commands/yap/display.h

   1 /* Copyright (c) 1985 Ceriel J.H. Jacobs */
   2
   3 /* $Header$ */
   4
   5 # ifndef _DISPLAY_
   6 # define PUBLIC extern
   7 # else
   8 # define PUBLIC
   9 # endif
  10
  11 # define MINPAGESIZE 5
  12
  13 PUBLIC int      pagesize;       /* How many lines on a page */
  14 PUBLIC int      maxpagesize;    /* Maximum # of lines on a page */
  15 PUBLIC int      scrollsize;     /* number of lines in a scroll */
  16 struct scr_info {
  17         struct linelist {
  18             int cnt;            /* # of screenlines for this line */
  19             long line;          /* lineno of this line */
  20 # define firstline head->line
  21 # define lastline tail->line
  22             struct linelist *next;
  23             struct linelist *prev;
  24         } *tail, *head;         /* Of all lines of the input file that are
  25                                  * on the screen, remember how many
  26                                  * screenlines they occupy. Keep this
  27                                  * info in a doubly linked list.
  28                                  */
  29         int     nf;             /* How many screenlines of the first line
  30                                  * on the screen are not on the screen?
  31                                  */
  32         int     currentpos;     /* Y coordinate of first free line */
  33         struct linelist ssaavv; /* Mark */
  34 # define savfirst ssaavv.line
  35 # define savnf ssaavv.cnt
  36 };
  37
  38 PUBLIC struct scr_info scr_info;
  39 PUBLIC int      status;         /* EOFILE on end of file
  40                                  * START on start of file
  41                                  * logical "or" if both
  42                                  */
  43 /* Flags for status field */
  44
  45 # define EOFILE 01
  46 # define START 02
  47
  48 VOID    redraw();
  49 /*
  50  * void redraw(flag)
  51  * int flag;                    Either 0 or 1
  52  *
  53  * Redraws the screen. If flag = 1, the screen is redrawn as precisely
  54  * as possible, otherwise one page is displayed (which possibly does not
  55  * take a whole screen.
  56  */
  57
  58 int     display();
  59 /*
  60  * int display(firstline, nodispl, nlines, really)
  61  * long firstline;              Line with which to start
  62  * int nodispl;                 Do not display nodispl lines of it
  63  * int nlines;                  Number of screen lines that must be displayed
  64  * int really;                  Either 0 or 1
  65  *
  66  * Displays nlines as a page. if "really" = 0, the actual displaying is not
  67  * performed. Only the computing associated with it is done.
  68  */
  69
  70 int     scrollf();
  71 /*
  72  * int scrollf(nlines,really)
  73  * int nlines;                  Number of lines to scroll
  74  * int really;                  Either 0 or 1, see explanation above
  75  *
  76  * Scroll forwards "nlines" (screen)lines.
  77  */
  78
  79 int     scrollb();
  80 /*
  81  * int scrollb(nlines,really)
  82  * int nlines;                  Number of lines to scroll
  83  * int really;                  Either 0 or 1, see explanation above
  84  *
  85  * Scroll backwards "nlines" (screen)lines.
  86  */
  87
  88 int     tomark();
  89 /*
  90  * int tomark(cnt)
  91  * long cnt;                    (Argument ignored)
  92  *
  93  * Display a page starting at the mark. If there was no
  94  * mark, display the first page of the file.
  95  * (There is always assumed to be a mark, the initial one is on the first page
  96  * of the file).
  97  */
  98
  99 int     setmark();
 100 /*
 101  * int setmark(cnt)
 102  * long cnt;                    (Argument ignored)
 103  *
 104  * Sets a mark on the current page.
 105  * It returns nothing (but the address is taken ...)
 106  */
 107
 108 int     exgmark();
 109 /*
 110  * int exgmark(cnt)
 111  * long cnt;                    (Argumewnt ignored)
 112  *
 113  * Sets the mark on the current page and displays the
 114  * previously marked page.
 115  */
 116
 117 VOID    d_clean();
 118 /*
 119  * void d_clean()
 120  *
 121  * Clean up and initialize. To be called before displaying a new file
 122  */
 123
 124 # undef PUBLIC