Add a "prevent" context manager

[willmcgugan]

Context manager to temporarily prevent a message from being sent.

[darrenburns]

Not particularly bothered but I'll just mention that I think I prefer suppress as it makes me think of reducing/preventing the output of something from travelling further. prevent sounds like I'd be prevented from using the button.

e.g. suppress in the standard library doesn't prevent an exception, it stops it from travelling further; a suppressor on a gun stops the sound from travelling further; when you suppress speech you don't stop it from occurring but instead limit its reach.

[darrenburns]

Oh, here we are preventing the message from being posted. Never mind then.

[darrenburns]

Although, I do think prevent_message is a better name personally 😄 otherwise it's kind of like "prevent what?"

[willmcgugan]

Although, I do think prevent_message is a better name personally 😄 otherwise it's kind of like "prevent what?"

Does it make a difference that prevent takes message types as positional args. i.e. if you were to read this, would it be clear?

with input.prevent(Input.Changed):
    input.value = ''

[rodrigogiraoserrao]

I like the idea and the implementation! I just left a couple of comments regarding nitpicks that are up for discussion and some tidying up.