newwin.c

操作系统源代码

#include <stdlib.h>
#include <curses.h>
#include "curspriv.h"

/****************************************************************/
/* Makenew() allocates all data for a new window except the	*/
/* Actual lines themselves.					*/
/****************************************************************/

_PROTOTYPE(static WINDOW *makenew, (int nlines, int ncols, int begy,int begx));

static WINDOW *makenew(num_lines, num_columns, begy, begx)
int num_lines, num_columns, begy, begx;
{
  int i;
  WINDOW *win;

  /* Allocate the window structure itself */
  if ((win = (WINDOW *) malloc(sizeof(WINDOW))) == NULL) 
	return((WINDOW *) ERR);

  /* Allocate the line pointer array */
  if ((win->_line = (int **) calloc(num_lines, sizeof(int *))) == NULL) {
	free(win);
	return((WINDOW *) ERR);
  }

  /* Allocate the minchng and maxchng arrays */
  if ((win->_minchng = (int *) calloc(num_lines, sizeof(int))) == NULL) {
	free(win);
	free(win->_line);
	return((WINDOW *) ERR);
  }
  if ((win->_maxchng = (int *) calloc(num_lines, sizeof(int))) == NULL) {
	free(win);
	free(win->_line);
	free(win->_minchng);
	return((WINDOW *) ERR);
  }

  /* Initialize window variables */
  win->_curx = 0;
  win->_cury = 0;
  win->_maxy = num_lines - 1;
  win->_maxx = num_columns - 1;
  win->_begy = begy;
  win->_begx = begx;
  win->_flags = 0;
  win->_attrs = ATR_NRM;
  win->_tabsize = 8;
  win->_clear = FALSE;
  win->_leave = FALSE;
  win->_scroll = FALSE;
  win->_nodelay = FALSE;
  win->_keypad = FALSE;
  win->_regtop = 0;
  win->_regbottom = num_lines - 1;

  /* Init to say window unchanged */
  for (i = 0; i < num_lines; i++) {
	win->_minchng[i] = 0;
	win->_maxchng[i] = num_columns - 1;
  }

  /* Set flags for window properties */
  if ((begy + num_lines) == LINES) {
	win->_flags |= _ENDLINE;
	if ((begx == 0) && (num_columns == COLS) && (begy == 0))
		win->_flags |= _FULLWIN;
  }				/* if */
  if (((begy + num_lines) == LINES) && ((begx + num_columns) == COLS))
	win->_flags |= _SCROLLWIN;
  return(win);
}


/****************************************************************/
/* Newwin() creates a new window with size num_lines * num_co-	*/
/* Lumns, and origin begx,begy relative to the SCREEN. Special	*/
/* Case: if num_lines and/or num_columns is 0, the remainder of	*/
/* The screen is used.						*/
/****************************************************************/
WINDOW *newwin(num_lines, num_columns, begy, begx)
int num_lines, num_columns, begy, begx;
{
  WINDOW *win;
  int *ptr;
  int i, j;

  if (num_lines == 0) num_lines = LINES - begy;
  if (num_columns == 0) num_columns = COLS - begx;
  if ((win = makenew(num_lines, num_columns, begy, begx)) == (WINDOW *) ERR)
	return((WINDOW *) ERR);
  for (i = 0; i < num_lines; i++) {	/* make and clear the lines */
	if ((win->_line[i] = (int *)calloc(num_columns, sizeof(int))) == NULL){
		for (j = 0; j < i; j++)	/* if error, free all the data */
			free(win->_line[j]);
		free(win->_minchng);
		free(win->_maxchng);
		free(win->_line);
		free(win);
		return((WINDOW *) ERR);
	} else {
		for (ptr = win->_line[i]; ptr < win->_line[i] + num_columns;)
			*ptr++ = ' ' | ATR_NRM;
	}
  }
  return(win);
}


/****************************************************************/
/* Subwin() creates a sub-window in the 'orig' window, with	*/
/* Size num_lines * num_columns, and with origin begx, begy	*/
/* Relative to the SCREEN. Special case: if num_lines and/or	*/
/* Num_columns is 0, the remainder of the original window is	*/
/* Used. The subwindow uses the original window's line buffers	*/
/* To store it's own lines.					*/
/****************************************************************/
WINDOW *subwin(orig, num_lines, num_columns, begy, begx)
WINDOW *orig;
int num_lines, num_columns, begy, begx;
{
  WINDOW *win;
  int i, j, k;

  /* Make sure window fits inside the original one */
  if (begy < orig->_begy || begx < orig->_begx ||
		      (begy + num_lines) > (orig->_begy + orig->_maxy) ||
		      (begx + num_columns) > (orig->_begx + orig->_maxx) )
	return((WINDOW *) ERR);

  if (num_lines == 0) num_lines = orig->_maxy - (begy - orig->_begy);
  if (num_columns == 0) num_columns = orig->_maxx - (begx - orig->_begx);
  if ((win = makenew(num_lines, num_columns, begy, begx)) == (WINDOW *) ERR)
	return((WINDOW *) ERR);

  /* Set line pointers the same as in the original window */
  j = begy - orig->_begy;
  k = begx - orig->_begx;
  for (i = 0; i < num_lines; i++) win->_line[i] = (orig->_line[j++]) + k;
  win->_flags |= _SUBWIN;
  return(win);
}