Elevation doesn't work on LinearLayout

Question

I'm building my custom layout for my Android application and I'm trying adding elevation to one LinearLayout but it doesn't work, I tried a lot of solutions found on web but nothing with success.

My xml is this:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="10dp">

<de.hdodenhof.circleimageview.CircleImageView
    android:layout_width="40dp"
    android:layout_height="40dp"
    android:src="@drawable/admin_gray"
    app:civ_border_width="2dp"
    app:civ_border_color="@android:color/darker_gray"
    android:layout_marginRight="10dp"/>

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <TextView
            android:id="@+id/tvNewsAggiuntoCommentoDescrizione"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Username ha commentato una ricetta:"/>

        <TextView
            android:id="@+id/tvNewsAggiuntoCommentoData"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="25/05/1989 12:58:07"
            android:textColor="@android:color/darker_gray" />

    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        android:background="@color/white"
        android:elevation="10dp">

        <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
            android:orientation="vertical" android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="@drawable/rounded_linear_layout_tile_ricetta"
            android:layout_marginBottom="5dp"
            >

            <ImageView
                android:id="@+id/imageViewRicetta"
                android:layout_width="match_parent"
                android:layout_height="150dp"
                android:src="@mipmap/cibo"
                android:scaleType="centerCrop"/>

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Antipasto"
                android:background="@color/colorCategoriaRicetta"
                android:layout_alignBaseline="@id/imageViewRicetta"
                android:layout_gravity="right|top"
                android:textAppearance="?android:attr/textAppearanceMedium"
                android:textColor="@android:color/white"
                android:padding="3dp"
                android:id="@+id/tvCategoriaRicetta"
                android:elevation="4dp"/>

            <TextView
                android:id="@+id/tvTitoloRicetta"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text="Maxi hamburger con maionese"
                android:background="@color/colorBackgroundTextViewNomeRicetta"
                android:layout_alignBaseline="@id/imageViewRicetta"
                android:layout_gravity="left|bottom"
                android:textAppearance="?android:attr/textAppearanceLarge"
                android:textColor="@android:color/white"
                android:paddingLeft="5dp"
                android:textStyle="bold" />

        </FrameLayout>

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal">

            <de.hdodenhof.circleimageview.CircleImageView
                android:id="@+id/imageViewFotoAltroUtente"
                android:layout_width="40dp"
                android:layout_height="40dp"
                android:layout_marginRight="10dp"
                android:layout_marginLeft="10dp"
                android:src="@drawable/admin_gray"
                app:civ_border_width="2dp"
                app:civ_border_color="@android:color/darker_gray" />

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:orientation="vertical"
                android:padding="5dp">

                <TextView
                    android:id="@+id/tvUsernameUtenteCommento"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:textStyle="bold"
                    android:text="Username"/>

                <TextView
                    android:id="@+id/tvNewsAggiuntoCommentoCommento"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:text="Questo è il testo di esempio di un commento a una ricetta"/>

            </LinearLayout>

        </LinearLayout>

    </LinearLayout>


</LinearLayout>

Attention, the layout with elevation is not the top LinearLayout, it's the layout with "elevation" attribute...

Can you help me to find a solution in order to obtain the elevation correctly?

Thanks a lot.

Answer 1

Add this propriety to you LinearLayout:

android:outlineProvider="bounds"

Make sure all view parents from the element you wanna to set elevation has no padding. This can cause the shadow to be clipped. A solution for that is add this property to all parent view:

android:clipToPadding="false"

Also, shadows will not show if you have this line in the manifest:

android:hardwareAccelerated="false"