Hey jessicah 
Thanks a lot for the input.
After what you said, I looked into the code more and found this line that was causing the issue - menu->SetTargetForItems(TextView);
It was causing all of the messages to be handled by a completely different handler than the one in which I had put in my case for the specific message.
Most of the stuff works now, some things still need to be fixed. Have created a PR, and will start working on the buggy stuff that remains.
Thanks once again :D