linphone-android/app/src/main/res/layout/tabs_fragment.xml

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android">

    <data>
        <import type="android.view.View"/>
        <variable
            name="historyClickListener"
            type="android.view.View.OnClickListener"/>
        <variable
            name="contactsClickListener"
            type="android.view.View.OnClickListener"/>
        <variable
            name="dialerClickListener"
            type="android.view.View.OnClickListener"/>
        <variable
            name="chatClickListener"
            type="android.view.View.OnClickListener"/>
        <variable
            name="viewModel"
            type="org.linphone.activities.main.viewmodels.TabsViewModel" />
    </data>

    <LinearLayout
        android:baselineAligned="false"
        android:id="@+id/footer"
        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:orientation="horizontal">

        <RelativeLayout
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:onClick="@{historyClickListener}"
            android:background="@drawable/footer_button">

            <ImageView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_centerInParent="true"
                android:padding="15dp"
                android:contentDescription="@string/content_description_menu_history"
                android:src="@drawable/footer_history" />

            <View
                android:layout_width="match_parent"
                android:layout_height="5dp"
                android:layout_alignParentBottom="true"
                android:background="?attr/accentColor"
                android:visibility="@{viewModel.historySelected ? View.VISIBLE : View.GONE, default=gone}" />

            <TextView
                style="@style/unread_count_font"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_margin="15dp"
                android:background="@drawable/unread_message_count_bg"
                android:gravity="center"
                android:text="@{String.valueOf(viewModel.missedCallsCount)}"
                android:visibility="@{viewModel.missedCallsCount == 0 ? View.GONE : View.VISIBLE}" />

        </RelativeLayout>

        <RelativeLayout
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:onClick="@{contactsClickListener}"
            android:background="@drawable/footer_button">

            <ImageView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_centerInParent="true"
                android:padding="15dp"
                android:contentDescription="@string/content_description_menu_contacts"
                android:src="@drawable/footer_contacts" />

            <View
                android:layout_width="match_parent"
                android:layout_height="5dp"
                android:layout_alignParentBottom="true"
                android:background="?attr/accentColor"
                android:visibility="@{viewModel.contactsSelected ? View.VISIBLE : View.GONE, default=gone}" />

        </RelativeLayout>

        <RelativeLayout
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:onClick="@{dialerClickListener}"
            android:background="@drawable/footer_button">

            <ImageView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_centerInParent="true"
                android:padding="15dp"
                android:contentDescription="@string/content_description_menu_dialer"
                android:src="@drawable/footer_dialer" />

            <View
                android:layout_width="match_parent"
                android:layout_height="5dp"
                android:layout_alignParentBottom="true"
                android:background="?attr/accentColor"
                android:visibility="@{viewModel.dialerSelected ? View.VISIBLE : View.GONE, default=visible}" />

        </RelativeLayout>

        <RelativeLayout
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:onClick="@{chatClickListener}"
            android:background="@drawable/footer_button">

            <ImageView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_centerInParent="true"
                android:padding="15dp"
                android:contentDescription="@string/content_description_menu_chat"
                android:src="@drawable/footer_chat" />

            <View
                android:layout_width="match_parent"
                android:layout_height="5dp"
                android:layout_alignParentBottom="true"
                android:background="?attr/accentColor"
                android:visibility="@{viewModel.chatSelected ? View.VISIBLE : View.GONE, default=gone}" />

            <TextView
                style="@style/unread_count_font"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_margin="15dp"
                android:background="@drawable/unread_message_count_bg"
                android:gravity="center"
                android:text="@{String.valueOf(viewModel.unreadMessagesCount)}"
                android:visibility="@{viewModel.unreadMessagesCount == 0 ? View.GONE : View.VISIBLE}" />

        </RelativeLayout>

    </LinearLayout>

</layout>