feat: config for floating preview window (#74)

lua/oil/config.lua

@@ -74,6 +74,29 @@ local default_config = {
       winblend = 10,
     },
   },
+  -- Configuration for the actions floating preview window
+  preview = {
+    -- Width dimensions can be integers or a float between 0 and 1 (e.g. 0.4 for 40%)
+    -- min_width and max_width can be a single value or a list of mixed integer/float types.
+    -- max_width = {100, 0.8} means "the lesser of 100 columns or 80% of total"
+    max_width = 0.9,
+    -- min_width = {40, 0.4} means "the greater of 40 columns or 40% of total"
+    min_width = { 40, 0.4 },
+    -- optionally define an integer/float for the exact width of the preview window
+    width = nil,
+    -- Height dimensions can be integers or a float between 0 and 1 (e.g. 0.4 for 40%)
+    -- min_height and max_height can be a single value or a list of mixed integer/float types.
+    -- max_height = {80, 0.9} means "the lesser of 80 columns or 90% of total"
+    max_height = 0.9,
+    -- min_height = {5, 0.1} means "the greater of 5 columns or 10% of total"
+    min_height = { 5, 0.1 },
+    -- optionally define an integer/float for the exact height of the preview window
+    height = nil,
+    border = "rounded",
+    win_options = {
+      winblend = 0,
+    },
+  },
 }
 
 -- The adapter API hasn't really stabilized yet. We're not ready to advertise or encourage people to

lua/oil/layout.lua

@@ -0,0 +1,100 @@
+local M = {}
+
+local function is_float(value)
+  local _, p = math.modf(value)
+  return p ~= 0
+end
+
+local function calc_float(value, max_value)
+  if value and is_float(value) then
+    return math.min(max_value, value * max_value)
+  else
+    return value
+  end
+end
+
+M.get_editor_width = function()
+  return vim.o.columns
+end
+
+M.get_editor_height = function()
+  local editor_height = vim.o.lines - vim.o.cmdheight
+  -- Subtract 1 if tabline is visible
+  if vim.o.showtabline == 2 or (vim.o.showtabline == 1 and #vim.api.nvim_list_tabpages() > 1) then
+    editor_height = editor_height - 1
+  end
+  -- Subtract 1 if statusline is visible
+  if
+    vim.o.laststatus >= 2 or (vim.o.laststatus == 1 and #vim.api.nvim_tabpage_list_wins(0) > 1)
+  then
+    editor_height = editor_height - 1
+  end
+  return editor_height
+end
+
+local function calc_list(values, max_value, aggregator, limit)
+  local ret = limit
+  if not max_value or not values then
+    return nil
+  elseif type(values) == "table" then
+    for _, v in ipairs(values) do
+      ret = aggregator(ret, calc_float(v, max_value))
+    end
+    return ret
+  else
+    ret = aggregator(ret, calc_float(values, max_value))
+  end
+  return ret
+end
+
+local function calculate_dim(desired_size, exact_size, min_size, max_size, total_size)
+  local ret = calc_float(exact_size, total_size)
+  local min_val = calc_list(min_size, total_size, math.max, 1)
+  local max_val = calc_list(max_size, total_size, math.min, total_size)
+  if not ret then
+    if not desired_size then
+      if min_val and max_val then
+        ret = (min_val + max_val) / 2
+      else
+        ret = 80
+      end
+    else
+      ret = calc_float(desired_size, total_size)
+    end
+  end
+  if max_val then
+    ret = math.min(ret, max_val)
+  end
+  if min_val then
+    ret = math.max(ret, min_val)
+  end
+  return math.floor(ret)
+end
+
+M.calculate_width = function(desired_width, opts)
+  return calculate_dim(
+    desired_width,
+    opts.width,
+    opts.min_width,
+    opts.max_width,
+    M.get_editor_width()
+  )
+end
+
+M.calculate_height = function(desired_height, opts)
+  return calculate_dim(
+    desired_height,
+    opts.height,
+    opts.min_height,
+    opts.max_height,
+    M.get_editor_height()
+  )
+end
+
+M.calculate_dims = function(desired_width, desired_height, opts)
+  local width = M.calculate_width(desired_width, opts)
+  local height = M.calculate_height(desired_height, opts)
+  return width, height
+end
+
+return M

lua/oil/mutator/preview.lua

@@ -1,5 +1,6 @@
 local columns = require("oil.columns")
 local config = require("oil.config")
+local layout = require("oil.layout")
 local util = require("oil.util")
 local M = {}
 
@@ -44,6 +45,8 @@ end
 ---@param should_confirm nil|boolean
 ---@param cb fun(proceed: boolean)
 M.show = vim.schedule_wrap(function(actions, should_confirm, cb)
+  -- The schedule wrap ensures that we actually enter the floating window.
+  -- Not sure why it doesn't work without that
   if should_confirm == false or #actions == 0 then
     cb(true)
     return
@@ -52,36 +55,52 @@ M.show = vim.schedule_wrap(function(actions, should_confirm, cb)
     cb(true)
     return
   end
-  -- The schedule wrap ensures that we actually enter the floating window.
-  -- Not sure why it doesn't work without that
+
+  -- Create the buffer
   local bufnr = vim.api.nvim_create_buf(false, true)
   vim.bo[bufnr].bufhidden = "wipe"
-  local width = 120
-  local height = 40
+  local lines = {}
+  local max_line_width = 0
+  for _, action in ipairs(actions) do
+    local adapter = util.get_adapter_for_action(action)
+    local line
+    if action.type == "change" then
+      line = columns.render_change_action(adapter, action)
+    else
+      line = adapter.render_action(action)
+    end
+    table.insert(lines, line)
+    local line_width = vim.api.nvim_strwidth(line)
+    if line_width > max_line_width then
+      max_line_width = line_width
+    end
+  end
+  table.insert(lines, "")
+
+  -- Create the floating window
+  local width, height = layout.calculate_dims(max_line_width, #lines + 1, config.preview)
   local winid = vim.api.nvim_open_win(bufnr, true, {
     relative = "editor",
     width = width,
     height = height,
-    row = math.floor((vim.o.lines - vim.o.cmdheight - height) / 2),
-    col = math.floor((vim.o.columns - width) / 2),
+    row = math.floor((layout.get_editor_height() - height) / 2),
+    col = math.floor((layout.get_editor_width() - width) / 2),
     zindex = 152, -- render on top of the floating window title
     style = "minimal",
-    border = "rounded",
+    border = config.preview.border,
   })
   vim.bo[bufnr].filetype = "oil_preview"
   vim.bo[bufnr].syntax = "oil_preview"
-
-  local lines = {}
-  for _, action in ipairs(actions) do
-    local adapter = util.get_adapter_for_action(action)
-    if action.type == "change" then
-      table.insert(lines, columns.render_change_action(adapter, action))
-    else
-      table.insert(lines, adapter.render_action(action))
-    end
+  for k, v in pairs(config.preview.win_options) do
+    vim.api.nvim_win_set_option(winid, k, v)
   end
-  table.insert(lines, "")
+
+  -- Finish setting the last line and highlights on the buffer
   width = vim.api.nvim_win_get_width(0)
+  height = vim.api.nvim_win_get_height(0)
+  while #lines < height - 1 do
+    table.insert(lines, "")
+  end
   local last_line = "[O]k    [C]ancel"
   local highlights = {}
   local padding = string.rep(" ", math.floor((width - last_line:len()) / 2))
@@ -97,6 +116,7 @@ M.show = vim.schedule_wrap(function(actions, should_confirm, cb)
     vim.api.nvim_buf_add_highlight(bufnr, ns, unpack(hl))
   end
 
+  -- Attach autocmds and keymaps
   local cancel
   local confirm
   local function make_callback(value)