form/frm_data.c

   1 /****************************************************************************
   2  * Copyright (c) 1998,2000 Free Software Foundation, Inc.                   *
   3  *                                                                          *
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   9  * copies of the Software, and to permit persons to whom the Software is    *
  10  * furnished to do so, subject to the following conditions:                 *
  11  *                                                                          *
  12  * The above copyright notice and this permission notice shall be included  *
  13  * in all copies or substantial portions of the Software.                   *
  14  *                                                                          *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
  16  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
  17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
  18  * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
  19  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
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  21  * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
  22  *                                                                          *
  23  * Except as contained in this notice, the name(s) of the above copyright   *
  24  * holders shall not be used in advertising or otherwise to promote the     *
  25  * sale, use or other dealings in this Software without prior written       *
  26  * authorization.                                                           *
  27  ****************************************************************************/
  28
  29 /****************************************************************************
  30  *   Author:  Juergen Pfeifer, 1995,1997                                    *
  31  *   Contact: http://www.familiepfeifer.de/Contact.aspx?Lang=en             *
  32  ****************************************************************************/
  33
  34 #include "form.priv.h"
  35
  36 MODULE_ID("$Id: frm_data.c,v 1.8 2002/07/06 15:33:27 juergen Exp $")
  37
  38 /*---------------------------------------------------------------------------
  39 |   Facility      :  libnform
  40 |   Function      :  bool data_behind(const FORM *form)
  41 |
  42 |   Description   :  Check for off-screen data behind. This is nearly trivial
  43 |                    becose the begin of a field is fixed.
  44 |
  45 |   Return Values :  TRUE   - there are off-screen data behind
  46 |                    FALSE  - there are no off-screen data behind
  47 +--------------------------------------------------------------------------*/
  48 NCURSES_EXPORT(bool)
  49 data_behind (const FORM *form)
  50 {
  51   bool result = FALSE;
  52
  53   if (form && (form->status & _POSTED) && form->current)
  54     {
  55       FIELD *field;
  56
  57       field = form->current;
  58       if (!Single_Line_Field(field))
  59         {
  60           result = (form->toprow==0) ? FALSE : TRUE;
  61         }
  62       else
  63         {
  64           result = (form->begincol==0) ? FALSE : TRUE;
  65         }
  66     }
  67   return(result);
  68 }
  69
  70 /*---------------------------------------------------------------------------
  71 |   Facility      :  libnform
  72 |   Function      :  static char * After_Last_Non_Pad_Position(
  73 |                                    char *buffer,
  74 |                                    int len,
  75 |                                    int pad)
  76 |
  77 |   Description   :  Find the last position in the buffer that doesn't
  78 |                    contain a padding character.
  79 |
  80 |   Return Values :  The pointer to this position
  81 +--------------------------------------------------------------------------*/
  82 INLINE
  83 static char * After_Last_Non_Pad_Position(char *buffer, int len, int pad)
  84 {
  85   char *end = buffer + len;
  86
  87   assert(buffer && len>=0);
  88   while ( (buffer < end) && (*(end-1)==pad) )
  89     end--;
  90
  91   return end;
  92 }
  93
  94 #define SMALL_BUFFER_SIZE (80)
  95
  96 /*---------------------------------------------------------------------------
  97 |   Facility      :  libnform
  98 |   Function      :  bool data_ahead(const FORM *form)
  99 |
 100 |   Description   :  Check for off-screen data ahead. This is more difficult
 101 |                    because a dynamic field has a variable end.
 102 |
 103 |   Return Values :  TRUE   - there are off-screen data ahead
 104 |                    FALSE  - there are no off-screen data ahead
 105 +--------------------------------------------------------------------------*/
 106 NCURSES_EXPORT(bool)
 107 data_ahead (const FORM *form)
 108 {
 109   bool result = FALSE;
 110
 111   if (form && (form->status & _POSTED) && form->current)
 112     {
 113       static char buffer[SMALL_BUFFER_SIZE + 1];
 114       FIELD *field;
 115       bool large_buffer;
 116       bool cursor_moved = FALSE;
 117       char *bp;
 118       char *found_content;
 119       int pos;
 120
 121       field = form->current;
 122       assert(form->w);
 123
 124       large_buffer = (field->cols > SMALL_BUFFER_SIZE);
 125       if (large_buffer)
 126         bp = (char *)malloc((size_t)(field->cols) + 1);
 127       else
 128         bp = buffer;
 129
 130       assert(bp);
 131
 132       if (Single_Line_Field(field))
 133         {
 134           int check_len;
 135
 136           pos = form->begincol + field->cols;
 137           while (pos < field->dcols)
 138             {
 139               check_len = field->dcols - pos;
 140               if ( check_len >= field->cols )
 141                 check_len = field->cols;
 142               cursor_moved = TRUE;
 143               wmove(form->w,0,pos);
 144               winnstr(form->w,bp,check_len);
 145               found_content =
 146                 After_Last_Non_Pad_Position(bp,check_len,field->pad);
 147               if (found_content==bp)
 148                   pos += field->cols;
 149               else
 150                 {
 151                   result = TRUE;
 152                   break;
 153                 }
 154             }
 155         }
 156       else
 157         {
 158           pos = form->toprow + field->rows;
 159           while (pos < field->drows)
 160             {
 161               cursor_moved = TRUE;
 162               wmove(form->w,pos,0);
 163               pos++;
 164               winnstr(form->w,bp,field->cols);
 165               found_content =
 166                 After_Last_Non_Pad_Position(bp,field->cols,field->pad);
 167               if (found_content!=bp)
 168                 {
 169                   result = TRUE;
 170                   break;
 171                 }
 172             }
 173         }
 174
 175       if (large_buffer)
 176         free(bp);
 177
 178       if (cursor_moved)
 179         wmove(form->w,form->currow,form->curcol);
 180     }
 181   return(result);
 182 }
 183
 184 /* frm_data.c ends here */