Mouse events in QGraphicsItem

[Kevin Miao]

I'm trying to embed a PlotWidget in a QGraphicsItem, but it seems like mousePress/Move/Release events are being consumed by the container widget and not forwarded to the plot (but hover and scroll events still work as expected). This breaks all click-based functionality of the plot. If I just embed the PlotWidget directly using QGraphicsProxyWidget (and without a container QWidget), then mouse events function correctly. Is there anything that I'm missing in getting the mouse events to register when a PlotWidget is in a embedded QWidget container?

The following snippet should demonstrate the problem:

from PyQt5 import QtWidgets, QtCore, QtGui

import pyqtgraph as pg

import numpy as np

def main():

    app = QtWidgets.QApplication([])

    view = QtWidgets.QGraphicsView()

    scene = QtWidgets.QGraphicsScene(parent=view)

    view.setScene(scene)

    plot = pg.PlotWidget()

    curve = plot.plot()

    # uncomment to disable PlotWidget click functionality

    # container_widget = QtWidgets.QWidget()

    # layout = QtWidgets.QHBoxLayout(container_widget)

    # layout.addWidget(plot)

    # layout.setContentsMargins(0, 0, 0, 0)

    # container_widget.setLayout(layout)

    # plot = container_widget

    xs = list()

    ys = list()

    idx = 0

    def update():

        nonlocal idx

        curve.setData(x=xs, y=ys)

        xs.append(idx)

        ys.append(np.sin(idx / 20))

        idx += 1

        return

    proxy = QtWidgets.QGraphicsProxyWidget()

    proxy.setWidget(plot)

    proxy.setGeometry(QtCore.QRectF(0, 0, 600, 600))

    x, y, w, h = plot.x(), plot.y(), plot.width(), plot.height()

    border_size = 10

    container = QtWidgets.QGraphicsRectItem()

    container.setPen(QtGui.QPen(QtGui.QColor(0, 0, 0)))

    container.setBrush(QtGui.QBrush(QtGui.QColor(100, 100, 100)))

    container.setRect(x - border_size, y - border_size, w + 2 * border_size, h + 2 * border_size)

    proxy.setParentItem(container)

    scene.addItem(container)

    timer = QtCore.QTimer()

    timer.timeout.connect(update)

    timer.start(10)

    view.resize(800, 800)

    view.show()

    app.exec_()

if __name__ == '__main__':

    main()