feat: enable to preview themes (#980)

doc/telescope.txt

@@ -670,6 +670,9 @@ builtin.colorscheme({opts}) *builtin.colorscheme()*
  Parameters: ~
  {opts} (table) options to pass to the picker
 
+ Fields: ~
+ {enable_preview} (boolean) if true, will preview the selected color
+
 
 builtin.marks({opts}) *builtin.marks()*
  Lists vim marks and their value, jumps to the mark on `<cr>`

lua/telescope/builtin/init.lua

@@ -254,6 +254,7 @@ builtin.buffers = require('telescope.builtin.internal').buffers
 
 --- Lists available colorschemes and applies them on `<cr>`
 ---@param opts table: options to pass to the picker
+---@field enable_preview boolean: if true, will preview the selected color
 builtin.colorscheme = require('telescope.builtin.internal').colorscheme
 
 --- Lists vim marks and their value, jumps to the mark on `<cr>`

lua/telescope/builtin/internal.lua

@@ -635,26 +635,101 @@ internal.buffers = function(opts)
 end
 
 internal.colorscheme = function(opts)
- local colors = vim.list_extend(opts.colors or {}, vim.fn.getcompletion('', 'color'))
+ local before_color = vim.api.nvim_exec('colorscheme', true)
+ local need_restore = true
 
- pickers.new(opts,{
- prompt = 'Change Colorscheme',
+ local colors = opts.colors or { before_color }
+ if not vim.tbl_contains(colors, before_color) then
+ table.insert(colors, 1, before_color)
+ end
+
+ colors = vim.list_extend(
+ colors,
+ vim.tbl_filter(function(color)
+ return color ~= before_color
+ end, vim.fn.getcompletion(
+ '',
+ 'color'
+ ))
+ )
+
+ local previewer
+ if opts.enable_preview then
+ -- define previewer
+ local bufnr = vim.api.nvim_get_current_buf()
+ local p = vim.api.nvim_buf_get_name(bufnr)
+
+ -- don't need previewer
+ if vim.fn.buflisted(bufnr) ~= 1 then
+ local deleted = false
+ local function del_win(win_id)
+ if win_id and vim.api.nvim_win_is_valid(win_id) then
+ utils.buf_delete(vim.api.nvim_win_get_buf(win_id))
+ pcall(vim.api.nvim_win_close, win_id, true)
+ end
+ end
+
+ previewer = previewers.new {
+ preview_fn = function(_, entry, status)
+ if not deleted then
+ deleted = true
+ del_win(status.preview_win)
+ del_win(status.preview_border_win)
+ end
+ vim.cmd('colorscheme ' .. entry.value)
+ end,
+ }
+ else
+ -- show current buffer content in previewer
+ previewer = previewers.new_buffer_previewer {
+ get_buffer_by_name = function()
+ return p
+ end,
+ define_preview = function(self, entry)
+ if vim.loop.fs_stat(p) then
+ conf.buffer_previewer_maker(p, self.state.bufnr, { bufname = self.state.bufname })
+ else
+ local lines = vim.api.nvim_buf_get_lines(bufnr, 0, -1, false)
+ vim.api.nvim_buf_set_lines(self.state.bufnr, 0, -1, false, lines)
+ end
+ vim.cmd('colorscheme ' .. entry.value)
+ end,
+ }
+ end
+ end
+
+ local picker = pickers.new(opts, {
+ prompt_title = 'Change Colorscheme',
  finder = finders.new_table {
- results = colors
+ results = colors,
  },
- -- TODO: better preview?
  sorter = conf.generic_sorter(opts),
+ previewer = previewer,
  attach_mappings = function(prompt_bufnr)
  actions.select_default:replace(function()
  local selection = action_state.get_selected_entry()
-
  actions.close(prompt_bufnr)
- vim.cmd("colorscheme " .. selection.value)
+
+ need_restore = false
+ vim.cmd('colorscheme ' .. selection.value)
  end)
 
  return true
+ end,
+ })
+
+ if opts.enable_preview then
+ -- rewrite picker.close_windows. restore color if needed
+ local close_windows = picker.close_windows
+ picker.close_windows = function(status)
+ close_windows(status)
+ if need_restore then
+ vim.cmd('colorscheme ' .. before_color)
+ end
  end
- }):find()
+ end
+
+ picker:find()
 end
 
 internal.marks = function(opts)