Keyboard

[A1Qicks]

I've made a messaging app and one of the non-critical things I want to tidy is the keyboard.

When you tap into the message box for the first time, the keyboard opens up naturally. And if you tap onto something else, then tap back again, it opens it (except on some buttons that don't cause it to open for some unknown reason).

But if you lower the keyboard, for example through the Nexus 5 back button, tapping on the message box doesn't bring it back up. I'm wondering what one uses to do this.