Do you often need to use the mouse to place the caret into the 1024 space (further than the one-page would allow).
Me not. My code normally is within 80 characters and comments may be longer but starting within the screen width. I won't start anything on character 720 (and for that use the mouse).
- LongestLine + WindowWidthInChars
Basically it should be alright also as default. But the considerations should be on (unexpected) side effects. E.g. using 'LongestLine' means the scrollbar is adjusted after each key pressed while being in the longest line. This could be unbeautiful. Perhaps having fixed steps could be a solution, e.g. using
Screenwidth + n * 128
steps. Then n is determined depending on LongestLine and WindowWidthInChars.
On the other hand horizontal scrolling is more obvious, when there is less white space "reserved".
Another question is, would large files influence the time of determening LongestLine while typing.