beremiz

fix Traceback if search icon on library panel is clicked, when no
category/item is selected in the library.

The problem is here, that if nothing is selected method GetSelection()
returns root item, that doesn't have any python data associated with it.
This issue seems to be wx3.0 specified, because it doesn't exist
with wx2.8 on Windows.
<?xml version='1.0' encoding='utf-8'?>
<CFile xmlns:xhtml="http://www.w3.org/1999/xhtml">
<includes>
<xhtml:p><![CDATA[
]]></xhtml:p>
</includes>
<variables>
<variable name="TestInput" type="SINT" initial="0"/>
<variable name="TestOutput" type="SINT"/>
</variables>
<globals>
<xhtml:p><![CDATA[
volatile long Lock=0;
volatile char PtoC=1,CtoP=2;
extern long AtomicCompareExchange(long*,long, long);
extern char *PLC_ID;
int Simple_C_Call(int val){
return val+1;
}
int Python_to_C_Call(char toC, char *fromC){
/* Code called by python should never touch to
variables modified by PLC thread directly
AtomicCompareExchange comes from
beremiz' runtime implementation */
int res = 0;
if(!AtomicCompareExchange((long*)&Lock, 0, 1)){
PtoC=toC;
*fromC=CtoP;
AtomicCompareExchange((long*)&Lock, 1, 0);
res=1;
}
printf("C code called by Python: toC %d fromC %d\n",toC,*fromC);
printf("PLC_ID id %s\n",PLC_ID);
return res;
}
int PLC_C_Call(char fromPLC, char *toPLC){
/* PLC also have to be realy carefull not to
conflict with asynchronous python access */
if(!AtomicCompareExchange((long*)&Lock, 0, 1)){
CtoP = fromPLC;
*toPLC = PtoC;
AtomicCompareExchange((long*)&Lock, 1, 0);
return 1;
}
return 0;
}
]]></xhtml:p>
</globals>
<initFunction>
<xhtml:p><![CDATA[
]]></xhtml:p>
</initFunction>
<cleanUpFunction>
<xhtml:p><![CDATA[
]]></xhtml:p>
</cleanUpFunction>
<retrieveFunction>
<xhtml:p><![CDATA[
]]></xhtml:p>
</retrieveFunction>
<publishFunction>
<xhtml:p><![CDATA[
if(!AtomicCompareExchange((long*)&Lock, 0, 1)){
TestInput = CtoP + PtoC + TestOutput;
AtomicCompareExchange((long*)&Lock, 1, 0);
}
]]></xhtml:p>
</publishFunction>
</CFile>