how to get both qgraphicsscene and qgraphicsitem drops? - qt

Question

I have some items on a qgraphicsscene and I want to be able to drag and drop an item onto another or onto a blank part of the scene. Depending on whether the drop occurs over another item or over a blank part of the scene two different things happen. How to approach this? i have implemented scene and graphics item drag and drop. but this approach not working, by this both scene and item handles drop events, for me only one should handle based on dropping position.
Below is working example.
when i drag rect1 and droppped on rect2, i should get rect2 drop event.
when i drag rect1 and droppped on blank scene, i should get scene drop event.
graphicsview.h
class GraphicsView : public QGraphicsView
{
public:
GraphicsView();
};
graphicsview.cpp
GraphicsView::GraphicsView()
{
//setAcceptDrops(true);
}
graphicsScene.h
class GraphicsScene : public QGraphicsScene
{
public:
GraphicsScene();
protected:
void dragEnterEvent(QGraphicsSceneDragDropEvent *event);
void dragMoveEvent(QGraphicsSceneDragDropEvent *event);
void dropEvent(QGraphicsSceneDragDropEvent *event);
};
graphicsScene.cpp
GraphicsScene::GraphicsScene()
{
}
void GraphicsScene::dragEnterEvent(QGraphicsSceneDragDropEvent *event)
{
qDebug() << "Scene::dragEnterEvent";
event->acceptProposedAction();
}
void GraphicsScene::dragMoveEvent(QGraphicsSceneDragDropEvent *event)
{
qDebug() << "Scene::dragMoveEvent";
event->acceptProposedAction();
}
void GraphicsScene::dropEvent(QGraphicsSceneDragDropEvent *event)
{
qDebug() << "Scene::dropEvent";
event->acceptProposedAction();
}
graphicsRectItem.h
class GraphicsRectItem : public QGraphicsRectItem
{
public:
GraphicsRectItem();
static QString MimeType() { return QStringLiteral("job/x-job"); }
protected:
void mousePressEvent(QGraphicsSceneMouseEvent *event);
void mouseMoveEvent(QGraphicsSceneMouseEvent *event);
void mouseReleaseEvent(QGraphicsSceneMouseEvent *event);
void dragEnterEvent(QGraphicsSceneDragDropEvent *event);
void dragMoveEvent(QGraphicsSceneDragDropEvent *event);
void dropEvent(QGraphicsSceneDragDropEvent *event);
};
graphicsRectItem.cpp
GraphicsRectItem::GraphicsRectItem()
{
setAcceptDrops(true);
}
void GraphicsRectItem::mousePressEvent(QGraphicsSceneMouseEvent *event)
{
qDebug() << "RectItem::mousePressEvent";
setCursor(Qt::ClosedHandCursor);
}
void GraphicsRectItem::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
{
qDebug() << "RectItem::mouseMoveEvent";
if (QLineF(event->screenPos(), event-
>buttonDownScreenPos(Qt::LeftButton))
.length() < QApplication::startDragDistance()) {
QGraphicsRectItem::mouseMoveEvent(event);
return;
}
qDebug() << "drag before executed";
QByteArray itemData;
QString m_jobName = "rect";
DataStream dataStream(&itemData, QIODevice::WriteOnly);
dataStream << m_jobName ;
QMimeData *mimeData = new QMimeData;
mimeData->setData(GraphicsRectItem::MimeType(), itemData);
QDrag *drag = new QDrag(event->widget());
drag->setMimeData(mimeData);
drag->exec();
qDebug() << "drag executed";
setCursor(Qt::OpenHandCursor);
}
void GraphicsRectItem::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
{
qDebug() << "RectItem::mouseReleaseEvent";
setCursor(Qt::OpenHandCursor);
}
void GraphicsRectItem::dragEnterEvent(QGraphicsSceneDragDropEvent *event)
{
qDebug() << "RectItem::dragEnterEvent";
event->acceptProposedAction();
}
void GraphicsRectItem::dragMoveEvent(QGraphicsSceneDragDropEvent *event)
{
qDebug() << "RectItem::dragMoveEvent";
event->acceptProposedAction();
}
void GraphicsRectItem::dropEvent(QGraphicsSceneDragDropEvent *event)
{
qDebug() << "RectItem::dropEvent";
event->acceptProposedAction();
}
Mainwindow.cpp
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
m_pView = new GraphicsView;
m_pScene = new GraphicsScene;
m_pView->setScene(m_pScene);
GraphicsRectItem *rect1 = new GraphicsRectItem;
rect1->setRect(10,10,55,55);
GraphicsRectItem *rect2 = new GraphicsRectItem;
rect2->setRect(75,10,55,55);
m_pScene->addItem(rect1);
m_pScene->addItem(rect2);
this->setCentralWidget(m_pView);
}
MainWindow::~MainWindow()
{
delete ui;
}