Material TabLayout elevation not working

Question

For some reason the elevation attribute does not seem to be working on the new TabLayout in the material design support library. Any ideas? XML:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">

<android.support.design.widget.TabLayout
    android:id="@+id/tab_layout"
    android:layout_width="match_parent"
    android:layout_height="?attr/actionBarSize"
    android:elevation="6dp" />

<android.support.v4.view.ViewPager
    android:id="@+id/view_pager"
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:layout_weight="1" />
</LinearLayout>

hooked up like this in a parent fragment:

ViewPager viewPager = (ViewPager) view.findViewById(R.id.view_pager);
TabLayout tabLayout = (TabLayout) view.findViewById(R.id.tab_layout);
AppPagerAdapter appPagerAdapter = new AppPagerAdapter(getChildFragmentManager());
viewPager.setAdapter(appPagerAdapter);
tabLayout.setupWithViewPager(viewPager);

image:

The activity has a toolbar but this is outside of the fragment and should not affect the tablayout's ability to have a shadow:

relevant activity xml:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="com.bluckapps.appinfomanager.ui.MainActivity">

<android.support.v7.widget.Toolbar
    android:id="@+id/toolbar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="?attr/colorPrimary"
    android:elevation="6dp"
    android:minHeight="?attr/actionBarSize"
    tools:ignore="UnusedAttribute" />

<FrameLayout
    android:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:layout_weight="1" />

</LinearLayout>

Answer 1

To make the shadow show, you have to set a background on your TabLayout. It can be the same color as your window background (as long as it's a solid color with no alpha).

<android.support.design.widget.TabLayout
    android:id="@+id/tab_layout"
    android:layout_width="match_parent"
    android:layout_height="?attr/actionBarSize"
    android:elevation="6dp"
    android:background="@color/white" />

Answer 2

You'll need to use CoordinatorLayout as a container layout for your activity and then place your TabLayout right below AppBarLayout. According to Material Design specs you should use

android:elevation="4dp"

elevation and make your TabLayout be a part of AppBarLayout. Also note that elevation will only be visible on v21 (5.0) or higher.

Answer 3

All answers above didn't work for me ,so i found out this:

app:tabIndicatorHeight="4dp"
app:tabIndicatorColor="@color/colorAccent"

then allright!

Answer 4

Keep the tablayout inside appbarLayout. It'll work.

Answer 5

No need to use a Fragment. An Activity layout is enough. Like:

<android.support.design.widget.CoordinatorLayout
    android:id="@+id/home_coordinator_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.design.widget.AppBarLayout
        android:id="@+id/home_appbar_layout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
        app:elevation="2dp"
        app:paddingEnd="0dp"
        app:paddingStart="0dp">

        <include layout="@layout/toolbar_appcompat"></include>

        <android.support.design.widget.TabLayout
            android:id="@+id/home_tab_layout"
            style="@style/TabLayoutStyle"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:tabContentStart="2dp"
            app:tabGravity="fill"
            app:tabIndicatorColor="@android:color/white"
            app:tabIndicatorHeight="2dp"
            app:tabMinWidth="24dp"
            app:tabMode="fixed"
            app:tabPadding="1dp"
            app:tabSelectedTextColor="@android:color/tab_indicator_text"
            app:tabTextColor="@android:color/darker_gray" />
    </android.support.design.widget.AppBarLayout>

    <android.support.v4.view.ViewPager
        android:id="@+id/home_view_pager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="@string/appbar_scrolling_view_behavior"
        app:paddingEnd="0dp"
        app:paddingStart="0dp" />

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab_home"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="20dp"
        android:src="@drawable/arrow_toggle"
        app:borderWidth="1dp"
        app:elevation="3dp"
        app:fabSize="normal"
        app:layout_anchor="@+id/home_coordinator_layout"
        app:layout_anchorGravity="bottom|right|end"
        app:pressedTranslationZ="2dp"
        app:rippleColor="@color/swipe_refresh_color_scheme_green" />

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

Meanwhile, elevation is useful on Lollipop. If you want to be compatible backwards, you'd better use app:elevation. If app:elevation doesn't work, you'd better add a shadow below TabLayout manually, just like android:background="@drawable/myrect":

<!-- res/drawable/myrect.xml -->
<shape xmlns:android="http://schemas.android.com/apk/res/android"
       android:shape="rectangle">
    <solid android:color="#42000000" />
    <corners android:radius="5dp" />
</shape>

Answer 6

You are supposed to use ToolBar with TabLayout. Then you can put them both inside an AppBarLayout and get a shadow. This only works on Lollipop+.

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:orientation="vertical">

    <android.support.design.widget.AppBarLayout
        android:id="@+id/appbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <android.support.v7.widget.Toolbar
            style="@style/ToolBarStyle"
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="?attr/colorPrimary"
            android:minHeight="@dimen/abc_action_bar_default_height_material"/>

        <android.support.design.widget.TabLayout
            android:id="@+id/tab_layout"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize" />
    </android.support.design.widget.AppBarLayout>

    <android.support.v4.view.ViewPager
        android:id="@+id/view_pager"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1" />
</LinearLayout>

See http://inthecheesefactory.com/blog/android-design-support-library-codelab/en