fix(hint): nolazyredraw

[ivanbrennan]

Fix a rendering issue that causes the cursor to appear at the end of the hint if lazyredraw is enabled and hint is shown in the echo area.

Problem

If a hydra shows its hint in the echo area (config.hint.type = 'cmdline') and the user has lazyredraw on, the hint renders correctly when first invoked, but any subsequent action (within the hydra) causes the cursor to appear at the end of the hint.

Solution

Add an on_enter function to the default config to turn lazyredraw off for the duration of the hydra.

---

Minimal reproducible example

The problem can be demonstrated (prior to this commit) by invoking nvim like,

nvim -u minimal.lua +'call append(0, "1234")' +'goto 1'

with the following minimal.lua init file:

vim.opt.lazyredraw = true
vim.opt.wrap = false -- allow horizontal scrolling
local hydra = require('hydra')
hydra({
  name = 'scroll',
  mode = 'n',
  body = 'z',
  heads = { { 'l', 'zl' }, { 'h', 'zh' } },
  config = { hint = { type = 'cmdline' } },
})

Type zl to invoke the hydra, and the hint is drawn correctly.

Type l to scroll again, and now the cursor is drawn at the end of the hint.

[folke]

Just don't set lazyredraw? That option is not meant to be set by a user.
I don't think a plugin should take care of that tbh.

 'lazyredraw' 'lz'	boolean	(default off)
			global
	When this option is set, the screen will not be redrawn while
	executing macros, registers and other commands that have not been
	typed.  Also, updating the window title is postponed.  To force an
	update use |:redraw|.
	This may occasionally cause display errors.  It is only meant to be set
	temporarily when performing an operation where redrawing may cause
	flickering or cause a slow down.

[ivanbrennan]

@folke Some users set lazyredraw to improve the performance of macros. It does seem there's been some back and forth on how advisable it is to do so, e.g.

• set lazyredraw tpope/vim-sensible#78
• tpope/vim-sensible@2fb074e
• tpope/vim-sensible@9e91be7

Your point is valid, and this is a bit beyond the plugin's responsibility. But I think it's worth mentioning the issue (and solution) in the docs. I ended up bisecting my configuration before finally identifying lazyredraw as the root cause.