xenocara/app/xterm/scrollback.c

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/* $XTermId: scrollback.c,v 1.17 2014/05/11 14:08:11 tom Exp $ */
/*
* Copyright 2009-2013,2014 by Thomas E. Dickey
*
* All Rights Reserved
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE ABOVE LISTED COPYRIGHT HOLDER(S) BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* Except as contained in this notice, the name(s) of the above copyright
* holders shall not be used in advertising or otherwise to promote the
* sale, use or other dealings in this Software without prior written
* authorization.
*/
#include <xterm.h>
#define REAL_ROW(screen, row) ((row) + (screen)->saved_fifo)
#define ROW2FIFO(screen, row) \
(unsigned) (REAL_ROW(screen, row) % (screen)->savelines)
/*
* Given a row-number, find the corresponding data for the line in the VT100
* widget's saved-line FIFO. The row-number (from getLineData) is negative.
* So we just count backwards from the last saved line.
*/
LineData *
getScrollback(TScreen *screen, int row)
{
LineData *result = 0;
if (screen->saved_fifo > 0 && REAL_ROW(screen, row) >= 0) {
unsigned which = ROW2FIFO(screen, row);
ScrnBuf where = scrnHeadAddr(screen, screen->saveBuf_index, which);
result = (LineData *) where;
}
TRACE(("getScrollback %d -> %d -> %p\n",
row, ROW2FIFO(screen, row),
(void *) result));
return result;
}
/*
* Allocate a new row in the scrollback FIFO, returning a pointer to it.
*/
LineData *
addScrollback(TScreen *screen)
{
ScrnBuf where = 0;
unsigned which;
unsigned ncols = (unsigned) MaxCols(screen);
Char *block;
if (screen->saveBuf_index != 0) {
TRACE(("addScrollback %lu\n", screen->saved_fifo));
/* first, see which index we'll use */
which = (unsigned) (screen->saved_fifo % screen->savelines);
where = scrnHeadAddr(screen, screen->saveBuf_index, which);
/* discard any obsolete index data */
if (screen->saved_fifo > screen->savelines) {
LineData *prior = (LineData *) where;
/*
* setupLineData uses the attribs as the first address used from the
* data block.
*/
if (prior->attribs != 0) {
TRACE(("...freeing prior FIFO data in slot %d: %p->%p\n",
which, (void *) prior, (void *) prior->attribs));
free(prior->attribs);
prior->attribs = 0;
}
if (screen->saved_fifo > 2 * screen->savelines) {
screen->saved_fifo -= screen->savelines;
}
}
/* allocate the new data */
block = allocScrnData(screen, 1, ncols);
/* record the new data in the index */
setupLineData(screen, where, (Char *) block, 1, ncols);
TRACE(("...storing new FIFO data in slot %d: %p->%p\n",
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which, (void *) where, block));
screen->saved_fifo++;
}
return (LineData *) where;
}
void
deleteScrollback(TScreen *screen)
{
unsigned which = ROW2FIFO(screen, -1);
ScrnBuf where = scrnHeadAddr(screen, screen->saveBuf_index, which);
LineData *prior = (LineData *) where;
/*
* setupLineData uses the attribs as the first address used from the
* data block.
*/
if (prior->attribs != 0) {
TRACE(("...freeing prior FIFO data in slot %d: %p->%p\n",
which, (void *) prior, (void *) prior->attribs));
free(prior->attribs);
prior->attribs = 0;
}
screen->saved_fifo--;
}