lib_refresh.c

ncurses 库 可能有用酒用 没用就算了 我觉得还可以用

/****************************************************************************
 * Copyright (c) 1998-2002,2005 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       *
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 ****************************************************************************/

/****************************************************************************
 *  Author: Zeyd M. Ben-Halim <[e-mail]> 1992,1995               *
 *     and: Eric S. Raymond <[e-mail]>                         *
 *     and: Thomas E. Dickey                        1996-on                 *
 ****************************************************************************/

/*
 *	lib_refresh.c
 *
 *	The routines wrefresh() and wnoutrefresh().
 *
 */

#include <curses.priv.h>

MODULE_ID("$Id: lib_refresh.c,v 1.33 2005/04/09 15:20:58 tom Exp $")

NCURSES_EXPORT(int)
wrefresh(WINDOW *win)
{
    int code;

    T((T_CALLED("wrefresh(%p)"), win));

    if (win == 0) {
	code = ERR;
    } else if (win == curscr) {
	curscr->_clear = TRUE;
	code = doupdate();
    } else if ((code = wnoutrefresh(win)) == OK) {
	if (win->_clear)
	    newscr->_clear = TRUE;
	code = doupdate();
	/*
	 * Reset the clearok() flag in case it was set for the special
	 * case in hardscroll.c (if we don't reset it here, we'll get 2
	 * refreshes because the flag is copied from stdscr to newscr).
	 * Resetting the flag shouldn't do any harm, anyway.
	 */
	win->_clear = FALSE;
    }
    returnCode(code);
}

NCURSES_EXPORT(int)
wnoutrefresh(WINDOW *win)
{
    NCURSES_SIZE_T limit_x;
    NCURSES_SIZE_T i, j;
    NCURSES_SIZE_T begx;
    NCURSES_SIZE_T begy;
    NCURSES_SIZE_T m, n;
#if USE_SCROLL_HINTS
    bool wide;
#endif

    T((T_CALLED("wnoutrefresh(%p)"), win));
#ifdef TRACE
    if (_nc_tracing & TRACE_UPDATE)
	_tracedump("...win", win);
#endif /* TRACE */

    /*
     * This function will break badly if we try to refresh a pad.
     */
    if ((win == 0)
	|| (win->_flags & _ISPAD))
	returnCode(ERR);

    /* put them here so "win == 0" won't break our code */
    begx = win->_begx;
    begy = win->_begy;

    newscr->_nc_bkgd = win->_nc_bkgd;
    newscr->_attrs = win->_attrs;

    /* merge in change information from all subwindows of this window */
    wsyncdown(win);

#if USE_SCROLL_HINTS
    /*
     * For pure efficiency, we'd want to transfer scrolling information
     * from the window to newscr whenever the window is wide enough that
     * its update will dominate the cost of the update for the horizontal
     * band of newscr that it occupies.  Unfortunately, this threshold
     * tends to be complex to estimate, and in any case scrolling the
     * whole band and rewriting the parts outside win's image would look
     * really ugly.  So.  What we do is consider the window "wide" if it
     * either (a) occupies the whole width of newscr, or (b) occupies
     * all but at most one column on either vertical edge of the screen
     * (this caters to fussy people who put boxes around full-screen
     * windows).  Note that changing this formula will not break any code,
     * merely change the costs of various update cases.
     */
    wide = (begx <= 1 && win->_maxx >= (newscr->_maxx - 1));
#endif

    win->_flags &= ~_HASMOVED;

    /*
     * Microtweaking alert!  This double loop is one of the genuine
     * hot spots in the code.  Even gcc doesn't seem to do enough
     * common-subexpression chunking to make it really tense,
     * so we'll force the issue.
     */

    /* limit(n) */
    limit_x = win->_maxx;
    /* limit(j) */
    if (limit_x > newscr->_maxx - begx)
	limit_x = newscr->_maxx - begx;

    for (i = 0, m = begy + win->_yoffset;
	 i <= win->_maxy && m <= newscr->_maxy;
	 i++, m++) {
	register struct ldat *nline = &newscr->_line[m];
	register struct ldat *oline = &win->_line[i];

	if (oline->firstchar != _NOCHANGE) {
	    int last = oline->lastchar;

	    if (last > limit_x)
		last = limit_x;

	    for (j = oline->firstchar, n = j + begx; j <= last; j++, n++) {
		if (!CharEq(oline->text[j], nline->text[n])) {
		    nline->text[n] = oline->text[j];
		    CHANGED_CELL(nline, n);
		}
	    }

	}
#if USE_SCROLL_HINTS
	if (wide) {
	    int oind = oline->oldindex;

	    nline->oldindex = (oind == _NEWINDEX) ? _NEWINDEX : begy + oind
		+ win->_yoffset;
	}
#endif /* USE_SCROLL_HINTS */

	oline->firstchar = oline->lastchar = _NOCHANGE;
	if_USE_SCROLL_HINTS(oline->oldindex = i);
    }

    if (win->_clear) {
	win->_clear = FALSE;
	newscr->_clear = TRUE;
    }

    if (!win->_leaveok) {
	newscr->_cury = win->_cury + win->_begy + win->_yoffset;
	newscr->_curx = win->_curx + win->_begx;
    }
    newscr->_leaveok = win->_leaveok;

#ifdef TRACE
    if (_nc_tracing & TRACE_UPDATE)
	_tracedump("newscr", newscr);
#endif /* TRACE */
    returnCode(OK);
}