122 lines
2.8 KiB
C
122 lines
2.8 KiB
C
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/* This work is copyrighted. See COPYRIGHT.OLD & COPYRIGHT.NEW for *
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* details. If they are missing then this copy is in violation of *
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* the copyright conditions. */
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/*
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** lib_scroll.c
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**
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** The routine wscrl(win, n).
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** positive n scroll the window up (ie. move lines down)
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** negative n scroll the window down (ie. move lines up)
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**
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*/
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#include <stdlib.h>
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#include "curses.priv.h"
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#include <nterm.h>
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int
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wscrl(WINDOW *win, int n)
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{
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int line, i;
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chtype *ptr, *temp;
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chtype **saved;
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chtype blank = ' ';
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T(("wscrl(%x,%d) called", win, n));
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if (! win->_scroll)
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return ERR;
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if (n == 0)
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return OK;
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/* test for scrolling region == entire screen */
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saved = (chtype **)malloc(sizeof(chtype *) * abs(n));
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if (n < 0) {
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/* save overwritten lines */
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for (i = 0; i < -n; i++)
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saved[i] = win->_line[win->_regbottom-i];
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/* shift n lines */
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for (line = win->_regbottom; line > win->_regtop+n; line--)
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win->_line[line] = win->_line[line+n];
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/* restore saved lines and blank them */
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for (i = 0, line = win->_regtop; line < win->_regtop-n; line++, i++) {
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win->_line[line] = saved[i];
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temp = win->_line[line];
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for (ptr = temp; ptr - temp <= win->_maxx; ptr++)
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*ptr = blank;
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}
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}
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if (n > 0) {
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/* save overwritten lines */
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for (i = 0; i < n; i++)
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saved[i] = win->_line[win->_regtop+i];
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/* shift n lines */
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for (line = win->_regtop; line < win->_regbottom; line++)
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win->_line[line] = win->_line[line+n];
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/* restore saved lines and blank them */
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for (i = 0, line = win->_regbottom; line > win->_regbottom - n; line--, i++) {
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win->_line[line] = saved[i];
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temp = win->_line[line];
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for (ptr = temp; ptr - temp <= win->_maxx; ptr++)
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*ptr = blank;
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}
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}
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free(saved);
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/* as an optimization, if the scrolling region is the entire screen
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scroll the physical screen */
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/* should we extend this to include smaller scrolling ranges by using
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change_scroll_region? */
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if (win->_maxx == columns && win->_regtop == 0 && win->_regbottom == lines) {
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wrefresh(win);
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/* at the moment this relies on scroll_reverse and scroll_forward
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or parm_rindex and parm_index.
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we should add idl support as an alternative */
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if (n > 0) {
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mvcur(-1, -1, win->_regtop, 0);
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if (parm_rindex) {
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putp(tparm(parm_rindex, n));
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} else if (scroll_reverse) {
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while (n--)
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putp(scroll_reverse);
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}
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}
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if (n < 0) {
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mvcur(-1, -1, win->_regbottom, columns);
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n = abs(n);
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if (parm_index) {
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putp(tparm(parm_index, n));
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} else if (scroll_forward) {
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while (n--)
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putp(scroll_forward);
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}
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}
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mvcur(-1, -1, win->_cury, win->_curx);
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} else
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touchline(win, win->_regtop, win->_regbottom - win->_regtop + 1);
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return OK;
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}
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