Change cursor on widget mouseover (PyGObject)

Question

I've been trying to change the cursor on Gtk.ScrolledWindow() (it has an image widget in it) mouseover:

import gi
gi.require_version('Gtk', '3.0')
from gi.repository import Gtk, Gdk, GdkPixbuf

class MainWindow(Gtk.Window):

  def __init__(self):
    Gtk.Window.__init__(self, title = "Test")

    self.maximize()

    grid = Gtk.Grid()
    self.add(grid)

    scrolled = Gtk.ScrolledWindow()
    scrolled.set_hexpand(True)
    scrolled.set_vexpand(True)
    scrolled.connect("motion-notify-event", self.mousemove)
    grid.add(scrolled)

    pixbuf = GdkPixbuf.Pixbuf.new_from_file("anyimage.jpg")
    image = Gtk.Image.new_from_pixbuf(pixbuf)
    scrolled.add(image)

  def mousemove(self, widget, event):
    print("Mouseover triggered")
    circle = Gdk.Cursor(Gdk.CursorType.CIRCLE)
    widget.get_window().set_cursor(circle)

win = MainWindow()
win.connect("destroy", Gtk.main_quit)
win.show_all()

The event is triggered but instead of a circle the cursor is displayed as an arrow with a "disabled" symbol as its subscript.

Am I missing something here?

Answer 1

I was wrong, it's not a bug. It's entirely up to the cursor theme in use. I was recommended to stick to cursors listed by name here:

https://developer.gnome.org/gdk3/3.24/gdk3-Cursors.html#gdk-cursor-new-from-name

Those correspond to CSS and are most likely to be available across cursor themes.