[WIP] Popup documentation (#507)

* Show documentation in Vim popup

* Use timer

* Reuse logic from output.vim

* Change default text

* Rename functions

* Refactor

* Use v:event

* Add comment

* Remove log

* Refactor

* Implement documentation in Neovim

* Cleanup Neovim popup

* Let Neovim float take all available space

* Extract get_size_info

* Reuse sizing logic from output.vim

* Fix Neovim positioning being reset

* Update autoload/lsp/ui/vim/documentation.vim

Co-Authored-By: Christian Clason <christian.clason@uni-due.de>

* Make vint happy

* Retrigger Travis CI

* add g:lsp_documentation_float flag

* fix lint issues

Co-authored-by: Christian Clason <christian.clason@uni-due.de>
Co-authored-by: Prabir Shrestha <mail@prabir.me>

autoload/lsp.vim

@@ -802,6 +802,8 @@ function! s:handle_initialize(server_name, data) abort
         call l:Init_callback(a:data)
     endfor
 
+    call lsp#ui#vim#documentation#setup()
+
     doautocmd User lsp_server_init
 endfunction
 

autoload/lsp/ui/vim/documentation.vim

@@ -0,0 +1,76 @@
+let s:use_vim_popup = has('patch-8.1.1517') && !has('nvim')
+let s:use_nvim_float = exists('*nvim_open_win') && has('nvim')
+
+let s:last_popup_id = -1
+
+function! s:complete_done() abort
+    if !g:lsp_documentation_float | return | endif
+    " Use a timer to avoid textlock (see :h textlock).
+    let l:event = deepcopy(v:event)
+    call timer_start(0, {-> s:show_documentation(l:event)})
+endfunction
+
+function! s:show_documentation(event) abort
+    call s:close_popup()
+
+    if !has_key(a:event['completed_item'], 'info') || empty(a:event['completed_item']['info'])
+        return
+    endif
+
+    let l:right = wincol() < winwidth(0) / 2
+
+    " TODO: Neovim
+    if l:right
+        let l:line = a:event['row'] + 1
+        let l:col = a:event['col'] + a:event['width'] + 1 + (a:event['scrollbar'] ? 1 : 0)
+    else
+        let l:line = a:event['row'] + 1
+        let l:col = a:event['col'] - 1
+    endif
+
+    " TODO: Support markdown
+    let l:data = split(a:event['completed_item']['info'], '\n')
+    let l:lines = []
+    let l:syntax_lines = []
+    let l:ft = lsp#ui#vim#output#append(l:data, l:lines, l:syntax_lines)
+
+    let l:current_win_id = win_getid()
+
+    if s:use_vim_popup
+        let s:last_popup_id = popup_create('(no documentation available)', {'line': l:line, 'col': l:col, 'pos': l:right ? 'topleft' : 'topright', 'padding': [0, 1, 0, 1]})
+    elseif s:use_nvim_float
+        let l:height = winheight(0) - l:line + 1
+        let l:width = l:right ? winwidth(0) - l:col + 1 : l:col
+        let s:last_popup_id = lsp#ui#vim#output#floatingpreview([])
+        call nvim_win_set_config(s:last_popup_id, {'relative': 'win', 'anchor': l:right ? 'NW' : 'NE', 'row': l:line - 1, 'col': l:col - 1, 'height': l:height, 'width': l:width})
+    endif
+
+    call setbufvar(winbufnr(s:last_popup_id), 'lsp_syntax_highlights', l:syntax_lines)
+    call setbufvar(winbufnr(s:last_popup_id), 'lsp_do_conceal', 1)
+    call lsp#ui#vim#output#setcontent(s:last_popup_id, l:lines, l:ft)
+    let [l:bufferlines, l:maxwidth] = lsp#ui#vim#output#get_size_info()
+
+    call win_gotoid(l:current_win_id)
+
+    if s:use_nvim_float
+        call lsp#ui#vim#output#adjust_float_placement(l:bufferlines, l:maxwidth)
+        call nvim_win_set_config(s:last_popup_id, {'relative': 'win', 'row': l:line - 1, 'col': l:col - 1})
+    endif
+endfunction
+
+function! s:close_popup() abort
+    if s:last_popup_id >= 0
+        if s:use_vim_popup | call popup_close(s:last_popup_id) | endif
+        if s:use_nvim_float | call nvim_win_close(s:last_popup_id, 1) | endif
+
+        let s:last_popup_id = -1
+    endif
+endfunction
+
+function! lsp#ui#vim#documentation#setup() abort
+    augroup lsp_documentation_popup
+        autocmd!
+        autocmd CompleteChanged * call s:complete_done()
+        autocmd CompleteDone * call s:close_popup()
+    augroup end
+endfunction

autoload/lsp/ui/vim/output.vim

@@ -149,10 +149,10 @@ function! lsp#ui#vim#output#floatingpreview(data) abort
     return s:winid
 endfunction
 
-function! s:setcontent(lines, ft) abort
+function! lsp#ui#vim#output#setcontent(winid, lines, ft) abort
     if s:use_vim_popup
         " vim popup
-        call setbufline(winbufnr(s:winid), 1, a:lines)
+        call setbufline(winbufnr(a:winid), 1, a:lines)
         call win_execute(s:winid, 'setlocal filetype=' . a:ft . '.lsp-hover')
     else
         " nvim floating or preview
@@ -162,7 +162,7 @@ function! s:setcontent(lines, ft) abort
     endif
 endfunction
 
-function! s:adjust_float_placement(bufferlines, maxwidth) abort
+function! lsp#ui#vim#output#adjust_float_placement(bufferlines, maxwidth) abort
     if s:use_nvim_float
         let l:win_config = {}
         let l:height = min([winheight(s:winid), a:bufferlines])
@@ -279,6 +279,27 @@ function! s:align_preview(options) abort
     endif
 endfunction
 
+function! lsp#ui#vim#output#get_size_info() abort
+    " Get size information while still having the buffer active
+    let l:maxwidth = max(map(getline(1, '$'), 'strdisplaywidth(v:val)'))
+    if g:lsp_preview_max_width > 0
+      let l:bufferlines = 0
+      let l:maxwidth = min([g:lsp_preview_max_width, l:maxwidth])
+
+      " Determine, for each line, how many "virtual" lines it spans, and add
+      " these together for all lines in the buffer
+      for l:line in getline(1, '$')
+        let l:num_lines = str2nr(string(ceil(strdisplaywidth(l:line) * 1.0 / g:lsp_preview_max_width)))
+        let l:bufferlines += max([l:num_lines, 1])
+      endfor
+    else
+      let l:bufferlines = line('$')
+    endif
+
+    return [l:bufferlines, l:maxwidth]
+  return [l:bufferlines, l:maxwidth]
+endfunction
+
 function! lsp#ui#vim#output#float_supported() abort
     return s:use_vim_popup || s:use_nvim_float
 endfunction
@@ -307,7 +328,7 @@ function! lsp#ui#vim#output#preview(server, data, options) abort
     let s:preview_data = a:data
     let l:lines = []
     let l:syntax_lines = []
-    let l:ft = s:append(a:data, l:lines, l:syntax_lines)
+    let l:ft = lsp#ui#vim#output#append(a:data, l:lines, l:syntax_lines)
 
     " If the server response is empty content, we don't display anything.
     if empty(l:lines) && empty(l:syntax_lines)
@@ -328,23 +349,9 @@ function! lsp#ui#vim#output#preview(server, data, options) abort
 
     call setbufvar(winbufnr(s:winid), 'lsp_syntax_highlights', l:syntax_lines)
     call setbufvar(winbufnr(s:winid), 'lsp_do_conceal', l:do_conceal)
-    call s:setcontent(l:lines, l:ft)
+    call lsp#ui#vim#output#setcontent(s:winid, l:lines, l:ft)
 
-    " Get size information while still having the buffer active
-    let l:maxwidth = max(map(getline(1, '$'), 'strdisplaywidth(v:val)'))
-    if g:lsp_preview_max_width > 0
-        let l:bufferlines = 0
-        let l:maxwidth = min([g:lsp_preview_max_width, l:maxwidth])
-
-        " Determine, for each line, how many "virtual" lines it spans, and add
-        " these together for all lines in the buffer
-        for l:line in getline(1, '$')
-            let l:num_lines = str2nr(string(ceil(strdisplaywidth(l:line) * 1.0 / g:lsp_preview_max_width)))
-            let l:bufferlines += max([l:num_lines, 1])
-        endfor
-    else
-        let l:bufferlines = line('$')
-    endif
+    let [l:bufferlines, l:maxwidth] = lsp#ui#vim#output#get_size_info()
 
     if s:use_preview
         " Set statusline
@@ -361,17 +368,16 @@ function! lsp#ui#vim#output#preview(server, data, options) abort
     echo ''
 
     if s:winid && (s:use_vim_popup || s:use_nvim_float)
-        if s:use_nvim_float
-            " Neovim floats
-            call s:adjust_float_placement(l:bufferlines, l:maxwidth)
-            call s:set_cursor(l:current_window_id, a:options)
-            call s:add_float_closing_hooks()
-        elseif s:use_vim_popup
-            " Vim popups
-            call s:set_cursor(l:current_window_id, a:options)
-        endif
-
-        doautocmd User lsp_float_opened
+      if s:use_nvim_float
+        " Neovim floats
+        call lsp#ui#vim#output#adjust_float_placement(l:bufferlines, l:maxwidth)
+        call s:set_cursor(l:current_window_id, a:options)
+        call s:add_float_closing_hooks()
+      elseif s:use_vim_popup
+        " Vim popups
+        call s:set_cursor(l:current_window_id, a:options)
+      endif
+	  doautocmd User lsp_float_opened
     endif
 
     if !g:lsp_preview_keep_focus
@@ -385,10 +391,10 @@ function! s:escape_string_for_display(str) abort
     return substitute(substitute(a:str, '\r\n', '\n', 'g'), '\r', '\n', 'g')
 endfunction
 
-function! s:append(data, lines, syntax_lines) abort
-    if type(a:data) ==# type([])
+function! lsp#ui#vim#output#append(data, lines, syntax_lines) abort
+    if type(a:data) == type([])
         for l:entry in a:data
-            call s:append(l:entry, a:lines, a:syntax_lines)
+            call lsp#ui#vim#output#append(l:entry, a:lines, a:syntax_lines)
         endfor
 
         return 'markdown'

doc/vim-lsp.txt

@@ -20,10 +20,11 @@ CONTENTS                                                  *vim-lsp-contents*
       g:lsp_preview_doubletap               |g:lsp_preview_doubletap|
       g:lsp_insert_text_enabled             |g:lsp_insert_text_enabled|
       g:lsp_text_edit_enabled               |g:lsp_text_edit_enabled|
+      g:lsp_documentation_float             |g:lsp_documentation_float|
       g:lsp_diagnostics_echo_cursor         |g:lsp_diagnostics_echo_cursor|
       g:lsp_diagnostics_echo_delay          |g:lsp_diagnostics_echo_delay|
-      g:lsp_diagnostics_float_cursor         |g:lsp_diagnostics_float_cursor|
-      g:lsp_diagnostics_float_delay          |g:lsp_diagnostics_float_delay|
+      g:lsp_diagnostics_float_cursor        |g:lsp_diagnostics_float_cursor|
+      g:lsp_diagnostics_float_delay         |g:lsp_diagnostics_float_delay|
       g:lsp_signs_enabled                   |g:lsp_signs_enabled|
       g:lsp_signs_priority                  |g:lsp_signs_priority|
       g:lsp_signs_priority_map              |g:lsp_signs_priority_map|
@@ -368,6 +369,16 @@ g:lsp_text_edit_enabled                           *g:lsp_text_edit_enabled*
 	let g:lsp_text_edit_enabled = 1
 	let g:lsp_text_edit_enabled = 0
 
+g:lsp_documentation_float                      *g:lsp_documentation_float*
+    Type: |Number|
+    Default: `1`
+
+    Enables floating window documentation for complete items.
+
+    Example: >
+	let g:lsp_documentation_float = 1
+	let g:lsp_documentation_float = 0
+
 g:lsp_diagnostics_echo_cursor                *g:lsp_diagnostics_echo_cursor*
     Type: |Number|
     Default: `0`

plugin/lsp.vim

@@ -21,6 +21,7 @@ let g:lsp_signs_information = get(g:, 'lsp_signs_information', {})
 let g:lsp_signs_hint = get(g:, 'lsp_signs_hint', {})
 let g:lsp_signs_priority = get(g:, 'lsp_signs_priority', 10)
 let g:lsp_signs_priority_map = get(g:, 'lsp_signs_priority_map', {})
+let g:lsp_documentation_float = get(g:, 'lsp_documentation_float', 1)
 let g:lsp_diagnostics_enabled = get(g:, 'lsp_diagnostics_enabled', 1)
 let g:lsp_diagnostics_echo_cursor = get(g:, 'lsp_diagnostics_echo_cursor', 0)
 let g:lsp_diagnostics_echo_delay = get(g:, 'lsp_diagnostics_echo_delay', 500)