Android: Drawing a line/border in toolbar layout?

Question

I have the requirement that the appBar should look like this:

The background is simply transparent.

I use this layout to get an appBar (details hidden):

<android.support.v7.widget.Toolbar>
  <TextView>
  <ImageView>
</android.support.v7.widget.Toolbar>

Simply adding a view with height=1dp below the ImageView with layout_gravity="bottom won't work.

Is it even possible to draw a line or a border in the ToolbarLayout?

Answer 1

Using RelativeLayout like this:

<android.support.v7.widget.Toolbar>
    <RelativeLayout>
         <TextView>
         <ImageView>
         <View  android:layout_width="match_parent" 
                android:layout_height="1dp"
                android:layout_below="@+id/button_menu"/>
    </RelativeLayout>
</android.support.v7.widget.Toolbar>

Answer 2

Wrap the Toolbar in an AppBarLayout (which extends LinearLayout) and add the line as a view there:

<android.support.design.widget.AppBarLayout
    android:id="@+id/app_bar"
    android:layout_width="match_parent"
    android:layout_height="?attr/actionBarSize"
    ...>

    <android.support.v7.widget.Toolbar
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        .../>

    <View android:layout_width="match_parent"
          android:layout_height="1dp"
          android:background="..."
          />

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

With AppBarLayout there will be a default "key line" on Android 21 and up and I had to turn it off in code with:

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
    findViewById (R.id.app_bar).setOutlineProvider (null);
}