On Thu, 2008-02-07 at 11:19 +0200, Tero Saarni wrote:
> On Feb 7, 2008 10:04 AM, Tero Saarni <[EMAIL PROTECTED]> wrote:
> > Here's an another example. It has Screen class based on clutter.Group
> > that contains just a label. When pressing a key the old Screen is
> > faded out, removed from the stage and finally new Screen enters the
> > stage. Old Screens never seem to get garbage collected.
>
> Below is modified version with garbage collection working ok. This
> one does not use clutter.effect_fade() helper function but instead
> creates clutter.BehaviourOpacity() which is stored in global variable.
> That seems to prevent reference cycles.
>
> However when implementing animation in Screen class itself and storing
> BehaviourOpacity as a member variable (instead of global variable;
> every widget of course needs to have it's own behaviour) I've caused
> an reference cycle again...
>
>
> current_screen = None
> counter = 1
> behaviour = None
> def on_key_press_event(a,b):
> global behaviour
> timeline = clutter.Timeline(duration=300)
> alpha = clutter.Alpha(timeline, clutter.ramp_inc_func)
> behaviour = clutter.BehaviourOpacity(alpha=alpha, opacity_start=255,
> opacity_end=0)
again, you are recreating a behaviour all the time. I'm afraid this is
entirely python, as the underlying C library does not leak references
and the pyclutter bindings for behaviours are completely autogenerated.
if I update on_key_press_event() to this:
def on_key_press_event(a,b):
global behaviour
timeline = None
if not behaviour:
timeline = clutter.Timeline(duration=300)
alpha = clutter.Alpha(timeline, clutter.ramp_inc_func)
behaviour = clutter.BehaviourOpacity(alpha=alpha, opacity_start=255,
opacity_end=0)
behaviour.apply(current_screen)
timeline.connect('completed', on_fade_out_completed)
else:
timeline = behaviour.get_alpha().get_timeline()
assert(timeline != None)
timeline.start()
return True
I can't see any leakage.
ciao,
Emmanuele.
--
Emmanuele Bassi, OpenedHand Ltd.
Unit R, Homesdale Business Centre
216-218 Homesdale Rd., Bromley - BR12QZ
http://www.o-hand.com
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