android_button_instantiate_listener.java

// Button listener implemented by not implmenting this class with
// OnClickListener. When button is pressed, it will invoke the onClick method
// inside the OnClickListener object created when the listener has been set.
Button implementListenerButton = (Button) findViewById(R.id.button_object_onclicklistener);
implementListenerButton.setOnClickListener(new OnClickListener() {
    @Override
    public void onClick(View arg0) {
        Toast.makeText(ButtonMainActivity.this, "Button listener created while setting the button listener pressed!", Toast.LENGTH_LONG).show();
    }
});