frm_data.c revision 1.2 
1/*-----------------------------------------------------------------------------+
2|           The ncurses form library is  Copyright (C) 1995-1997               |
3|             by Juergen Pfeifer <Juergen.Pfeifer@T-Online.de>                 |
4|                          All Rights Reserved.                                |
5|                                                                              |
6| Permission to use, copy, modify, and distribute this software and its        |
7| documentation for any purpose and without fee is hereby granted, provided    |
8| that the above copyright notice appear in all copies and that both that      |
9| copyright notice and this permission notice appear in supporting             |
10| documentation, and that the name of the above listed copyright holder(s) not |
11| be used in advertising or publicity pertaining to distribution of the        |
12| software without specific, written prior permission.                         |
13|                                                                              |
14| THE ABOVE LISTED COPYRIGHT HOLDER(S) DISCLAIM ALL WARRANTIES WITH REGARD TO  |
15| THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FIT-  |
16| NESS, IN NO EVENT SHALL THE ABOVE LISTED COPYRIGHT HOLDER(S) BE LIABLE FOR   |
17| ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RE- |
18| SULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, |
19| NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH    |
20| THE USE OR PERFORMANCE OF THIS SOFTWARE.                                     |
21+-----------------------------------------------------------------------------*/
22
23#include "form.priv.h"
24
25MODULE_ID("Id: frm_data.c,v 1.3 1997/05/01 16:47:54 juergen Exp $")
26
27/*---------------------------------------------------------------------------
28|   Facility      :  libnform
29|   Function      :  bool data_behind(const FORM *form)
30|
31|   Description   :  Check for off-screen data behind. This is nearly trivial
32|                    becose the begin of a field is fixed.
33|
34|   Return Values :  TRUE   - there are off-screen data behind
35|                    FALSE  - there are no off-screen data behind
36+--------------------------------------------------------------------------*/
37bool data_behind(const FORM *form)
38{
39  bool result = FALSE;
40
41  if (form && (form->status & _POSTED) && form->current)
42    {
43      FIELD *field;
44
45      field = form->current;
46      if (!Single_Line_Field(field))
47	{
48	  result = (form->toprow==0) ? FALSE : TRUE;
49	}
50      else
51	{
52	  result = (form->begincol==0) ? FALSE : TRUE;
53	}
54    }
55  return(result);
56}
57
58/*---------------------------------------------------------------------------
59|   Facility      :  libnform
60|   Function      :  static char * After_Last_Non_Pad_Position(
61|                                    char *buffer,
62|                                    int len,
63|                                    int pad)
64|
65|   Description   :  Find the last position in the buffer that doesn't
66|                    contain a padding character.
67|
68|   Return Values :  The pointer to this position
69+--------------------------------------------------------------------------*/
70INLINE
71static char * After_Last_Non_Pad_Position(char *buffer, int len, int pad)
72{
73  char *end = buffer + len;
74
75  assert(buffer && len>=0);
76  while ( (buffer < end) && (*(end-1)==pad) )
77    end--;
78
79  return end;
80}
81
82#define SMALL_BUFFER_SIZE (80)
83
84/*---------------------------------------------------------------------------
85|   Facility      :  libnform
86|   Function      :  bool data_ahead(const FORM *form)
87|
88|   Description   :  Check for off-screen data ahead. This is more difficult
89|                    because a dynamic field has a variable end.
90|
91|   Return Values :  TRUE   - there are off-screen data ahead
92|                    FALSE  - there are no off-screen data ahead
93+--------------------------------------------------------------------------*/
94bool data_ahead(const FORM *form)
95{
96  bool result = FALSE;
97
98  if (form && (form->status & _POSTED) && form->current)
99    {
100      static char buffer[SMALL_BUFFER_SIZE + 1];
101      FIELD *field;
102      bool large_buffer;
103      bool cursor_moved = FALSE;
104      char *bp;
105      char *found_content;
106      int pos;
107
108      field = form->current;
109      assert(form->w);
110
111      large_buffer = (field->cols > SMALL_BUFFER_SIZE);
112      if (large_buffer)
113	bp = (char *)malloc((size_t)(field->cols) + 1);
114      else
115	bp = buffer;
116
117      assert(bp);
118
119      if (Single_Line_Field(field))
120	{
121	  int check_len;
122
123	  pos = form->begincol + field->cols;
124	  while (pos < field->dcols)
125	    {
126	      check_len = field->dcols - pos;
127	      if ( check_len >= field->cols )
128		check_len = field->cols;
129	      cursor_moved = TRUE;
130	      wmove(form->w,0,pos);
131	      winnstr(form->w,bp,check_len);
132	      found_content =
133		After_Last_Non_Pad_Position(bp,check_len,field->pad);
134	      if (found_content==bp)
135		  pos += field->cols;
136	      else
137		{
138		  result = TRUE;
139		  break;
140		}
141	    }
142	}
143      else
144	{
145	  pos = form->toprow + field->rows;
146	  while (pos < field->drows)
147	    {
148	      cursor_moved = TRUE;
149	      wmove(form->w,pos,0);
150	      pos++;
151	      winnstr(form->w,bp,field->cols);
152	      found_content =
153		After_Last_Non_Pad_Position(bp,field->cols,field->pad);
154	      if (found_content!=bp)
155		{
156		  result = TRUE;
157		  break;
158		}
159	    }
160	}
161
162      if (large_buffer)
163	free(bp);
164
165      if (cursor_moved)
166	wmove(form->w,form->currow,form->curcol);
167    }
168  return(result);
169}
170
171/* frm_data.c ends here */
172