How to map <C-u> and <C-d>?

[michaelfortunato]

Hi,
I have tried to map <C-u> and <C-d> to the following but cannot get it to work. Could I get some help?

return {
  "saghen/blink.cmp",
  -- optional: provides snippets for the snippet source
  -- WARN: I am using latest but the docs say to use
  -- dependencies = { "L3MON4D3/LuaSnip", version = "2.*" },
  dependencies = { "L3MON4D3/LuaSnip" },
  version = "1.*",
  opts = {
    enabled = function()
      return true
    end,
    keymap = {
      preset = "default",
      -- FIXME: Not working
      -- These are only being mapped to insert mode, not normal mode
      ["<C-u>"] = {
        function(cmp)
          -- return true
          return cmp.scroll_documentation_up(8)
        end,
        "fallback",
      },
      ["<C-d>"] = {
        function(cmp)
          -- return true
          return cmp.scroll_documentation_down(8)
        end,
        "fallback",
      },
    }
  }
}

[ChuYanLon]

This is possible

[XavierRolex]

Hey @michaelfortunato

It looks like you're trying to map and for scrolling documentation in blink.cmp, but they're only being mapped in insert mode.
The issue is likely due to how cmp handles keymaps—it primarily maps in insert mode by default. If you want to control these keys globally or in normal mode, you may need to set them manually using vim.keymap.set() outside of the plugin config, or ensure you're in the right mode where cmp is active.
Also double-check that the functions scroll_documentation_up and scroll_documentation_down are actually returning true to prevent fallback behavior from overriding them.
Try explicitly setting the return values like this:

["<C-u>"] = {
  function(cmp)
    cmp.scroll_documentation(-8)
    return true
  end,
  "fallback",
},
["<C-d>"] = {
  function(cmp)
    cmp.scroll_documentation(8)
    return true
  end,
  "fallback",
},

let me know if it works.

[michaelfortunato]

I think my initial question was misleading. With my config the fallback worked fine in normal mode. So modes are irrelevant here I suspect. The issue is that cmp.scroll_documentation() does not scroll my docs. I tried directly vim.set with unreserved keymaps like u and the docs still don't scroll. Probably something to do with my config

[Saghen]

blink.cmp doesn't show docs in normal mode, perhaps you're looking to scroll the vim.lsp.buf.hover() window?

[michaelfortunato]

Ah yea! I want to scroll the hover window. I thought that was the documentation window.