Differences in Border and Line Support

Although there are no differences in coding, output differences will occur when lines, boxes, and borders (including scroll bars) are drawn by Vermont Views functions. These differences are handled automatically by the system and are described here:

• nThe lower border character and the upper border character will always be the same on terminals. Likewise, the left and right border characters will be the same. Only memory-mapped consoles can use different characters in each location.
  
  
• nWhen a double-line border, single-line border, single line, or double line is drawn, the characters specified in vvtermcap, if such commands are included in the entry for that type of terminal, are used.
  
  
• nMost terminals do not support double-line borders. For terminals that do not support double-line borders, references to the BORDER structure for double-line borders (BDR_DLNP) will be treated the same as a reference to a single-line border. This allows code that includes double-line borders to operate successfully on all terminals.
  
  
• nIf you specify one of the pre-defined Vemont Views attributes for single or double lines, boxes, or borders, that attribute will be ignored on most terminals. Only memory-mapped consoles can use border attributes. Vermont Views uses the BLK_GRAPH attribute to display single and double lines on terminals, so that the correct line-drawing characters are displayed.
  
  
• nIf the terminal supports the intersecting line characters, Vermont Views will use the correct characters for intersecting lines, as long as the two lines that intersect are of the same type. The correct intersection character will not be used if a single-line border type intersects a double-line border type. You must specify the correct intersection characters in vvtermcap.
  
  
• nUnder UNIX, POSIX and VMS, the dot border (BDR_DOTP) is made up of periods and colons, and the solid border (BDR_SOLIDP) is made up of spaces. Under PCDOS and on memory-mapped consoles, these borders use the stippled block and solid block characters, respectively.
  
  
• nScroll bars will be displayed differently, since the default characters are initialized differently. This is because the graphics characters available on memory-mapped displays are not available on terminals. You can always change the defaults for either or both systems.