/************************************************************************ 
 * This file is part of PDCurses. PDCurses is public domain software;	*
 * you may use it for any purpose. This software is provided AS IS with	*
 * NO WARRANTY whatsoever.						*
 *									*
 * If you use PDCurses in an application, an acknowledgement would be	*
 * appreciated, but is not mandatory. If you make corrections or	*
 * enhancements to PDCurses, please forward them to the current		*
 * maintainer for the benefit of other users.				*
 *									*
 * See the file maintain.er for details of the current maintainer.	*
 ************************************************************************/

#include <curspriv.h>

RCSID("$Id: pad.c,v 1.47 2007/06/21 23:23:50 wmcbrine Exp $")

/*man-start**************************************************************

  Name:								pad

  Synopsis:
	WINDOW *newpad(int nlines, int ncols);
	WINDOW *subpad(WINDOW *orig, int nlines, int ncols,
		       int begy, int begx);
	int prefresh(WINDOW *win, int py, int px, int sy1, int sx1,
		     int sy2, int sx2);
	int pnoutrefresh(WINDOW *w, int py, int px, int sy1, int sx1,
			 int sy2, int sx2);
	int pechochar(WINDOW *pad, chtype ch);
	int pecho_wchar(WINDOW *pad, const cchar_t *wch);

  Description:
	newpad() creates a new pad data structure.  A pad is a special 
	case of a window, which is not restricted by the screen size, 
	and is not necessarily associated with a particular part of the 
	screen.  A pad can be used when a large window is needed, and 
	only a part of the window will be on the screen at one tme.  
	Automatic refreshes of pads (e.g., from scrolling or echoing of 
	input) do not occur.  It is not legal to call refresh() with a 
	pad as an argument; the routines prefresh() or pnoutrefresh() 
	should be called instead.  Note that these routines require 
	additional parameters to specify the part of the pad to be 
	displayed and the location on the screen to be used for display.

	subpad() creates a new sub-pad within a pad.  The dimensions of 
	the sub-pad are nlines lines and ncols columns.  The sub-pad is 
	at position (begy, begx) in the the parent pad.  This position 
	is relative to the pad, and not to the screen as with subwin. 
	The sub-pad is made in the middle of the pad orig, so that 
	changes made to either pad will affect both.  When using this 
	routine, it will often be necessary to call touchwin() before 
	calling prefresh().

	prefresh() copies the specified pad to the physical terminal 
	screen.  It takes account of what is already displayed on the 
	screen to optimize cursor movement. pnoutrefresh() copies the 
	named pad to the virtual screen. It then compares the virtual 
	screen with the physical screen and performs the actual update. 
	These routines are analogous to wrefresh() and wnoutrefresh(), 
	just with pads instead of windows. Additional parameters are 
	also needed to indicate what part of the pad and screen are 
	involved. The upper left corner of the part of the pad to be 
	displayed is specified by py and px.  The coordinates sy1, sx1, 
	sy2, and sx2 specify the edges of the screen rectangle that will 
	contain the selected part of the pad.

	The lower right corner of the pad rectangle to be displayed is 
	calculated from the screen co-ordinates.  This ensures that the 
	screen rectangle and the pad rectangle are the same size. Both 
	rectangles must be entirely contained within their respective 
	structures.

	pechochar() is functionally equivalent to addch() followed by 
	a call to prefresh().

  Return Value:
	All functions return OK on success and ERR on error.

  Portability				     X/Open    BSD    SYS V
	newpad					Y	-	Y
	subpad					Y	-	Y
	prefresh				Y	-	Y
	pnoutrefresh				Y	-	Y
	pechochar				Y	-      3.0
	pecho_wchar				Y

**man-end****************************************************************/

#include <string.h>

/* save values for pechochar() */

static int save_pminrow, save_pmincol;
static int save_sminrow, save_smincol, save_smaxrow, save_smaxcol;

WINDOW *newpad(int nlines, int ncols)
{
	WINDOW *win;

	PDC_LOG(("newpad() - called: lines=%d cols=%d\n", nlines, ncols));

	if ((win = PDC_makenew(nlines, ncols, -1, -1)) == (WINDOW *)NULL
	 || (win = PDC_makelines(win)) == (WINDOW *)NULL)
		return (WINDOW *)NULL;

	werase(win);

	win->_flags = _PAD;

	/* save default values in case pechochar() is the first call
	   to prefresh(). */

	save_pminrow = 0;
	save_pmincol = 0;
	save_sminrow = 0;
	save_smincol = 0;
	save_smaxrow = min(LINES, nlines) - 1;
	save_smaxcol = min(COLS, ncols) - 1;

	return win;
}

WINDOW *subpad(WINDOW *orig, int nlines, int ncols, int begy, int begx)
{
	WINDOW *win;
	int i;
	int j = begy;
	int k = begx;

	PDC_LOG(("subpad() - called: lines=%d cols=%d begy=%d begx=%d\n",
		nlines, ncols, begy, begx));

	if (!orig || !(orig->_flags & _PAD))
		return (WINDOW *)NULL;

	/* make sure window fits inside the original one */

	if ((begy < orig->_begy) || (begx < orig->_begx) ||
	    (begy + nlines) > (orig->_begy + orig->_maxy) ||
	    (begx + ncols)  > (orig->_begx + orig->_maxx))
		return (WINDOW *)NULL;

	if (!nlines) 
		nlines = orig->_maxy - 1 - j;

	if (!ncols) 
		ncols = orig->_maxx - 1 - k;

	if ((win = PDC_makenew(nlines, ncols, begy, begx)) ==
	    (WINDOW *)NULL)
		return (WINDOW *)NULL;

	/* initialize window variables */

	win->_attrs = orig->_attrs;
	win->_leaveit = orig->_leaveit;
	win->_scroll = orig->_scroll;
	win->_nodelay = orig->_nodelay;
	win->_use_keypad = orig->_use_keypad;
	win->_parent = orig;

	for (i = 0; i < nlines; i++)
		win->_y[i] = (orig->_y[j++]) + k;

	win->_flags = _SUBPAD;

	/* save default values in case pechochar() is the first call
	   to prefresh(). */

	save_pminrow = 0;
	save_pmincol = 0;
	save_sminrow = 0;
	save_smincol = 0;
	save_smaxrow = min(LINES, nlines) - 1;
	save_smaxcol = min(COLS, ncols) - 1;

	return win;
}

int prefresh(WINDOW *win, int py, int px, int sy1, int sx1, int sy2, int sx2)
{
	PDC_LOG(("prefresh() - called\n"));

	if (pnoutrefresh(win, py, px, sy1, sx1, sy2, sx2) == ERR)
		return ERR;

	doupdate();
	return OK;
}

int pnoutrefresh(WINDOW *w, int py, int px, int sy1, int sx1, int sy2, int sx2)
{
	int num_cols;
	int sline = sy1;
	int pline = py;

	PDC_LOG(("pnoutrefresh() - called\n"));

	if (!w || !(w->_flags & (_PAD|_SUBPAD)) ||
	    (sy2 >= LINES) || (sy2 >= COLS))
		return ERR;

	if (py < 0)
		py = 0;
	if (px < 0)
		px = 0;
	if (sy1 < 0)
		sy1 = 0;
	if (sx1 < 0)
		sx1 = 0;

	if (sy2 < sy1 || sx2 < sx1)
		return ERR;

	num_cols = min((sx2 - sx1 + 1), (w->_maxx - px));

	while (sline <= sy2)
	{
		if (pline < w->_maxy)
		{
			memcpy(curscr->_y[sline] + sx1, w->_y[pline] + px,
				num_cols * sizeof(chtype));

			if ((curscr->_firstch[sline] == _NO_CHANGE) 
			    || (curscr->_firstch[sline] > sx1))
				curscr->_firstch[sline] = sx1;

			if (sx2 > curscr->_lastch[sline])
				curscr->_lastch[sline] = sx2;

			w->_firstch[pline] = _NO_CHANGE;  /* updated now */
			w->_lastch[pline] = _NO_CHANGE;  /* updated now */
		}

		sline++;
		pline++;
	}

	if (w->_clear)
	{
		w->_clear = FALSE;
		curscr->_clear = TRUE;
	}

	/* position the cursor to the pad's current position if
	   possible -- is the pad current position going to end up 
	   displayed? if not, then don't move the cursor; if so, move it 
	   to the correct place */

	if (!w->_leaveit && w->_cury >= py && w->_curx >= px &&
	     w->_cury <= py + (sy2 - sy1) &&
	     w->_curx <= px + (sx2 - sx1))
	{
		curscr->_cury = (w->_cury - py) + sy1;
		curscr->_curx = (w->_curx - px) + sx1;
	}

	return OK;
}

int pechochar(WINDOW *pad, chtype ch)
{
	PDC_LOG(("pechochar() - called\n"));

	if (waddch(pad, ch) == ERR)
		return ERR;

	return prefresh(pad, save_pminrow, save_pmincol, save_sminrow, 
		save_smincol, save_smaxrow, save_smaxcol);
}

#ifdef PDC_WIDE
int pecho_wchar(WINDOW *pad, const cchar_t *wch)
{
	PDC_LOG(("pecho_wchar() - called\n"));

	if (!wch || (waddch(pad, *wch) == ERR))
		return ERR;

	return prefresh(pad, save_pminrow, save_pmincol, save_sminrow, 
		save_smincol, save_smaxrow, save_smaxcol);
}
#endif