dark action bar with Theme.AppCompat

I am using Theme.AppCompat for my app to get the dark look. Everything looks good, except the action bar using this theme looks ancient i.e. it has a bright blue bottom divider.

I want the action bar to look like it is in Theme.AppCompat.Light.DarkActionBar.

Looking at themes.xml, i find :

<style name="Theme.AppCompat.Light.DarkActionBar"
       parent="Theme.Base.AppCompat.Light.DarkActionBar">
    <item name="windowActionBar">true</item>
</style>


<style name="Theme.Base.AppCompat.Light.DarkActionBar" parent="Theme.Base.AppCompat.Light">
    <item name="actionBarDivider">@drawable/appcompat_divider_dark</item>
</style>

So i create my own style as below :

<style name="myTheme" parent="@style/Theme.AppCompat">
    <item name="actionBarDivider">@drawable/appcompat_divider_dark</item>
</style>

But i get the build error :

No resource found that matches the given name (at 'actionBarDivider' with value 
 '@drawable/appcompat_divider_dark')

Why can't i use the same drawable that is being used by the framework?

Solution

The blue line is part of the background image used for the action bar. For example, you can find it in : sdk/platforms/android-19/data/res/drawable-xxhdpi/ab_transparent_dark_holo.9.png

The trick is to create your own Widget style by inheriting Widget.AppCompat.ActionBar and set the background attribute with your desired png, which does not have the blue line. I use the support library's existing@drawable/abc_ab_bottom_transparent_dark_holo. You can find it in the folder sdk/extras/android/support/v7/appcompat/res/drawable-hdpi/.

So create the below element in the styles.xml file.

<style name="myActionBar" parent="@style/Widget.AppCompat.ActionBar">
        <item name="android:background">@drawable/abc_ab_bottom_transparent_dark_holo</item>
</style>

Then include this newly created style in your theme(already present in the styles.xml file) :

<style name="AppBaseTheme" parent="@style/Theme.AppCompat">
        <item name="android:actionBarStyle">@style/myActionBar</item>
</style>

To enable this change in older APIs, make the same changes in all 3 folder - values-v14, values-v12 and values. One important thing to note is that the "android:" namespace should not be used for the name attributes in the values-v12 and values folders.