frm_data.c revision 1.1 
1
2/***************************************************************************
3*                            COPYRIGHT NOTICE                              *
4****************************************************************************
5*                ncurses is copyright (C) 1992-1995                        *
6*                          Zeyd M. Ben-Halim                               *
7*                          zmbenhal@netcom.com                             *
8*                          Eric S. Raymond                                 *
9*                          esr@snark.thyrsus.com                           *
10*                                                                          *
11*        Permission is hereby granted to reproduce and distribute ncurses  *
12*        by any means and for any fee, whether alone or as part of a       *
13*        larger distribution, in source or in binary form, PROVIDED        *
14*        this notice is included with any such distribution, and is not    *
15*        removed from any of its header files. Mention of ncurses in any   *
16*        applications linked with it is highly appreciated.                *
17*                                                                          *
18*        ncurses comes AS IS with no warranty, implied or expressed.       *
19*                                                                          *
20***************************************************************************/
21
22#include "form.priv.h"
23
24/*---------------------------------------------------------------------------
25|   Facility      :  libnform
26|   Function      :  bool data_behind(const FORM *form)
27|
28|   Description   :  Check for off-screen data behind. This is nearly trivial
29|                    becose the begin of a field is fixed.
30|
31|   Return Values :  TRUE   - there are off-screen data behind
32|                    FALSE  - there are no off-screen data behind
33+--------------------------------------------------------------------------*/
34bool data_behind(const FORM *form)
35{
36  bool result = FALSE;
37
38  if (form && (form->status & _POSTED) && form->current)
39    {
40      FIELD *field;
41
42      field = form->current;
43      if (!Single_Line_Field(field))
44	{
45	  result = (form->toprow==0) ? FALSE : TRUE;
46	}
47      else
48	{
49	  result = (form->begincol==0) ? FALSE : TRUE;
50	}
51    }
52  return(result);
53}
54
55/*---------------------------------------------------------------------------
56|   Facility      :  libnform
57|   Function      :  static char * After_Last_Non_Pad_Position(
58|                                    char *buffer,
59|                                    int len,
60|                                    int pad)
61|
62|   Description   :  Find the last position in the buffer that doesn't
63|                    contain a padding character.
64|
65|   Return Values :  The pointer to this position
66+--------------------------------------------------------------------------*/
67INLINE
68static char * After_Last_Non_Pad_Position(char *buffer, int len, int pad)
69{
70  char *end = buffer + len;
71
72  assert(buffer && len>=0);
73  while ( (buffer < end) && (*(end-1)==pad) )
74    end--;
75
76  return end;
77}
78
79#define SMALL_BUFFER_SIZE (80)
80
81/*---------------------------------------------------------------------------
82|   Facility      :  libnform
83|   Function      :  bool data_ahead(const FORM *form)
84|
85|   Description   :  Check for off-screen data ahead. This is more difficult
86|                    because a dynamic field has a variable end.
87|
88|   Return Values :  TRUE   - there are off-screen data ahead
89|                    FALSE  - there are no off-screen data ahead
90+--------------------------------------------------------------------------*/
91bool data_ahead(const FORM *form)
92{
93  bool result = FALSE;
94
95  if (form && (form->status & _POSTED) && form->current)
96    {
97      static char buffer[SMALL_BUFFER_SIZE + 1];
98      FIELD *field;
99      bool large_buffer;
100      bool cursor_moved = FALSE;
101      char *bp;
102      char *found_content;
103      int pos;
104
105      field = form->current;
106      assert(form->w);
107
108      large_buffer = (field->cols > SMALL_BUFFER_SIZE);
109      if (large_buffer)
110	bp = (char *)malloc((size_t)(field->cols) + 1);
111      else
112	bp = buffer;
113
114      assert(bp);
115
116      if (Single_Line_Field(field))
117	{
118	  int check_len;
119
120	  pos = form->begincol + field->cols;
121	  while (pos < field->dcols)
122	    {
123	      check_len = field->dcols - pos;
124	      if ( check_len >= field->cols )
125		check_len = field->cols;
126	      cursor_moved = TRUE;
127	      wmove(form->w,0,pos);
128	      winnstr(form->w,bp,check_len);
129	      found_content =
130		After_Last_Non_Pad_Position(bp,check_len,field->pad);
131	      if (found_content==bp)
132		  pos += field->cols;
133	      else
134		{
135		  result = TRUE;
136		  break;
137		}
138	    }
139	}
140      else
141	{
142	  pos = form->toprow + field->rows;
143	  while (pos < field->drows)
144	    {
145	      cursor_moved = TRUE;
146	      wmove(form->w,pos,0);
147	      pos++;
148	      winnstr(form->w,bp,field->cols);
149	      found_content =
150		After_Last_Non_Pad_Position(bp,field->cols,field->pad);
151	      if (found_content!=bp)
152		{
153		  result = TRUE;
154		  break;
155		}
156	    }
157	}
158
159      if (large_buffer)
160	free(bp);
161
162      if (cursor_moved)
163	wmove(form->w,form->currow,form->curcol);
164    }
165  return(result);
166}
167
168/* frm_data.c ends here */
169