[Android] send easier with external keyboard

[ajorg]

It would be great if the Android app would send when enter is pressed with a modifier, or something similar. Google Messages uses shift+enter to send. Signal uses ctrl+enter. Google Chat knows when you're using a hardware keyboard so that with the on-screen keyboard enter adds a newline, but with an external keyboard it sends, and shift+enter adds a newline.

I think I like what Chat does best, of these options, but I'm open to the modifier instead. One problem with a modifier is there's not enough consistency between apps which modifier does what you want. I think I've seen shift+enter more places than ctrl+enter if that's where we go.

There was an issue about this earlier, but it was resolved with a feature that doesn't really address it. The feature there added a preference that makes enter send always, with either the soft keyboard or a hardware keyboard, which is helpful but not really what we want. We don't want to not have a way to add a newline, nor do we even want to make that harder.