Jetpack Compose theming: difference between XML theme file and Kotlin theme file

Question

I'm a Android beginner and I'm getting started with Jetpack Compose. I'm confused about these two set files created by new Compose project template: themes.xml vs Theme.kt, and colors.xml vs Color.kt. Both colors.xml and Color.kt contain color definitions, and both themes.xml and Theme.kt contain primary color definition.

What's the difference between the XML file and the Kotlin file? Am I supposed to manually sync their contents?

Answer 1

What's the difference between the XML file and the Kotlin file?

By default, android uses the XML files for setting the theme ... If you are using the compose (which is obviously you are doing) then you need to set theme like this

 setContent {
      AppThemeName { //AppThemeName is the name of your theme .. its autogenerated at the beginning by AppName+Theme
       
        }
 } 

Compose uses Theme.kt to get the theme information and similarly Color.kt for colors

Am I supposed to manually sync their contents?

No, But It depends ... generally if you are using only compose throughout your app then you don't need to manually sync the XML file since the Theme.kt file has the theme information that you will be using.

But there are cases where you need to mention some attributes in theme.xml for example windowSplashScreenAnimatedIcon, statusBarColor which cant be defined by default in compose Theme.kt