help: How do I center the header?

[hyawara]

Neovim version (nvim -v)

0.10.0

Neovim distribution

N/A

Description

I want to center the title, like this:

[MeanderingProgrammer]

There is no way to do this. You can specify a left_pad value for headings but that will apply a constant padding to all heading levels and naturally will not change when the window resizes.

I'm not really aware of a markdown renderer that supports this kind of thing and in general I don't think I want to support centering content mostly because it would need to interoperate with all the existing options. I gave implementing it a shot and it ended up messy with a lot of gaps.

If I made left_pad accept a function that takes a window_id and the current line of text would that be enough?

I imagine the implementation in your config would look something like:

require('render-markdown').setup({
  heading = {
    left_pad = function(win, line)
      local window_width = vim.api.nvim_win_get_width(win)
      local line_width = vim.fn.strdisplaywidth(line)
      return math.floor((window_width - line_width) / 2)
    end,
  },
})

Basically any weird offsets and things specific to your config just end being something you solve rather than me needing to handle more edge cases.

[MeanderingProgrammer]

I actually ended up implementing this internally here: 0986638

It applies to both headings and code blocks, since they're alignment configs are the same.

By providing floating point values between 0 & 1 to left_pad, right_pad and left_margin you can get different effects.

Here are a few configs to try:

require('render-markdown').setup({
  heading = {
    left_pad = 0.5,
  },
})

require('render-markdown').setup({
  heading = {
    left_pad = 0.5, 
    position = 'inline',
  },
})

require('render-markdown').setup({
  heading = {
    left_margin = 0.5,
    position = 'inline',
    width = 'block',
  },
})

require('render-markdown').setup({
  heading = {
    left_margin = 0.5,
    position = 'inline',
    width = 'block',
    left_pad = 0.2,
    right_pad = 0.2,
  },
})

[tristone13th]

Just want to know can we have a specific type of header (e.g., header 1) centered without touching other headers' style?

[MeanderingProgrammer]

You can provide a list of values to the various properties, the last value gets used for all remaining headers.

So to center just h1:

require('render-markdown').setup({
  heading = {
    left_pad = { 0.5, 0 },
    -- This is equivalent to:
    -- left_pad = { 0.5, 0, 0, 0, 0, 0 },
  },
})

To center h2 & h4 only:

require('render-markdown').setup({
  heading = {
    left_pad = { 0, 0.5, 0, 0.5, 0 },
  },
})