With uicontrol() tt's not possible to use callbacks with more than one Lhs arg

Reported by Ulrich Koch

-- Bug description --


With uicontrol() tt's not possible to use callbacks with more than one 
Lhs argument.


-- Scilab error message --


-->uicontrol(h,'callback','[txt,val]=testf(''myString'',37)')
 !--error 999
Tcl Error invalid command name "txt,val"
at line      34 of function uicontrol called by :
uicontrol(h,'callback','[txt,val]=testf(''myString'',37)')


-- How to reproduce the bug --


//Define function:
deff('[out1, out2]=testf(in1, in2)',['out1 = in1'; 'out2 = in2'; 'disp
(''Function TestF'')']);
//Create figure with pushbutton:
h=figure(1);
//The next line causes the descripted error
uicontrol(h,'callback','[txt,val]=testf(''myString'',37)');
// while this line works:
uicontrol(h,'callback','txt=testf(''myString'',37)');
// After pressing the pushbutton txt is defined:
// Output of pushbutton:
// Function TestF
// check variable txt:
txt
// Scilab Output:
// txt  =
//
// myString

//-->

assigned to @vincent.couvert

added 4.x and older Bugzilla Minor Windows 2000 and more uicontrol + 1 deleted label

By François VOGEL

uicontrol(h,'callback','[txt,val]=testf(''myString'',37)')

i.e. escaping the brackets removes the error.

But pressing the button does not trigger the function run...

Francois

By Enrico SEGRE

That's because the callback string is substituted evidently twice. This works as expected:

uicontrol(1,'callback','\[txt,val\]=testf(''myString'',37)')

I can't rather understand why single \ do not result in a tcl error.

Enrico

By Enrico SEGRE

see #596 (closed), http://groups.google.com/group/comp.soft-sys.math.scilab/tree/browse_frm/thread/096072d065ecd541/a0627d341a408a3d?rnum=11&hl=en&_done=%2Fgroup%2Fcomp.soft-sys.math.scilab%2Fbrowse_frm%2Fthread%2F096072d065ecd541%2Fd2944a874d74a62b%3Fhl%3Den%26#doc_8d97af1319fb5d7c (and probably some more similar threads, anyway).

By Ulrich Koch

Enrico's solution is working, but addin some spaces as with "'\[ txt, val \] =" has the same effect as Francois' proposal: pressing the button does not trigger the function run.

U.K.

By Enrico SEGRE

That is also logical if you see it in tcl terms and what happens to

SciCallback $name $callback

when the variable $callback expands to a string containing spaces. Alternative solutions for your amusement:

uicontrol(1,'callback','\[txt,\\ val\]=testf(''myString'',37)')

uicontrol(1,'callback','{[txt, val]=testf(''myStr ans =7)}')

that is: also spaces have to be escaped ("\\ " --> "\ " -> " "), or {} enforces literal passing rather than tcl expansion.

Enrico

By Enrico SEGRE

uicontrol(1,'callback','{[txt, val]=testf(''myString'',37)}') //(wrong copy-paste)

By François VOGEL

(In reply to #2111 (comment 1125927336))

I can't rather understand why single \ do not result in a tcl error.

Because the error is evidently not returned by the C glue between Tcl and Scilab.

More precisely, line 65 of function uicontrol sets the "callback" to its string value and this line reads:

set(h,GetUiControlPropertyName(varargin(i)),varargin(i+1));

This is interfaced to intTclSet, that calls InterfaceScilabToUiSet, in turn calling SetVarAString, that ultimately performs:

if ( !Tcl_SetVar(TCLinterpreter, VarName, Str[0], TCL_GLOBAL_ONLY) )
{
	bOK=(int)(FALSE);
}
else
{
	bOK=(int)(TRUE);
}

return bOK;

i.e. the possible error is not returned because the return value from SetVarAString is ignored in function InterfaceScilabToUiSet.

Francois

By Vincent COUVERT (@vincent.couvert)

Fixed in Java uicontrols for Scilab 5.x releases.

Vincent

closed

By Francois Granade

(originally entered in version "4.0 final version")

marked this issue as related to #596 (closed)