//
//  AUTOSCROLL.VDM                     Christian Ziemski   07.10.2004
//                                                         08.10.2004
//
//
//  Key-Usage:
//  ----------
//  Page Up           Scroll up page per page
//  Page Down         Scroll down page per page
//  Home              Goto BeginOfFile and scroll down
//  End               Goto EndOfFile and scroll up
//  Cursor Up         Scroll up line per line
//  Cursor Down       Scroll down line per line
//  Cursor left       Decrease speed (use alternating with other keys to work!)
//  Cursor Up         Increase speed (use alternating with other keys to work!)
//
//  Backspace or ESC  Stop the macro
//
//

#100=0
#104=1
#105=1
#106=0

Key_Purge

repeat (ALL) {
  #103=Previous_Key(0)

  if (#103 != #100) {
    #106=#103
    #100=#103
  } else {
    Sleep(#104)
  }
  Key_Purge

  if (#106 == 'E'+'S'*256) { break }
  if (#106 == 'B'+'S'*256) { break }
  if (#106 == 'L'+'B'*256) { BoF #105=1   }
  if (#106 == 'L'+'E'*256) { EoF #105=-1  }
  if (#106 == 'P'+'U'*256) { #105=-Win_Lines #104=10 }
  if (#106 == 'P'+'D'*256) { #105=Win_Lines  #104=10 }
  if (#106 == 'C'+'U'*256) { #105=-1 } // Goto_Line(Cur_Line - Win_Vert + 3)
  if (#106 == 'C'+'D'*256) { #105=1 }  // Goto_Line(Cur_Line + Win_Vert - 3)
  if (#106 == 'C'+'R'*256) { #104=Max(0, #104-=1)   }
  if (#106 == 'C'+'L'*256) { #104=Min(#104+=1, 255) }

  if (#105 > 0)  { #106='C'+'D'*256  }
  if (#105 < 0)  { #106='C'+'U'*256  }
  if (#105 > 1)  { #106='P'+'D'*256  }
  if (#105 < -1) { #106='P'+'U'*256  }

  Line(#105, NOERR)
  Update
  Statline_Message(" ")
  if ((#105 > 0) && At_EoF) { Statline_Message("End of file reached!") }
  if ((#105 < 0) && At_BoF) { Statline_Message("Begin of file reached!") }
}