[picker]: Cycle between your preferred layouts!

[pkazmier]

With the ability to dynamically change picker layouts on the fly, I wrote this to allow me to quickly cycle between my preferred layouts. While picker allows you to maximize the layout and toggle on/off the preview, sometimes I still need a wider preview. So with this I simply press <a-c> to cycle between layouts. My preferred layout is ivy, but I wanted slight variations as well, so I've defined the following 4 preferred layouts:

• the default ivy version
• ivy with wider results list (shrinks the preview, could accomplish the same by toggling off preview)
• ivy with wider preview (shrinks the results list so I can have my wider preview when needed)
• a taller ivy for times when I want to see more vertically

Here is a video showing the cycling of layouts with <a-c>. When I get to my layout with the wider preview, I maximized with <a-m> to show how I combine these.

Screen.Recording.2025-01-14.at.5.13.09.PM.mov

Here is the little utility I wrote in my util/snacks_picker.lua:

local M = {}

local layouts = require("snacks.picker.config.layouts")

layouts.ivy_taller = vim.tbl_deep_extend("keep", { layout = { height = 0.8 } }, layouts.ivy)

layouts.ivy_wider_results = vim.deepcopy(layouts.ivy)
layouts.ivy_wider_results.layout[2][2].width = 0.1

layouts.ivy_wider_preview = vim.deepcopy(layouts.ivy)
layouts.ivy_wider_preview.layout[2][2].width = 0.9

local idx = 1
local preferred = {
  "ivy",
  "ivy_wider_results",
  "ivy_wider_preview",
  "ivy_taller",
}

M.preferred_layout = function()
  return preferred[idx]
end

M.set_next_preferred_layout = function(picker)
  idx = idx % #preferred + 1
  picker:set_layout(preferred[idx])
end

return M

And then I set the keybinding as well as set my preferred layout in my snacks.picker spec:

  {
    "snacks.nvim",
    opts = {
      ---@type snacks.picker.Config
      picker = {
        win = {
          input = {
            keys = {
              ["<a-c>"] = { "cycle_layouts", mode = { "i", "n" } },
            },
          },
        },
        actions = {
          cycle_layouts = function() require("util.snacks_picker").set_next_preferred_layout() end,
        },
        layout = {
          preset = function() require("util.snacks_picker").preferred_layout() end,
        },
      },
    },
  },

[drowning-cat]

Cycle preview sizes:

opts = {
  picker = {
    actions = {
      cycle_preview = function(picker)
        local layout_config = vim.deepcopy(picker.resolved_layout)

        if layout_config.preview == 'main' or not picker.preview.win:valid() then
          return
        end

        local function find_preview(root) ---@param root snacks.layout.Box|snacks.layout.Win
          if root.win == 'preview' then
            return root
          end
          if #root then
            for _, w in ipairs(root) do
              local preview = find_preview(w)
              if preview then
                return preview
              end
            end
          end
          return nil
        end

        local preview = find_preview(layout_config.layout)

        if not preview then
          return
        end

        local eval = function(s)
          return type(s) == 'function' and s(preview.win) or s
        end
        --- @type number?, number?
        local width, height = eval(preview.width), eval(preview.height)

        if not width and not height then
          return
        end

        local cycle_sizes = { 0.1, 0.9 }
        local size_prop, size

        if height then
          size_prop, size = 'height', height
        else
          size_prop, size = 'width', width
        end

        picker.init_size = picker.init_size or size ---@diagnostic disable-line: inject-field
        table.insert(cycle_sizes, picker.init_size)
        table.sort(cycle_sizes)

        for i, s in ipairs(cycle_sizes) do
          if size == s then
            local smaller = cycle_sizes[i - 1] or cycle_sizes[#cycle_sizes]
            preview[size_prop] = smaller
            break
          end
        end

        for i, h in ipairs(layout_config.hidden) do
          if h == 'preview' then
            table.remove(layout_config.hidden, i)
          end
        end

        picker:set_layout(layout_config)
      end,

[dpetka2001]

Tnx for this @drowning-cat. Really useful as well. Incorporated this in my config 😄

[flowfelis]

Perfect! I needed wide preview view.
Toggling wide preview should be one of the default options.

[frontiercity]

Awesome! I can now preview at 0.9 width ratios. Thanks a lot!

[drowning-cat]

I updated the code. It should better handle edge cases.