Tutorial 3

Understand the first Android project.

Beginners often get lost because Android projects contain many files. In Phase 1, focus on a small set: MainActivity, build files, manifest, and resources.

Files that matter first

MainActivity.kt	Your first screen starts here. Compose UI is usually called from setContent.
build.gradle.kts	Dependencies, plugins, SDK versions, and build settings.
AndroidManifest.xml	Declares app components and permissions.
res/	Strings, colors, icons, themes, and other resources.

MainActivity pattern

class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            HabitApp()
        }
    }
}

@Composable
fun HabitApp() {
    Text(text = "My first Android app")
}

The activity hosts the screen. The composable describes the UI. Keep that distinction clear from the beginning.

Practice task

Find MainActivity.kt in your project.
Rename the first composable to something meaningful.
Find the app name string in resources if your template created one.
Write down which file you would open to change UI, app name, and dependencies.

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