Listen to Control + mouse wheel scroll event in Python GTK3

Question

I am building a Python GTK application and I need to listen to the "Ctrl+Mouse wheel" event. I want to implement "zoom" feature in Webview. Do I need to setup an accelerator? If yes, what is the key code for mouse wheel?

There isn't really much documentation on these topics.

Any help?

Thank you.

Answer 1

As it happens many times, After posting in SO I found the solution :)

Here it is:

Listen the "scroll event" on webview:

 self.connect('scroll-event', self.on_scroll)

Signal handler

 def on_scroll(self, widget, event):
    """ handles on scroll event"""

   # Handles zoom in / zoom out on Ctrl+mouse wheel
   accel_mask = Gtk.accelerator_get_default_mod_mask()
   if event.state & accel_mask == Gdk.ModifierType.CONTROL_MASK:
     direction = event.get_scroll_deltas()[2]
     if direction > 0:  # scrolling down -> zoom out
        self.set_zoom_level(self.get_zoom_level() - 0.1)
     else:
        self.set_zoom_level(self.get_zoom_level() + 0.1)

Reference: GDK signal, keypress, and key masks