Added Doc:on_close() for plugins

data/core/doc/init.lua

@@ -1,5 +1,6 @@
 local Object = require "core.object"
 local Highlighter = require "core.doc.highlighter"
+local core = require "core"
 local syntax = require "core.syntax"
 local config = require "core.config"
 local common = require "core.common"
@@ -493,5 +494,10 @@ end
 function Doc:on_text_change(type)
 end
 
+-- For plugins to get notified when a document is closed
+function Doc:on_close()
+  core.log_quiet("Closed doc \"%s\"", self:get_name())
+end
+
 
 return Doc

data/core/init.lua

@@ -972,7 +972,7 @@ function core.step()
     local doc = core.docs[i]
     if #core.get_views_referencing_doc(doc) == 0 then
       table.remove(core.docs, i)
-      core.log_quiet("Closed doc \"%s\"", doc:get_name())
+      doc:on_close()
     end
   end