Use locationLink for definition preview (#498)

* use locationLink for definition preview

* remove cursor setting for location link

* make vint happy

* also advertise support for declaration, typeDefinition, implementation

* small refactor

* refactor to avoid code duplication

* restore lost check for file

Author: Christian Clason

autoload/lsp.vim

@@ -390,6 +390,18 @@ function! lsp#default_get_supported_capabilities(server_info) abort
     \              'valueSet': lsp#omni#get_completion_item_kinds()
     \           }
     \       },
+    \       'declaration': {
+    \           'linkSupport' : v:true
+    \       },
+    \       'definition': {
+    \           'linkSupport' : v:true
+    \       },
+    \       'typeDefinition': {
+    \           'linkSupport' : v:true
+    \       },
+    \       'implementation': {
+    \           'linkSupport' : v:true
+    \       },
     \       'documentSymbol': {
     \           'symbolKind': {
     \              'valueSet': lsp#ui#vim#utils#get_symbol_kinds()

autoload/lsp/ui/vim.vim

@@ -488,11 +488,19 @@ function! s:handle_location(ctx, server, type, data) abort "ctx = {counter, list
                 botright copen
             else
                 let l:lines = readfile(fnameescape(l:loc['filename']))
-                call lsp#ui#vim#output#preview(a:server, l:lines, {
-                            \   'statusline': ' LSP Peek ' . a:type,
-                            \   'cursor': { 'line': l:loc['lnum'], 'col': l:loc['col'], 'align': g:lsp_peek_alignment },
-                            \   'filetype': &filetype
-                            \ })
+                if has_key(l:loc,'viewstart') " showing a locationLink
+                    let l:view = l:lines[l:loc['viewstart'] : l:loc['viewend']]
+                    call lsp#ui#vim#output#preview(a:server, l:view, {
+                                \   'statusline': ' LSP Peek ' . a:type,
+                                \   'filetype': &filetype
+                                \ })
+                else " showing a location
+                    call lsp#ui#vim#output#preview(a:server, l:lines, {
+                                \   'statusline': ' LSP Peek ' . a:type,
+                                \   'cursor': { 'line': l:loc['lnum'], 'col': l:loc['col'], 'align': g:lsp_peek_alignment },
+                                \   'filetype': &filetype
+                                \ })
+                endif
             endif
         endif
     endif

autoload/lsp/ui/vim/utils.vim

@@ -7,16 +7,26 @@ function! lsp#ui#vim#utils#locations_to_loc_list(result) abort
 
     let l:locations = type(a:result['response']['result']) == type({}) ? [a:result['response']['result']] : a:result['response']['result']
 
+    if has_key(l:locations[0],'targetUri') " server returns locationLinks
+        let l:use_link = 1
+        let l:uri = 'targetUri'
+        let l:range = 'targetSelectionRange'
+    else
+        let l:use_link = 0
+        let l:uri = 'uri'
+        let l:range = 'range'
+    endif
+
     if !empty(l:locations) " some servers also return null so check to make sure it isn't empty
         let l:cache={}
         for l:location in l:locations
-            if s:is_file_uri(l:location['uri'])
-                let l:path = lsp#utils#uri_to_path(l:location['uri'])
-                let l:line = l:location['range']['start']['line'] + 1
-                let l:char = l:location['range']['start']['character']
+            if s:is_file_uri(l:location[l:uri])
+                let l:path = lsp#utils#uri_to_path(l:location[l:uri])
+                let l:line = l:location[l:range]['start']['line'] + 1
+                let l:char = l:location[l:range]['start']['character']
                 let l:col = lsp#utils#to_col(l:path, l:line, l:char)
-                let l:index = l:line - 1
 
+                let l:index = l:line - 1
                 if has_key(l:cache, l:path)
                     let l:text = l:cache[l:path][l:index]
                 else
@@ -29,12 +39,25 @@ function! lsp#ui#vim#utils#locations_to_loc_list(result) abort
                         let l:text = l:contents[l:index]
                     endif
                 endif
-                call add(l:list, {
-                    \ 'filename': l:path,
-                    \ 'lnum': l:line,
-                    \ 'col': l:col,
-                    \ 'text': l:text,
-                    \ })
+                if l:use_link
+                    let l:viewstart = l:location['targetRange']['start']['line']
+                    let l:viewend = l:location['targetRange']['end']['line'] 
+                    call add(l:list, {
+                                \ 'filename': l:path,
+                                \ 'lnum': l:line,
+                                \ 'col': l:col,
+                                \ 'text': l:text,
+                                \ 'viewstart': l:viewstart,
+                                \ 'viewend': l:viewend
+                                \ })
+                else
+                    call add(l:list, {
+                                \ 'filename': l:path,
+                                \ 'lnum': l:line,
+                                \ 'col': l:col,
+                                \ 'text': l:text,
+                                \ })
+                endif
             endif
         endfor
     endif