Pack all resources to assets on the android target. (#4965)

The PR changes the android resources packaging. Now all resources are
packed to the android assets (not only fonts). It unblocks usage android
URIs to the resources in a WebView or other external resource consumers.
Additionally the PR fixes Android Studio Compose Previews work with
multiplatform resources:


![](https://private-user-images.githubusercontent.com/3532155/341182790-ef26b667-ad0d-4efd-b7f9-23cff92ab49d.png?jwt=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.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.xgUAr_2--ZHo6txhdAANRbe8ju2SQ5EACvK96gaGJnY)

For a backward compatibility the resources library tries to read
resources in java resources if assets were not found.

Fixes #4877
Fixes #4503
Fixes #4932
Fixes #4476

## Release Notes

### Features - Resources
- Android Studio Preview works with Compose Multiplatform resources now
- Compose Multiplatform resources are stored in the android assets now.
This fixes such cases as a rendering resource files in WebViews or Media
Players

components/build.gradle.kts

@@ -5,7 +5,7 @@ plugins {
 }
 
 subprojects {
-    version = findProperty("deploy.version") ?: property("compose.version")!!
+    version = findProperty("deploy.version")!!
 
     plugins.withId("java") {
         configureIfExists<JavaPluginExtension> {

components/gradle.properties

@@ -8,12 +8,11 @@ android.useAndroidX=true
 
 #Versions
 kotlin.version=1.9.23
-compose.version=1.6.10-beta02
 agp.version=8.2.2
+deploy.version=0.1.0-SNAPSHOT
 
 #Compose
 org.jetbrains.compose.experimental.jscanvas.enabled=true
-org.jetbrains.compose.experimental.wasm.enabled=true
 org.jetbrains.compose.experimental.macos.enabled=true
 compose.desktop.verbose=true
 compose.useMavenLocal=false

components/gradle/libs.versions.toml

@@ -13,4 +13,6 @@ androidx-activity-compose = { module = "androidx.activity:activity-compose", ver
 androidx-test-core = { module = "androidx.test:core", version.ref = "androidx-test" }
 androidx-compose-ui-test = { module = "androidx.compose.ui:ui-test", version.ref = "androidx-compose" }
 androidx-compose-ui-test-manifest = { module = "androidx.compose.ui:ui-test-manifest", version.ref = "androidx-compose" }
-androidx-compose-ui-test-junit4 = { module = "androidx.compose.ui:ui-test-junit4", version.ref = "androidx-compose" }
+androidx-compose-ui-test-junit4 = { module = "androidx.compose.ui:ui-test-junit4", version.ref = "androidx-compose" }
+androidx-ui-tooling = { group = "androidx.compose.ui", name = "ui-tooling", version.ref = "androidx-compose" }
+androidx-ui-tooling-preview = { group = "androidx.compose.ui", name = "ui-tooling-preview", version.ref = "androidx-compose" }

components/resources/demo/shared/build.gradle.kts

@@ -52,6 +52,10 @@ kotlin {
         desktopMain.dependencies {
             implementation(compose.desktop.common)
         }
+        androidMain.dependencies {
+            implementation(libs.androidx.ui.tooling)
+            implementation(libs.androidx.ui.tooling.preview)
+        }
 
         val nonAndroidMain by creating {
             dependsOn(commonMain.get())
@@ -73,6 +77,12 @@ android {
         sourceCompatibility = JavaVersion.VERSION_11
         targetCompatibility = JavaVersion.VERSION_11
     }
+    buildFeatures {
+        compose = true
+    }
+    composeOptions {
+        kotlinCompilerExtensionVersion = "1.5.11"
+    }
 }
 
 compose.experimental {

components/resources/demo/shared/src/androidMain/kotlin/org/jetbrains/compose/resources/demo/shared/main.android.kt

@@ -5,9 +5,27 @@
 
 package org.jetbrains.compose.resources.demo.shared
 
+import androidx.compose.foundation.layout.PaddingValues
 import androidx.compose.runtime.Composable
+import androidx.compose.ui.tooling.preview.Preview
+import org.jetbrains.compose.resources.ExperimentalResourceApi
+import org.jetbrains.compose.resources.PreviewContextConfigurationEffect
 
 @Composable
 fun MainView() {
     UseResources()
 }
+
+@Preview(showBackground = true)
+@Composable
+fun ImagesResPreview() {
+    ImagesRes(PaddingValues())
+}
+
+@OptIn(ExperimentalResourceApi::class)
+@Preview(showBackground = true)
+@Composable
+fun FileResPreview() {
+    PreviewContextConfigurationEffect()
+    FileRes(PaddingValues())
+}

components/resources/library/api/android/library.api

@@ -1,3 +1,7 @@
+public final class org/jetbrains/compose/resources/AndroidContextProviderKt {
+	public static final fun PreviewContextConfigurationEffect (Landroidx/compose/runtime/Composer;I)V
+}
+
 public final class org/jetbrains/compose/resources/DensityQualifier$Companion {
 	public final fun selectByDensity (F)Lorg/jetbrains/compose/resources/DensityQualifier;
 	public final fun selectByValue (I)Lorg/jetbrains/compose/resources/DensityQualifier;

components/resources/library/build.gradle.kts

@@ -10,8 +10,6 @@ plugins {
     id("org.jetbrains.kotlinx.binary-compatibility-validator")
 }
 
-val composeVersion = extra["compose.version"] as String
-
 kotlin {
     jvm("desktop")
     androidTarget {
@@ -187,6 +185,7 @@ android {
             assets.srcDir("src/androidInstrumentedTest/assets")
         }
         named("test") { resources.srcDir(commonTestResources) }
+        named("main") { manifest.srcFile("src/androidMain/AndroidManifest.xml") }
     }
 }
 
@@ -202,11 +201,6 @@ apiValidation {
     nonPublicMarkers.add("org.jetbrains.compose.resources.InternalResourceApi")
 }
 
-// adding it here to make sure skiko is unpacked and available in web tests
-compose.experimental {
-    web.application {}
-}
-
 //utility task to generate CLDRPluralRuleLists.kt file by 'CLDRPluralRules/plurals.xml'
 tasks.register<GeneratePluralRuleListsTask>("generatePluralRuleLists") {
     val projectDir = project.layout.projectDirectory

components/resources/library/src/androidMain/AndroidManifest.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+
+    <application>
+        <provider
+                android:authorities="${applicationId}.resources.AndroidContextProvider"
+                android:name="org.jetbrains.compose.resources.AndroidContextProvider"
+                android:exported="false"
+                android:enabled="true">
+        </provider>
+    </application>
+
+</manifest>

components/resources/library/src/androidMain/kotlin/org/jetbrains/compose/resources/AndroidContextProvider.kt

@@ -0,0 +1,81 @@
+package org.jetbrains.compose.resources
+
+import android.annotation.SuppressLint
+import android.content.ContentProvider
+import android.content.ContentValues
+import android.content.Context
+import android.content.pm.ProviderInfo
+import android.database.Cursor
+import android.net.Uri
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.platform.LocalInspectionMode
+
+internal val androidContext get() = AndroidContextProvider.ANDROID_CONTEXT
+
+/**
+ * The function configures the android context
+ * to be used for non-composable resource read functions
+ *
+ * e.g. `Res.readBytes(...)`
+ *
+ * Example usage:
+ * ```
+ * @Preview
+ * @Composable
+ * fun MyPreviewComponent() {
+ *     PreviewContextConfigurationEffect()
+ *     //...
+ * }
+ * ```
+ */
+@ExperimentalResourceApi
+@Composable
+fun PreviewContextConfigurationEffect() {
+    if (LocalInspectionMode.current) {
+        AndroidContextProvider.ANDROID_CONTEXT = LocalContext.current
+    }
+}
+
+//https://andretietz.com/2017/09/06/autoinitialise-android-library/
+internal class AndroidContextProvider : ContentProvider() {
+    companion object {
+        @SuppressLint("StaticFieldLeak")
+        var ANDROID_CONTEXT: Context? = null
+    }
+
+    override fun onCreate(): Boolean {
+        ANDROID_CONTEXT = context
+        return true
+    }
+
+    override fun attachInfo(context: Context, info: ProviderInfo?) {
+        if (info == null) {
+            throw NullPointerException("AndroidContextProvider ProviderInfo cannot be null.")
+        }
+        // So if the authorities equal the library internal ones, the developer forgot to set his applicationId
+        if ("org.jetbrains.compose.components.resources.resources.AndroidContextProvider" == info.authority) {
+            throw IllegalStateException("Incorrect provider authority in manifest. Most likely due to a "
+                    + "missing applicationId variable your application\'s build.gradle.")
+        }
+
+        super.attachInfo(context, info)
+    }
+
+    override fun query(
+        uri: Uri,
+        projection: Array<out String>?,
+        selection: String?,
+        selectionArgs: Array<out String>?,
+        sortOrder: String?
+    ): Cursor? = null
+    override fun getType(uri: Uri): String? = null
+    override fun insert(uri: Uri, values: ContentValues?): Uri? = null
+    override fun delete(uri: Uri, selection: String?, selectionArgs: Array<out String>?): Int = 0
+    override fun update(
+        uri: Uri,
+        values: ContentValues?,
+        selection: String?,
+        selectionArgs: Array<out String>?
+    ): Int = 0
+}

components/resources/library/src/androidMain/kotlin/org/jetbrains/compose/resources/FontResources.android.kt

@@ -9,5 +9,6 @@ import androidx.compose.ui.text.font.*
 actual fun Font(resource: FontResource, weight: FontWeight, style: FontStyle): Font {
     val environment = LocalComposeEnvironment.current.rememberEnvironment()
     val path = remember(environment, resource) { resource.getResourceItemByEnvironment(environment).path }
-    return Font(path, LocalContext.current.assets, weight, style)
+    val assets = LocalContext.current.assets
+    return Font(path, assets, weight, style)
 }

components/resources/library/src/androidMain/kotlin/org/jetbrains/compose/resources/ResourceReader.android.kt

@@ -1,9 +1,21 @@
 package org.jetbrains.compose.resources
 
-import java.io.File
+import android.content.res.AssetManager
+import android.net.Uri
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.ProvidableCompositionLocal
+import java.io.FileNotFoundException
 import java.io.InputStream
 
 internal actual fun getPlatformResourceReader(): ResourceReader = object : ResourceReader {
+    private val assets: AssetManager by lazy {
+        val context = androidContext ?: error(
+            "Android context is not initialized. " +
+                    "If it happens in the Preview mode then call PreviewContextConfigurationEffect() function."
+        )
+        context.assets
+    }
+
     override suspend fun read(path: String): ByteArray {
         val resource = getResourceAsStream(path)
         return resource.readBytes()
@@ -33,39 +45,52 @@ internal actual fun getPlatformResourceReader(): ResourceReader = object : Resou
     private fun InputStream.readBytes(byteArray: ByteArray, offset: Int, size: Int) {
         var readBytes = 0
         while (readBytes < size) {
-            val count = read(byteArray,  offset + readBytes, size - readBytes)
+            val count = read(byteArray, offset + readBytes, size - readBytes)
             if (count <= 0) break
             readBytes += count
         }
     }
 
     override fun getUri(path: String): String {
-        val classLoader = getClassLoader()
-        val resource = classLoader.getResource(path) ?: run {
-            //try to find a font in the android assets
-            if (File(path).isFontResource()) {
-                classLoader.getResource("assets/$path")
-            } else null
-        } ?: throw MissingResourceException(path)
-        return resource.toURI().toString()
+        val uri = if (assets.hasFile(path)) {
+            Uri.parse("file:///android_asset/$path")
+        } else {
+            val classLoader = getClassLoader()
+            val resource = classLoader.getResource(path) ?: throw MissingResourceException(path)
+            resource.toURI()
+        }
+        return uri.toString()
     }
 
     private fun getResourceAsStream(path: String): InputStream {
-        val classLoader = getClassLoader()
-        val resource = classLoader.getResourceAsStream(path) ?: run {
-            //try to find a font in the android assets
-            if (File(path).isFontResource()) {
-                classLoader.getResourceAsStream("assets/$path")
-            } else null
-        } ?: throw MissingResourceException(path)
-        return resource
-    }
-
-    private fun File.isFontResource(): Boolean {
-        return this.parentFile?.name.orEmpty().startsWith("font")
+        return try {
+            assets.open(path)
+        } catch (e: FileNotFoundException) {
+            val classLoader = getClassLoader()
+            classLoader.getResourceAsStream(path) ?: throw MissingResourceException(path)
+        }
     }
 
     private fun getClassLoader(): ClassLoader {
         return this.javaClass.classLoader ?: error("Cannot find class loader")
     }
-}
+
+    private fun AssetManager.hasFile(path: String): Boolean {
+        var inputStream: InputStream? = null
+        val result = try {
+            inputStream = open(path)
+            true
+        } catch (e: FileNotFoundException) {
+            false
+        } finally {
+            inputStream?.close()
+        }
+        return result
+    }
+}
+
+internal actual val ProvidableCompositionLocal<ResourceReader>.currentOrPreview: ResourceReader
+    @Composable get() {
+        PreviewContextConfigurationEffect()
+        return current
+    }

components/resources/library/src/commonMain/kotlin/org/jetbrains/compose/resources/ImageResources.kt

@@ -55,7 +55,7 @@ private val emptyImageBitmap: ImageBitmap by lazy { ImageBitmap(1, 1) }
  */
 @Composable
 fun imageResource(resource: DrawableResource): ImageBitmap {
-    val resourceReader = LocalResourceReader.current
+    val resourceReader = LocalResourceReader.currentOrPreview
     val imageBitmap by rememberResourceState(resource, resourceReader, { emptyImageBitmap }) { env ->
         val path = resource.getResourceItemByEnvironment(env).path
         val cached = loadImage(path, resourceReader) {
@@ -78,7 +78,7 @@ private val emptyImageVector: ImageVector by lazy {
  */
 @Composable
 fun vectorResource(resource: DrawableResource): ImageVector {
-    val resourceReader = LocalResourceReader.current
+    val resourceReader = LocalResourceReader.currentOrPreview
     val density = LocalDensity.current
     val imageVector by rememberResourceState(resource, resourceReader, density, { emptyImageVector }) { env ->
         val path = resource.getResourceItemByEnvironment(env).path
@@ -98,7 +98,7 @@ private val emptySvgPainter: Painter by lazy { BitmapPainter(emptyImageBitmap) }
 
 @Composable
 private fun svgPainter(resource: DrawableResource): Painter {
-    val resourceReader = LocalResourceReader.current
+    val resourceReader = LocalResourceReader.currentOrPreview
     val density = LocalDensity.current
     val svgPainter by rememberResourceState(resource, resourceReader, density, { emptySvgPainter }) { env ->
         val path = resource.getResourceItemByEnvironment(env).path

components/resources/library/src/commonMain/kotlin/org/jetbrains/compose/resources/PluralStringResources.kt

@@ -26,7 +26,7 @@ class PluralStringResource
  */
 @Composable
 fun pluralStringResource(resource: PluralStringResource, quantity: Int): String {
-    val resourceReader = LocalResourceReader.current
+    val resourceReader = LocalResourceReader.currentOrPreview
     val pluralStr by rememberResourceState(resource, quantity, { "" }) { env ->
         loadPluralString(resource, quantity, resourceReader, env)
     }
@@ -93,7 +93,7 @@ private suspend fun loadPluralString(
  */
 @Composable
 fun pluralStringResource(resource: PluralStringResource, quantity: Int, vararg formatArgs: Any): String {
-    val resourceReader = LocalResourceReader.current
+    val resourceReader = LocalResourceReader.currentOrPreview
     val args = formatArgs.map { it.toString() }
     val pluralStr by rememberResourceState(resource, quantity, args, { "" }) { env ->
         loadPluralString(resource, quantity, args, resourceReader, env)

components/resources/library/src/commonMain/kotlin/org/jetbrains/compose/resources/ResourceReader.kt

@@ -1,5 +1,7 @@
 package org.jetbrains.compose.resources
 
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.ProvidableCompositionLocal
 import androidx.compose.runtime.staticCompositionLocalOf
 
 class MissingResourceException(path: String) : Exception("Missing resource with path: $path")
@@ -34,3 +36,7 @@ internal val DefaultResourceReader = getPlatformResourceReader()
 
 //ResourceReader provider will be overridden for tests
 internal val LocalResourceReader = staticCompositionLocalOf { DefaultResourceReader }
+
+//For an android preview we need to initialize the resource reader with the local context
+internal expect val ProvidableCompositionLocal<ResourceReader>.currentOrPreview: ResourceReader
+    @Composable get

components/resources/library/src/commonMain/kotlin/org/jetbrains/compose/resources/StringArrayResources.kt

@@ -30,7 +30,7 @@ class StringArrayResource
  */
 @Composable
 fun stringArrayResource(resource: StringArrayResource): List<String> {
-    val resourceReader = LocalResourceReader.current
+    val resourceReader = LocalResourceReader.currentOrPreview
     val array by rememberResourceState(resource, { emptyList() }) { env ->
         loadStringArray(resource, resourceReader, env)
     }