fix(menu): highlighting issues that occur during menu navigation (#52)

* fix(menu): preview doesn't update on menu reopen

- remove the check if cursor is same as prev_cursor field, which
  prevents preview updating when returning to an existing menu window

* fix(menu): context highlight not restored when submenu closed

When a submenu is closed and the parent menu regains focus, restore the
context highlight if it is set (i.e. if the cursor field is set).
Otherwise clear the context highlight.

* fix(menu): hover highlight broken if quick navigation disabled

In CursorMoved autocmd, the prev_cursor field is only updated through
the quick_navigation function. The hover highlight update takes the
prev_cursor field as an argument and so prior to this fix, the hover
highlight would only be updated when the quick navigation config option
was enabled

lua/dropbar/menu.lua

@@ -418,15 +418,14 @@ function dropbar_menu_t:make_buf()
     callback = function()
       local cursor = vim.api.nvim_win_get_cursor(self.win)
 
-      if
-        configs.opts.menu.preview
-        and not vim.deep_equal(cursor, self.prev_cursor)
-      then
+      if configs.opts.menu.preview then
         self:preview_symbol_at(cursor, true)
       end
 
       if configs.opts.menu.quick_navigation then
         self:quick_navigation(cursor)
+      else
+        self.prev_cursor = cursor
       end
 
       -- Update hover highlights
@@ -529,6 +528,14 @@ function dropbar_menu_t:close(restore_view)
   end
   -- Move cursor to the previous window
   if self.prev_win and vim.api.nvim_win_is_valid(self.prev_win) then
+    local prev_menu = _G.dropbar.menus[self.prev_win]
+    if prev_menu then
+      if prev_menu.cursor then
+        prev_menu:update_current_context_hl(prev_menu.cursor[1])
+      else
+        prev_menu:update_current_context_hl(nil)
+      end
+    end
     vim.api.nvim_set_current_win(self.prev_win)
   end
   -- Close the menu window and dereference it in the lookup table