Question

I have a button style defined like this:

<style name="button_style">
    <item name="android:textColor">#ffffff</item>
    <item name="android:background">@drawable/button_on_red</item>
</style>

I am wondering if I can setup a background image inside this like:

<style name="button_style">
            <item name="android:background_when_pressed">@drawable/button_off_red</item>
    <item name="android:textColor">#ffffff</item>
    <item name="android:background">@drawable/button_on_red</item>
</style>

Thanks.

Answer 1

You’ll want to use what’s called a “statelist drawable”. You’d create the drawable as an xml file like this:

button_states.xml

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_pressed="true"
          android:drawable="@drawable/button_pressed" /> <!-- pressed -->
    <item android:state_focused="true"
          android:drawable="@drawable/button_focused" /> <!-- focused -->
    <item android:state_hovered="true"
          android:drawable="@drawable/button_focused" /> <!-- hovered -->
    <item android:drawable="@drawable/button_normal" /> <!-- default -->
</selector>

For each state, you specify which drawable to use on the button. You then use this xml as the background for your button like so:

<style name="button_style">
    <item name="android:textColor">#ffffff</item>
    <item name="android:background">@drawable/button_states</item>
</style>

For details, checkout this documentation.