From 1de82e16c1216e1dbe22cf7a8ec9ea9e9e69b631 Mon Sep 17 00:00:00 2001 From: fredizzimo Date: Wed, 5 Jul 2023 16:31:34 +0300 Subject: fix(ui): delay win_viewport until screen update #24182 Problem: Sometimes, when nvim sends the `win_viewport` event, for example when scrolling with visible folds on the screen, it reports the `scroll_delta` value one batch into "future". So when the client application is trying to show the new viewport it's not yet updated, resulting in temporary corruption / screen flickering. For more details see #23609, and starting from [this comment]( https://github.com/neovide/neovide/pull/1790#issuecomment-1518697747) in https://github.com/neovide/neovide/pull/1790,, where the issue was first detected. Note that some of the conclusions in those are not fully accurate, but the general observations are. Solution: When there are pending updates to a Window, delay the `win_viewport` UI event until the updates are sent. This ensures that there's no flush between sending the viewport and updating of the lines corresponding to the new viewport. Document the existing viewport behaviour (for cases where there are no extra flushes), give a hint about how applications can deal with the slightly surprising behaviour of the viewport event being sent after the updates. Fixes https://github.com/neovim/neovim/issues/23609 --- test/functional/ui/multigrid_spec.lua | 1 - 1 file changed, 1 deletion(-) (limited to 'test/functional/ui') diff --git a/test/functional/ui/multigrid_spec.lua b/test/functional/ui/multigrid_spec.lua index 2e66068037..1778c8218b 100644 --- a/test/functional/ui/multigrid_spec.lua +++ b/test/functional/ui/multigrid_spec.lua @@ -3808,7 +3808,6 @@ describe('ext_multigrid', function() ]], win_viewport={ [2] = {win = {id = 1000}, topline = 30586, botline = 30592, curline = 30591, curcol = 0, linecount = 30592, sum_scroll_delta = 30588}; }} - command('autocmd CursorMoved * ++once call line("w$")') -- FIXME: this should not be needed feed('gg') screen:expect{grid=[[ ## grid 1 -- cgit