contrib/ncurses-5.4/form/frm_data.c

   1 /****************************************************************************
   2  * Copyright (c) 1998-2002,2003 Free Software Foundation, Inc.              *
   3  *                                                                          *
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   5  * copy of this software and associated documentation files (the            *
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  10  * furnished to do so, subject to the following conditions:                 *
  11  *                                                                          *
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  13  * in all copies or substantial portions of the Software.                   *
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  28
  29 /****************************************************************************
  30  *   Author:  Juergen Pfeifer, 1995,1997                                    *
  31  ****************************************************************************/
  32
  33 #include "form.priv.h"
  34
  35 MODULE_ID("$Id: frm_data.c,v 1.10 2003/11/08 20:38:14 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 |                    because the beginning 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 */