ar4@sage.cc.purdue.edu (Piper Keairnes) (03/20/90)
Got a problem folks... what's wrong with this simple code???
int handleDialog(theItem, dp)
int theItem;
DialogPtr dp;
{
return(theItem);
}
GetDir()
{
Point where = {80,80};
SFReply reply;
ProcPtr ppr = handleDialog;
SFPGetFile(where, NIL, NIL, 1, "", ppr, &reply, GET_DIALOG, NIL);
}
Several problems (first time into handleDialog):
1) when items are passed into handleDialog in their stated order
I get a value of 9 for theItem, and dp points to boofoo land
2) when items are passed in opposite order (dp, theItem) I get
a value of -1 for theItem and dp points to something reasonable
Are the order of the items screwed up in IM ??
When handleDialog returns I get an illegal instruction command from the
debugger and when I select from the pop-up menu the last procedure,
it indicates the position at the bracket below the Getfile.... huh?
Help me!!!!!
-----
Piper Keairnes
ar4@sage.cc.purdue.edurdclark@Apple.COM (Richard Clark) (03/20/90)
In article <3830@sage.cc.purdue.edu> ar4@sage.cc.purdue.edu (Piper Keairnes) writes: >Got a problem folks... what's wrong with this simple code??? > >int handleDialog(theItem, dp) >int theItem; >DialogPtr dp; >{ > return(theItem); >} > >GetDir() >{ > Point where = {80,80}; > SFReply reply; > ProcPtr ppr = handleDialog; > > SFPGetFile(where, NIL, NIL, 1, "", ppr, &reply, GET_DIALOG, NIL); >} > OK, we'll take it from the top. First, C passes paramaters and function results in a different way than Pascal (C reverses the order of the parms, and uses register D0 for function results (Pascal uses the stack.)) The simple fix for this is to use the "pascal" keyword thusly: pascal int handleDialog(int theItem, DialogPtr dp) The reason you have to do this is that the Toolbox uses the Pascal calling conventions, and expects callback/filter routines to do the same. Another (potential) problem is the use of "int". Pascal INTEGERs are 16 bits. C integers are 16 or 32 bits on the Macintosh depending on which C compiler you use (THINK C: 16 bits; MPW C: 32 bits.) For this reason, you should use "short" which is _always_ 16 bits. Now, on to the SFP statement. For the TypeList, you really do have to declare a variable of SFTypeList and fill in 1 (or more) of the fields, then pass the address of that structure. If you want "all files", then pass 0 for the type count and NIL for the pointer to the type list. Hope this helps. -- -----------------------------+----------------------------------------------- Richard Clark | "If you don't know where you're going, Instructor/Designer | don't go there" -- Sybalski's Law Apple Developer University +----------------------------------------------- AppleLink, GEnie, Delphi, MCI, Internet: rdclark CI$: 71401, 2071
keith@Apple.COM (Keith Rollin) (03/20/90)
In article <39665@apple.Apple.COM> rdclark@Apple.COM (Richard Clark) writes: > >Now, on to the SFP statement. For the TypeList, you really do have to declare a >variable of SFTypeList and fill in 1 (or more) of the fields, then pass the >address of that structure. If you want "all files", then pass 0 for the type >count and NIL for the pointer to the type list. > Two out of three, Richard. You have to pass -1 as the count if you want "all files". >-----------------------------+----------------------------------------------- >Richard Clark | "If you don't know where you're going, >Instructor/Designer | don't go there" -- Sybalski's Law >Apple Developer University +----------------------------------------------- >AppleLink, GEnie, Delphi, MCI, Internet: rdclark CI$: 71401, 2071 > -- ------------------------------------------------------------------------------ Keith Rollin --- Apple Computer, Inc. --- Developer Technical Support INTERNET: keith@apple.com UUCP: {decwrl, hoptoad, nsc, sun, amdahl}!apple!keith "Argue for your Apple, and sure enough, it's yours" - Keith Rollin, Contusions
siegel@endor.harvard.edu (Rich Siegel) (03/20/90)
In article <3830@sage.cc.purdue.edu> ar4@sage.cc.purdue.edu (Piper Keairnes) writes: >Got a problem folks... what's wrong with this simple code??? > >int handleDialog(theItem, dp) Bzzt. Dialog hooks, filters, and all other Toolbox callbacks have to be declared "pascal", since the Toolbox doesn't know to call them with the C conventions. Upon return of your function, the stack is getting misaligned. You're also getting the wrong results within your hook because the arguments are getting passed in the reverse of what the routine expects. R. ~~~~~~~~~~~~~~~ Rich Siegel Staff Software Developer Symantec Corporation, Language Products Group Internet: siegel@endor.harvard.edu UUCP: ..harvard!endor!siegel "When someone who makes four hundred and fifty dollars an hour wants to tell you something for free, it's a good idea to listen." ~~~~~~~~~~~~~~~
rdclark@Apple.COM (Richard Clark) (03/21/90)
In article <39667@apple.Apple.COM> keith@Apple.COM (Keith Rollin) writes: >In article <39665@apple.Apple.COM> rdclark@Apple.COM (Richard Clark) writes: >> >>Now, on to the SFP statement. For the TypeList, you really do have to declare a >>variable of SFTypeList and fill in 1 (or more) of the fields, then pass the >>address of that structure. If you want "all files", then pass 0 for the type >>count and NIL for the pointer to the type list. >> > >Two out of three, Richard. You have to pass -1 as the count if you want "all >files". > That's what I get for not looking at the documentation. Does anybody know how to get red text (to match the color of my face?) -- -----------------------------+----------------------------------------------- Richard Clark | "If you don't know where you're going, Instructor/Designer | don't go there" -- Sybalski's Law Apple Developer University +----------------------------------------------- AppleLink, GEnie, Delphi, MCI, Internet: rdclark CI$: 71401, 2071