Android BottomNavigationView with Badge

Question

There is no support for adding badges to the BottomNavigationView in Android.

How can I add a badge with a number to a specific tab in the BottomNavigationView. I need it to be done natively with no third party libraries.

I am using Xamarin native with MvvmCross.

Answer 1

---Note---

Badges will soon be supported out the box. However this might be useful if you really want to add custom views to your tabs.

Create Layout With BottomNavigationView

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:local="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <FrameLayout
        android:id="@+id/tabsRootFrameLayout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_above="@+id/tabsRootBottomNavigation" />
    <android.support.design.widget.BottomNavigationView
        android:id="@+id/tabsRootBottomNavigation"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:background="@android:color/white"
        local:menu="@menu/root_bottom_navigation_menu"
        local:itemIconTint="@color/bottom_navigation_selector"
        local:itemTextColor="@color/bottom_navigation_selector"
        local:elevation="16dp" />
</RelativeLayout>

Menu: root_bottom_navigation_menu.xml

<?xml version="1.0" encoding="utf-8"?>
<menu
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    <item
        android:id="@+id/tab_search"
        android:enabled="true"
        android:icon="@drawable/search_icon"
        app:showAsAction="ifRoom" />
    <item
        android:id="@+id/tab_profile"
        android:enabled="true"
        android:icon="@drawable/profile_icon"
        app:showAsAction="ifRoom" />
    <item
        android:id="@+id/tab_my_car"
        android:enabled="true"
        android:icon="@drawable/car_icon"
        app:showAsAction="ifRoom" />
    <item
        android:id="@+id/tab_notifications"
        android:enabled="true"
        android:icon="@drawable/bell_icon"
        app:showAsAction="ifRoom" />
</menu>

Create Badge Layout: component_tabbar_badge.axml

<?xml version="1.0" encoding="UTF-8"?>
<FrameLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="@dimen/margin_tiny">
    <TextView
        android:id="@+id/notificationsBadgeTextView"
        android:layout_width="16dp"
        android:layout_height="16dp"
        android:layout_gravity="top|center_horizontal"
        android:layout_marginLeft="10dp"
        android:layout_marginStart="10dp"
        android:background="@drawable/notification_red_dot"
        android:gravity="center"
        android:textColor="@color/white"
        android:textSize="9dp" />
</FrameLayout>

Red Dot Background: notification_red_dot.xml

<?xml version="1.0" encoding="UTF-8"?>
<shape
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="oval">
    <solid
        android:color="@color/red" />
    <size
        android:width="10dp"
        android:height="10dp" />
</shape>

Add Badge Layout To Bottom Navigation

private void SetNotificationBadge()
{
    _bottomNavigation = FindViewById<BottomNavigationView>(Resource.Id.tabsRootBottomNavigation);
    var notificationsTab = _bottomNavigation.FindViewById<BottomNavigationItemView>(Resource.Id.tab_notifications);
    View badge = LayoutInflater.From(this).Inflate(Resource.Layout.component_tabbar_badge, notificationsTab, false);
    _notificationBadgeTextView = badge.FindViewById<TextView>(Resource.Id.notificationsBadgeTextView);
    notificationsTab.AddView(badge);
}

Bind Badge Text

    var set = this.CreateBindingSet<TabsRootActivity, TabsRootViewModel>();
    set.Bind(_notificationBadgeTextView).To(vm => vm.UnreadNotificationsCount);
    set.Apply();

Result