Howto Maintain GtkSourceCompletion When Changing Buffers in a GtkSourceView? - gtk

Question

All,
I have an editor that holds the open files in a treeview/treemodel on the left of the main window and displays the buffer associated with the highlighted treeview entry in the focused textview (sourceview) window on the right.
Each GtkSourceView shown is contained within an editor instance struct which also contains a pointer to its GtkSourceCompletionWords 'provider' (prov_words). The word-completion works fine for the first buffer shown in the window, but when I change files and display a different buffer in the sourceview window, word competion is not active for that buffer, even through I unregister the first buffer from the prov_words provider and register the current buffer for the words provider to use as its source.
Essentially I create the initial completion object as:
GtkSourceCompletion *completion;
GtkSourceCompletionWords *prov_words;
completion = gtk_source_view_get_completion (view);
prov_words = gtk_source_completion_words_new (NULL, NULL);
gtk_source_completion_words_register (prov_words,
gtk_text_view_get_buffer (GTK_TEXT_VIEW (view)));
gtk_source_completion_add_provider (completion,
GTK_SOURCE_COMPLETION_PROVIDER (prov_words), NULL);
/* store a pointer to the completions words provider as part of
* the editor instance.
*/
einst->prov_words = prov_words;
When displaying a new buffer in the textview, I use the treeview "changed" signal to display the new buffer, update the window title, etc.. and to unregister the current buffer from the prov_words provider and then register the new buffer as the word source with:
GtkSourceCompletionWords *prov_words = einst->prov_words;
/* unregister current buffer from words completion provider */
gtk_source_completion_words_unregister (prov_words,
GTK_TEXT_BUFFER(oldbuf));
/* register new buffer with words completion provider */
gtk_source_completion_words_register (prov_words,
GTK_TEXT_BUFFER(newbuf));
This results in no completion functionality at all in the new buffer -- but when switching back to the first buffer, completion continues to work just fine. So it seems I am conceptually missing a piece of the puzzle for what is required to switch buffers associated with a sourceview window (where the completion object and provider remain unchanged) and have completion work with the new buffer in that same sourceview window.
Since the completion object is part of the sourceview, the provider part of the completion object and the words proposed by the provider are derived from the buffer, e.g.
-- GtkSourceView
|
-- GtkSourceCompletion
| |
| -- GtkSourceCompletionWords
|
-- GtkSourceBuffer
it seems the only requirement would be to unregister the words in the first buffer from the provider and then register the words in the new buffer with the provider -- but that does not seem to be the case. The documentation is silent on what is required in this instance (or it escapes me), Gtk SourceView Completion API
So how do you enable completion for a sourceview widget and then change the displayed buffer and have the completion continue to work using the words in the new bufffer?