Re: NSTableView limitations?

FROM : David Christensen
DATE : Wed Dec 22 20:36:24 2004

Alexey,

I have had a circumstance where the scrolling view runs into problems
with huge data views -- turns out it was a problem with the float
representing the coordinates running out of precision.

I don't know off-hand at what point the float loses its precisions, but
I assume it is the maximal value of the mantissa (23 bits, as google
just informed me...).

That would mean that 8388608 would be the highest integer addressable
in this case, so if your table allocated 20 pixels per row you would be
limited to 419430.4 rows without visual distortion.

You may be able to get NSScroller to treat its coordinates as doubles
or integers, in which case you could have a view into a partition of
the total set, but  I pretty much moved on to something else and never
got it working.

Regards,

David
-----
David Christensen
Founder and CTO
Yin Yan Software

On Dec 22, 2004, at 1:12 PM, Alexey Zakhlestine wrote:

> Hi!
>
> What is the limitation of NSTableView for columns and rows?
>
> Is it 2147483647? (I assume it uses a signed int32, because that's what
> it returns for "numberOfRows:" method)
>
> or can it safely use values up to 4294967295?
>
> or, meybe, the safe limit is smaller, because of some internal design
> problem?
>
> I ask all this, because I try to put really lot of date in NSTableView,
> and starting at some point it draws some strange garbage of
> characters..
> I just wonder, what that limit is..
>
> It is difficult to locate the border-point visually :-/
>
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