Android centering example: ImageButton in a Toolbar

As a quick Android “centering” tip, I found that by adding this snippet to the ImageButton below:

android:layout_gravity="center"

I was able to get the ImageButton to center itself in the Toolbar. Here’s the layout code for the Toolbar and the ImageButton:

<android.support.v7.widget.Toolbar
    android:id="@+id/bottomToolbar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:background="#ffffa302"
    android:minHeight="@android:dimen/notification_large_icon_height">

    <ImageButton
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/pinButton"
        android:layout_centerHorizontal="true"
        android:layout_gravity="center"
        android:drawable="@drawable/pinterest_pin"
        android:clickable="true"/>

</android.support.v7.widget.Toolbar>

I don’t think I needed this line in the ImageButton:

android:layout_centerHorizontal="true"

but I could be wrong. Once I got this Toolbar floated down to the bottom of the display I decided I didn’t like the look of it after all, so I deleted this code before getting a screenshot. But I do know that the android:layout_gravity setting was the one that centered my ImageButton. (Also, a lot of that other layout configuration code is unnecessary. I was experimenting with several different things when I was working on this button centering problem.)