feat: basic features

lua/screenkey/init.lua

@@ -0,0 +1,223 @@
+local M = {}
+local api = vim.api
+
+local keys = {
+    ["<tab>"] = "TAB",
+    ["<cr>"] = "ENTER",
+    ["<esc>"] = "ESC",
+    [" "] = "SPACE",
+    ["<bs>"] = "BACKSPACE",
+    ["<del>"] = "DEL",
+    ["<left>"] = "LEFT",
+    ["<right>"] = "RIGHT",
+    ["<up>"] = "UP",
+    ["<down>"] = "DOWN",
+    ["<home>"] = "HOME",
+    ["<end>"] = "END",
+    ["<pageup>"] = "PGUP",
+    ["<pagedown>"] = "PGDN",
+    ["<insert>"] = "INS",
+    ["<f1>"] = "F1",
+    ["<f2>"] = "F2",
+    ["<f3>"] = "F3",
+    ["<f4>"] = "F4",
+    ["<f5>"] = "F5",
+    ["<f6>"] = "F6",
+    ["<f7>"] = "F7",
+    ["<f8>"] = "F8",
+    ["<f9>"] = "F9",
+    ["<f10>"] = "F10",
+    ["<f11>"] = "F11",
+    ["<f12>"] = "F12",
+    ["CTRL"] = "CTRL",
+}
+local transformed_keys = {}
+for key, value in pairs(keys) do
+    transformed_keys[vim.keycode(key)] = value
+end
+keys = transformed_keys
+
+local config = {
+    win_opts = {
+        relative = "editor",
+        anchor = "SE",
+        width = 40,
+        height = 3,
+        border = "single",
+    },
+    compress_after = 2,
+}
+
+local active = false
+local bufnr, winnr = -1, -1
+local ns_id = api.nvim_create_namespace("screenkey")
+local queued_keys = {}
+
+local function create_window()
+    if active then
+        return
+    end
+
+    bufnr = api.nvim_create_buf(false, true)
+    winnr = api.nvim_open_win(bufnr, false, {
+        relative = config.win_opts.relative,
+        anchor = config.win_opts.anchor,
+        title = "Screenkey",
+        title_pos = "center",
+        row = vim.o.lines - vim.o.cmdheight - 1,
+        col = vim.o.columns - 1,
+        width = config.win_opts.width,
+        height = config.win_opts.height,
+        style = "minimal",
+        border = config.win_opts.border,
+        focusable = false,
+        noautocmd = true,
+    })
+
+    if winnr == 0 then
+        error("Screenkey: failed to create window")
+    end
+
+    api.nvim_set_option_value("filetype", "screenkey", { buf = bufnr })
+end
+
+local function close_window()
+    if not active then
+        return
+    end
+
+    if bufnr ~= -1 and api.nvim_buf_is_valid(bufnr) then
+        api.nvim_buf_delete(bufnr, { force = true })
+    end
+
+    if winnr ~= -1 and api.nvim_win_is_valid(winnr) then
+        api.nvim_win_close(winnr, true)
+    end
+
+    bufnr, winnr = -1, -1
+end
+
+---@param key string
+---@return string
+local function transform_key(key)
+    if keys[key] then
+        return keys[key]
+    end
+
+    ---@type string
+    local translated_key = vim.fn.keytrans(key)
+    -- check ctrl combo keys
+    local ctrl_match = translated_key:match("^<C.-(.)>$")
+    if ctrl_match then
+        -- check ctrl-shift combo keys
+        local shift_match = translated_key:match("^<C%-S%-.>$")
+        if not shift_match then
+            ctrl_match = ctrl_match:lower()
+        end
+        return string.format("%s+%s", keys["CTRL"], ctrl_match)
+    end
+
+    -- ignore mouse input (use keyboard!)
+    if
+        translated_key:match("Left")
+        or translated_key:match("Right")
+        or translated_key:match("Middle")
+        or translated_key:match("Scroll")
+    then
+        return ""
+    end
+
+    return translated_key
+end
+
+---@return string
+local function compress_output()
+    local compressed_keys = {}
+
+    local last_key = queued_keys[1]
+    local duplicates = 0
+    for _, key in ipairs(queued_keys) do
+        if key == last_key then
+            duplicates = duplicates + 1
+        else
+            if duplicates >= config.compress_after then
+                table.insert(compressed_keys, string.format("%s..x%d", last_key, duplicates))
+            else
+                for _ = 1, duplicates do
+                    table.insert(compressed_keys, last_key)
+                end
+            end
+            last_key = key
+            duplicates = 1
+        end
+    end
+    -- check the last key
+    if duplicates >= config.compress_after then
+        table.insert(compressed_keys, string.format("%s..x%d", last_key, duplicates))
+    else
+        for _ = 1, duplicates do
+            table.insert(compressed_keys, last_key)
+        end
+    end
+
+    -- remove old entries
+    local text = table.concat(compressed_keys, " ")
+    while #text > config.win_opts.width - 2 do
+        local removed = table.remove(compressed_keys, 1)
+        local num_removed = tonumber(string.match(removed:match("%.%.x%d$") or "1", "%d$"))
+        -- local compressed = removed:match("%.%.x%d$")
+        -- local num_removed = 1
+        -- if compressed then
+        --     local num = tonumber(compressed:match("%d$") or "0")
+        --     num_removed = num_removed + num
+        -- end
+        for _ = 1, num_removed do
+            table.remove(queued_keys, 1)
+        end
+        text = table.concat(compressed_keys, " ")
+    end
+
+    return text
+end
+
+local function display_text()
+    local text = compress_output()
+    -- center text inside of screenkey window
+    local padding =
+        string.rep(" ", math.floor((config.win_opts.width - api.nvim_strwidth(text)) / 2))
+    local line = math.floor(config.win_opts.height / 2)
+    api.nvim_buf_set_lines(
+        bufnr,
+        line,
+        line + 1,
+        false,
+        { string.format("%s%s%s", padding, text, padding) }
+    )
+end
+
+---@param opts? table
+function M.setup(opts)
+    config = vim.tbl_deep_extend("force", config, opts or {})
+end
+
+function M.toggle()
+    if active then
+        close_window()
+    else
+        create_window()
+    end
+    active = not active
+end
+
+vim.on_key(function(_, typed)
+    if not active or #typed == 0 then
+        return
+    end
+    local key = transform_key(typed)
+    if #key > 0 then
+        table.insert(queued_keys, transform_key(typed))
+    end
+    display_text()
+end, ns_id)
+
+return M

plugin/screenkey.lua

@@ -0,0 +1,9 @@
+vim.api.nvim_create_user_command("Screenkey", function(event)
+    if #event.fargs > 0 then
+        error("Screenkey: command does not accept arguments")
+    end
+    require("screenkey").toggle()
+end, {
+    nargs = 0,
+    desc = "Toggle Screenkey",
+})