Android new Bottom Navigation bar or BottomNavigationView

You should use BottomNavigationView from v25 Android Support Library. It represents a standard bottom navigation bar for application.

Here is a post on Medium that has a step by step guide: https://medium.com/@hitherejoe/exploring-the-android-design-support-library-bottom-navigation-drawer-548de699e8e0#.9vmiekxze

Google has launched the BottomNavigationView after the version 25.0.0 of the design support library. But it came with the following limitations:

1. You can't remove titles and center icon.
2. You cant't change titles text size.
3. Y̶o̶u̶ ̶c̶a̶n̶'̶t̶ ̶c̶h̶a̶n̶g̶e̶ ̶t̶h̶e̶ ̶b̶a̶c̶k̶g̶r̶o̶u̶n̶d̶ ̶c̶o̶l̶o̶r̶ ̶i̶t̶ ̶i̶s̶ ̶a̶l̶w̶a̶y̶s̶ ̶t̶h̶e̶ ̶c̶o̶l̶o̶r̶P̶r̶i̶m̶a̶r̶y̶.̶
4. It doesn't have a BottomNavigationBehavior: so no integration with FAB or SnackBar through CordinatorLayout.
5. Every menuItem is a pure extension of FrameLayout so it doesn't have any nice circle reveal effect

So the max you can do with this fist version of BottomNavigationView is: (without any reflection or implementing the lib by yourself).

So, If you want any of these. You can use a third part library like roughike/BottomBar or implement the lib by yourself.

As Sanf0rd mentioned, Google launched the BottomNavigationView as part of the Design Support Library version 25.0.0. The limitations he mentioned are mostly true, except that you CAN change the background color of the view and even the text color and icon tint color. It also has an animation when you add more than 4 items (sadly it cannot be enabled or disabled manually).

I wrote a detailed tutorial about it with examples and an accompanying repository, which you can read here: https://blog.autsoft.hu/now-you-can-use-the-bottom-navigation-view-in-the-design-support-library/

The gist of it

You have to add these in your app level build.gradle:

compile 'com.android.support:appcompat-v7:25.0.0'  
compile 'com.android.support:design:25.0.0'

You can include it in your layout like this:

<android.support.design.widget.BottomNavigationView  
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:id="@+id/bottom_navigation_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:itemBackground="@color/darkGrey"
        app:itemIconTint="@color/bottom_navigation_item_background_colors"
        app:itemTextColor="@color/bottom_navigation_item_background_colors"
        app:menu="@menu/menu_bottom_navigation" />

You can specify the items via a menu resource like this:

<?xml version="1.0" encoding="utf-8"?>  
<menu  
    xmlns:android="http://schemas.android.com/apk/res/android">
    <item
        android:id="@+id/action_one"
        android:icon="@android:drawable/ic_dialog_map"
        android:title="One"/>
    <item
        android:id="@+id/action_two"
        android:icon="@android:drawable/ic_dialog_info"
        android:title="Two"/>
    <item
        android:id="@+id/action_three"
        android:icon="@android:drawable/ic_dialog_email"
        android:title="Three"/>
    <item
        android:id="@+id/action_four"
        android:icon="@android:drawable/ic_popup_reminder"
        android:title="Four"/>
</menu>

And you can set the tint and text color as a color list, so the currently selected item is highlighted:

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

    <item
        android:color="@color/colorAccent"
        android:state_checked="false"/>
    <item
        android:color="@android:color/white"
        android:state_checked="true"/>

</selector>

Finally, you can handle the selection of the items with an OnNavigationItemSelectedListener:

bottomNavigationView.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {  
    @Override
    public boolean onNavigationItemSelected(@NonNull MenuItem item) {
        Fragment fragment = null;
        switch (item.getItemId()) {
            case R.id.action_one:
                // Switch to page one
                break;
            case R.id.action_two:
                // Switch to page two
                break;
            case R.id.action_three:
                // Switch to page three
                break;
        }
        return true;
    }
});

There is a new official BottomNavigationView in version 25 of the Design Support Library

https://developer.android.com/reference/android/support/design/widget/BottomNavigationView.html add in gradle compile 'com.android.support:design:25.0.0'

XML

<android.support.design.widget.BottomNavigationView
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:design="http://schema.android.com/apk/res/android.support.design"
    android:id="@+id/navigation"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:layout_gravity="start"
    design:menu="@menu/my_navigation_items" />

This library, BottomNavigationViewEx, extends Google's BottomNavigationView. You can easily customise Google's library to have bottom navigation bar the way you want it to be. You can disable the shifting mode, change visibility of the icons and texts and so much more. Definitely try it out.

You can create the layouts according to the above-mentioned answers If anyone wants to use this in kotlin:-

 private val mOnNavigationItemSelectedListener = BottomNavigationView.OnNavigationItemSelectedListener { item ->
    when (item.itemId) {
        R.id.images -> {
          // do your work....
            return@OnNavigationItemSelectedListener true
        }
       R.id.videos ->
         {
          // do your work....
            return@OnNavigationItemSelectedListener true
        }
    }
    false
}

then in oncreate you can set the above listener to your view

   mDataBinding?.navigation?.setOnNavigationItemSelectedListener(mOnNavigationItemSelectedListener)