Terminal consistently flickers when scrolling through paginated list of options

[aq17]

What operating system and terminal are you using?
MacOS+default terminal, also saw same issue on Windows+PowerShell

An example that showcases the bug.
(short clip to fit 10mb limit, but continues as you scroll down the list and paginate)
https://user-images.githubusercontent.com/54565933/179568187-b4d8e098-a23b-4484-b988-ca143dda607a.mov

What did you expect to see?
No flickering when scrolling through paginated list

What did you see instead?
Flickering when scrolling through paginated list

[jquick]

I have this issue also, using Alacrity terminal

[ekini]

Same behaviour on Linux (Wayland) in "foot" terminal.

[mislav]

I also experience this and wanted to find ways to mitigate. This is the redrawing logic:

survey/renderer.go

Lines 135 to 145 in e47352f

	func (r *Renderer) resetPrompt(lines int) {
	// clean out current line in case tmpl didnt end in newline
	cursor := r.NewCursor()
	cursor.HorizontalAbsolute(0)
	terminal.EraseLine(r.stdio.Out, terminal.ERASE_LINE_ALL)
	// clean up what we left behind last time
	for i := 0; i < lines; i++ {
	cursor.PreviousLine(1)
	terminal.EraseLine(r.stdio.Out, terminal.ERASE_LINE_ALL)
	}
	}

Perhaps there is a way to redraw the last N lines in a terminal in a way that doesn't cause flickering. Ideas welcome!

[dnkl]

Perhaps there is a way to redraw the last N lines in a terminal in a way that doesn't cause flickering. Ideas welcome!

There are application synchronized updates: https://gitlab.freedesktop.org/terminal-wg/specifications/-/merge_requests/2

TL;DR application emits one escape at the beginning of a "frame" (update) and another one when done.

Note that there are two variants; the DCS initially suggested in the MR, which was the first one implemented by terminals. Later, it was generally agreed that a "private mode" was better, and the 2026 private mode was added.

Another option is writing the erase commands into a buffer, and doing a single actual terminal write.