I have played with the Adafruit Waveshield before..
before any sample code can be given..
what is it you are even trying to do? or do different that isnt outlined in the example sketches?
the basic 'approach' is that it checks for the states of your button(s).. and makes note of the button state.
in the main loop.. you check this 'state' and act accordingly based on those state results.
I have use the WaveHC lib in several projects (props).. sci-fi blasters/guns, Spider-Man webshooters...etc..etc..