Solve concurrent thread termination problem

[abiel-lozano]

When users want to make a correction to their question (whether it is about spoken syntax or object placement) they often press the Ask Question button while the process is already running. This causes UI freezes, crashes, and embarassment. Find a way to stop all threads when user double-stacks questions in order to attend their new question.

[abiel-lozano]

A simpler solution was chosen over complex thread management. Now all buttons are disabled while the threads are executing, and are enabled after the question is answered.