How to enter SmartResizeMode with Wezterm leader key

[ryanmsnyder]

I'd like to enter SmartResizeMode using my Wezterm leader key (ctrl-a) that I've set for other pane management tasks such as splitting horizontally/vertically and closing panes. Here's how I've set my leader key and pane management in wezterm.lua:

local function split_nav(resize_or_move, key)
  return {
    key = key,
    mods = resize_or_move == 'resize' and 'META' or 'CTRL',
    action = wezterm.action_callback(function(win, pane)
      if is_vim(pane) then
        -- pass the keys through to vim/nvim
        win:perform_action({
          SendKey = { key = key, mods = resize_or_move == 'resize' and 'META' or 'CTRL' },
        }, pane)
      else
        if resize_or_move == 'resize' then
          win:perform_action({ AdjustPaneSize = { direction_keys[key], 3 } }, pane)
        else
          win:perform_action({ ActivatePaneDirection = direction_keys[key] }, pane)
        end
      end
    end),
  }
end

config.keys = {
  leader = { key = 'a', mods = 'CTRL', timeout_milliseconds = 2000 },
  keys = {
    -- pane management
    {
      key = "\\",
      mods = 'LEADER',
      action = act.SplitHorizontal { domain = 'CurrentPaneDomain' },
    },
    {
      key = "-",
      mods = 'LEADER',
      action = act.SplitVertical { domain = 'CurrentPaneDomain' },
    },
    {
      key = 'x',
      mods = 'LEADER',
      action = wezterm.action.CloseCurrentPane { confirm = true },
    },
  
    -- smart-splits.nvim 
    -- move between split panes
    split_nav('move', 'h'),
    split_nav('move', 'j'),
    split_nav('move', 'k'),
    split_nav('move', 'l'),

    -- resize panes
    split_nav('resize', 'h'),
    split_nav('resize', 'j'),
    split_nav('resize', 'k'),
    split_nav('resize', 'l'),
  },
}

return config

Here are my NeoVim mappings in my mappings.lua file:

local M = {}

M.general = {
  n = {
    -- moving between splits (smart-splits.nvim)
    ["<C-h>"] = { "<cmd> SmartCursorMoveLeft <CR>"},
    ["<C-l>"] = { "<cmd> SmartCursorMoveRight <CR>"},
    ["<C-j>"] = { "<cmd> SmartCursorMoveDown <CR>"},
    ["<C-k>"] = { "<cmd> SmartCursorMoveUp <CR>"},
  },
}

return M

I've configured smart-splits in NeoVim with the same exact configuration from the README.

Moving between Wezterm panes and NeoVim works great with the above configuration. I would just like to figure out how to use ctrl-a to enter SmartResizeMode. Thanks for the plugin!

[mrjones2014]

I don't think there is a way to do what you're asking, due to how LEADER works in general.

In order to do what you want, you would need a way to have Wezterm's LEADER by itself (not combined with another keystroke like <LEADER>\) send keystrokes into nvim when nvim is the foreground process, like the resize and cursor move keymaps do (with the is_vim function).

However there is no way to map LEADER on its own in Wezterm, at least I don't think there is (it wouldn't really make sense to, since it's whole purpose is to combine with other keys for keymaps).

I would recommend just choosing another leader mapping, like maybe <LEADER>r, and mapping that in Wezterm like:

{
  key = 'r',
  mods = 'LEADER',
  action = wezterm.action_callback(function(win, pane)
    if is_vim(pane) then
      -- pass the keys through to vim/nvim
      -- send '<C-a>'
      win:perform_action({
        SendKey = { key ='a', mods = 'CTRL' },
      }, pane)
      -- send 'r'
      win:perform_action({
        SendKey = { key ='r' },
      }, pane)
    end
  end)

And then on the Neovim side just set the mapping on <C-a>r.

[ryanmsnyder]

@mrjones2014 thanks for the quick reply. I figured that was the case. I ultimately decided to map it to <LEADER>r as you suggested, which works just fine. The only reason I was looking for a persistent resize with just using the <LEADER> key (CTRL-a in my case) was because that's how I had it setup with tmux. However, I've been able to replace tmux with WezTerm + smart-splits so I'm ok with adding an r to my original keybinding. I was able to imitate your SmartResizeMode (persistent resize) outside of NeoVim using WezTerm's key_tables. So now I get persistent resize in NeoVim as well as non-NeoVim panes. Thanks again for the plugin.

Here's my config in case this helps someone in the future:

wezterm.lua:

local wezterm = require("wezterm")
local mux = wezterm.mux
local act = wezterm.action

local function is_vim(pane)
  -- this is set by the plugin, and unset on ExitPre in Neovim
  return pane:get_user_vars().IS_NVIM == 'true'
end

local direction_keys = {
  Left = 'h',
  Down = 'j',
  Up = 'k',
  Right = 'l',
  -- reverse lookup
  h = 'Left',
  j = 'Down',
  k = 'Up',
  l = 'Right',
}

local function pane_nav_and_resize(resize_or_move, key)
  return {
    key = key,
    mods = resize_or_move == 'resize' and 'LEADER' or 'CTRL',
    action = wezterm.action_callback(function(win, pane)
      -- if NeoVim is running in current pane, send keys to NeoVim
      -- if resizing, CTRL + a will be sent to NeoVim, else CTRL + h|j|k|l (pane navigation) will be sent
      -- the keybindings set in custom/mappings.lua will "catch" the bindings that WezTerm sends it
      if is_vim(pane) then
        -- resizing panes
        if resize_or_move == 'resize' then
          -- pass the keys through to vim/nvim
          -- send '<C-a>'
          win:perform_action({
            SendKey = { key ='a', mods = 'CTRL' },
          }, pane)
          -- send 'r'
          win:perform_action({
            SendKey = { key ='r' },
          }, pane)
        -- moving between panes
        else
          win:perform_action({
            SendKey = { key = key, mods = 'CTRL' },
          }, pane)
        end
      -- if it's a non-NeoVim pane
      else
        -- if resizing (LEADER + r), activate resize_pane key_table defined below
        if resize_or_move == 'resize' then
          win:perform_action({ ActivateKeyTable = {
              name = 'resize_pane',
              one_shot = false,
            }
          }, pane)
        
        -- if navigating between panes (CTRL + h|j|k|l), 
        else
          win:perform_action({ ActivatePaneDirection = direction_keys[key] }, pane)
        end
      end
    end)
  }
end

local config = {
  color_scheme = "Catppuccin Macchiato",
  --   window_background_opacity = 0.95,

  inactive_pane_hsb = {
    saturation = 0.9,
    brightness = 0.7,
  },
  enable_tab_bar = false,
  hide_tab_bar_if_only_one_tab = true,
  show_update_window = true,
  window_decorations = "RESIZE",
  font = wezterm.font_with_fallback({
    "JetBrainsMono Nerd Font",
    "Apple Color Emoji",
  }),
  allow_square_glyphs_to_overflow_width = "Always",
  -- changes spacing of characters
  cell_width = 0.9,
  unicode_version = 14,
  -- Padding
  window_padding = { left = 0, right = 0, top = 0, bottom = 0 },
  font_size = 14,
  adjust_window_size_when_changing_font_size = false,
  native_macos_fullscreen_mode = true,

  leader = { key = 'a', mods = 'CTRL', timeout_milliseconds = 2000 },
  keys = {
    {
      key = "f",
      mods = "LEADER",
      action = act.ToggleFullScreen,
    },

    -- pane management
    {
      key = "\\",
      mods = 'LEADER',
      action = act.SplitHorizontal { domain = 'CurrentPaneDomain' },
    },
    {
      key = "-",
      mods = 'LEADER',
      action = act.SplitVertical { domain = 'CurrentPaneDomain' },
    },
    {
      key = 'x',
      mods = 'LEADER',
      action = wezterm.action.CloseCurrentPane { confirm = true },
    },
    {
      key = 'z',
      mods = 'LEADER',
      action = wezterm.action.TogglePaneZoomState,
    },

    -- move between split panes
    pane_nav_and_resize('move', 'h'),
    pane_nav_and_resize('move', 'j'),
    pane_nav_and_resize('move', 'k'),
    pane_nav_and_resize('move', 'l'),
    pane_nav_and_resize('resize', 'r')

  },

  key_tables = {
    -- Defines the keys that are active in our resize-pane mode.
    -- Since we're likely to want to make multiple adjustments,
    -- we made the activation one_shot=false. We therefore need
    -- to define a key assignment for getting out of this mode.
    -- 'resize_pane' here corresponds to the name="resize_pane" in
    -- the pane_nav_and_resize function above.
    resize_pane = {
      { key = 'LeftArrow', action = act.AdjustPaneSize { 'Left', 2 } },
      { key = 'h', action = act.AdjustPaneSize { 'Left', 2 } },
  
      { key = 'RightArrow', action = act.AdjustPaneSize { 'Right', 2 } },
      { key = 'l', action = act.AdjustPaneSize { 'Right', 2 } },
  
      { key = 'UpArrow', action = act.AdjustPaneSize { 'Up', 2 } },
      { key = 'k', action = act.AdjustPaneSize { 'Up', 2 } },
  
      { key = 'DownArrow', action = act.AdjustPaneSize { 'Down', 2 } },
      { key = 'j', action = act.AdjustPaneSize { 'Down', 2 } },
  
      -- Cancel the mode by pressing escape
      { key = 'Escape', action = 'PopKeyTable' },
    },
  }
}

return config

mappings.lua (NeoVim keyboard bindings):

local M = {}

M.general = {
  n = {
    [";"] = { ":", "enter command mode", opts = { nowait = true } },

    -- moving between splits (smart-splits.nvim)
    ["<C-h>"] = { "<cmd> SmartCursorMoveLeft <CR>"},
    ["<C-l>"] = { "<cmd> SmartCursorMoveRight <CR>"},
    ["<C-j>"] = { "<cmd> SmartCursorMoveDown <CR>"},
    ["<C-k>"] = { "<cmd> SmartCursorMoveUp <CR>"},

    -- resizing splits (smart-splits.nvim)
    ["<C-a>r"] = { "<cmd> SmartResizeMode <CR>"},
  },
}

return M

As far as configuring smart-splits.nvim plugin in NeoVim, I just have the default config found in the README.

[mrjones2014]

That's neat, I didn't think about a similar resize mode in Wezterm itself!