frm_data.c revision 76726 
1/****************************************************************************
2 * Copyright (c) 1998,2000 Free Software Foundation, Inc.                   *
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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 1.7 2000/12/10 02:09:38 tom 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+--------------------------------------------------------------------------*/
47NCURSES_EXPORT(bool)
48data_behind (const FORM *form)
49{
50  bool result = FALSE;
51
52  if (form && (form->status & _POSTED) && form->current)
53    {
54      FIELD *field;
55
56      field = form->current;
57      if (!Single_Line_Field(field))
58	{
59	  result = (form->toprow==0) ? FALSE : TRUE;
60	}
61      else
62	{
63	  result = (form->begincol==0) ? FALSE : TRUE;
64	}
65    }
66  return(result);
67}
68
69/*---------------------------------------------------------------------------
70|   Facility      :  libnform
71|   Function      :  static char * After_Last_Non_Pad_Position(
72|                                    char *buffer,
73|                                    int len,
74|                                    int pad)
75|
76|   Description   :  Find the last position in the buffer that doesn't
77|                    contain a padding character.
78|
79|   Return Values :  The pointer to this position
80+--------------------------------------------------------------------------*/
81INLINE
82static char * After_Last_Non_Pad_Position(char *buffer, int len, int pad)
83{
84  char *end = buffer + len;
85
86  assert(buffer && len>=0);
87  while ( (buffer < end) && (*(end-1)==pad) )
88    end--;
89
90  return end;
91}
92
93#define SMALL_BUFFER_SIZE (80)
94
95/*---------------------------------------------------------------------------
96|   Facility      :  libnform
97|   Function      :  bool data_ahead(const FORM *form)
98|
99|   Description   :  Check for off-screen data ahead. This is more difficult
100|                    because a dynamic field has a variable end.
101|
102|   Return Values :  TRUE   - there are off-screen data ahead
103|                    FALSE  - there are no off-screen data ahead
104+--------------------------------------------------------------------------*/
105NCURSES_EXPORT(bool)
106data_ahead (const FORM *form)
107{
108  bool result = FALSE;
109
110  if (form && (form->status & _POSTED) && form->current)
111    {
112      static char buffer[SMALL_BUFFER_SIZE + 1];
113      FIELD *field;
114      bool large_buffer;
115      bool cursor_moved = FALSE;
116      char *bp;
117      char *found_content;
118      int pos;
119
120      field = form->current;
121      assert(form->w);
122
123      large_buffer = (field->cols > SMALL_BUFFER_SIZE);
124      if (large_buffer)
125	bp = (char *)malloc((size_t)(field->cols) + 1);
126      else
127	bp = buffer;
128
129      assert(bp);
130
131      if (Single_Line_Field(field))
132	{
133	  int check_len;
134
135	  pos = form->begincol + field->cols;
136	  while (pos < field->dcols)
137	    {
138	      check_len = field->dcols - pos;
139	      if ( check_len >= field->cols )
140		check_len = field->cols;
141	      cursor_moved = TRUE;
142	      wmove(form->w,0,pos);
143	      winnstr(form->w,bp,check_len);
144	      found_content =
145		After_Last_Non_Pad_Position(bp,check_len,field->pad);
146	      if (found_content==bp)
147		  pos += field->cols;
148	      else
149		{
150		  result = TRUE;
151		  break;
152		}
153	    }
154	}
155      else
156	{
157	  pos = form->toprow + field->rows;
158	  while (pos < field->drows)
159	    {
160	      cursor_moved = TRUE;
161	      wmove(form->w,pos,0);
162	      pos++;
163	      winnstr(form->w,bp,field->cols);
164	      found_content =
165		After_Last_Non_Pad_Position(bp,field->cols,field->pad);
166	      if (found_content!=bp)
167		{
168		  result = TRUE;
169		  break;
170		}
171	    }
172	}
173
174      if (large_buffer)
175	free(bp);
176
177      if (cursor_moved)
178	wmove(form->w,form->currow,form->curcol);
179    }
180  return(result);
181}
182
183/* frm_data.c ends here */
184