android - BottomNavigationView is not full width

Question

I am working on an Android app and implementing BottomNavigationView from the design library. I have looked at many examples and I can't figure out what is wrong with my layout. The BottomNavigationView is not displayed as full width.

Another issue is the status bar color is not getting applied.

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">

<!-- Include the toolbar -->
<include layout="@layout/toolbar"/>

<RelativeLayout android:id="@+id/fragment_container"
            xmlns:android="http://schemas.android.com/apk/res/android"
            android:layout_width="match_parent"
            android:layout_height="match_parent"/>


<android.support.design.widget.BottomNavigationView
    android:id="@+id/bottom_navigation"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:layout_gravity="bottom"
    app:itemBackground="@color/colorPrimary"
    app:itemIconTint="@android:color/white"
    app:itemTextColor="@android:color/white"
    app:menu="@menu/bottom_navigation_main"/>

</android.support.design.widget.CoordinatorLayout>

toolbar.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.AppBarLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="@style/AppTheme.AppBarOverlay">

<android.support.v7.widget.Toolbar
    android:id="@+id/toolbar"
    android:layout_width="match_parent"
    android:layout_height="?attr/actionBarSize"
    android:background="?attr/colorPrimary"
    app:popupTheme="@style/AppTheme.PopupOverlay"/>

</android.support.design.widget.AppBarLayout>

Edit: Added solution for Status Color not being set

android:fitsSystemWindows="true"

(colorPrimaryDark) status bar color not working on android v21?

Answer 1

The BottomNavigationView is not displayed as full width.

It is not supposed to.

According to design guidelines the width of an action can vary between 80dp and 168dp. The two actions you have defined are not sufficient to fill the whole area horizontally.
(As a side note, also according to guidelines the view should contain between three and five actions.)

If you want to fill the space behind the BottomNavigationView, you can set the background color of the view to be the same color as the items background:

<android.support.design.widget.BottomNavigationView
     android:background="@color/bottom_view_color"
     app:itemBackground="@color/bottom_view_color"

     // .... />