How can you make a custom keyboard in Android?

Question

I want to make a custom keyboard. I don\'t know how to do it using XML and Java. The following picture is a model of the keyboard I want to make. It only needs numbers.

Answer 1

I came across this post recently when I was trying to decide what method to use to create my own custom keyboard. I found the Android system API to be very limited, so I decided to make my own in-app keyboard. Using Suragch's answer as the basis for my research, I went on to design my own keyboard component. It's posted on GitHub with an MIT license. Hopefully this will save somebody else a lot of time and headache.

The architecture is pretty flexible. There is one main view (CustomKeyboardView) that you can inject with whatever keyboard layout and controller you want.

You just have to declare the CustomKeyboardView in you activity xml (you can do it programmatically as well):

Then register your EditText's with it and tell it what type of keyboard they should use:

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main)

    val numberField: EditText = findViewById(R.id.testNumberField)
    val numberDecimalField: EditText = findViewById(R.id.testNumberDecimalField)
    val qwertyField: EditText = findViewById(R.id.testQwertyField)

    keyboard = findViewById(R.id.customKeyboardView)
    keyboard.registerEditText(CustomKeyboardView.KeyboardType.NUMBER, numberField)
    keyboard.registerEditText(CustomKeyboardView.KeyboardType.NUMBER_DECIMAL, numberDecimalField)
    keyboard.registerEditText(CustomKeyboardView.KeyboardType.QWERTY, qwertyField)
}

The CustomKeyboardView handles the rest!

I've got the ball rolling with a Number, NumberDecimal, and QWERTY keyboard. Feel free to download it and create your own layouts and controllers. It looks like this:

Even if this is not the architecture you decide to go with, hopefully it'll be helpful to see the source code for a working in-app keyboard.

Again, here's the link to the project: Custom In-App Keyboard

EDIT: I'm no longer an Android developer, and I no longer maintain this GitHub project. There are probably more modern approaches and architectures at this point, but please feel free to reference the GitHub project if you'd like and fork it.