[Swarm-Support] In need of help : X error generated by call to [Pixmap setWidget:]

[Thomas Louail]

Hello swarm people,

We develop a urban simulation model with swarm. The model simulates the 
localisation of different kinds of socio-economical activities inside a 
city's neighbourhoods. To observe how each socio-economical activity is 
localized as a result of the model execution, we produce at each time 
step for each type of activity a map (drawn in a zoomraster) of its 
localisations. We want to export these raster images in files through 
the use of swarm's Pixmap facilities, and the save method.

Here is how i coded that (in ObserverSwarm.m) :

Below is the method responsible to create and to save these png files. 
It's called at each timestep
> - takeScreenShots
> {
> ...
>
> for (i=0; i<[modelSwarm getNumFunctions];i++)
>     {
>       ...
>       id <ZoomRaster> raster = [ZoomRaster createBegin:self];
>       SET_WINDOW_GEOMETRY_RECORD_NAME (raster);
>       [raster createEnd];
>      
>       [raster setZoomFactor:1];
>       [raster setWidth: [[modelSwarm getWorld] getSizeX]
>           Height: [[modelSwarm getWorld] getSizeY]];
>       [raster setColormap : functionColors]; // this colormap is a 
> ObserverSwarm instance variable
>      
>       char rasterName [100];
>      
>       ...
>       aPix =[Pixmap createBegin: self]; // Create the pixmap necessary 
> to create
>                      // a screenshot
>
>      sprintf(rasterName, "%s in %4d",
>           [function getName],
>           [modelSwarm getDate]);
>      
>       [raster setWindowTitle:rasterName];
>       [raster pack];
>      
>       functionDisplay = [Value2dDisplay create: self
>                     setDisplayWidget: raster
>                     colormap: functionColors
>                     setDiscrete2dToDisplay: gridOfQuartiersId];
>      
>       [raster erase];
>       [functionDisplay display];
>      
>      
>       [aPix setWidget: raster];
>       [aPix setDecorationsFlag: YES];
>       aPix= [aPix createEnd];        
>      
>       [aPix save: filename];
>
>       [aPix drop];
>       [functionDisplay drop];
>       [raster drop];
>
> } // enf of the loop on functions
>
> return self;
> }

*At run time, the model runs fine until it reaches the call to [aPix 
setWidget: raster], which generates a X error* :

> X Error of failed request:  BadWindow (invalid Window parameter)
>   Major opcode of failed request:  15 (X_QueryTree)
>   Resource id in failed request:  0x0
>   Serial number of failed request:  445047
>   Current serial number in output stream:  445047

GDB execution produces no stack (i'm not a GDB expert..)  :

> X Error of failed request:  BadWindow (invalid Window parameter)
>   Major opcode of failed request:  15 (X_QueryTree)
>   Resource id in failed request:  0x0
>   Serial number of failed request:  194159
>   Current serial number in output stream:  194159
>
> Program exited with code 01.
> (gdb) bt
> No stack.
> (gdb)
so it's difficult to trak down the error.

I work on an Ubuntu 8.4 workstation, and my swarm version is 2.2.4. The 
funny thing is that i've test the same code on my laptop (which runs 
swarm 2.2.4 on an ubuntu 8.04 too) and the same code does'nt generate 
any error, and the png outputs are fine...

I'm a little bit lost right now... does any of you swarm members already 
encounter X Error of the same kind ? I've browsed the archived support 
mailing list but couldn't find any relevant topic for this problem.

Thanks in advance for your help,

Have a good day,

thomas