Re: using timers in the GUI

[Jacob Dawid]

> 1) It is somewhat inefficient to be updating the workspace so often.
> From the code, it appears that the workspace tree is rebuilt every
> half second if Octave is sitting idle at the command line.  If one's
> workspace variables become numerous, not a difficult thing, that 
> could
> be a lot of unnecessary machine cycles.  Being event driven is more
> efficient.

That is true, but at the time of development there was no possibility 
to have it work without making major changes (ie. implementing a 
thread-safe event system into octave core).


> One way would be to do a variable-by-variable comparison in the GUI
> code.  A before and after tree, as it were.  Another approach is that
> if John could make the variable table shared memory and include some
> flag for each variable that is changed or added whenever the value of
> that object changes, it might be easier to figure out.  Then again,
> setting such a flag again-and-again within a big loop might be less
> efficient than just doing a before and after variable comparison.
> That design element can be a future project, but I think that using
> some method other than a timer would be a good change early on.

Comparing variable by variable was extremely inefficient for large sets 
of data, as I found out. It was much faster to drop the old data and 
renew it again. Anyways, I agree that your suggestion 1) would be the 
proper way to handle things.