Android: How to create custom shape keys on keyboard?

I wonder how could is possible to make custom shape key on android keyboard. To create custom keyboard is relatively easy, but what needs to be done to create new buttons. They also need to respond with all events as normal keyboard.

Any ideas where to start?

From stackoverflow

• You need to create an image for each key you want on your custom keyboard, and then, create the xml supporting the design of your keyboard and load it in your application with they Keyboard class. Do you need more details? If so, I will prepare one if you want, I've been wanting to have a go at this class for a while.

  Solata : Isn't enough just overriding the createKeyFromXml() function of Keyboard class?

  Sephy : oh yeah, I suppose it is possible, though I never tried it. Didn't understand you properly, I thought you wanted to change the whole keyboard

  Solata : You understood right, I just thought this would be easier way. I guess not. Perhaps you should go a little more in details :)

• Yes, that would be great if you can post more explanation !