Created attachment 288876 [details] [review]
Allow select-reply through message menu

This leaves us with a bit of duplication between the on_*_message() and 
on_*_message_action() methods.  I tried to combine them into one method 
with a nullable callback, but Vala wouldn't accept that as an acceptible 
callback for the action.

Review of attachment 288876 [details] [review]:

Could this be refactored something like this?

on_reply_to_message(message) {
  create_reply_forward_widget(ComposeType.REPLY, message);
}

on_reply_all_message(message) {
  create_reply_forward_widget(ComposeType.REPLY_ALL, message);
}

on_forward_message() {
  // you get the idea
}

create_reply_forward_widget(compose-type, message) {
  // get selected message, get quote, then call create_compose_widget
}

I'd be fine then replacing these 3 on_ calls with closures as signal handlers, if that makes sense.

I think the on_*_message_action calls could be refactored as well using a similar technique.  But I don't think all six could be refactored to use a single common helper method without some additional flags that would probably overcomplicate the problem.

Created attachment 289002 [details] [review]
Allow select-reply through message menu

It turns out that it's fairly easy to send all six calls through the 
same path.  I've added a commit explaining what's going on at the 
beginning; I can also try to explain the logic if you think it's not 
obvious.

If I were writing this from scratch, I'd probably use closures, but I 
don't think there's much of an advantage in replacing the method calls 
now.

Review of attachment 289002 [details] [review]:

Very nice.  Commit!

Attachment 289002 [details] pushed as da881c3 - Allow select-reply through message menu