[PD-dev] canvas_* functions and using glist_getcanvas()

[Miller Puckette]

Ok .. commited and pushed to SF...
On Wed, Jul 14, 2010 at 04:18:32PM -0400, Hans-Christoph Steiner wrote:
> 
> Ok, keep me posted.  If that turns out to be wrong, I can change it in  
> a lot of externals in SVN too.
> 
> .hc
> 
> On Jul 14, 2010, at 4:11 PM, Miller Puckette wrote:
> 
> >I think those are all wrong and will try changing them over here :)
> >
> >thanks
> >M
> >
> >On Wed, Jul 14, 2010 at 04:07:16PM -0400, Hans-Christoph Steiner  
> >wrote:
> >>
> >>Sounds like you are saying that calls to canvas_fixlinesfor()
> >>shouldn't have calls to glist_getcanvas() in them.  It seems not very
> >>straightforward, for example, the iemguis included in Pd-vanilla have
> >>this:
> >>
> >>canvas_fixlinesfor(glist_getcanvas(x->x_gui.x_glist), (t_text*)x);
> >>
> >>.hc
> >>
> >>On Jul 14, 2010, at 3:15 PM, Miller Puckette wrote:
> >>
> >>>I think glist_getcanvas() is only appropriate when getting or  
> >>>changing
> >>>properties that are inherited from the containing canvas (whether
> >>>visible
> >>>or not, for example) -- and many canvas_whatever(canvas, object) or
> >>>glist_whatever(canvas, object) calls assume tha the oject is indeed
> >>>in that
> >>>glist itself (glist is synonym for canvas) and will crash if not.
> >>>
> >>>cheers
> >>>Miller
> >>>
> >>>On Wed, Jul 14, 2010 at 01:17:41PM -0400, Hans-Christoph Steiner
> >>>wrote:
> >>>>
> >>>>I've noticed that in GUI objects, its quite common to call the
> >>>>canvas_* functions using glist_getcanvas().  I also just found out
> >>>>that this causes a crash in [envgen] when this is done for
> >>>>canvas_deletelinesfor().  See bug:
> >>>>
> >>>>http://sourceforge.net/tracker/index.php?func=detail&aid=2842897&group_id=55736&atid=478070
> >>>>
> >>>>So it seems to me that glist_getcanvas() should not be called on  
> >>>>the
> >>>>glist before sending it to one of these canvas functions.  I was
> >>>>wondering if this is kind of a blanket rule, and we should be
> >>>>removing
> >>>>the glist_getcanvas() calls in GUI objects.  For example:
> >>>>
> >>>>unauthorized/cooled~/cooled~.c:
> >>>>canvas_deletelinesfor( glist_getcanvas(glist), (t_text *)z);
> >>>>unauthorized/cooled~/cooled~.c:
> >>>>canvas_fixlinesfor( glist_getcanvas( x->x_glist ), (t_text*)x );
> >>>>
> >>>>In ggee/gui/w_envgen.h, I fixed the crasher by replacing:
> >>>>
> >>>> canvas_deletelinesfor(glist_getcanvas(glist), x);
> >>>>
> >>>>with this:
> >>>>
> >>>> canvas_deletelinesfor(glist, x);
> >>>>
> >>>>.hc
> >>>>
> >>>>----------------------------------------------------------------------------
> >>>>
> >>>>"Free software means you control what your computer does. Non-free
> >>>>software means someone else controls that, and to some extent
> >>>>controls
> >>>>you." - Richard M. Stallman
> >>>>
> >>>>
> >>>>
> >>>>_______________________________________________
> >>>>Pd-dev mailing list
> >>>>Pd-dev at iem.at
> >>>>http://lists.puredata.info/listinfo/pd-dev
> >>
> >>
> >>
> >>
> >>
> >>----------------------------------------------------------------------------
> >>
> >>'You people have such restrictive dress for women,? she said,  
> >>hobbling
> >>away in three inch heels and panty hose to finish out another pink-
> >>collar temp pool day.  - ?Hijab Scene #2", by Mohja Kahf
> >>
> 
> 
> 
> 
> 
> ----------------------------------------------------------------------------
> 
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> for machines to execute.
>  - from Structure and Interpretation of Computer Programs
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