Material Theme Preferences

Kotlin Multiplatform library for easy switching Dark/Light Material themes on Compose. Supported platforms:

• Android
• iOS
• Desktop JVM (MacOS, Linux, Windows)

Usage

Call composable functions for material theme wrap, preferences items on settings screen, showing dialog for select theme.

@Composable
fun App() = PreferableMaterialTheme { // provides composition locals
    SettingsScaffold { // includes TopAppBar
        Box {
            Column {
                ThemePreferencesCategory() // subtitle
                ThemePreferenceItem() // menu item
            }
            themePrefs.showDialogIfNeed() // shows when menu item clicked
        }
    }
}

The NoteDelight app is a real example.

Installation

The latest release is available on Maven Central.

Gradle

1. Add the Maven Central repository if it is not already there:

repositories {
    mavenCentral()
}

2. In multiplatform projects, add a dependency to the commonMain source set dependencies

commonMain {
    dependencies {
        implementation("io.github.softartdev:theme-material:$latestVersion") // Material Design 2
        implementation("io.github.softartdev:theme-material3:$latestVersion") // Material Design 3
        implementation("io.github.softartdev:theme-prefs:$latestVersion") // optional, if you need only preferences
    }
}

Implementation

Used moko-resources library for many languages (currently Russian and English are supported).

Persisting preferences is implemented using SharedPreferences on Android, and Java Preference API on JVM Desktop.

// common:
expect var themeEnum: ThemeEnum

// android:
private val preferences: SharedPreferences = PreferenceManager.getDefaultSharedPreferences(context)

actual var themeEnum: ThemeEnum
    get() = preferences.getInt(THEME_KEY, ThemeEnum.SystemDefault.ordinal).let(ThemeEnum.values()::get)
    set(value) = preferences.edit().putInt(THEME_KEY, value.ordinal).apply()

// desktop java:
private var preferences: Preferences = Preferences.userNodeForPackage(ThemeEnum::class.java)

actual var themeEnum: ThemeEnum
    get() = preferences.getInt(THEME_KEY, ThemeEnum.SystemDefault.ordinal).let(ThemeEnum.values()::get)
    set(value) = preferences.putInt(THEME_KEY, value.ordinal)

Also used composition local for access from theme-scoped as an implicit way:

val themePrefs: ThemePrefs = LocalThemePrefs.current