Re: Discuss-gnustep Digest, Vol 2, Issue 49

[Jonathan Gapen]

> Date: Mon, 20 Jan 2003 18:35:10 +0100
> From: =?iso-8859-1?q?Bj=F6rn=20Giesler?= <giesler@ira.uka.de>
> To: Nicolas Roard <nicolas@roard.com>
> Cc: discuss-gnustep@gnu.org
> Subject: Re: ANNOUNCE : HelpViewer 0.1
> [...]
> I think using HelpViewer for this doesn't seem to be such a good idea aft=
> er=20
> all. The NSHelpManager API has
>
> - (NSAttributedString*) contextHelpForObject: (id)object;
> - (void) removeContextHelpForObject: (id)object;
> - (void) setContextHelp: (NSAttributedString*) help withObject: (id) obje=
> ct;
> - (BOOL) showContextHelpForObject: (id)object locationHint: (NSPoint) poi=
> nt;
>
> =2E..so everything is done via object pointers, and the returned value is=
>  an=20
> attributed string. I see no way to make an object pointer into an ascii t=
> ag=20
> that could be read from a .xlp file (is there any?), and the returned=20
> attibuted string suggests that the application opens its own NSTextView.=20
> Which I don't like, because it raises issues such as scrolling, navigatio=
> n,=20
> images etc., plus adds code bloat.
>
> I think that this API is not one of the sparkling points of OPENSTEP. :-/=
>  Any=20
> ideas?

     I respectfully disagree!  I think that the API is just fine, as 
the OPENSTEP 4.2 documentation describes it.  What you do there is 
create an RTF file for each context help item, then use the compileHelp 
command-line utility to compile them all into a a Help.plist file.  The 
docs don't say, but it seems pretty clear that NSHelpManager can then 
just pull an NSAttributedString right out of the property list.
     Once you've got the NSAttributedString, you can just use -size on 
it, pop open a floating NSPanel with a content view that size, and then 
-drawInRect the string.  Very quick and simple.
     Well, after writing the above I decided to look at the current 
GNUstep implementation, and I've described more or less what's already 
there.  GNUstep does use an NSTextView, which I think is overkill, and 
not quite appropriate in that you can't directly put an 
NSAttributedString into an NSTextView.
     Unless I'm missing something, it looks like all that's left to do 
is to implement 'help' key handling in NSApplication.