kmp-resources

name	kmp-resources
description	Sharing images, strings, fonts, and raw files across Android/iOS/Desktop/Web with the `compose-resources` Gradle plugin. Covers folder layout, qualifier directories, and how platform asset loading still differs. Use when adding shared assets.

KMP Resources

Instructions

Use the org.jetbrains.compose resources Gradle plugin for all shared assets. It generates a type-safe Res object consumable from commonMain.

1. Setup

// shared/build.gradle.kts
plugins {
    alias(libs.plugins.composeMultiplatform)
    alias(libs.plugins.composeCompiler)
}

compose.resources {
    publicResClass = false                // keep `Res` internal to shared
    packageOfResClass = "com.example.shared.resources"
    generateResClass = auto
}

kotlin.sourceSets.commonMain.dependencies {
    implementation(compose.components.resources)
}

2. Folder layout

shared/src/commonMain/composeResources/
├── drawable/
│   ├── logo.xml
│   └── hero.png
├── drawable-night/
│   └── logo.xml                 # dark-mode variant
├── font/
│   └── Inter-Regular.ttf
├── values/
│   └── strings.xml
├── values-es/
│   └── strings.xml              # Spanish
├── values-ar/
│   └── strings.xml              # Arabic (RTL)
└── files/
    └── policy.md                # raw resource

Qualifiers follow Android conventions (-night, -es, -w600dp, -ldrtl). The plugin normalizes them across targets.

3. Using resources in Compose

@Composable
fun Header() {
    Column {
        Image(
            painter = painterResource(Res.drawable.logo),
            contentDescription = stringResource(Res.string.logo_description),
        )
        Text(
            text = stringResource(Res.string.greeting, "Ada"),
            fontFamily = FontFamily(Font(Res.font.Inter_Regular)),
        )
    }
}

strings.xml:

<resources>
    <string name="greeting">Hello, %1$s!</string>
    <string name="logo_description">Company logo</string>
    <plurals name="item_count">
        <item quantity="one">%d item</item>
        <item quantity="other">%d items</item>
    </plurals>
</resources>

Text(pluralStringResource(Res.plurals.item_count, count, count))

4. Loading raw files

suspend fun loadPolicy(): String =
    Res.readBytes("files/policy.md").decodeToString()

On iOS the file is embedded into the framework bundle; on Android into assets; on Desktop into the classpath.

5. Platform-only assets

Some assets must stay platform-native:

• Android: res/drawable/ic_notification.xml for notification small icons (must be VectorDrawable honoured by the system tray).
• iOS: Assets.xcassets for launch screens, app icons, and SF Symbols.

Keep shared art in composeResources/ and reference platform assets only from each app module.

6. Images on iOS — performance note

Compose MP on iOS rasterizes PNGs through Skia. For high-res artwork prefer SVG → @Composable ImageVector (converted via svg-to-compose) or multi-density WebP. Avoid giant PNGs; they bloat the framework.

Checklist

• All shared assets under src/commonMain/composeResources/, not inside feature modules unless the module owns them.
• strings.xml uses ICU positional args (%1$s) — never string concatenation.
• Dark-mode and locale variants use qualifier directories, not runtime branching.
• Fonts loaded via Font(Res.font.xxx), never per-platform file paths.
• Platform-specific icons (notification, launch) kept in each app module.
• Large raster assets converted to WebP or vector.