xref: /freebsd/contrib/ncurses/form/frm_data.c (revision 4f29da19bd44f0e99f021510460a81bf754c21d2)
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28 
29 /****************************************************************************
30  *   Author: Juergen Pfeifer <juergen.pfeifer@gmx.net> 1995,1997            *
31  ****************************************************************************/
32 
33 #include "form.priv.h"
34 
35 MODULE_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 +--------------------------------------------------------------------------*/
47 NCURSES_EXPORT(bool)
48 data_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 +--------------------------------------------------------------------------*/
81 INLINE
82 static 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 +--------------------------------------------------------------------------*/
105 NCURSES_EXPORT(bool)
106 data_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