[REBOL] Re: Bug in Area
From: media:quazart at: 2-Nov-2001 9:31
----- Original Message -----
From: "Brett Handley" <[brett--codeconscious--com]>
To: <[rebol-list--rebol--com]>
Sent: Friday, November 02, 2001 8:43 AM
Subject: [REBOL] Re: Bug in Area
Hi Brett,
> I must admit I thought that the line-list was part of the VID layer. Now
I'm
> not so sure. I have to agree with Gregg that manually clearning the
> line-list seems odd.
this strangely resembles a cache-coherency thing... when multiple different
things access the same information and there have been changes to that
cached information... its better to clear the cache and not rely on it.
because the others might not be aware of it. This is why the system only
uses the cached information if its still there...
on another note... cache improves speed only when the data remains pretty
static. If you expect to change the lines and recalculate the line list
with every redraw iteration, you'll actually be slowing down refresh A LOT!
my view is that all of this is ok (a part for the bug). There isn't much of
another way to do it... without heavily affecting performance...
> Though I think for performance the programmer should
> have some way to tell the engine to recalculate the cache when he/she has
> finished manipulating the text. For example you might be inserting text
all
> over the place in a large body of text - calculating on each modification
> may be expensive. Calling a function rather than clearing the field
seemed
> more natural to me.
But doesn't it redraws/recalculates only once for all modifications which
you AND others might have performed within the last redraw by re-calculating
it just before drawing?
-MAx
