How to forward Qt Mouse event to QQuickView?

eugeneoei

In my QMainWindow, I have a QFrame and a QWidget that wraps a QQuickView and displays the ui through a qml file.

I am trying to implement a drag and drop functionality where, on mouse-down and mouse-move in the QFrame, a thumbnail follows the cursor's position throughout until mouse-release. The mouse-release will happen within QQuickView.

The hover event within QQuickView has no issues and I can successfully get the hover event. The problem arises when on mouse-down within QFrame followed by a mouse-move into QQuickView, I am unable to get any mouse events in QQuickView.

On the left is the QFrame and the right is the QQuickView.

Hovering in QQuickView independently:

Mouse-down in QFrame and mouse-move into QQuickView:

Any mouse events can only be captured after mouse-release.

These are what I have written so far:

import sys
from PyQt5.QtWidgets import QApplication, QMainWindow, QWidget, QFrame, QLabel, QGridLayout, QVBoxLayout
from PyQt5.QtCore import Qt, QMimeData, QUrl
from PyQt5.QtGui import QDrag, QPixmap
from PyQt5.QtQuick import QQuickView

class MainWindow(QMainWindow):
    def __init__(self, parent=None):
        super().__init__(parent)
        self.centralWidget = QWidget(self)

        gridlayout = QGridLayout(self.centralWidget)
        gridlayout.setContentsMargins(0,0,0,0)
        gridlayout.setHorizontalSpacing(0)
        gridlayout.setVerticalSpacing(0)

        self.setCentralWidget(self.centralWidget)
        self.leftPanel = QVBoxLayout()
        self.rightPanel = QVBoxLayout()

        gridlayout.addLayout(self.leftPanel, 0, 0, 1, 1)
        gridlayout.addLayout(self.rightPanel, 0, 1, 1, 1)
        gridlayout.setSpacing(0)

        self.setStyleSheet("background:grey")
        self.resize(300, 200)
        self.show()

class Left(QFrame):
    def __init__(self):
        super().__init__()
        self.resize(500, 500)
        self.label = QLabel(self)
        self.label.resize(50, 50)

    def mouseMoveEvent(self, e):
        mimeData = QMimeData()
        drag = QDrag(self)
        self.thumbnail = QPixmap('./test.png').scaled(50, 50, Qt.KeepAspectRatio)
        drag.setPixmap(self.thumbnail)
        drag.setMimeData(mimeData)
        drag.exec_(Qt.MoveAction)

class Right(QQuickView):
    def __init__(self, parent=None):
        super().__init__(parent)
        self.rootContext().setContextProperty('Right', self)
        self.setSource(QUrl('./drag.qml'))
        self.setMinimumHeight(200)
        self.setMinimumWidth(150)

if __name__ == '__main__':
    app = QApplication(sys.argv)
    main_window = MainWindow()
    main_window.leftPanel.addWidget(Left())
    main_window.rightPanel.addWidget(QWidget.createWindowContainer(Right()))
    app.exec_()

Based on what I have read from different sources and the Qt documentation, I suppose I have to forward the events from the QFrame to the QQuickView or there seems to be some form of global mouse events to be handled.

How can I go about achieving this?

raven-worx

@eugeneoei said in How to forward Qt Mouse event to QQuickView?:

Based on what I have read from different sources and the Qt documentation, I suppose I have to forward the events from the QFrame to the QQuickView or there seems to be some form of global mouse events to be handled.

no, no event forwarding needed here. You are just listening to wrong events in QML.
Since you start a drag, you should also listen to drag events in QML. See DropArea element and it's containsDrag property.

eugeneoei

@raven-worx you sir saved my life! I cant believe i was stuck at this for 2 days, when it was simply just about using the right object in qml. thanks!