[comp.sys.mac.programmer] MacApp and DAs

ml27192@uxa.cso.uiuc.edu (lanett mark) (01/06/91)

tim@hoptoad.uucp (Tim Maroney) writes:

>In article <Jan.4.13.24.17.1991.14211@athos.rutgers.edu>
>wiechman@athos.rutgers.edu (NightMeower) writes:
>>One point to mention is that MacApp cannot be used to write DAs,
>>INITs, etc.  I imagine that it will be possible to do so in the future.

>I would be *very* surprised if it were.

The point here is that C++ objects dynamically allocate memory, which makes
them unsuitable for this kind of program (I'm not sure about Object Pascal).
Also, since they pass the hidden this/self pointer, you cannot pass a member
function to the toolbox--they have that extra parameter.

Mark Lanett

Lawson.English@p88.f15.n300.z1.fidonet.org (Lawson English) (01/07/91)

lanett mark writes in a message to All

LM>  The point here is that C++ objects dynamically allocate memory, 
LM> which makes them unsuitable for this kind of program (I'm not 
LM> sure about Object Pascal). Also, since they pass the hidden this/self 
LM> pointer, you cannot pass a member function to the toolbox--they 
LM> have that extra parameter. 

You CAN pass a member function to the Toolbox, albeit indirectly...

However you create "globals" for your DA, simply create a "gFilterFuncPtr" that
is accessed by your filter function, thusly:

void MyFilterFunction(void);
{
     gFilterFuncPtr->Filter();    { whatever the syntax is for C++ (I forget)
}
}


Lawson
 

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