tty_update.c

ncurses-5.4 需要的就来下把 一定会有用的哦

		&& can_clear_with(CHREF(ntext0))) {
		UpdateAttrs(AttrOf(ntext0));
		putp(tparm(erase_chars, runcount));

		/*
		 * If this is the last part of the given interval,
		 * don't bother moving cursor, since it can be the
		 * last update on the line.
		 */
		if (runcount < num) {
		    GoTo(SP->_cursrow, SP->_curscol + runcount);
		} else {
		    return 1;	/* cursor stays in the middle */
		}
	    } else if (repeat_char && runcount > SP->_rep_cost) {
		bool wrap_possible = (SP->_curscol + runcount >= screen_columns);
		int rep_count = runcount;

		if (wrap_possible)
		    rep_count--;

		UpdateAttrs(AttrOf(ntext0));
		tputs(tparm(repeat_char, CharOf(ntext0), rep_count),
		      rep_count, _nc_outch);
		SP->_curscol += rep_count;

		if (wrap_possible)
		    PutChar(CHREF(ntext0));
	    } else {
		for (i = 0; i < runcount; i++)
		    PutChar(CHREF(ntext[i]));
	    }
	    ntext += runcount;
	    num -= runcount;
	}
	return 0;
    }

    for (i = 0; i < num; i++)
	PutChar(CHREF(ntext[i]));
    return 0;
}

/*
 * Output the line in the given range [first .. last]
 *
 * If there's a run of identical characters that's long enough to justify
 * cursor movement, use that also.
 *
 * Returns: same as EmitRange
 */
static int
PutRange(const NCURSES_CH_T * otext,
	 const NCURSES_CH_T * ntext,
	 int row,
	 int first, int last)
{
    int i, j, same;

    TR(TRACE_CHARPUT, ("PutRange(%p, %p, %d, %d, %d)",
		       otext, ntext, row, first, last));

    if (otext != ntext
	&& (last - first + 1) > SP->_inline_cost) {
	for (j = first, same = 0; j <= last; j++) {
	    if (!same && isnac(otext[j]))
		continue;
	    if (CharEq(otext[j], ntext[j])) {
		same++;
	    } else {
		if (same > SP->_inline_cost) {
		    EmitRange(ntext + first, j - same - first);
		    GoTo(row, first = j);
		}
		same = 0;
	    }
	}
	i = EmitRange(ntext + first, j - same - first);
	/*
	 * Always return 1 for the next GoTo() after a PutRange() if we found
	 * identical characters at end of interval
	 */
	return (same == 0 ? i : 1);
    }
    return EmitRange(ntext + first, last - first + 1);
}

/* leave unbracketed here so 'indent' works */
#define MARK_NOCHANGE(win,row) \
		win->_line[row].firstchar = _NOCHANGE; \
		win->_line[row].lastchar = _NOCHANGE; \
		if_USE_SCROLL_HINTS(win->_line[row].oldindex = row)

NCURSES_EXPORT(int)
doupdate(void)
{
    int i;
    int nonempty;
#if USE_TRACE_TIMES
    struct tms before, after;
#endif /* USE_TRACE_TIMES */

    T((T_CALLED("doupdate()")));

#ifdef TRACE
    if (_nc_tracing & TRACE_UPDATE) {
	if (curscr->_clear)
	    _tracef("curscr is clear");
	else
	    _tracedump("curscr", curscr);
	_tracedump("newscr", newscr);
    }
#endif /* TRACE */

    _nc_signal_handler(FALSE);

    if (SP->_fifohold)
	SP->_fifohold--;

#if USE_SIZECHANGE
    if (SP->_endwin || SP->_sig_winch) {
	/*
	 * This is a transparent extension:  XSI does not address it,
	 * and applications need not know that ncurses can do it.
	 *
	 * Check if the terminal size has changed while curses was off
	 * (this can happen in an xterm, for example), and resize the
	 * ncurses data structures accordingly.
	 */
	_nc_update_screensize();
    }
#endif

    if (SP->_endwin) {

	T(("coming back from shell mode"));
	reset_prog_mode();

	_nc_mvcur_resume();
	_nc_screen_resume();
	SP->_mouse_resume(SP);

	SP->_endwin = FALSE;
    }
#if USE_TRACE_TIMES
    /* zero the metering machinery */
    _nc_outchars = 0;
    (void) times(&before);
#endif /* USE_TRACE_TIMES */

    /*
     * This is the support for magic-cookie terminals.  The
     * theory: we scan the virtual screen looking for attribute
     * turnons.  Where we find one, check to make sure it's
     * realizable by seeing if the required number of
     * un-attributed blanks are present before and after the
     * attributed range; try to shift the range boundaries over
     * blanks (not changing the screen display) so this becomes
     * true.  If it is, shift the beginning attribute change
     * appropriately (the end one, if we've gotten this far, is
     * guaranteed room for its cookie). If not, nuke the added
     * attributes out of the span.
     */
#if USE_XMC_SUPPORT
    if (magic_cookie_glitch > 0) {
	int j, k;
	attr_t rattr = A_NORMAL;

	for (i = 0; i < screen_lines; i++) {
	    for (j = 0; j < screen_columns; j++) {
		bool failed = FALSE;
		attr_t turnon = AttrOf(newscr->_line[i].text[j]) & ~rattr;

		/* is an attribute turned on here? */
		if (turnon == 0) {
		    rattr = AttrOf(newscr->_line[i].text[j]);
		    continue;
		}

		TR(TRACE_ATTRS, ("At (%d, %d): from %s...", i, j, _traceattr(rattr)));
		TR(TRACE_ATTRS, ("...to %s", _traceattr(turnon)));

		/*
		 * If the attribute change location is a blank with a
		 * "safe" attribute, undo the attribute turnon.  This may
		 * ensure there's enough room to set the attribute before
		 * the first non-blank in the run.
		 */
#define SAFE(a)	(!((a) & (attr_t)~NONBLANK_ATTR))
		if (ISBLANK(newscr->_line[i].text[j]) && SAFE(turnon)) {
		    RemAttr(newscr->_line[i].text[j], turnon);
		    continue;
		}

		/* check that there's enough room at start of span */
		for (k = 1; k <= magic_cookie_glitch; k++) {
		    if (j - k < 0
			|| !ISBLANK(newscr->_line[i].text[j - k])
			|| !SAFE(AttrOf(newscr->_line[i].text[j - k])))
			failed = TRUE;
		}
		if (!failed) {
		    bool end_onscreen = FALSE;
		    int m, n = j;

		    /* find end of span, if it's onscreen */
		    for (m = i; m < screen_lines; m++) {
			for (; n < screen_columns; n++) {
			    if (AttrOf(newscr->_line[m].text[n]) == rattr) {
				end_onscreen = TRUE;
				TR(TRACE_ATTRS,
				   ("Range attributed with %s ends at (%d, %d)",
				    _traceattr(turnon), m, n));
				goto foundit;
			    }
			}
			n = 0;
		    }
		    TR(TRACE_ATTRS,
		       ("Range attributed with %s ends offscreen",
			_traceattr(turnon)));
		  foundit:;

		    if (end_onscreen) {
			NCURSES_CH_T *lastline = newscr->_line[m].text;

			/*
			 * If there are safely-attributed blanks at the
			 * end of the range, shorten the range.  This will
			 * help ensure that there is enough room at end
			 * of span.
			 */
			while (n >= 0
			       && ISBLANK(lastline[n])
			       && SAFE(AttrOf(lastline[n])))
			    RemAttr(lastline[n--], turnon);

			/* check that there's enough room at end of span */
			for (k = 1; k <= magic_cookie_glitch; k++)
			    if (n + k >= screen_columns
				|| !ISBLANK(lastline[n + k])
				|| !SAFE(AttrOf(lastline[n + k])))
				failed = TRUE;
		    }
		}

		if (failed) {
		    int p, q = j;

		    TR(TRACE_ATTRS,
		       ("Clearing %s beginning at (%d, %d)",
			_traceattr(turnon), i, j));

		    /* turn off new attributes over span */
		    for (p = i; p < screen_lines; p++) {
			for (; q < screen_columns; q++) {
			    if (AttrOf(newscr->_line[p].text[q]) == rattr)
				goto foundend;
			    RemAttr(newscr->_line[p].text[q], turnon);
			}
			q = 0;
		    }
		  foundend:;
		} else {
		    TR(TRACE_ATTRS,
		       ("Cookie space for %s found before (%d, %d)",
			_traceattr(turnon), i, j));

		    /*
		     * back up the start of range so there's room
		     * for cookies before the first nonblank character
		     */
		    for (k = 1; k <= magic_cookie_glitch; k++)
			AddAttr(newscr->_line[i].text[j - k], turnon);
		}

		rattr = AttrOf(newscr->_line[i].text[j]);
	    }
	}

#ifdef TRACE
	/* show altered highlights after magic-cookie check */
	if (_nc_tracing & TRACE_UPDATE) {
	    _tracef("After magic-cookie check...");
	    _tracedump("newscr", newscr);
	}
#endif /* TRACE */
    }
#endif /* USE_XMC_SUPPORT */

    nonempty = 0;
    if (curscr->_clear || newscr->_clear) {	/* force refresh ? */
	TR(TRACE_UPDATE, ("clearing and updating from scratch"));
	ClrUpdate();
	curscr->_clear = FALSE;	/* reset flag */
	newscr->_clear = FALSE;	/* reset flag */
    } else {
	int changedlines = CHECK_INTERVAL;

	if (check_pending())
	    goto cleanup;

	nonempty = min(screen_lines, newscr->_maxy + 1);

	if (SP->_scrolling) {
	    _nc_scroll_optimize();
	}

	nonempty = ClrBottom(nonempty);

	TR(TRACE_UPDATE, ("Transforming lines, nonempty %d", nonempty));
	for (i = 0; i < nonempty; i++) {
	    /*
	     * Here is our line-breakout optimization.
	     */
	    if (changedlines == CHECK_INTERVAL) {
		if (check_pending())
		    goto cleanup;
		changedlines = 0;
	    }

	    /*
	     * newscr->line[i].firstchar is normally set
	     * by wnoutrefresh.  curscr->line[i].firstchar
	     * is normally set by _nc_scroll_window in the
	     * vertical-movement optimization code,
	     */
	    if (newscr->_line[i].firstchar != _NOCHANGE
		|| curscr->_line[i].firstchar != _NOCHANGE) {
		TransformLine(i);
		changedlines++;
	    }

	    /* mark line changed successfully */
	    if (i <= newscr->_maxy) {
		MARK_NOCHANGE(newscr, i);
	    }
	    if (i <= curscr->_maxy) {
		MARK_NOCHANGE(curscr, i);
	    }
	}
    }

    /* put everything back in sync */
    for (i = nonempty; i <= newscr->_maxy; i++) {
	MARK_NOCHANGE(newscr, i);
    }
    for (i = nonempty; i <= curscr->_maxy; i++) {
	MARK_NOCHANGE(curscr, i);
    }

    if (!newscr->_leaveok) {
	curscr->_curx = newscr->_curx;
	curscr->_cury = newscr->_cury;

	GoTo(curscr->_cury, curscr->_curx);
    }

  cleanup:
    /*
     * Keep the physical screen in normal mode in case we get other
     * processes writing to the screen.
     */
    UpdateAttrs(A_NORMAL);

    _nc_flush();
    curscr->_attrs = newscr->_attrs;

#if USE_TRACE_TIMES
    (void) times(&after);
    TR(TRACE_TIMES,
       ("Update cost: %ld chars, %ld clocks system time, %ld clocks user time",
	_nc_outchars,
	(long) (after.tms_stime - before.tms_stime),
	(long) (after.tms_utime - before.tms_utime)));
#endif /* USE_TRACE_TIMES */

    _nc_signal_handler(TRUE);

    returnCode(OK);
}

/*
 *	ClrBlank(win)
 *
 *	Returns the attributed character that corresponds to the "cleared"
 *	screen.  If the terminal has the back-color-erase feature, this will be
 *	colored according to the wbkgd() call.
 *
 *	We treat 'curscr' specially because it isn't supposed to be set directly
 *	in the wbkgd() call.  Assume 'stdscr' for this case.
 */
#define BCE_ATTRS (A_NORMAL|A_COLOR)
#define BCE_BKGD(win) (((win) == curscr ? stdscr : (win))->_nc_bkgd)

static inline NCURSES_CH_T
ClrBlank(WINDOW *win)
{
    NCURSES_CH_T blank = NewChar(BLANK_TEXT);
    if (back_color_erase)
	AddAttr(blank, (AttrOf(BCE_BKGD(win)) & BCE_ATTRS));
    return blank;
}

/*
**	ClrUpdate()
**
**	Update by clearing and redrawing the entire screen.
**
*/

static void
ClrUpdate(void)
{
    int i;
    NCURSES_CH_T blank = ClrBlank(stdscr);
    int nonempty = min(screen_lines, newscr->_maxy + 1);

    TR(TRACE_UPDATE, ("ClrUpdate() called"));

    ClearScreen(blank);

    TR(TRACE_UPDATE, ("updating screen from scratch"));

    nonempty = ClrBottom(nonempty);

    for (i = 0; i < nonempty; i++)
	TransformLine(i);
}

/*
**	ClrToEOL(blank)
**
**	Clear to end of current line, starting at the cursor position
*/

static void
ClrToEOL(NCURSES_CH_T blank, bool needclear)
{
    int j;

    if (curscr != 0
	&& SP->_cursrow >= 0) {
	for (j = SP->_curscol; j < screen_columns; j++) {
	    if (j >= 0) {
		NCURSES_CH_T *cp = &(curscr->_line[SP->_cursrow].text[j]);

		if (!CharEq(*cp, blank)) {
		    *cp = blank;
		    needclear = TRUE;
		}
	    }
	}
    } else {
	needclear = TRUE;
    }

    if (needclear) {
	UpdateAttrs(AttrOf(blank));
	TPUTS_TRACE("clr_eol");
	if (clr_eol && SP->_el_cost <= (screen_columns - SP->_curscol)) {
	    putp(clr_eol);
	} else {
	    int count = (screen_columns - SP->_curscol);
	    while (count-- > 0)
		PutChar(CHREF(blank));
	}
    }
}

/*
**	ClrToEOS(blank)