Ending a QDrag Prematurely - qt

Question

I want my application to terminate all drag and drops in a dragLeaveEvent, without the user releasing the mouse button.
The problem is that the loop suspends all events that could cancel a QDrag while it is happening, even though the documentation states:
"On Linux and Mac OS X, the drag and drop operation can take some
time, but this function does not block the event loop. Other events
are still delivered to the application while the operation is
performed. On Windows, the Qt event loop is blocked during the
operation. However, QDrag.exec() on Windows causes processEvents() to
be called frequently to keep the GUI responsive. If any loops or
operations are called while a drag operation is active, it will block
the drag operation."
Because of this, I cannot call events which would end the drag.
So far, I've tried what is suggested here, as seen in the code. I'm using PyQt5, but if a solution works in Qt it should work in PyQt.
Edit: I'm a little scared to delete the drag, as the scene does not own it. I suppose I could set it up to own it though, but as was posted here it should not work.
Edit2: Added code with my non-working attempts to fix it. I'd really like to solve this issue without having to make my own drag-drop framework. Also trimmed post.
import sys
from PyQt5.QtWidgets import (QMainWindow, QApplication,
QGraphicsView, QGraphicsScene, QGraphicsWidget, QGraphicsRectItem)
from PyQt5.QtCore import (QMimeData, Qt, QByteArray, QCoreApplication,
QEvent, QPoint)
from PyQt5.QtGui import QBrush, QColor, QDrag, QPen, QMouseEvent
class MainWindow(QMainWindow):
def __init__(self):
super().__init__()
self.scene = CustomScene()
self.view = QGraphicsView(self.scene, self)
self.setGeometry(100, 100, 600, 600)
self.view.setGeometry(0, 0, 500, 500)
self.show()
class CustomScene(QGraphicsScene):
def __init__(self):
super().__init__()
self.customWidgets = []
for i in range(5):
newItem = CustomDragWidget()
self.addItem(newItem)
self.customWidgets.append(newItem)
newItem.setGeometry(i * 50, i * 50, 50, 50)
def dragLeaveEvent(self, event):
# Work your magic here. I've tried the following:
# 1)
self.customWidgets[0].dropEvent(event)
# 2)
self.dropEvent(event)
# 3)
eve = QMouseEvent(QEvent.MouseButtonRelease, QPoint(0, 0), Qt.LeftButton, Qt.LeftButton, Qt.NoModifier)
QCoreApplication.sendEvent(self.views()[0], eve)
QCoreApplication.processEvents()
# 4)
eve = QMouseEvent(QEvent.MouseButtonRelease, QPoint(0, 0), Qt.LeftButton, Qt.LeftButton, Qt.NoModifier)
QCoreApplication.sendEvent(self.customWidgets[0], eve)
QCoreApplication.processEvents()
def dropEvent(self, QGraphicsSceneDragDropEvent):
# a dummy dropevent that tries to stop the drop, but doesnt work
QGraphicsSceneDragDropEvent.accept()
class CustomDragWidget(QGraphicsWidget):
def __init__(self,):
super().__init__()
self.squareItem = QGraphicsRectItem()
self.squareItem.setBrush(QBrush(QColor(Qt.blue)))
self.squareItem.setPen(QPen(QColor(Qt.black), 2))
self.squareItem.setRect(0, 0, 50, 50)
self.squareItem.setParentItem(self)
self.setAcceptDrops(True)
def mousePressEvent(self, event):
mime = QMimeData()
itemData = QByteArray()
mime.setData('application/x-dnditemdata', itemData)
drag = QDrag(self)
drag.setMimeData(mime)
drag.exec(Qt.MoveAction)
def dropEvent(self, event):
event.accept()
if __name__ == '__main__':
app = QApplication(sys.argv)
win = MainWindow()
win.show()
sys.exit(app.exec_())

Answer 1

This is a little bit hackish, but it seems to work (on Linux, anyway):
def dragLeaveEvent(self, event):
QCoreApplication.postEvent(self,
QKeyEvent(QEvent.KeyPress, Qt.Key_Escape, Qt.NoModifier))