Address #5: allow window placement at edge of editor

README.md

@@ -95,6 +95,10 @@ vim.g.aerial = {
   -- different buffer in the way of the preferred direction
   default_direction = 'prefer_right',
 
+  -- Set to true to only open aerial at the far right/left of the editor
+  -- Default behavior opens aerial relative to current window
+  placement_editor_edge = false,
+
   -- Fetch document symbols when LSP diagnostics change.
   -- If you set this to false, you will need to manually fetch symbols
   diagnostics_trigger_update = true,

doc/aerial.txt

@@ -112,6 +112,11 @@ g:aerial_default_direction                           *g:aerial_default_direction
         prefer_right  Open to the right unless there are other windows right
                       and none to the left (default)
 
+g:aerial_placement_editor_edge                   *g:aerial_placement_editor_edge*
+    If `true`, only open aerial at the far right/left of the editor. Default
+    behavior will open aerial as far right/left as possible while remaining
+    adjacent to a window containing the source buffer.
+
 g:aerial_diagnostics_trigger_update         *g:aerial_diagnostics_trigger_update*
     Call |vim.lsp.buf.document_symbol()| to update symbols whenenever the LSP
     client receives diagnostics. Default `true`.

doc/tags

@@ -51,6 +51,7 @@ g:aerial_nerd_font	aerial.txt	/*g:aerial_nerd_font*
 g:aerial_open_automatic	aerial.txt	/*g:aerial_open_automatic*
 g:aerial_open_automatic_min_lines	aerial.txt	/*g:aerial_open_automatic_min_lines*
 g:aerial_open_automatic_min_symbols	aerial.txt	/*g:aerial_open_automatic_min_symbols*
+g:aerial_placement_editor_edge	aerial.txt	/*g:aerial_placement_editor_edge*
 g:aerial_post_jump_cmd	aerial.txt	/*g:aerial_post_jump_cmd*
 g:aerial_update_when_errors	aerial.txt	/*g:aerial_update_when_errors*
 symbol	aerial.txt	/*symbol*

lua/aerial/config.lua

@@ -20,6 +20,10 @@ local default_options = {
   -- different buffer in the way of the preferred direction
   default_direction = 'prefer_right',
 
+  -- Set to true to only open aerial at the far right/left of the editor
+  -- Default behavior opens aerial relative to current window
+  placement_editor_edge = false,
+
   -- Fetch document symbols when LSP diagnostics change.
   -- If you set this to false, you will need to manually fetch symbols
   diagnostics_trigger_update = true,

lua/aerial/util.lua

@@ -153,25 +153,31 @@ M.detect_split_direction = function(bufnr)
   elseif default == 'right' then
     return 'right'
   end
-  if not bufnr or bufnr == 0 then
-    bufnr = vim.api.nvim_get_current_buf()
-  end
   local wins = M.get_fixed_wins()
-  local first_window = vim.fn.winbufnr(wins[1]) == bufnr
-  local last_window = vim.fn.winbufnr(wins[#wins]) == bufnr
+  local left_available, right_available
+  if config.placement_editor_edge then
+    left_available = not M.is_aerial_buffer(vim.api.nvim_win_get_buf(wins[1]))
+    right_available = not M.is_aerial_buffer(vim.api.nvim_win_get_buf(wins[#wins]))
+  else
+    if not bufnr or bufnr == 0 then
+      bufnr = vim.api.nvim_get_current_buf()
+    end
+    left_available = vim.api.nvim_win_get_buf(wins[1]) == bufnr
+    right_available = vim.api.nvim_win_get_buf(wins[#wins]) == bufnr
+  end
 
   if default == 'prefer_left' then
-    if first_window then
+    if left_available then
       return 'left'
-    elseif last_window then
+    elseif right_available then
       return 'right'
     else
       return 'left'
     end
   else
-    if last_window then
+    if right_available then
       return 'right'
-    elseif first_window then
+    elseif left_available then
       return 'left'
     else
       return 'right'

lua/aerial/window.lua

@@ -63,7 +63,12 @@ local function create_aerial_window(bufnr, aer_bufnr, direction, existing_win)
   end
   local my_winid = vim.api.nvim_get_current_win()
   if not existing_win then
-    local winids = util.get_fixed_wins(bufnr)
+    local winids
+    if config.placement_editor_edge then
+      winids = util.get_fixed_wins()
+    else
+      winids = util.get_fixed_wins(bufnr)
+    end
     local split_target
     if direction == 'left' then
       split_target = winids[1]