Touchscreen to Keyboard

I am using the GVR touchscreen process (Using a google cardboard) to trigger buttons on my Canvas. What I would like to do is hook up a keyboard to my Android and be able to click on buttons using my gaze focus and a simple keystroke. For instance - I look at a button, it highlights, and then I hit the "space" bar to trigger the button. Walla! Thanks for all of your consideration. Michael 651-503-9796