Android: Floating Button Icon is not centred

Question

I'm trying to create a floating button in my app. The button is there, but the image in the button is a bit upwards (see image).

I can't figure out what's wrong with it. Below is part of the XML for floating button.

<android.support.design.widget.FloatingActionButton
        android:id="@+id/buttonUp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginRight="16dp"
        android:layout_marginTop="480dp"
        android:clickable="true"
        android:scaleType="center"
        android:src="@drawable/btn_back_to_top_3x"
        app:layout_anchor="@id/layout"
        app:layout_anchorGravity="bottom|right|end"
        app:backgroundTint="@android:color/background_light"
        app:fabSize="normal" />

The button is showing where I wanted it. The only problem seems to be the image inside isn't center. Why is this happening?

EDIT: After some more looking around I realized the image itself was having problem where the image isn't actually centered and there are space at the bottom side (which cause the image to being push upward).

Answer 1

I have faced the same problem. the following solution have worked for me

app:fabCustomSize="40dp"