引用：https://www.jianshu.com/p/64a825915da9

drawable文件夹下
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@drawable/ic_history_more" android:state_pressed="true"></item>
    <item android:drawable="@drawable/ic_history_more" android:state_focused="true"></item>
    <item android:drawable="@drawable/ic_history_more" android:state_selected="true"></item>
    <item android:drawable="@drawable/ic_history_more"></item>

</selector>
drawable-v21文件夹下
<?xml version="1.0" encoding="utf-8"?>
<ripple xmlns:android="http://schemas.android.com/apk/res/android"
    android:color="@color/ripple_color">
    <item>
        <selector>
            <item
                android:drawable="@drawable/ic_history_more"
                android:state_pressed="true">

            </item>
            <item
                android:drawable="@drawable/ic_history_more"
                android:state_pressed="false">

            </item>
        </selector>
    </item>
</ripple>

RelativeLayout水波纹

   android:clickable="true"
 android:background="@drawable/selector_bg_ripple"

drawable文件夹下
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@color/ripple_color" android:state_focused="true" />
    <item android:drawable="@color/ripple_color" android:state_pressed="true" />
    <item android:drawable="@color/ripple_color" android:state_selected="true" />
    <item android:drawable="@android:color/transparent" />

</selector>
drawable-v21文件夹下
<?xml version="1.0" encoding="utf-8"?>
<ripple xmlns:android="http://schemas.android.com/apk/res/android"
    android:color="@color/ripple_color">
    <item>
        <color android:color="@color/colorTransparent" />
    </item>
    <item android:id="@android:id/mask">
        <shape android:shape="rectangle">
            <solid android:color="?android:colorAccent"></solid>
        </shape>
    </item>
</ripple>

TabLayout 自定义

 <com.google.android.material.tabs.TabLayout
        android:id="@+id/tabLayoutMainActivity"
        android:layout_width="match_parent"
        android:layout_height="?actionBarSize"
        android:background="@color/color_theme"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@id/toolBarMainActivity"
        app:tabIndicatorColor="@color/color_white"
        app:tabIndicatorHeight="2.3dp"
        app:tabMode="fixed"
        app:tabPaddingStart="-1dp"
        app:tabPaddingEnd="-1dp"
        app:tabTextAppearance="@style/CustomTabLayoutTextAppearance"
        app:tabTextColor="@color/color_white" />

    tabFirstItem = tabLayoutMainActivity.newTab().setCustomView(R.layout.layout_tab_download)

layout_tab_download如下：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/selector_bg_ripple"
    android:padding="@dimen/dp_0"
    android:gravity="center">

    <RelativeLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content">

        <TextView
            android:id="@+id/tvTabDownLoad"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:gravity="center"
            android:text="@string/str_download"
            android:textColor="@color/color_white"
            android:textSize="@dimen/sp_16" />
    </RelativeLayout>

</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>
<ripple xmlns:android="http://schemas.android.com/apk/res/android"
    android:color="@color/ripple_color">
    <item>
        <color android:color="@color/colorTransparent" />
    </item>
    <item android:id="@android:id/mask">
        <shape android:shape="rectangle">
            <solid android:color="?android:colorAccent"></solid>
        </shape>
    </item>
</ripple>

注意事项：

    app:tabPaddingStart="-1dp" 表示tab的paddingleft 是多少 
    app:tabPaddingEnd="-1dp"   表示tab的paddingright 是多少
如果不添加这两句，则自定义的布局未完全填充tabLayout