OpenEuphoria

RE: Update on the Fast-Switching/Judith's IDE issue

• Posted by Derek Parnell <ddparnell at bigpond.com> Jan 27, 2004
• 401 views

Travis Beaty wrote:
> 
> 
> Hello all!
> 
> Just to let you know, Euman and I have been working on the problem, 
> which 
> we are now sure is not being caused by win32lib.ew.  (Sorry about that, 
> Derek, you may flog me with a wet noodle at your convenience.)

FLOG! Did you feel that?  

I'm back from 2 weeks vacation and find 560+ emails waiting (not 
including ones from EUForum). It may be a little time before I can 
address any win32lib issues. 


> We believe at this point that the issue is somewhere in prop.ew.  I 
> replaced the warnErr() call in win32lib.ew's bitBlt() routine with the 
> classic ? 1/0 crash, and from that it seems that the cascade of errors 
> in 
> Judith's IDE is originating from onPaint_Properties() in prop.ew. (Line 
> 170).  I'm thinking at this point that there is an unforeseen change 
> occurring in the window handles as this routine is being called, during 
> the 
> time that it is running in one account while someone is logged into 
> another 
> one.  I've checked the values of the parameters pWin,  pPixmap, 
> pScrollPts, 
> pCX, and pCY up until the error actually happens, and if these values 
> are 
> changing in an uncouth way, I sure can't see it.  (I checked by logging 
> the 
> values to a dumpfile via printf().)

A common problem is when a coder does not handle the situation where a 
Paint handler gets invoked while already inside the paint handler. This 
can sometimes lead to a recursive error, of the nature being described.


> By the way, Judith ...
> 
> In IDE_syntax.ew, at line 2611, you have the following code:
> 
>          Void = getDC( Syntax )
>          putFontIntoDC( Syntax, Void, "Fixedsys", 9 )
>          releaseDC( Syntax )
> 
> Are you sure that the last line should not read
> 
> releaseDC(Void)  ?
> 
> Euman noticed this as we were investigating.  Not sure it has a bearing 
> on 
> the problem at hand, but may be a bug nevertheless.

This should NOT read "releaseDC(Void)". Judith's code is correct, but 
unfortunately a waste of energy.

If this code is not in a Paint handler then it could be deleted as it 
does nothing effective. 

-- 
Derek