Add the ability to pass popup_params when creating a custom ycm_hover

README.md

@@ -3019,6 +3019,7 @@ buffer-local variable can be set to a dictionary with the following keys:
 * `command`: The YCM completer subcommand which should be run on hover
 * `syntax`: The syntax to use (as in `set syntax=`) in the popup window for
   highlighting.
+* `popup_params`: The params passed to a popup window which gets opened.
 
 For example, to use C/C++ syntax highlighting in the popup for C-family
 languages, add something like this to your vimrc:
@@ -3033,6 +3034,25 @@ augroup MyYCMCustom
 augroup END
 ```
 
+You can also modify the opened popup with `popup_params` key.
+For example, you can limit the popup's maximum width and add a border to it:
+
+```viml
+augroup MyYCMCustom
+  autocmd!
+  autocmd FileType c,cpp let b:ycm_hover = {
+    \ 'command': 'GetDoc',
+    \ 'syntax': &filetype
+    \ 'popup_params': {
+    \     'maxwidth': 80,
+    \     'border': [],
+    \     'borderchars': ['─', '│', '─', '│', '┌', '┐', '┘', '└'],
+    \   },
+    \ }
+augroup END
+```
+See `:help popup_create-arguments` for the list of available popup window options.
+
 Default: `'CursorHold'`
 
 ### The `g:ycm_filter_diagnostics` option

autoload/youcompleteme.vim

@@ -1650,18 +1650,22 @@ if exists( '*popup_atcursor' )
       let wrap = 1
     endif
 
-    let s:cursorhold_popup = popup_atcursor(
-          \   lines,
-          \   {
-          \     'col': col,
-          \     'wrap': wrap,
-          \     'padding': [ 0, 1, 0, 1 ],
-          \     'moved': 'word',
-          \     'maxwidth': &columns,
-          \     'close': 'click',
-          \     'fixed': 0,
-          \   }
-          \ )
+    let popup_params = {
+          \ 'col': col,
+          \ 'wrap': wrap,
+          \ 'padding': [ 0, 1, 0, 1 ],
+          \ 'moved': 'word',
+          \ 'maxwidth': &columns,
+          \ 'close': 'click',
+          \ 'fixed': 0,
+          \ }
+
+    if has_key( b:ycm_hover, 'popup_params' )
+      let popup_params = extend( copy( popup_params ),
+                               \ b:ycm_hover.popup_params )
+    endif
+
+    let s:cursorhold_popup = popup_atcursor( lines, popup_params )
     call setbufvar( winbufnr( s:cursorhold_popup ),
                             \ '&syntax',
                             \ b:ycm_hover.syntax )

doc/youcompleteme.txt

@@ -3277,6 +3277,7 @@ This buffer-local variable can be set to a dictionary with the following keys:
 - 'command': The YCM completer subcommand which should be run on hover
 - 'syntax': The syntax to use (as in 'set syntax=') in the popup window for
   highlighting.
+- 'popup_params': The params passed to a popup window which gets opened.
 
 For example, to use C/C++ syntax highlighting in the popup for C-family
 languages, add something like this to your vimrc:
@@ -3289,6 +3290,27 @@ languages, add something like this to your vimrc:
       \ }
   augroup END
 <
+You can also modify the opened popup with 'popup_params' key. For example, you
+can limit the popup's maximum width and add a border to it:
+
+
+>
+  augroup MyYCMCustom
+    autocmd!
+    autocmd FileType c,cpp let b:ycm_hover = {
+      \ 'command': 'GetDoc',
+      \ 'syntax': &filetype
+      \ 'popup_params': {
+      \     'maxwidth': 80,
+      \     'border': [],
+      \     'borderchars': ['─', '│', '─', '│', '┌', '┐', '┘', '└'],
+      \   },
+      \ }
+  augroup END
+<
+See ':help popup_create-arguments' for the list of available popup window
+options.
+
 Default: "'CursorHold'"
 
 -------------------------------------------------------------------------------

test/hover.test.vim

@@ -387,6 +387,53 @@ function! TearDown_Test_Hover_Custom_Command()
   silent! au! MyYCMCustom
 endfunction
 
+function! SetUp_Test_Hover_Custom_Popup()
+  augroup MyYCMCustom
+    autocmd!
+    autocmd FileType cpp let b:ycm_hover = {
+      \ 'command': 'GetDoc',
+      \ 'syntax': 'cpp',
+      \ 'popup_params': {
+      \     'maxwidth': 10,
+      \   }
+      \ }
+  augroup END
+endfunction
+
+function! Test_Hover_Custom_Popup()
+  call youcompleteme#test#setup#OpenFile( '/test/testdata/cpp/completion.cc',
+                                        \ {} )
+  call assert_equal( 'cpp', &filetype )
+  call assert_equal( {
+                   \   'command': 'GetDoc',
+                   \   'syntax': 'cpp',
+                   \   'popup_params': { 'maxwidth': 10 }
+                   \ }, b:ycm_hover )
+
+  call setpos( '.', [ 0, 6, 8 ] )
+  doautocmd CursorHold
+  call assert_equal( {
+                   \   'command': 'GetDoc',
+                   \   'syntax': 'cpp',
+                   \   'popup_params': { 'maxwidth': 10 }
+                   \ }, b:ycm_hover )
+
+  call s:CheckPopupVisibleScreenPos( { 'row': 7, 'col': 9 },
+                                   \ s:cpp_lifetime.GetDoc,
+                                   \ 'cpp' )
+  " Check that popup's width is limited by maxwidth being passed
+  call s:CheckPopupNotVisibleScreenPos( { 'row': 7, 'col': 20 }, v:false )
+
+  normal \D
+  call s:CheckPopupNotVisibleScreenPos( { 'row': 7, 'col': 9 }, v:false )
+
+  call popup_clear()
+endfunction
+
+function! TearDown_Test_Hover_Custom_Popup()
+  silent! au! MyYCMCustom
+endfunction
+
 function! Test_Long_Single_Line()
   call youcompleteme#test#setup#OpenFile( '/test/testdata/python/doc.py', {} )
   call cursor( [ 37, 3 ] )