+ <com.google.android.material.floatingactionbutton.FloatingActionButton
+ android:id="@+id/fab"
+ android:layout_width="wrap_content"
+ android:layout_height="wrap_content"
+ android:layout_gravity="center"
+ android:padding="@dimen/fab_margin"
+ android:tint="@android:color/white"
+ android:visibility="gone"
+ app:backgroundTint="?colorPrimary"
+ app:layout_constraintBottom_toBottomOf="@id/save_transaction_progress"
+ app:layout_constraintEnd_toEndOf="@id/save_transaction_progress"
+ app:layout_constraintStart_toStartOf="@id/save_transaction_progress"
+ app:layout_constraintTop_toTopOf="@id/save_transaction_progress"
+ app:srcCompat="@drawable/ic_save_white_24dp" />