"Best" way to append text in a ScrollView

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2 total messages Started by Todd Enders Wed, 04 Nov 1992 04:10

#132

Author: Todd Enders
Date: Wed, 04 Nov 1992 04:10

18 lines
1244 bytes

     This has probably been asked a lot, but humour me...

     I'm trying to put some text into a ScrollView, in the following fashion:

     [text_out setText:"foo!\n"];
     ...
     ** now I want to append some more text **

     The $64 question is what is the "best" way to do this?  I can't really
see a way short of sucking the existing text into a string and strcat()-ing
the new text on the end.  I fooled around with setSel::, but the new text
always overwrites the old.  I'm sure there's an easy/elegant way to do this, 
but I haven't seen it in any of the examples.  *HELP*!!!

Todd     enders@bolshoi.uucp     NeXTMail Welcome!!!
         uunet!bolshoi!enders
         enders@bolshoi.cc.misu.nodak.edu

Re: "Best" way to append text in a ScrollView

#138

Author: Eric P. Scott
Date: Wed, 04 Nov 1992 10:20

51 lines
1861 bytes

"Best" is a judgment call.  I'll offer one approach--extending
the Text class--but I wouldn't go so far as to call it "best."

[This is for 2.x.  No promises for 3.0.]

// The corressponding interface file should #import <appkit/Text.h>

#import <stdarg.h>
#import <streams/streams.h>

@implementation Text(PutSomethingCuteHere)

// Like setText:, but appends.  I recommend messaging
// scrollSelToVisible to the Text object afterwards, or placing
// one before the return.
- appendText:(const char *)aString
{
    int e;

    if ((e=[self textLength])<=0) [self setText:aString];
    else [[self setSel:e:e] replaceSel:aString];
    return self;
}

// For even more fun, we can build a printf: method upon
// appendText:.  Since all parameters after the format
// string are optional as far as Objective-C is concerned,
// delimit them with commas instead of colons.  Extend
// with NXRegisterPrintfProc() for even more flexibility!
- printf:(const char *)format,...
{
    NXStream *s;
    char *streambuf;
    int len, maxlen;
    va_list ap;

    va_start(ap, format);
    s=NXOpenMemory(NULL,0,NX_WRITEONLY);
    NXVPrintf(s, format, ap);
    (void)NXPutc(s, '\0');
    NXFlush(s);
    NXGetMemoryBuffer(s, &streambuf, &len, &maxlen);
    [self appendText:streambuf];
    NXCloseMemory(s, NX_FREEBUFFER);      
    va_end(ap);
}


@end

					-=EPS=-

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