xref: /openbsd/lib/libform/frm_data.c (revision 404b540a)
1 /*	$OpenBSD: frm_data.c,v 1.6 2001/01/22 18:02:14 millert Exp $	*/
2 
3 /****************************************************************************
4  * Copyright (c) 1998,2000 Free Software Foundation, Inc.                   *
5  *                                                                          *
6  * Permission is hereby granted, free of charge, to any person obtaining a  *
7  * copy of this software and associated documentation files (the            *
8  * "Software"), to deal in the Software without restriction, including      *
9  * without limitation the rights to use, copy, modify, merge, publish,      *
10  * distribute, distribute with modifications, sublicense, and/or sell       *
11  * copies of the Software, and to permit persons to whom the Software is    *
12  * furnished to do so, subject to the following conditions:                 *
13  *                                                                          *
14  * The above copyright notice and this permission notice shall be included  *
15  * in all copies or substantial portions of the Software.                   *
16  *                                                                          *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
19  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
20  * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
21  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
22  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
23  * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
24  *                                                                          *
25  * Except as contained in this notice, the name(s) of the above copyright   *
26  * holders shall not be used in advertising or otherwise to promote the     *
27  * sale, use or other dealings in this Software without prior written       *
28  * authorization.                                                           *
29  ****************************************************************************/
30 
31 /****************************************************************************
32  *   Author: Juergen Pfeifer <juergen.pfeifer@gmx.net> 1995,1997            *
33  ****************************************************************************/
34 
35 #include "form.priv.h"
36 
37 MODULE_ID("$From: frm_data.c,v 1.7 2000/12/10 02:09:38 tom Exp $")
38 
39 /*---------------------------------------------------------------------------
40 |   Facility      :  libnform
41 |   Function      :  bool data_behind(const FORM *form)
42 |
43 |   Description   :  Check for off-screen data behind. This is nearly trivial
44 |                    becose the begin of a field is fixed.
45 |
46 |   Return Values :  TRUE   - there are off-screen data behind
47 |                    FALSE  - there are no off-screen data behind
48 +--------------------------------------------------------------------------*/
49 NCURSES_EXPORT(bool)
50 data_behind (const FORM *form)
51 {
52   bool result = FALSE;
53 
54   if (form && (form->status & _POSTED) && form->current)
55     {
56       FIELD *field;
57 
58       field = form->current;
59       if (!Single_Line_Field(field))
60 	{
61 	  result = (form->toprow==0) ? FALSE : TRUE;
62 	}
63       else
64 	{
65 	  result = (form->begincol==0) ? FALSE : TRUE;
66 	}
67     }
68   return(result);
69 }
70 
71 /*---------------------------------------------------------------------------
72 |   Facility      :  libnform
73 |   Function      :  static char * After_Last_Non_Pad_Position(
74 |                                    char *buffer,
75 |                                    int len,
76 |                                    int pad)
77 |
78 |   Description   :  Find the last position in the buffer that doesn't
79 |                    contain a padding character.
80 |
81 |   Return Values :  The pointer to this position
82 +--------------------------------------------------------------------------*/
83 INLINE
84 static char * After_Last_Non_Pad_Position(char *buffer, int len, int pad)
85 {
86   char *end = buffer + len;
87 
88   assert(buffer && len>=0);
89   while ( (buffer < end) && (*(end-1)==pad) )
90     end--;
91 
92   return end;
93 }
94 
95 #define SMALL_BUFFER_SIZE (80)
96 
97 /*---------------------------------------------------------------------------
98 |   Facility      :  libnform
99 |   Function      :  bool data_ahead(const FORM *form)
100 |
101 |   Description   :  Check for off-screen data ahead. This is more difficult
102 |                    because a dynamic field has a variable end.
103 |
104 |   Return Values :  TRUE   - there are off-screen data ahead
105 |                    FALSE  - there are no off-screen data ahead
106 +--------------------------------------------------------------------------*/
107 NCURSES_EXPORT(bool)
108 data_ahead (const FORM *form)
109 {
110   bool result = FALSE;
111 
112   if (form && (form->status & _POSTED) && form->current)
113     {
114       static char buffer[SMALL_BUFFER_SIZE + 1];
115       FIELD *field;
116       bool large_buffer;
117       bool cursor_moved = FALSE;
118       char *bp;
119       char *found_content;
120       int pos;
121 
122       field = form->current;
123       assert(form->w);
124 
125       large_buffer = (field->cols > SMALL_BUFFER_SIZE);
126       if (large_buffer)
127 	bp = (char *)malloc((size_t)(field->cols) + 1);
128       else
129 	bp = buffer;
130 
131       assert(bp);
132 
133       if (Single_Line_Field(field))
134 	{
135 	  int check_len;
136 
137 	  pos = form->begincol + field->cols;
138 	  while (pos < field->dcols)
139 	    {
140 	      check_len = field->dcols - pos;
141 	      if ( check_len >= field->cols )
142 		check_len = field->cols;
143 	      cursor_moved = TRUE;
144 	      wmove(form->w,0,pos);
145 	      winnstr(form->w,bp,check_len);
146 	      found_content =
147 		After_Last_Non_Pad_Position(bp,check_len,field->pad);
148 	      if (found_content==bp)
149 		  pos += field->cols;
150 	      else
151 		{
152 		  result = TRUE;
153 		  break;
154 		}
155 	    }
156 	}
157       else
158 	{
159 	  pos = form->toprow + field->rows;
160 	  while (pos < field->drows)
161 	    {
162 	      cursor_moved = TRUE;
163 	      wmove(form->w,pos,0);
164 	      pos++;
165 	      winnstr(form->w,bp,field->cols);
166 	      found_content =
167 		After_Last_Non_Pad_Position(bp,field->cols,field->pad);
168 	      if (found_content!=bp)
169 		{
170 		  result = TRUE;
171 		  break;
172 		}
173 	    }
174 	}
175 
176       if (large_buffer)
177 	free(bp);
178 
179       if (cursor_moved)
180 	wmove(form->w,form->currow,form->curcol);
181     }
182   return(result);
183 }
184 
185 /* frm_data.c ends here */
186