bmyers@garnet.berkeley.edu (Brian Myers) (10/09/90)
The following simple program does not work (in THINK's Lightspeed Pascal):
program ChangeTitle;
var
wPtr: WindowPtr;
theTitle: Str255;
begin
ShowText; {makes TextWindow visible, active}
wPtr:=FrontWindow; {should give handle to Text Window}
GetWTitle(wPtr, theTitle); {should retrieve title string}
WriteLn(theTitle); {should display title string}
end.
What actually happens is a string of garbage appears as output from that last
WriteLn. SetWTitle also has no effect--this program was what I tried when I
couldn't make SetWTitle work.
I now suspect that THINK Pascal somehow protects its standard windows (Text,
Drawing, etc) from your own programs as they run. Might the compiler
somehow remove these windows, even though they exist on the screen, from the
system queue? Is that even possible? Or why else am I getting garbage?
Thanks for any help.
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Brian Myers bmyers@garnet.berkeley.edustevec@Apple.COM (Steve Christensen) (10/09/90)
bmyers@garnet.berkeley.edu (Brian Myers) writes: >The following simple program does not work (in THINK's Lightspeed Pascal): > >program ChangeTitle; >var > wPtr: WindowPtr; > theTitle: Str255; >begin > ShowText; {makes TextWindow visible, active} > wPtr:=FrontWindow; {should give handle to Text Window} > GetWTitle(wPtr, theTitle); {should retrieve title string} > WriteLn(theTitle); {should display title string} >end. > >What actually happens is a string of garbage appears as output from that last >WriteLn. SetWTitle also has no effect--this program was what I tried when I >couldn't make SetWTitle work. > >I now suspect that THINK Pascal somehow protects its standard windows (Text, >Drawing, etc) from your own programs as they run. Might the compiler >somehow remove these windows, even though they exist on the screen, from the >system queue? Is that even possible? Or why else am I getting garbage? Have you thought about initializing theTitle with something. Otherwise, whatever was in that part of memory when your routine got called would be used. Stuff like: theTitle:='A Real Title' or theTitle:=GetString(5)^^ work pretty well... :-) steve -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ whoami? Steve Christensen snail: Apple Computer, 20525 Mariani Ave, MS-81CS, Cupertino, CA 95014 Internet: stevec@goofy.apple.com AppleLink: stevec CompuServe: 76174,1712
mxmora@unix.SRI.COM (Matt Mora) (10/10/90)
In article <10623@goofy.Apple.COM> stevec@Apple.COM (Steve Christensen) writes: >bmyers@garnet.berkeley.edu (Brian Myers) writes: >>The following simple program does not work (in THINK's Lightspeed Pascal): > >Have you thought about initializing theTitle with something. Otherwise, >whatever was in that part of memory when your routine got called would >be used. Stuff like: theTitle:='A Real Title' or theTitle:=GetString(5)^^ >work pretty well... :-) I don't think that is the will help. I believe that THINK Pascal mucks around with the window list (or creates its own) so that the front window command will work even if the front window is the source code or Lightsbug window. For example if you are tracing code execution, if your code calls frontwindow and the source code window is actually in front, frontwindow will return a ptr to your window not the source code window. If I get time I'll look into it. Sorry I dont have an answer. >steve > >-- >~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > whoami? Steve Christensen -- ___________________________________________________________ Matthew Mora | my Mac Matt_Mora@sri.com SRI International | my unix mxmora@unix.sri.com ___________________________________________________________
smoke@well.sf.ca.us (Nicholas Jackiw) (10/11/90)
In article <1990Oct9.062443.18141@agate.berkeley.edu> bmyers@garnet.berkeley.edu (Brian Myers) writes: >The following simple program does not work (in THINK's Lightspeed Pascal): > > ShowText; {makes TextWindow visible, active} > wPtr:=FrontWindow; {should give handle to Text Window} > GetWTitle(wPtr, theTitle); {should retrieve title string} > WriteLn(theTitle); {should display title string} >I now suspect that THINK Pascal somehow protects its standard windows (Text, >Drawing, etc) from your own programs as they run. Might the compiler >somehow remove these windows, even though they exist on the screen, from the >system queue? Is that even possible? Or why else am I getting garbage? That's right and that's possible. THINK Pascal patches FrontWindow so that it never returns one of the (internal) windows--e. g. the Text window, the Lightsbug window, a source code window, etc. Whether this patch is installed only when running "under the environment" is unclear to me. Regardless, if you're trying to work under the environment, it's in effect. That's why you'll want to go to the WindowList constant, which is not accessed through a (potentially patchable) trap, as you mentioned in your last post. Or you could ignore your aversion to the title TEXT. -- --- * --- Nicholas Jackiw Smoke@well.sf.ca.us | Jackiw@cs.swarthmore.edu Key Curriculum Press, Inc. Applelink: D3970 | (415) 548-2304 --- * ---