This code snippet calls the intent Google Now is listening for.
Intent intent= new Intent("android.intent.action.ASSIST");
startActivityForResult(intent,1);
The whole thing would look like this:
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final Button button = (Button) findViewById(R.id.yourButtonID);
//Test button
button.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent intent= new Intent("android.intent.action.ASSIST");
startActivityForResult(intent,1);
}
});
}
}