navigation.xml
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
<item android:id="@+id/navigation_clock"
android:icon="@drawable/time"
android:title="" />
<item android:id="@+id/navigation_medicine"
android:icon="@drawable/medicine"
android:title="" />
<item android:id="@+id/navigation_user"
android:icon="@drawable/users"
android:title="" />
<item android:id="@+id/navigation_setting"
android:icon="@drawable/setting"
android:title="" />
</menu>
activity_mail.xml BottomNavigationView component
<android.support.design.widget.BottomNavigationView android:id="@+id/navigation"
android:layout_width="0dp" android:layout_height="wrap_content"
android:layout_marginEnd="0dp" android:layout_marginStart="0dp"
android:background="?android:attr/windowBackground"
app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent" app:menu="@menu/navigation" />
when I added 3 tabs BottomNavigationView got symmetrical.but when it's come to 4 tabs BottomNavigationView not symmetrical.how can I solve that? I really appreciate your suggestions.Thanks in advance.