Default style in Android project with specific Android versions

Question

I want to accommodate for older Android versions (say 17 to 20) with specific style specs. So I made these:

• values/styles.xml (what I think should be the default)
• values-v17/styles.xml
• values-v18/styles.xml
• values-v19/styles.xml
• values-v20/styles.xml

In my values/styles.xml file I keep the default for versions 21+. However, the style that's actually applied in both the preview and the virtual device is that of v20, for display versions 21 and up. If I erase values-v20/styles.xml then it's the next one down the line, v19, that takes over. Why isn't the default style taking over?

Simple example:

values-v20/styles.xml:

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <style name="Button.AccentButton" parent="Theme.AppCompat">
        <item name="android:textColor">@android:color/white</item>
        <item name="android:background">@color/red</item>
    </style>
</resources>

values/styles.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <style name="Button.AccentButton" parent="Theme.AppCompat">
        <item name="android:textColor">@android:color/white</item>
        <item name="android:background">@color/green</item>
    </style>
</resources>

Final result: v21+ button shows red, should be green.

Answer 1

It works the other way around!

• values/styles.xml (the default for all versions below lowest specified)
• values-v21/styles.xml (values for v21+)

In other words, the first versioned folder applies to all the following versions too. The un-versioned folder applies to versions below the lowest versioned folder.