Known issues:

• Touchpads can drag the mouse pointer using a light touch or a heavy click. On Linux, drags using the light touch get interrupted when a key is pressed. You'll have to press down to drag.
• No support yet for Unicode graphemes spanning multiple codepoints.
• The text cursor will always stay on the screen. This can have some strange implications:
  • A long series of drawings will get silently skipped when you hit page-down, until a line of text can be showed on screen.
  • If there's no line of text at the top of the file, you may not be able to scroll back up to the top with page-up. So far this app isn't really designed for drawing-heavy files. For now I'm targeting mostly-text files with a few drawings mixed in.