QuLogic left a comment

Sometimes, the mouse_release_event ending a pan/zoom can be lost, if itoccurs while the canvas does not have focus (a typical case is when acontext menu is implemented on top of the canvas, see example below);this can result in rather confusing behavior as the pan/zoom continueswhich no mouse button is pressed.  To fix this, always check that thecorrect button is still pressed in the motion_notify_event handlers.To test, use e.g.```from matplotlib import pyplot as pltfrom matplotlib.backends.qt_compat import QtWidgetsdef on_button_press(event):    if event.button != 3:  # Right-click.        return    menu = QtWidgets.QMenu()    menu.addAction("Some menu action", lambda: None)    menu.exec(event.guiEvent.globalPosition().toPoint())fig = plt.figure()fig.canvas.mpl_connect("button_press_event", on_button_press)fig.add_subplot()plt.show()```enter pan/zoom mode, right-click to open the context menu, exit themenu, and continue moving the mouse.