Re: How to capture mouse movements independend of a Window?

[Andreas Stricker <andy knitter ch>]

Yo tomas!

> OK, here is a rough sketch (tested). As soon as the pointer crosses the
> window boundary (inward), it is grabbed (the app changes the cursor's
> appearance to show it). WARNING! IT IS A TRAP! Once your pointer is
> inside, you won't be let out. See to it that you have a console around
> (a virtual console wth ctrl-alt-Fn will do) to kill the app. Keep out of
> reach of children ;-)

You're great. This at least solve the problem that the pointer cannot leave
the application window. One step further.

But the main problem remains: Once the pointer (Pirate!!) touch the border
or the window, the mouse coordinate don't change anymore.

Remember: I need to get the relative mouse movement independend of the
absolute cursor position.

Maybe there is a function to place the cursor in the middle of the window?

I've tested your application and rewrote it in PyGTK. (This one you can
even give to children, the pointer is released after 15 seconds ;-) )

Thank you.

Cheers, Andy

import pygtk
pygtk.require("2.0")
import gobject, gtk

def release_me():
    gtk.main_quit()
    return True

def on_destroy(widget):
    gtk.main_quit()

def on_enter(widget, event):
    if event.type == gtk.gdk.ENTER_NOTIFY:
        cursor = gtk.gdk.Cursor(gtk.gdk.PIRATE)     # Pirates!!
        gtk.gdk.pointer_grab(widget.window, False, gtk.gdk.POINTER_MOTION_MASK,
                             widget.window, cursor, long(event.time))
        gobject.timeout_add(15000, release_me)
    else:
        # leaving: won't happen
        gtk.gdk.pointer_ungrab(long(event.time))
    return False

def on_move(widget, event):
    print "move to:", event.x, event.y

def main():
    w = gtk.Window()
    w.set_title("Grabby")

    w.connect('destroy', on_destroy)
    w.connect('enter-notify-event', on_enter)
    w.connect('motion-notify-event', on_move)

    w.show_all()

    gtk.main()

    gdk.pointer_ungrab(long(event.time))

if __name__ == '__main__':
    main()