mesh handles not working?

[John W. Eaton]

On  6-Mar-2007, Daniel J Sebald wrote:

| I think that mesh() in CVS isn't working correctly in terms of the
| handles.  It appears the handle from __uiobject_get_handle__.m is
| returning a handle value which is one too high so that every time
| mesh() is called the old surface remains.
| 
| There may also be another problem inside __uiobject_draw_axes__.m
| with surfaces but I can't get that far to isolate things.
| 
| Anyway, I think the problem is near lines 106 to 111, but these
| globals with lock and unlock is too much for me to follow at the
| moment.

All the files that use the globals directly are generated
automatically from the corresponding .in files.  But anyway, those are
all going away in favor of managing the properties in C++.  Doing all
of that bookkeeping in the scripting language was a noble experiment,
but I think the "Matlab language" is just not up to the task.

| Plus I probably wouldn't come up with a good fix.  The
| attached patch is simply to show where the problem lies.  Try the
| following code:
| 
| figure(1);
| x = ones(3,1) * [0:2];
| y = x';
| z = x.*y;
| mesh(x,y,z);
| x = ones(21,1) * [0:20];
| y = x';
| z = x.*y;
| mesh(x,y,z);
| 
| figure(2);
| plot([0:30],-[0:30]);
| plot([0:30],[0:30]);
| 
| Notice how the first lines add another number to the kids list.  The second 
doesn't.

I think the fix is just ot add a call to newplot at the beginning of
mesh.m.

jwe