516read-line.mu

   1 # read line from keyboard into stream while also echoing to screen
   2 # abort on stream overflow
   3 fn read-line-from-keyboard keyboard: (addr keyboard), out: (addr stream byte), screen: (addr screen), fg: int, bg: int {
   4   clear-stream out
   5   $read-line-from-keyboard:loop: {
   6     draw-cursor screen, 0x20/space
   7     var key/eax: byte <- read-key keyboard
   8     compare key, 0xa/newline
   9     break-if-=
  10     compare key, 0
  11     loop-if-=
  12     compare key, 8/backspace
  13     {
  14       break-if-!=
  15       undo-append-byte out
  16       draw-code-point-at-cursor-over-full-screen screen, 0x20/space, fg 0/bg  # clear cursor
  17       move-cursor-left screen
  18       move-cursor-left screen
  19       draw-code-point-at-cursor-over-full-screen screen, 0x20/space, fg 0/bg  # clear old cursor
  20       move-cursor-left screen
  21       loop $read-line-from-keyboard:loop
  22     }
  23     var key2/eax: int <- copy key
  24     append-byte out, key2
  25     var c/eax: code-point <- copy key2
  26     draw-code-point-at-cursor-over-full-screen screen, c, fg bg
  27     loop
  28   }
  29   # clear cursor
  30   draw-code-point-at-cursor-over-full-screen screen, 0x20/space, fg bg
  31 }