is it possible to implement fzf_get_matched_items and fzf_set_cursor function?

[aidancz]

I’m writing a custom provider and would like it to have this action:

["load,change"] = {
		exec_silent = true,
		fn = function(selected, opts)

local items = fzf_get_matched_items()
local cursor_index = items_get_cursor(items)
fzf_set_cursor(cursor_index)

		end,
}

the fzf_get_matched_items function returns a list of string

the fzf_set_cursor function is similar to FZF’s built-in pos() action

This way, as soon as FZF starts or the query changes, the selected entry in FZF will be exactly what I want

is it possible?

[nenahp]

Maybe this is what you want?

       --track
              Make  fzf track the current selection when the result list is up‐
              dated.  This can be useful when  browsing  logs  using  fzf  with
              sorting  disabled.  It is not recommended to use this option with
              --tac as the resulting behavior can be confusing. Also,  consider
              using track action instead of this option.

EDIT: I seems seeing what you mean. This don't work...

[nenahp]

I think this is what you want: seq 1000 | fzf --bind 'result:next-selected'

To always use the first:

seq 1000 | fzf --bind 'result:first+prev-selected+next-selected'

EDIT: need prev-selected+next-selected in case current focused one is selected..

[aidancz]

What I’m trying to achieve is similar to --track, but a bit more complex: in the items_get_cursor function, I have some logic to determine where the fzf cursor should be based on the current items, so using this Lua function is necessary.

The information you shared is very helpful! thank you for your reply😊

[nenahp]

local cursor_index = items_get_cursor(items)
fzf_set_cursor(cursor_index)

This part is not trivial. We can get absolute index from the origin list (e.g. with actions.xx.field_index="{+n}"). But pos() only accept index for current "filtered" list (e.g. something like $FZF_POS).

Another approach is --listen, you can inspect by:

seq 1000 | fzf --listen --preview 'curl -sL localhost:$FZF_PORT | jq'

But you cannot find a value in the json can be directly used by pos(). From the action implementation...

https://github.com/junegunn/fzf/blob/4811e52af3ed7f89e82baa908f9a8a25fb593361/src/terminal.go#L6598-L6609

The implementation above iterate all the list to find a pos. So I would guess what you need to do is similar -> to iterate the json table...

[aidancz]

Yes! The --listen option is exactly what I’ve been looking for!

Basically,

This gives me the information I want:

local json = vim.system({"curl", "-sL", port}):wait().stdout
local state = vim.json.decode(json)

This sets the cursor in fzf:

vim.system({
	"curl",
	"-XPOST",
	port,
	"-d",
	string.format("pos(%s)", idx_matches)
}):wait()

The final effect is like this: a simple treesitter outline picker, where the cursor stays on the nearest symbol when it's opened or when the query changes.

20250627-141116-539828919.mp4

Thank you so much for your help!