"Fossies" - the Fresh Open Source Software Archive

Member "xterm-379/scrollback.c" (9 Mar 2022, 4205 Bytes) of package /linux/misc/xterm-379.tgz:

    1 /* $XTermId: scrollback.c,v 1.23 2022/03/09 00:38:51 tom Exp $ */
    2 
    3 /*
    4  * Copyright 2009-2020,2022 by Thomas E. Dickey
    5  *
    6  *                         All Rights Reserved
    7  *
    8  * Permission is hereby granted, free of charge, to any person obtaining a
    9  * copy of this software and associated documentation files (the
   10  * "Software"), to deal in the Software without restriction, including
   11  * without limitation the rights to use, copy, modify, merge, publish,
   12  * distribute, sublicense, and/or sell copies of the Software, and to
   13  * permit persons to whom the Software is furnished to do so, subject to
   14  * the following conditions:
   15  *
   16  * The above copyright notice and this permission notice shall be included
   17  * in all copies or substantial portions of the Software.
   18  *
   19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
   20  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   21  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
   22  * IN NO EVENT SHALL THE ABOVE LISTED COPYRIGHT HOLDER(S) BE LIABLE FOR ANY
   23  * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
   24  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
   25  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
   26  *
   27  * Except as contained in this notice, the name(s) of the above copyright
   28  * holders shall not be used in advertising or otherwise to promote the
   29  * sale, use or other dealings in this Software without prior written
   30  * authorization.
   31  */
   32 
   33 #include <xterm.h>
   34 
   35 #define REAL_ROW(screen, row) ((row) + (screen)->saved_fifo)
   36 #define ROW2FIFO(screen, row) \
   37     (unsigned) (REAL_ROW(screen, row) % (screen)->savelines)
   38 
   39 /*
   40  * Given a row-number, find the corresponding data for the line in the VT100
   41  * widget's saved-line FIFO.  The row-number (from getLineData) is negative.
   42  * So we just count backwards from the last saved line.
   43  */
   44 LineData *
   45 getScrollback(TScreen *screen, int row)
   46 {
   47     LineData *result = 0;
   48 
   49     if (screen->saved_fifo > 0 && REAL_ROW(screen, row) >= 0) {
   50     unsigned which = ROW2FIFO(screen, row);
   51     ScrnBuf where = scrnHeadAddr(screen, screen->saveBuf_index, which);
   52     result = (LineData *) where;
   53     }
   54 
   55     TRACE(("getScrollback %d -> %d -> %p\n",
   56        row, ROW2FIFO(screen, row),
   57        (void *) result));
   58     return result;
   59 }
   60 
   61 /*
   62  * Allocate a new row in the scrollback FIFO, returning a pointer to it.
   63  */
   64 LineData *
   65 addScrollback(TScreen *screen)
   66 {
   67     ScrnBuf where = 0;
   68     unsigned ncols = (unsigned) MaxCols(screen);
   69 
   70     if (screen->saveBuf_index != 0 && screen->savelines != 0) {
   71     unsigned which;
   72     Char *block;
   73 
   74     TRACE(("addScrollback %lu\n", screen->saved_fifo));
   75 
   76     /* first, see which index we'll use */
   77     which = (unsigned) (screen->saved_fifo % screen->savelines);
   78     where = scrnHeadAddr(screen, screen->saveBuf_index, which);
   79 
   80     /* discard any obsolete index data */
   81     if (screen->saved_fifo > screen->savelines) {
   82         LineData *prior = (LineData *) where;
   83         /*
   84          * setupLineData uses the attribs as the first address used from the
   85          * data block.
   86          */
   87         if (prior->attribs != 0) {
   88         TRACE(("...freeing prior FIFO data in slot %d: %p->%p\n",
   89                which, (void *) prior, (void *) prior->attribs));
   90         FreeAndNull(prior->attribs);
   91         }
   92         if (screen->saved_fifo > 2 * screen->savelines) {
   93         screen->saved_fifo -= screen->savelines;
   94         }
   95     }
   96 
   97     /* allocate the new data */
   98     block = allocScrnData(screen, 1, ncols, False);
   99 
  100     /* record the new data in the index */
  101     setupLineData(screen, where, (Char *) block, 1, ncols, False);
  102 
  103     TRACE(("...storing new FIFO data in slot %d: %p->%p\n",
  104            which, (void *) where, block));
  105 
  106     screen->saved_fifo++;
  107     }
  108     return (LineData *) where;
  109 }
  110 
  111 void
  112 deleteScrollback(TScreen *screen)
  113 {
  114     unsigned which = ROW2FIFO(screen, -1);
  115     ScrnBuf where = scrnHeadAddr(screen, screen->saveBuf_index, which);
  116     LineData *prior = (LineData *) where;
  117     /*
  118      * setupLineData uses the attribs as the first address used from the
  119      * data block.
  120      */
  121     if (prior->attribs != 0) {
  122     TRACE(("...freeing prior FIFO data in slot %d: %p->%p\n",
  123            which, (void *) prior, (void *) prior->attribs));
  124     FreeAndNull(prior->attribs);
  125     }
  126     screen->saved_fifo--;
  127 }