frm_data.c revision 50276 
1/****************************************************************************
2 * Copyright (c) 1998 Free Software Foundation, Inc.                        *
3 *                                                                          *
4 * Permission is hereby granted, free of charge, to any person obtaining a  *
5 * copy of this software and associated documentation files (the            *
6 * "Software"), to deal in the Software without restriction, including      *
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8 * distribute, distribute with modifications, sublicense, and/or sell       *
9 * copies of the Software, and to permit persons to whom the Software is    *
10 * furnished to do so, subject to the following conditions:                 *
11 *                                                                          *
12 * The above copyright notice and this permission notice shall be included  *
13 * in all copies or substantial portions of the Software.                   *
14 *                                                                          *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
16 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
17 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
18 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
19 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
20 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
21 * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
22 *                                                                          *
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24 * holders shall not be used in advertising or otherwise to promote the     *
25 * sale, use or other dealings in this Software without prior written       *
26 * authorization.                                                           *
27 ****************************************************************************/
28
29/****************************************************************************
30 *   Author: Juergen Pfeifer <juergen.pfeifer@gmx.net> 1995,1997            *
31 ****************************************************************************/
32
33#include "form.priv.h"
34
35MODULE_ID("$Id: frm_data.c,v 1.6 1999/05/16 17:20:29 juergen Exp $")
36
37/*---------------------------------------------------------------------------
38|   Facility      :  libnform
39|   Function      :  bool data_behind(const FORM *form)
40|
41|   Description   :  Check for off-screen data behind. This is nearly trivial
42|                    becose the begin of a field is fixed.
43|
44|   Return Values :  TRUE   - there are off-screen data behind
45|                    FALSE  - there are no off-screen data behind
46+--------------------------------------------------------------------------*/
47bool data_behind(const FORM *form)
48{
49  bool result = FALSE;
50
51  if (form && (form->status & _POSTED) && form->current)
52    {
53      FIELD *field;
54
55      field = form->current;
56      if (!Single_Line_Field(field))
57	{
58	  result = (form->toprow==0) ? FALSE : TRUE;
59	}
60      else
61	{
62	  result = (form->begincol==0) ? FALSE : TRUE;
63	}
64    }
65  return(result);
66}
67
68/*---------------------------------------------------------------------------
69|   Facility      :  libnform
70|   Function      :  static char * After_Last_Non_Pad_Position(
71|                                    char *buffer,
72|                                    int len,
73|                                    int pad)
74|
75|   Description   :  Find the last position in the buffer that doesn't
76|                    contain a padding character.
77|
78|   Return Values :  The pointer to this position
79+--------------------------------------------------------------------------*/
80INLINE
81static char * After_Last_Non_Pad_Position(char *buffer, int len, int pad)
82{
83  char *end = buffer + len;
84
85  assert(buffer && len>=0);
86  while ( (buffer < end) && (*(end-1)==pad) )
87    end--;
88
89  return end;
90}
91
92#define SMALL_BUFFER_SIZE (80)
93
94/*---------------------------------------------------------------------------
95|   Facility      :  libnform
96|   Function      :  bool data_ahead(const FORM *form)
97|
98|   Description   :  Check for off-screen data ahead. This is more difficult
99|                    because a dynamic field has a variable end.
100|
101|   Return Values :  TRUE   - there are off-screen data ahead
102|                    FALSE  - there are no off-screen data ahead
103+--------------------------------------------------------------------------*/
104bool data_ahead(const FORM *form)
105{
106  bool result = FALSE;
107
108  if (form && (form->status & _POSTED) && form->current)
109    {
110      static char buffer[SMALL_BUFFER_SIZE + 1];
111      FIELD *field;
112      bool large_buffer;
113      bool cursor_moved = FALSE;
114      char *bp;
115      char *found_content;
116      int pos;
117
118      field = form->current;
119      assert(form->w);
120
121      large_buffer = (field->cols > SMALL_BUFFER_SIZE);
122      if (large_buffer)
123	bp = (char *)malloc((size_t)(field->cols) + 1);
124      else
125	bp = buffer;
126
127      assert(bp);
128
129      if (Single_Line_Field(field))
130	{
131	  int check_len;
132
133	  pos = form->begincol + field->cols;
134	  while (pos < field->dcols)
135	    {
136	      check_len = field->dcols - pos;
137	      if ( check_len >= field->cols )
138		check_len = field->cols;
139	      cursor_moved = TRUE;
140	      wmove(form->w,0,pos);
141	      winnstr(form->w,bp,check_len);
142	      found_content =
143		After_Last_Non_Pad_Position(bp,check_len,field->pad);
144	      if (found_content==bp)
145		  pos += field->cols;
146	      else
147		{
148		  result = TRUE;
149		  break;
150		}
151	    }
152	}
153      else
154	{
155	  pos = form->toprow + field->rows;
156	  while (pos < field->drows)
157	    {
158	      cursor_moved = TRUE;
159	      wmove(form->w,pos,0);
160	      pos++;
161	      winnstr(form->w,bp,field->cols);
162	      found_content =
163		After_Last_Non_Pad_Position(bp,field->cols,field->pad);
164	      if (found_content!=bp)
165		{
166		  result = TRUE;
167		  break;
168		}
169	    }
170	}
171
172      if (large_buffer)
173	free(bp);
174
175      if (cursor_moved)
176	wmove(form->w,form->currow,form->curcol);
177    }
178  return(result);
179}
180
181/* frm_data.c ends here */
182