form/frm_data.c

   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
  25 MODULE_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 +--------------------------------------------------------------------------*/
  37 bool 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 +--------------------------------------------------------------------------*/
  70 INLINE
  71 static 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 +--------------------------------------------------------------------------*/
  94 bool 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 */