From 3a2337cd630825c8459e64ab5567a8d63a99d314 Mon Sep 17 00:00:00 2001
From: "Kenneth Benzie (Benie)" <benie@infektor.net>
Date: Mon, 22 Feb 2021 20:48:33 +0000
Subject: [PATCH] Add do#show_documentation() using coc.nvim

Change the `K` normal mode overrides to use the example given in the
coc.nvim README file which uses Vim's builtin help when in `vim` or
`help` files, or checks if coc.nvim is ready and invokes
`CocActionAsync('doHover')`, otherwise fallback to using `keywordprg`.
---
 after/ftplugin/c.vim      |  2 --
 after/ftplugin/cpp.vim    |  2 --
 after/ftplugin/python.vim |  3 ---
 after/ftplugin/vim.vim    |  3 ---
 autoload/do.vim           | 11 +++++++++++
 plugin/mappings.vim       | 13 ++++++-------
 6 files changed, 17 insertions(+), 17 deletions(-)

diff --git a/after/ftplugin/c.vim b/after/ftplugin/c.vim
index c2145ba..dbd2fea 100644
--- a/after/ftplugin/c.vim
+++ b/after/ftplugin/c.vim
@@ -15,5 +15,3 @@ nnoremap K :YcmCompleter GetDoc<CR>
 let b:surround_{char2nr("t")} = "TODO(\r):"
 " "ys{motion}/" turns "text" into "/*text*/"
 let b:surround_{char2nr("/")} = "/*\r*/"
-" Map K to get YouCompleteMe documentation.
-nnoremap K :YcmCompleter GetDoc<CR>
diff --git a/after/ftplugin/cpp.vim b/after/ftplugin/cpp.vim
index 5ae0746..8dffb38 100644
--- a/after/ftplugin/cpp.vim
+++ b/after/ftplugin/cpp.vim
@@ -1,5 +1,3 @@
 " Add Doxygen documentation generation plugin.
 packadd DoxygenToolkit.vim
 nnoremap <leader>d :Dox<CR>
-" Map K to get YouCompleteMe documentation
-nnoremap K :YcmCompleter GetDoc<CR>
diff --git a/after/ftplugin/python.vim b/after/ftplugin/python.vim
index 68da4dd..9917a89 100644
--- a/after/ftplugin/python.vim
+++ b/after/ftplugin/python.vim
@@ -25,6 +25,3 @@ setlocal encoding=utf-8
 " Set up file format
 setlocal fileformat=unix
 let g:python_highlight_all=1
-
-" Mappings
-nnoremap K :YcmCompleter GetDoc<CR>
diff --git a/after/ftplugin/vim.vim b/after/ftplugin/vim.vim
index 771dc9c..c66d826 100644
--- a/after/ftplugin/vim.vim
+++ b/after/ftplugin/vim.vim
@@ -1,9 +1,6 @@
 " Add omnifunc completion package.
 packadd vimomni
 
-" Mapping for Vim help of the word under cursor.
-nnoremap K :help <C-r><C-w><CR>
-
 " Set custom fold expression
 setlocal foldmethod=expr
 setlocal foldexpr=VimFold(v:lnum)
diff --git a/autoload/do.vim b/autoload/do.vim
index aca11c8..9855f11 100644
--- a/autoload/do.vim
+++ b/autoload/do.vim
@@ -100,3 +100,14 @@ endfunction
 " A sink for mappings to do nothing
 function! do#sink() abort
 endfunction
+
+" Used by normal mode K mapping to show documentation
+function! do#show_documentation()
+  if index(['vim','help'], &filetype) >= 0
+    execute 'help '.expand('<cword>')
+  elseif coc#rpc#ready()  " TODO: Check if the LS supports doHover
+    call CocActionAsync('doHover')
+  else
+    execute '!'.&keywordprg.' '.expand('<cword>')
+  endif
+endfunction
diff --git a/plugin/mappings.vim b/plugin/mappings.vim
index 8c3bc78..8d6b467 100644
--- a/plugin/mappings.vim
+++ b/plugin/mappings.vim
@@ -1,9 +1,10 @@
 " coc.nvim
-nmap <leader>fi <Plug>(coc-fix-current)
-nmap <leader>gd <Plug>(coc-definition)
-nmap <leader>gt <Plug>(coc-type-definition)
-nmap <leader>sd <Plug>(coc-diagnostic-info)
-nmap <leader>gr <Plug>(coc-references)
+nnoremap <silent> <leader>fi <Plug>(coc-fix-current)
+nnoremap <silent> <leader>gd <Plug>(coc-definition)
+nnoremap <silent> <leader>gt <Plug>(coc-type-definition)
+nnoremap <silent> <leader>sd <Plug>(coc-diagnostic-info)
+nnoremap <silent> <leader>gr <Plug>(coc-references)
+nnoremap <silent> K :call do#show_documentation()<CR>
 
 if has('nvim')
   " Make nvim :terminal more like vim :terminal
@@ -110,8 +111,6 @@ nnoremap <C-s> i<C-g>u<C-X>s
 
 " Disable 'Q' from opening Ex mode
 nnoremap Q <nop>
-" Disable 'K' from loading man pages
-noremap K <nop>
 
 " Split line at the cursor
 nnoremap [j i<CR><Esc>