Android 9 Development Cookbook - Third Edition

How to do it...

We start by adding a new theme to the existing styles.xml file to make our activity look like a dialog. Here are the steps to create the new theme and set the activity to use the new theme:

1. Since themes are defined in the same resource as styles, open the styles.xml file located in res/values and create a new style. We will create a new style based on the AppTheme already provided, and set windowIsFloating. The XML will be as follows:

<style name="AppTheme.MyDialog"> 
    <item name="android:windowIsFloating">true</item> 
</style> 

2. Next, set the activity to use this new dialog theme. Open the AndroidManifest.xml file and add a theme attribute to the activity element, as shown:

<activity android:name=".MainActivity" android:theme="@style/AppTheme.MyDialog"> ...