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ripoffline.c revision 1.1 
      1 /*	$NetBSD: ripoffline.c,v 1.1 2017/01/11 20:43:03 roy Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2017 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Roy Marples.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 #ifndef lint
     34 __RCSID("$NetBSD: ripoffline.c,v 1.1 2017/01/11 20:43:03 roy Exp $");
     35 #endif				/* not lint */
     36 
     37 #include "curses.h"
     38 #include "curses_private.h"
     39 
     40 /* List of ripoffline calls */
     41 static struct ripoff {
     42 	int	nlines;
     43 	int	(*init)(WINDOW *, int);
     44 } ripoffs[MAX_RIPS];
     45 static int nrips;
     46 
     47 /*
     48  * ripoffline --
     49  *	Ripoff a line from the top of bottom of stdscr.
     50  *	Must be called before initscr or newterm.
     51  */
     52 int
     53 ripoffline(int line, int (*init)(WINDOW *, int))
     54 {
     55 
     56 #ifdef DEBUG
     57 	__CTRACE(__CTRACE_SCREEN, "ripoffline: %d\n", line);
     58 #endif
     59 
     60 	if (nrips >= MAX_RIPS || init == NULL)
     61 		return ERR; /* This makes sense, but not standards compliant. */
     62 	if (line == 0)
     63 		return OK;
     64 	ripoffs[nrips].nlines = line < 0 ? -1 : 1;
     65 	ripoffs[nrips++].init = init;
     66 	return OK;
     67 }
     68 
     69 /*
     70  * __rippedlines --
     71  *	Returns the number of ripped lines from the screen.
     72  */
     73 int
     74 __rippedlines(const SCREEN *screen)
     75 {
     76 	const struct __ripoff *rip;
     77 	int i, n;
     78 
     79 	n = 0;
     80 	for (i = 0, rip = screen->ripped; i < screen->nripped; i++, rip++) {
     81 		if (rip->nlines < 0)
     82 			n += -rip->nlines;
     83 		else
     84 			n += rip->nlines;
     85 	}
     86 	return n;
     87 }
     88 
     89 /*
     90  * __ripoffscreen --
     91  *	Rips lines from the screen by creating a WINDOW per ripoffline call.
     92  *	Although the POSIX API only allows for one line WINDOWS to be created,
     93  *	this implemenation allows for N lines if needed.
     94  */
     95 int
     96 __ripoffscreen(SCREEN *screen, int *rtop)
     97 {
     98 	int i, nlines;
     99 	const struct ripoff *srip;
    100 	struct __ripoff *rip;
    101 	WINDOW *w;
    102 
    103 	*rtop = 0;
    104 	rip = screen->ripped;
    105 	for (i = 0, srip = ripoffs; i < nrips; i++, srip++) {
    106 		nlines = srip->nlines < 0 ? -srip->nlines : srip->nlines;
    107 		w = __newwin(screen, nlines, 0,
    108 		    srip->nlines < 0 ? LINES - nlines : *rtop,
    109 		    0, FALSE);
    110 		if (w != NULL) {
    111 			rip->win = w;
    112 			rip->nlines = srip->nlines;
    113 			rip++;
    114 			screen->nripped++;
    115 			if (rip->nlines > 0)
    116 				(*rtop) += rip->nlines;
    117 			LINES -= nlines;
    118 		}
    119 		if (srip->init(w, COLS) == ERR)
    120 			return ERR;
    121 #ifdef DEBUG
    122 		if (w != NULL)
    123 			__CTRACE(__CTRACE_SCREEN,
    124 			    "newterm: ripped %d lines from the %s\n",
    125 			    nlines, srip->nlines < 0 ? "bottom" : "top");
    126 #endif
    127 	}
    128 	nrips = 0; /* Reset the stack. */
    129 	return OK;
    130 }
    131 
    132 /*
    133  * __ripoffresize --
    134  *	Called from resizeterm to ensure the ripped off lines are correctly
    135  *	placed and refreshed.
    136  */
    137 void
    138 __ripoffresize(SCREEN *screen)
    139 {
    140 	int rbot = _cursesi_screen->LINES, i;
    141 	struct __ripoff *rip;
    142 
    143 	for (i = 0, rip = _cursesi_screen->ripped;
    144 	     i < _cursesi_screen->nripped;
    145 	     i++, rip++)
    146 	{
    147 		if (rip->nlines > 0)
    148 			touchwin(rip->win);
    149 		else {
    150 			/* Reposition the lower windows. */
    151 			mvwin(rip->win, rbot + rip->nlines, 0);
    152 			rbot += rip->nlines;
    153 		}
    154 		wnoutrefresh(rip->win);
    155 	}
    156 }
    157