Button button = findViewById(R.id.button);
ImageView imageView = findViewById(R.id.imageView);

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {

        }
    });
}

<ImageView
    android:id="@+id/imageView"
    android:layout_width="0dp"
    android:layout_height="0dp"
    android:scaleType="fitXY"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent" />
<Button
    android:id="@+id/button"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:text="@string/start_button"
    android:visibility="invisible"/>