diff options
Diffstat (limited to 'ncurses-5.3/ncurses/base/lib_scroll.c')
-rw-r--r-- | ncurses-5.3/ncurses/base/lib_scroll.c | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/ncurses-5.3/ncurses/base/lib_scroll.c b/ncurses-5.3/ncurses/base/lib_scroll.c new file mode 100644 index 0000000..324e637 --- /dev/null +++ b/ncurses-5.3/ncurses/base/lib_scroll.c @@ -0,0 +1,152 @@ +/**************************************************************************** + * Copyright (c) 1998,2000,2001 Free Software Foundation, Inc. * + * * + * 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, distribute with modifications, 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 COPYRIGHT HOLDERS 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. * + ****************************************************************************/ + +/**************************************************************************** + * Author: Thomas E. Dickey 1996-2001 * + * and: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995 * + * and: Eric S. Raymond <esr@snark.thyrsus.com> * + ****************************************************************************/ + +/* +** lib_scroll.c +** +** The routine wscrl(win, n). +** positive n scroll the window up (ie. move lines down) +** negative n scroll the window down (ie. move lines up) +** +*/ + +#include <curses.priv.h> + +MODULE_ID("$Id$") + +NCURSES_EXPORT(void) +_nc_scroll_window(WINDOW *win, int const n, NCURSES_SIZE_T const top, + NCURSES_SIZE_T const bottom, NCURSES_CH_T blank) +{ + int limit; + int line; + int j; + size_t to_copy = (size_t) (sizeof(NCURSES_CH_T) * (win->_maxx + 1)); + + TR(TRACE_MOVE, ("_nc_scroll_window(%p, %d, %d, %d)", win, n, top, bottom)); + + if (top < 0 + || bottom < top + || bottom > win->_maxy) { + TR(TRACE_MOVE, ("nothing to scroll")); + return; + } + + /* + * This used to do a line-text pointer-shuffle instead of text copies. + * That (a) doesn't work when the window is derived and doesn't have + * its own storage, (b) doesn't save you a lot on modern machines + * anyway. Your typical memcpy implementations are coded in + * assembler using a tight BLT loop; for the size of copies we're + * talking here, the total execution time is dominated by the one-time + * setup cost. So there is no point in trying to be excessively + * clever -- esr. + */ + + /* shift n lines downwards */ + if (n < 0) { + limit = top - n; + if (limit > win->_maxy) + limit = win->_maxy; + for (line = bottom; line >= limit; line--) { + if (line + n >= 0) { + TR(TRACE_MOVE, ("...copying %d to %d", line + n, line)); + memcpy(win->_line[line].text, + win->_line[line + n].text, + to_copy); + if_USE_SCROLL_HINTS(win->_line[line].oldindex = + win->_line[line + n].oldindex); + } else { + TR(TRACE_MOVE, ("...filling %d", line)); + for (j = 0; j <= win->_maxx; j++) + win->_line[line].text[j] = blank; + if_USE_SCROLL_HINTS(win->_line[line].oldindex = _NEWINDEX); + } + } + for (line = top; line < limit; line++) { + TR(TRACE_MOVE, ("...filling %d", line)); + for (j = 0; j <= win->_maxx; j++) + win->_line[line].text[j] = blank; + if_USE_SCROLL_HINTS(win->_line[line].oldindex = _NEWINDEX); + } + } + + /* shift n lines upwards */ + if (n > 0) { + limit = bottom - n; + if (limit < 0) + limit = 0; + for (line = top; line <= limit; line++) { + if (line + n <= win->_maxy) { + TR(TRACE_MOVE, ("...copying %d to %d", line + n, line)); + memcpy(win->_line[line].text, + win->_line[line + n].text, + to_copy); + if_USE_SCROLL_HINTS(win->_line[line].oldindex = + win->_line[line + n].oldindex); + } else { + TR(TRACE_MOVE, ("...filling %d", line)); + for (j = 0; j <= win->_maxx; j++) + win->_line[line].text[j] = blank; + if_USE_SCROLL_HINTS(win->_line[line].oldindex = _NEWINDEX); + } + } + for (line = bottom; line > limit; line--) { + TR(TRACE_MOVE, ("...filling %d", line)); + for (j = 0; j <= win->_maxx; j++) + win->_line[line].text[j] = blank; + if_USE_SCROLL_HINTS(win->_line[line].oldindex = _NEWINDEX); + } + } + touchline(win, top, bottom - top + 1); +} + +NCURSES_EXPORT(int) +wscrl(WINDOW *win, int n) +{ + T((T_CALLED("wscrl(%p,%d)"), win, n)); + + if (!win || !win->_scroll) { + TR(TRACE_MOVE, ("...scrollok is false")); + returnCode(ERR); + } + + if (n == 0) + returnCode(OK); + + _nc_scroll_window(win, n, win->_regtop, win->_regbottom, win->_nc_bkgd); + + _nc_synchook(win); + returnCode(OK); +} |