I had some free time today so finally got around to writing a plugin I requested awhile back. This plugin artificially narrows the viewport such that scrolling up or down near the boundaries causes the visible region to change. This emulates the behavior of the vim scrolloff setting.
Add to your Key Bindings – User:
/* Scrolloff keybinds */
{ "keys": "up"], "command": "scroll_off", "args": { "forward": false } },
{ "keys": "down"], "command": "scroll_off", "args": { "forward": true } },
Add to your Settings – User: (Optional, defaults to 5)
"scrolloff": <positive integer>Save as Packages/User/ScrollOffCommand.py:
[code]import sublime, sublime_plugin
class ScrollOffCommand(sublime_plugin.TextCommand):
def run(self, edit, forward):
self.view.run_command(“move”, {“by”: “lines”, “forward”: forward})
limit = abs(int(self.view.settings().get("scrolloff"))) or 5
cursor = self.view.rowcol(self.view.sel()[0].begin())[0]
view_top = self.view.rowcol(self.view.visible_region().begin())[0]
view_bottom = self.view.rowcol(self.view.visible_region().end())[0]
absolute_bottom = self.view.rowcol(self.view.size())[0]
if cursor < view_top + limit:
self.view.set_viewport_position((0, (view_top - 1) * self.view.line_height()))
elif cursor <= absolute_bottom - limit and cursor >= view_bottom - limit:
self.view.set_viewport_position((0, (view_top + 1) * self.view.line_height()))
[/code]
Note that I opted to override the default up/down keybindings to avoid headaches with mouse selection and cursor jumping via CTRL+Home, CTRL+End, etc.
There is some strange behavior I don’t know how to sort out. For instance, the cursor moves faster than the viewport for long scrolls, so the scrolloff limit isn’t maintained. I’ve also had a few files where the cursor reaches the viewport bottom boundary when there is still content in the file (ie, not the absolute_bottom) . If anyone is willing to look into these issues I’d appreciate it. 