if the scene already accepts the drag!
If you eventually drop your drag - there is only one object to receive it - it's that one, that accepted the dragEnter/dragMove events.
Hypothetically, if you allowed both to dragEnter, which one should get the drop at the end? Both? The top one (on z-order)? The bottom one? Rolling dices?
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[quote author="Volker" date="1294923392"]gnarf ... of course it does not call the dragEnterEvent method of your item if the scene already accepts the drag!
If you eventually drop your drag - there is only one object to receive it - it's that one, that accepted the dragEnter/dragMove events.
Hypothetically, if you allowed both to dragEnter, which one should get the drop at the end? Both? The top one (on z-order)? The bottom one? Rolling dices?[/quote]
Yes I realized that ( after posting :D ) anyway modifing the above code like so to allow graphics scene to forward the event
@void Scene::dragMoveEvent(QGraphicsSceneDragDropEvent *event)
{
QGraphicsScene::dragMoveEvent(event);
SourceWidget *source = qobject_cast<SourceWidget *>(event->source());
if(source) {
event->setDropAction(Qt::CopyAction);
event->accept();
}}
void Scene::dropEvent(QGraphicsSceneDragDropEvent *event)
{
QGraphicsScene::dropEvent(event);
SourceWidget *source = qobject_cast<SourceWidget *>(event->source());
if(source) {
createWidget(static_castWidget::WidgetType(event->mimeData()->text().toInt()), event->scenePos());
event->setDropAction(Qt::CopyAction);
event->accept();
}
}@the drag enter and drop events are called for the items correctly.
as for who accepts the drop in my application that depend on the contents of mime type (scene accepts images for example and item accept text drops).Thanks everyone for your help.
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Yes it works now.