Add possibility to reuse a split when opening a link

Also, refactor and simplify the corresponding functions (and finally
remove the chat between long inactive developers in the comments!)

Fix #316

autoload/vimwiki/base.vim

@@ -1220,57 +1220,81 @@ function! vimwiki#base#find_prev_link() "{{{
 endfunction " }}}
 
 " vimwiki#base#follow_link
-function! vimwiki#base#follow_link(split, ...) "{{{ Parse link at cursor and pass 
+function! vimwiki#base#follow_link(split, reuse, move_cursor, ...) "{{{
-  " to VimwikiLinkHandler, or failing that, the default open_link handler
+  " Parse link at cursor and pass to VimwikiLinkHandler, or failing that, the
-  if exists('*vimwiki#'.VimwikiGet('syntax').'_base#follow_link')
+  " default open_link handler
-    " Syntax-specific links
+
-    " XXX: @Stuart: do we still need it?
+  " try WikiLink
-    " XXX: @Maxim: most likely!  I am still working on a seemless way to
+  let lnk = matchstr(vimwiki#base#matchstr_at_cursor(g:vimwiki_rxWikiLink),
-    " integrate regexp's without complicating syntax/vimwiki.vim
+        \ g:vimwiki_rxWikiLinkMatchUrl)
-    if a:0
+  " try WikiIncl
-      call vimwiki#{VimwikiGet('syntax')}_base#follow_link(a:split, a:1)
+  if lnk == ""
-    else
+    let lnk = matchstr(vimwiki#base#matchstr_at_cursor(g:vimwiki_rxWikiIncl),
-      call vimwiki#{VimwikiGet('syntax')}_base#follow_link(a:split)
+          \ g:vimwiki_rxWikiInclMatchUrl)
+  endif
+  " try Weblink
+  if lnk == ""
+    let lnk = matchstr(vimwiki#base#matchstr_at_cursor(g:vimwiki_rxWeblink),
+          \ g:vimwiki_rxWeblinkMatchUrl)
+  endif
+
+  if lnk != ""    " cursor is indeed on a link
+    let processed_by_user_defined_handler = VimwikiLinkHandler(lnk)
+    if processed_by_user_defined_handler
+      return
     endif
-  else
+
-    if a:split ==# "split"
+    if a:split ==# "hsplit"
       let cmd = ":split "
     elseif a:split ==# "vsplit"
       let cmd = ":vsplit "
-    elseif a:split ==# "tabnew"
+    elseif a:split ==# "tab"
       let cmd = ":tabnew "
     else
       let cmd = ":e "
     endif
 
-    " try WikiLink
+    " if we want to and can reuse a split window, jump to that window and open
-    let lnk = matchstr(vimwiki#base#matchstr_at_cursor(g:vimwiki_rxWikiLink),
+    " the new file there
-          \ g:vimwiki_rxWikiLinkMatchUrl)
+    if (a:split ==# 'hsplit' || a:split ==# 'vsplit') && a:reuse
-    " try WikiIncl
+      let previous_window_nr = winnr('#')
-    if lnk == ""
+      if previous_window_nr > 0 && previous_window_nr != winnr()
-      let lnk = matchstr(vimwiki#base#matchstr_at_cursor(g:vimwiki_rxWikiIncl),
+        execute previous_window_nr . 'wincmd w'
-          \ g:vimwiki_rxWikiInclMatchUrl)
+        let cmd = ':e'
-    endif
-    " try Weblink
-    if lnk == ""
-      let lnk = matchstr(vimwiki#base#matchstr_at_cursor(g:vimwiki_rxWeblink),
-            \ g:vimwiki_rxWeblinkMatchUrl)
-    endif
-
-    if lnk != ""
-      if !VimwikiLinkHandler(lnk)
-        call vimwiki#base#open_link(cmd, lnk)
       endif
-      return
     endif
 
+
+    if VimwikiGet('syntax') == 'markdown'
+      let processed_by_markdown_reflink = vimwiki#markdown_base#open_reflink(lnk)
+      if processed_by_markdown_reflink
+        return
+      endif
+
+      " remove the extension from the filename if exists, because non-vimwiki
+      " markdown files usually include the extension in links
+      let lnk = substitute(lnk, VimwikiGet('ext').'$', '', '')
+    endif
+
+    let current_tab_page = tabpagenr()
+
+    call vimwiki#base#open_link(cmd, lnk)
+
+    if !a:move_cursor
+      if (a:split ==# 'hsplit' || a:split ==# 'vsplit')
+        execute 'wincmd p'
+      elseif a:split ==# 'tab'
+        execute 'tabnext ' . current_tab_page
+      endif
+    endif
+
+  else
     if a:0 > 0
       execute "normal! ".a:1
     else		
       call vimwiki#base#normalize_link(0)
     endif
   endif
-
 endfunction " }}}
 
 " vimwiki#base#go_back_link

autoload/vimwiki/markdown_base.vim

@@ -70,61 +70,6 @@ endfunction " }}}
 
 " WIKI link following functions {{{
 
-" vimwiki#markdown_base#follow_link
-function! vimwiki#markdown_base#follow_link(split, ...) "{{{ Parse link at cursor and pass 
-  " to VimwikiLinkHandler, or failing that, the default open_link handler
-  " echom "markdown_base#follow_link"
-
-  if 0
-    " Syntax-specific links
-    " XXX: @Stuart: do we still need it?
-    " XXX: @Maxim: most likely!  I am still working on a seemless way to
-    " integrate regexp's without complicating syntax/vimwiki.vim
-  else
-    if a:split ==# "split"
-      let cmd = ":split "
-    elseif a:split ==# "vsplit"
-      let cmd = ":vsplit "
-    elseif a:split ==# "tabnew"
-      let cmd = ":tabnew "
-    else
-      let cmd = ":e "
-    endif
-
-    " try WikiLink
-    let lnk = matchstr(vimwiki#base#matchstr_at_cursor(g:vimwiki_rxWikiLink),
-          \ g:vimwiki_rxWikiLinkMatchUrl)
-    " try WikiIncl
-    if lnk == ""
-      let lnk = matchstr(vimwiki#base#matchstr_at_cursor(g:vimwiki_rxWikiIncl),
-          \ g:vimwiki_rxWikiInclMatchUrl)
-    endif
-    " try Weblink
-    if lnk == ""
-      let lnk = matchstr(vimwiki#base#matchstr_at_cursor(g:vimwiki_rxWeblink),
-            \ g:vimwiki_rxWeblinkMatchUrl)
-    endif
-
-    if lnk != ""
-      if !VimwikiLinkHandler(lnk)
-        if !vimwiki#markdown_base#open_reflink(lnk)
-          " remove the extension from the filename if exists
-          let lnk = substitute(lnk, VimwikiGet('ext').'$', '', '')
-          call vimwiki#base#open_link(cmd, lnk)
-        endif
-      endif
-      return
-    endif
-
-    if a:0 > 0
-      execute "normal! ".a:1
-    else		
-      call vimwiki#base#normalize_link(0)
-    endif
-  endif
-
-endfunction " }}}
-
 " LINK functions {{{
 
 " s:normalize_link_syntax_n

doc/vimwiki.txt

@@ -594,6 +594,9 @@ il                      A single list item.
 ------------------------------------------------------------------------------
 4.2. Local commands                                   *vimwiki-local-commands*
 
+These commands are only available (and meaningful) when you are currently in a
+Vimwiki file.
+
 *:VimwikiFollowLink*
     Follow wiki link (or create target wiki page if needed).
 
@@ -742,6 +745,34 @@ il                      A single list item.
     their instances.  Supports |cmdline-completion|.  If
     no arguments (tags) are specified, outputs all tags.
 
+------------------------------------------------------------------------------
+4.3. Functions                                              *vimwiki-functions*
+
+Functions to interact with Vimwiki. (It's intended that most commands will be
+replaced with corresponding function calls in the future.)
+Warning: this is currently unstable and likely to change.
+
+
+To map them to a key, use >
+ nnoremap <C-K> :call vimwiki#base#function_name(arg1, arg2)<CR>
+
+
+vimwiki#base#follow_link({split}, {reuse}, {move_cursor})         *follow_link*
+    Open the link under the cursor. {split} can have the following values:
+        'nosplit'       open the link in the current window
+        'vsplit'        open in a vertically split window
+        'hsplit'        open in a horizontally split window
+        'tab'           open in a new tab
+
+    If {reuse} is 1 and {split} one of 'vsplit' or 'hsplit', open the link in
+    a possibly existing split window instead of making a new split.
+
+    If {move_cursor} is 1 the cursor moves to the window or tab with the
+    opened link, otherwise, it stays in the window or tab with the link.
+
+    For example, <CR> is per default mapped to
+    vimwiki#base#follow_link('nosplit', 0, 1)
+
 
 ==============================================================================
 5. Wiki syntax                                                *vimwiki-syntax*

ftplugin/vimwiki.vim

@@ -264,14 +264,14 @@ command! -buffer VimwikiNextLink call vimwiki#base#find_next_link()
 command! -buffer VimwikiPrevLink call vimwiki#base#find_prev_link()
 command! -buffer VimwikiDeleteLink call vimwiki#base#delete_link()
 command! -buffer VimwikiRenameLink call vimwiki#base#rename_link()
-command! -buffer VimwikiFollowLink call vimwiki#base#follow_link('nosplit')
+command! -buffer VimwikiFollowLink call vimwiki#base#follow_link('nosplit', 0, 1)
 command! -buffer VimwikiGoBackLink call vimwiki#base#go_back_link()
-command! -buffer VimwikiSplitLink call vimwiki#base#follow_link('split')
+command! -buffer VimwikiSplitLink call vimwiki#base#follow_link('hsplit', 0, 1)
-command! -buffer VimwikiVSplitLink call vimwiki#base#follow_link('vsplit')
+command! -buffer VimwikiVSplitLink call vimwiki#base#follow_link('vsplit', 0, 1)
 
 command! -buffer -nargs=? VimwikiNormalizeLink call vimwiki#base#normalize_link(<f-args>)
 
-command! -buffer VimwikiTabnewLink call vimwiki#base#follow_link('tabnew')
+command! -buffer VimwikiTabnewLink call vimwiki#base#follow_link('tab', 0, 1)
 
 command! -buffer VimwikiGenerateLinks call vimwiki#base#generate_links()
 
@@ -327,7 +327,7 @@ command! -buffer -nargs=* -complete=custom,vimwiki#tags#complete_tags
 if g:vimwiki_use_mouse
   nmap <buffer> <S-LeftMouse> <NOP>
   nmap <buffer> <C-LeftMouse> <NOP>
-  nnoremap <silent><buffer> <2-LeftMouse> :call vimwiki#base#follow_link("nosplit", "\<lt>2-LeftMouse>")<CR>
+  nnoremap <silent><buffer> <2-LeftMouse> :call vimwiki#base#follow_link('nosplit', 0, 1, "\<lt>2-LeftMouse>")<CR>
   nnoremap <silent><buffer> <S-2-LeftMouse> <LeftMouse>:VimwikiSplitLink<CR>
   nnoremap <silent><buffer> <C-2-LeftMouse> <LeftMouse>:VimwikiVSplitLink<CR>
   nnoremap <silent><buffer> <RightMouse><LeftMouse> :VimwikiGoBackLink<CR>