zle_refresh uncommon bug fix and movement optimisation

[Geoff Wing <mason@primenet.com.au>]

Heyla,
 this will fix a bug and improve output on terminals with poor right 
 movement capabilities.  The bug is something I came across at the start of
 the year when I was rewriting that area and promptly forgot about.
 Someone (Zefram?) was doing a large change in the prompt stuff at that time
 and I forgot about the bug.  It's very minor and you should never have come
 across it.
 Terminals with poor right movement capabilities will have much less
 output, especially if users use RPROMPTs.
 The whole tc_rightcurs() routine has been reworked to be a bit smarter.

 If you come across any problems with it (hopefully not) just give me a yell.



*** zle_refresh.c.~1~	Wed Aug 28 20:02:25 1996
--- zle_refresh.c	Wed Aug 28 21:11:16 1996
***************
*** 233,256 ****
--- 233,258 ----
              if (tccan(TCCLEAREOD))
                  tcout(TCCLEAREOD);
              else
                  cleareol = 1;   /* request: clear to end of line */
          if (t0 > -1)
              olnct = t0;
          if (isset(SINGLELINEZLE) || termok != TERM_OK)
              vcs = 0;
          else if (!clearflag && lpptlen) {
              fwrite(lpptbuf, lpptlen, 1, shout);
+ 	    SELECT_ADD_COST(lpptlen);
  	    fflush(shout);
  	}
  	if (clearflag) {
  	    putc('\r', shout);
+ 	    SELECT_ADD_COST(1);
  	    vcs = 0;
  	    moveto(0, pptw);
  	}
  	clearf = clearflag;
      } else if (winw != columns)
  	resetvideo();
  
  /* now winw equals columns; now all width comparisons can be made to winw */
  
      if (isset(SINGLELINEZLE) || termok != TERM_OK) {
***************
*** 750,815 ****
  	    tcout(cap);
  	return 1;
      }
      return 0;
  }
  
  /**/
  void
  tc_rightcurs(int cl)
  {
!     int ct = cl - vcs,		/* number of characters to move across	    */
  	horz_tabs = 0,		/* number of horizontal tabs if we do them  */
  	i = vcs,		/* cursor position after initial movements  */
! 	j = 0;			/* number of chars outputted if we use tabs */
      char *t;
  
  /* calculate how many horizontal tabs it would take, if we can do them -
     tabs are assumed to be 8 spaces */
      if (tccan(TCNEXTTAB) && ((vcs | 7) < cl)) {
  	horz_tabs = 1;
  	i = (vcs | 7) + 1;
  	for (; i + 8 <= cl; i += 8)
  	    horz_tabs++;
  	j = cl - i;		/* number of chars after last tab */
- 	if (tccan(TCRIGHT))
- 	    j *= tclen[TCRIGHT];
  	j += (horz_tabs * tclen[TCNEXTTAB]); /* # of chars if we use tabs */
      }
  
  /* do a multright if we can - if it's cheaper or we can't use other tricks */
!     if (tccan(TCMULTRIGHT) &&
! 	(!tccan(TCRIGHT) || (tclen[TCMULTRIGHT] < tclen[TCRIGHT] * ct) ||
! 	 !tccan(TCNEXTTAB) || (tclen[TCMULTRIGHT] < j))) {
  	tcoutarg(TCMULTRIGHT, ct);
  	SELECT_ADD_COST(tclen[TCMULTRIGHT]);
  	return;
      }
  
  /* try to go with tabs if a multright is not feasible/convenient */
      if (horz_tabs) {
  	SELECT_ADD_COST((tclen[TCNEXTTAB] * horz_tabs));
  	for (; horz_tabs--;)
  	    tcout(TCNEXTTAB);
  	if ((ct = cl - i) == 0) /* number of chars still to move across */
  	    return;
      }
  
! /* or try to dump lots of right movements */
!     if (tccan(TCRIGHT)) {
! 	SELECT_ADD_COST((tclen[TCRIGHT] * ct));
! 	for (; ct--;)
! 	    tcout(TCRIGHT);
! 	return;
      }
  
- /* otherwise _carefully_ write the contents of the video buffer */
      SELECT_ADD_COST(ct);
      for (j = 0, t = nbuf[vln]; *t && (j < i); j++, t++);
      if (j == i)
  	for ( ; *t && ct; ct--, t++)
  	    putc(*t, shout);
      while (ct--)
  	putc(' ', shout);	/* not my fault your terminal can't go right */
  }
  
  /**/
--- 752,832 ----
  	    tcout(cap);
  	return 1;
      }
      return 0;
  }
  
  /**/
  void
  tc_rightcurs(int cl)
  {
!     int ct,			/* number of characters to move across	    */
  	horz_tabs = 0,		/* number of horizontal tabs if we do them  */
  	i = vcs,		/* cursor position after initial movements  */
! 	j;			/* number of chars outputted		    */
      char *t;
  
+     j = ct = cl - vcs;
+ 
  /* calculate how many horizontal tabs it would take, if we can do them -
     tabs are assumed to be 8 spaces */
      if (tccan(TCNEXTTAB) && ((vcs | 7) < cl)) {
  	horz_tabs = 1;
  	i = (vcs | 7) + 1;
  	for (; i + 8 <= cl; i += 8)
  	    horz_tabs++;
  	j = cl - i;		/* number of chars after last tab */
  	j += (horz_tabs * tclen[TCNEXTTAB]); /* # of chars if we use tabs */
      }
  
  /* do a multright if we can - if it's cheaper or we can't use other tricks */
!     if (tccan(TCMULTRIGHT)
! 	&& (!tccan(TCNEXTTAB) || (tclen[TCMULTRIGHT] <= j)
! 	    || (vln == 0 && i < pptw))) {
  	tcoutarg(TCMULTRIGHT, ct);
  	SELECT_ADD_COST(tclen[TCMULTRIGHT]);
  	return;
      }
  
  /* try to go with tabs if a multright is not feasible/convenient */
      if (horz_tabs) {
  	SELECT_ADD_COST((tclen[TCNEXTTAB] * horz_tabs));
  	for (; horz_tabs--;)
  	    tcout(TCNEXTTAB);
  	if ((ct = cl - i) == 0) /* number of chars still to move across */
  	    return;
      }
  
! /* otherwise _carefully_ write the contents of the video buffer.
!    if we're anywhere in the prompt, goto the left column and write the whole
!    prompt out unless lpptlen == pptw : we can cheat then */
!     if (vln == 0 && i < pptw) {
! 	if (lpptlen == pptw) {
! 	    SELECT_ADD_COST(lpptlen - i);
! 	    fwrite(lpptbuf + i, lpptlen - i, 1, shout);
! 	} else if (tclen[TCRIGHT] * ct < lpptlen) {
! 	    /* it is cheaper to send TCRIGHT than reprint the whole prompt */
! 	    SELECT_ADD_COST(ct);
! 	    for ( ; ct--; )
! 		tcout(TCRIGHT);
!         } else {
! 	    if (i != 0) {
! 		SELECT_ADD_COST(1);
! 		putc('\r', shout);
! 	    }
! 	    SELECT_ADD_COST(lpptlen);
! 	    fwrite(lpptbuf, lpptlen, 1, shout);
! 	}
! 	i = pptw;
! 	ct = cl - i;
      }
  
      SELECT_ADD_COST(ct);
      for (j = 0, t = nbuf[vln]; *t && (j < i); j++, t++);
      if (j == i)
  	for ( ; *t && ct; ct--, t++)
  	    putc(*t, shout);
      while (ct--)
  	putc(' ', shout);	/* not my fault your terminal can't go right */
  }
  
  /**/



-- 
Geoff Wing [mason@primenet.com.au]   PrimeNet - Internet Consultancy
  Web: http://www.primenet.com.au/   Facsimile: +61-3-9819 3788