feat(title): implement dynamic view title feature (#90)

## What is this PR for?
Accept and use function as view title. This provides option to implement
per view dynamic/context based title.

## Does this PR fix an existing issue?
Fixes #59

Co-authored-by: Folke Lemaitre <folke.lemaitre@gmail.com>

lua/edgy/edgebar.lua

@@ -157,7 +157,7 @@ function M:update(wins)
   -- check if the layout changed
   for _, view in ipairs(self.views) do
     if not vim.deep_equal(current[view], view.wins) then
-      -- dd(view.title, vim.tbl_map(tostring, view.wins), vim.tbl_map(tostring, current[view]))
+      -- dd(view.get_title(), vim.tbl_map(tostring, view.wins), vim.tbl_map(tostring, current[view]))
       -- vim.notify(before .. "\n---\n" .. tostring(self))
       return true
     end
@@ -274,9 +274,9 @@ function M:resize()
     elseif self.vertical then
       win[long] = 1
     else
-      local title_width = vim.fn.strdisplaywidth(win.view.title)
+      local title_width = vim.fn.strdisplaywidth(win.view.get_title())
       -- if vim.api.nvim_eval_statusline then
-      --   title_width = vim.api.nvim_eval_statusline(win.view.title, {
+      --   title_width = vim.api.nvim_eval_statusline(win.view.get_title(), {
       --     use_winbar = true,
       --     winid = win.win,
       --   }).width

lua/edgy/editor.lua

@@ -127,7 +127,7 @@ function M.select(pos, filter)
       prompt = "Select Edgy Window:",
       ---@param w Edgy.Window
       format_item = function(w)
-        local title = w.view.title
+        local title = w.view.get_title()
         if pos == nil then
           title = "[" .. w.view.edgebar.pos .. "] " .. title
         end

lua/edgy/view.lua

@@ -5,7 +5,7 @@ local Window = require("edgy.window")
 ---@class Edgy.View.Opts
 ---@field ft string
 ---@field filter? fun(buf:number, win:number):boolean?
----@field title? string
+---@field title? fun():string|string
 ---@field size? Edgy.Size
 -- When a view is pinned, it will always be shown
 -- in the edgebar, even if it has no windows.
@@ -15,7 +15,8 @@ local Window = require("edgy.window")
 ---@field wo? vim.wo View specific window options
 
 ---@class Edgy.View: Edgy.View.Opts
----@field title string
+---@field title fun():string|string
+---@field get_title fun():string
 ---@field wins Edgy.Window[]
 ---@field size Edgy.Size
 ---@field pinned_win? Edgy.Window
@@ -30,13 +31,19 @@ function M.new(opts, edgebar)
   self.edgebar = edgebar
   self.wins = {}
   self.title = self.title or self.ft:sub(1, 1):upper() .. self.ft:sub(2)
+  self.get_title = function()
+    if type(self.title) == "function" then
+      return self.title()
+    end
+    return self.title
+  end
   self.size = self.size or {}
   self.opening = false
   return self
 end
 
 function M:__tostring()
-  local lines = { "Edgy.View(" .. self.title .. ")" }
+  local lines = { "Edgy.View(" .. self.get_title() .. ")" }
   for _, win in ipairs(self.wins) do
     table.insert(lines, "  " .. tostring(win))
   end
@@ -88,7 +95,7 @@ function M:show_pinned(opts)
     vim.bo[buf].bufhidden = "wipe"
     vim.bo[buf].swapfile = false
     vim.bo[buf].filetype = "edgy"
-    vim.api.nvim_buf_set_name(buf, "edgy://" .. self.title)
+    vim.api.nvim_buf_set_name(buf, "edgy://" .. self.get_title())
     local win = vim.api.nvim_open_win(buf, false, {
       relative = "editor",
       width = 1,

lua/edgy/window.lua

@@ -191,7 +191,7 @@ function M:winbar()
   end
 
   parts[#parts + 1] = "%#" .. icon_hl .. "#" .. icon .. "%*%<"
-  parts[#parts + 1] = "%#EdgyTitle# " .. self.view.title .. "%*"
+  parts[#parts + 1] = "%#EdgyTitle# " .. self.view.get_title() .. "%*"
   parts[#parts + 1] = "%T"
 
   return table.concat(parts)