If you know how to pause / start / stop you just need to add a toast in your onClickListener for each button, if, however, you don't really know how to do that here is a simple example
in your layout XML containing the Buttons
<Button
android:id="@+id/Start"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="onClick" />
<Button
android:id="@+id/Stop"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="onClick" />
Then, in your java activity you need to create the defined "onClick" method to handle the click
public void onClick(View view){
int id = view.getId();
if(id == R.id.Start){
Toast.makeText(getApplicationContext(), "Start", Toast.LENGTH_SHORT).show();
}
else if(id == R.id.Stop){
Toast.makeText(getApplicationContext(), "Stop", Toast.LENGTH_SHORT).show();
}
}