make navigation window configurable and add key bindings

3 files changed, 137 insertions, 32 deletions

diff --git a/README.md b/README.md
index de1206a..a5ff2d5 100644
--- a/README.md
+++ b/README.md
@@ -76,7 +76,14 @@ Alternatively, a plugin manager like [vis-plug](https://github.com/erf/vis-plug)
 	<K> - hover over current position
 	Normal and Insert mode:
 	<C- > - get completions
+	< o> - open the symbol navigation window
 
+#### Non-Auto-Jump Navigation Window
+
+	Normal mode:
+	< s> - scroll to the selected symbol
+	< j> - jump to the selected symbol (switch to the code window)
+	< x> - close the navigaion window
 
 ### Available commands
 
@@ -133,6 +140,9 @@ Available options are:
 * `show_message = 'message'` - how to present information. `'message'`: use `vis:message`; `'open'`: use a new window supporting syntax highlighting.
 * `universal_root_globs = {}` - Globs to consider as workspace root for any language server (e.g. `*.git` or `*.hg`).
 * `fallback_dirname_as_root = false` - If set to true a file's directory is used as workspace root if no explicit root was found.
+* `navwin_symbols_format = '%s[%.1s] %s\n'` - The format string used to display a symbol in the symbol navigation window.
+* `navwin_auto_scroll = true` - If set to true the code window will scroll to the currently selected symbol in the navigation window without user interaction.
+* `navwin_layout = 'vr'` - Layout where the navigation window will be placed (`v[r|l]|h[t|b]`: vertical right or left; horizontal top or bottom).
 
 #### Configure your own Language Server
 
diff --git a/init.lua b/init.lua
index 8953847..d01969c 100644
--- a/init.lua
+++ b/init.lua
@@ -1610,9 +1610,8 @@ local function recursive_bfs_symbols_flatten(symbols, indent)
   for _, s in ipairs(symbols) do
     local range = s.selectionRange or s.location.range
     table.insert(ranges, range)
-    str = str ..
-              string.format('%s%s %s %d:%d\n', indent, lsp_symbol_kinds[s.kind], s.name,
-                            range.start.line + 1, range.start.character + 1)
+    str = str .. string.format(lspc.navwin_symbol_format, indent, lsp_symbol_kinds[s.kind], s.name,
+                               range.start.line + 1, range.start.character + 1)
     -- Remember DocumentSymbol.selectionRange or SymbolInformation.location.range
     if s.children then
       local cstr, cranges = recursive_bfs_symbols_flatten(s.children, indent .. '  ')
@@ -1625,60 +1624,115 @@ local function recursive_bfs_symbols_flatten(symbols, indent)
   return str, ranges
 end
 
+--- Scroll the code window to the definition of the symbol selected in the navigation window.
+local function lspc_navwin_scroll_codewin(switch_win)
+  local line = lspc.navctx.navwin.selection.line
+  -- No valid selection in the navigation window
+  if line > #lspc.navctx.ranges then
+    return
+  end
+  local sel = lsp_pos_to_vis_sel(lspc.navctx.ranges[line].start)
+
+  -- Set the selection in the code window to the selected symbol
+  lspc.navctx.codewin.selection:to(sel.line, sel.col)
+
+  if switch_win then
+    vis.win = lspc.navctx.codewin
+  end
+end
+
+--- Instantiate a new navigation context from the received symbols.
 local function lspc_navwin_from_symbols(symbols, ctx)
   local symbols_outline, ranges = recursive_bfs_symbols_flatten(symbols, '')
 
   local old_layout = vis.ui.layout
-  vis:command('vsplit')
-  local navwin = ctx.win
-  local codewin = vis.win
+  if lspc.navwin_layout:sub(1, 1) == 'v' then
+    vis.ui.layout = vis.ui.layouts.VERTICAL
+  elseif lspc.navwin_layout:sub(1, 1) == 'h' then
+    vis.ui.layout = vis.ui.layouts.HORIZONTAL
+  end
+
+  local navwin
+  local codewin
+  -- The right or bottom (old) window is our navigation window
+  if lspc.navwin_layout:sub(2) == 'r' or lspc.navwin_layout:sub(2) == 'b' then
+    vis:command('o ' .. ctx.win.file.path)
+    navwin = ctx.win
+    navwin.file = ''
+    navwin.file:delete(0, navwin.file.size)
+    codewin = vis.win
+    -- The new (old) window is our navigation window
+  else
+    vis:command('o')
+    navwin = vis.win
+    codewin = ctx.win
+  end
+
+  assert(navwin)
+  assert(codewin)
+  lspc.navctx = {
+    navwin = navwin,
+    codewin = codewin,
+    ranges = ranges,
+    old_layout = old_layout,
+  }
 
   -- Prepare window to be our symbol navigation window
-  navwin.file = 'symbols'
-  local navfile = navwin.file
-  navfile:delete(0, navfile.size)
-  navfile:insert(0, symbols_outline)
+  navwin.file:insert(0, symbols_outline)
   navwin:draw()
+
   -- Jump to navigation window
   vis.win = navwin
 
-  -- Create event handlers to connect the position in the navigation window to
-  -- the original window.
-  local function nav_win_win_highlight_handler(win)
-    -- This is not the navigation window
-    if win ~= navwin then
-      return true
-    end
+  -- Follow the position in the navigation window
+  local nav_win_win_highlight_handler
+  if lspc.navwin_auto_scroll then
+    -- Create event handlers to connect the position in the navigation window to
+    -- the original window.
+    nav_win_win_highlight_handler = function(win)
+      -- This is not the navigation window
+      if win ~= lspc.navctx.navwin then
+        return true
+      end
 
-    -- No valid selection in the navigation window
-    local line = navwin.selection.line
-    if line > #ranges then
+      -- scroll the code window without switching to it.
+      lspc_navwin_scroll_codewin(false)
       return true
     end
-    local sel = lsp_pos_to_vis_sel(ranges[navwin.selection.line].start)
-
-    -- Set the selection in the code window to the selected symbol
-    codewin.selection:to(sel.line, sel.col)
-    return true
+    vis.events.subscribe(vis.events.WIN_HIGHLIGHT, nav_win_win_highlight_handler)
+  else
+    navwin:map(vis.modes.NORMAL, ' j', function()
+      lspc_navwin_scroll_codewin(true)
+    end, 'jump to the selected symbol')
+    navwin:map(vis.modes.NORMAL, ' s', function()
+      lspc_navwin_scroll_codewin(false)
+    end, 'scroll to the selected symbol')
+    navwin:map(vis.modes.NORMAL, ' x', function()
+      lspc.navctx.navwin:close(true)
+    end, 'close the navgation window')
   end
-  vis.events.subscribe(vis.events.WIN_HIGHLIGHT, nav_win_win_highlight_handler)
 
   -- Remove the event handlers.
   local nav_win_close_handler
   nav_win_close_handler = function(win)
-    if win ~= navwin and win ~= codewin then
+    if win ~= lspc.navctx.navwin and win ~= lspc.navctx.codewin then
       return true
       -- The code windows was closed, therefore we can also close the navigation window
-    elseif win == codewin then
-      navwin:close(true)
+    elseif win == lspc.navctx.codewin then
+      lspc:log('Code window closed. Force close the navigation window.')
+      lspc.navctx.navwin:close(true)
       -- Reset everything after closing the navigation window
     else
       -- reset vis' layout
-      vis.ui.layout = old_layout
-      vis.ui.layout = vis.ui.layouts.HORIZONTAL
+      vis.ui.layout = lspc.navctx.old_layout
 
       -- remove the navigation window event handlers
-      vis.events.unsubscribe(vis.events.UI_DRAW, nav_win_win_highlight_handler)
+      if lspc.navwin_auto_jump then
+        vis.events.unsubscribe(vis.events.UI_DRAW, nav_win_win_highlight_handler)
+      end
+
+      -- remove the navigation context
+      lspc.navctx = nil
       vis.events.unsubscribe(vis.events.WIN_CLOSE, nav_win_close_handler)
     end
     return true
@@ -1928,9 +1982,33 @@ vis:command_register('lspc-navigate-symbols', function(argv, _, win)
   if not ls:is_file_opened(win.file.path) then
     lspc_open(ls, win, win.file)
   end
+  if lspc.navctx then
+    lspc:err('navigation window already active')
+    return
+  end
   lspc_nav_symbols(ls, win)
 end, 'navigate the file by its symbols')
 
+vis:command_register('lspc-navigate-close', function()
+  if not lspc.navctx then
+    lspc:err('no navigation window active')
+    return
+  end
+  lspc.navctx.navwin:close(true)
+end, 'close the navigation window')
+
+vis:command_register('lspc-navigate-jump', function(_, _, win)
+  if not lspc.navctx then
+    lspc:err('no navigation window active')
+    return
+  end
+  if win ~= lspc.navctx.navwin then
+    lspc:err('not in navigation window')
+    return
+  end
+
+end, 'navigate to the selected symbol')
+
 -- vis-lspc event hooks
 vis.events.subscribe(vis.events.WIN_OPEN, function(win)
   if lspc.autostart and win.syntax then
diff --git a/lspc.lua b/lspc.lua
index f34ba4d..b1b5e98 100644
--- a/lspc.lua
+++ b/lspc.lua
@@ -57,6 +57,23 @@ local lspc = {
   -- Should a file's directory be used as workspace root if no explicit root was found.
   fallback_dirname_as_root = false,
 
+  -- Format string how the symbols are presented in the navigation window.
+  -- The following arguments are passed to the string.format function:
+  -- indentation, symbol kind, name, line, column
+  navwin_symbol_format = '%s[%.1s] %s\n', -- short version
+  -- navwin_symbol_format = '%s[%s] %s %d:%d\n', -- verbose version
+
+  -- Automaticaly scroll the code window to the symbol selected in the navigation window.
+  navwin_auto_scroll = true,
+
+  -- The layout where the navigation window will be placed.
+  -- The following layout identifiers are supported:
+  -- 'vr' -- DEFAULT: vertical right
+  -- 'vl' -- vertical left
+  -- 'ht' -- horizontal top
+  -- 'hb' -- horizontak bottom
+  navwin_layout = 'vr',
+
   -- events
   events = {
     LS_INITIALIZED = 'LspcEvent::LS_INITIALIZED',