Revisit usage highlighting (#851)

autoload/jedi.vim

@@ -52,6 +52,8 @@ for [s:key, s:val] in items(s:default_settings)
     endif
 endfor
 
+let s:supports_buffer_usages = has('nvim') || exists('*prop_add')
+
 
 " ------------------------------------------------------------------------
 " Python initialization
@@ -304,16 +306,87 @@ function! jedi#goto_stubs() abort
 endfunction
 
 function! jedi#usages() abort
-    call jedi#remove_usages()
+    if exists('#jedi_usages#BufWinEnter')
+        call jedi#clear_usages()
+    endif
     PythonJedi jedi_vim.usages()
 endfunction
 
-function! jedi#remove_usages() abort
-    for match in getmatches()
-        if stridx(match['group'], 'jediUsage') == 0
-            call matchdelete(match['id'])
-        endif
+if !s:supports_buffer_usages
+" Hide usages in the current window.
+" Only handles the current window due to matchdelete() restrictions.
+function! jedi#_hide_usages_in_win() abort
+    let winnr = winnr()
+    let matchids = getwinvar(winnr, '_jedi_usages_vim_matchids', [])
+
+    for matchid in matchids[1:]
+        call matchdelete(matchid)
     endfor
+    call setwinvar(winnr, '_jedi_usages_vim_matchids', [])
+
+    " Remove the autocommands that might have triggered this function.
+    augroup jedi_usages
+        exe 'autocmd! * <buffer='.winbufnr(winnr).'>'
+    augroup END
+    unlet! b:_jedi_usages_needs_clear
+endfunction
+
+" Show usages for current window (Vim without textprops only).
+function! jedi#_show_usages_in_win() abort
+    PythonJedi jedi_vim.highlight_usages_for_vim_win()
+
+    if !exists('#jedi_usages#TextChanged#<buffer>')
+        augroup jedi_usages
+          " Unset highlights on any changes to this buffer.
+          " NOTE: Neovim's API handles movement of highlights, but would only
+          " need to clear highlights that are changed inline.
+          autocmd TextChanged <buffer> call jedi#_clear_buffer_usages()
+
+          " Hide usages when the buffer is removed from the window, or when
+          " entering insert mode (but keep them for later).
+          autocmd BufWinLeave,InsertEnter <buffer> call jedi#_hide_usages_in_win()
+        augroup END
+    endif
+endfunction
+
+" Remove usages for the current buffer (and all its windows).
+function! jedi#_clear_buffer_usages() abort
+    let bufnr = bufnr('%')
+    let nvim_src_ids = getbufvar(bufnr, '_jedi_usages_src_ids', [])
+    if !empty(nvim_src_ids)
+        for src_id in nvim_src_ids
+            " TODO: could only clear highlights below/after changed line?!
+            call nvim_buf_clear_highlight(bufnr, src_id, 0, -1)
+        endfor
+    else
+        call jedi#_hide_usages_in_win()
+    endif
+endfunction
+endif
+
+" Remove/unset global usages.
+function! jedi#clear_usages() abort
+    augroup jedi_usages
+        autocmd! BufWinEnter
+        autocmd! WinEnter
+    augroup END
+
+    if !s:supports_buffer_usages
+        " Vim without textprops: clear current window,
+        " autocommands will clean others on demand.
+        call jedi#_hide_usages_in_win()
+
+        " Setup autocommands to clear remaining highlights on WinEnter.
+        augroup jedi_usages
+        for b in range(1, bufnr('$'))
+            if getbufvar(b, '_jedi_usages_needs_clear')
+                exe 'autocmd WinEnter <buffer='.b.'> call jedi#_hide_usages_in_win()'
+            endif
+        endfor
+        augroup END
+    endif
+
+    PythonJedi jedi_vim.clear_usages()
 endfunction
 
 function! jedi#rename(...) abort
@@ -403,20 +476,56 @@ endfunction
 " helper functions
 " ------------------------------------------------------------------------
 
-function! jedi#add_goto_window(len) abort
-    set lazyredraw
-    cclose
+function! jedi#add_goto_window(for_usages, len) abort
     let height = min([a:len, g:jedi#quickfix_window_height])
-    execute 'belowright copen '.height
-    set nolazyredraw
-    if g:jedi#use_tabs_not_buffers == 1
-        noremap <buffer> <CR> :call jedi#goto_window_on_enter()<CR>
+
+    " Using :cwindow allows to stay in the current window in case it is opened
+    " already.
+    let win_count = winnr('$')
+    execute 'belowright cwindow '.height
+    let qfwin_was_opened = winnr('$') > win_count
+
+    if qfwin_was_opened
+        if &filetype !=# 'qf'
+            echoerr 'jedi-vim: unexpected ft with current window, please report!'
+        endif
+        if g:jedi#use_tabs_not_buffers == 1
+            noremap <buffer> <CR> :call jedi#goto_window_on_enter()<CR>
+        endif
+
+        augroup jedi_goto_window
+            if a:for_usages
+                autocmd BufWinLeave <buffer> call jedi#clear_usages()
+            else
+                autocmd WinLeave <buffer> q  " automatically leave, if an option is chosen
+            endif
+        augroup END
+    elseif a:for_usages && !s:supports_buffer_usages
+        " Init current window.
+        call jedi#_show_usages_in_win()
     endif
-    augroup jedi_goto_window
-      au!
-      au WinLeave <buffer> q  " automatically leave, if an option is chosen
-    augroup END
-    redraw!
+
+    if a:for_usages && !has('nvim')
+        if s:supports_buffer_usages
+            " Setup autocommand for pending highlights with Vim's textprops.
+            " (cannot be added to unlisted buffers)
+            augroup jedi_usages
+              autocmd! BufWinEnter * call s:usages_for_pending_buffers()
+            augroup END
+        else
+            " Setup global autocommand to display any usages for a window.
+            " Gets removed when closing the quickfix window that displays them, or
+            " when clearing them (e.g. on TextChanged).
+            augroup jedi_usages
+              autocmd! BufWinEnter,WinEnter * call jedi#_show_usages_in_win()
+            augroup END
+        endif
+    endif
+endfunction
+
+" Highlight usages for a buffer if not done so yet (Neovim only).
+function! s:usages_for_pending_buffers() abort
+    PythonJedi jedi_vim._handle_pending_usages_for_buf()
 endfunction