FloatingActionButton default margin not working in lollipop

Question

I am displaying FloatingActionButton along with a Recyclerview in a CoordinatorLayout, when the FAB is clicked a row would be added in Recyclerview. Now the problem is the FAB has margin when i tested in API 15 but when I test in API 22(lollipop 5.1.1-Nexus 4) I do not get any margin and the FAB is pressed to the edge of the screen.

My concern is FAB has default margin setup in API 15(didnt test other devices) but not in API 22 or am I missing something.

My layout code:

<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#6fbababa"
    android:fitsSystemWindows="true">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/my_recycler_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:clipToPadding="false"
        android:paddingBottom="@dimen/fab_padding_bottom"
        android:scrollbars="vertical"
        app:layout_behavior="@string/appbar_scrolling_view_behavior" />

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#ffffff">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:fitsSystemWindows="true"
            android:orientation="horizontal"
            app:layout_scrollFlags="scroll|enterAlwaysCollapsed">
            ---------------------
            ---------------------    
        </LinearLayout>

    </android.support.design.widget.AppBarLayout>

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/button_floating_action"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:clickable="true"
        android:src="@drawable/ic_plus"
        app:borderWidth="0dp"
        app:layout_anchor="@id/my_recycler_view"
        app:layout_anchorGravity="bottom|right|end"
        app:rippleColor="@color/wallet_highlighted_text_holo_light" />

</android.support.design.widget.CoordinatorLayout>

Answer 1

Just use:

app:useCompatPadding="true"

This should add required space.

Answer 2

I ended up using API-specific margin values. My action button is like this:

    <android.support.design.widget.FloatingActionButton
    android:contentDescription="@string/menu_compose"
    android:id="@+id/action"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:clickable="true"
    android:src="@drawable/ic_create_white"
    android:layout_gravity="bottom|right|end"
    android:layout_marginBottom="@dimen/action_button_margin"
    android:layout_marginRight="@dimen/action_button_margin"
    android:layout_marginEnd="@dimen/action_button_margin"
    app:elevation="6dp"
    app:pressedTranslationZ="12dp"
    app:fabSize="normal"/>

@dimen/action_button_margin is defined in both values/dimens.xml:

<dimen name="action_button_margin">0dp</dimen>

And in values-v21/dimens.xml:

<dimen name="action_button_margin">16dp</dimen>

Answer 3

I presume you have the same Problem as described in this question. The different margin is because of the shadow being calculated or not depending on the API version.