feat: route media uploads through native host for processing

android/Gutenberg/build.gradle.kts

@@ -63,6 +63,7 @@ dependencies {
     implementation(libs.jsoup)
     implementation(libs.okhttp)
 
+    testImplementation(libs.json)
     testImplementation(libs.junit)
     testImplementation(libs.kotlinx.coroutines.test)
     testImplementation(libs.mockito.core)

android/Gutenberg/src/main/java/org/wordpress/gutenberg/GutenbergView.kt

@@ -96,6 +96,24 @@ class GutenbergView : WebView {
 
     var requestInterceptor: GutenbergRequestInterceptor = DefaultGutenbergRequestInterceptor()
 
+    /** Optional delegate for customizing media upload behavior (resize, transcode, custom upload). */
+    var mediaUploadDelegate: MediaUploadDelegate? = null
+        set(value) {
+            field = value
+            // Stop any previously running server before starting a new one.
+            uploadServer?.stop()
+            uploadServer = null
+            // (Re)start the upload server so it captures the delegate.
+            // This handles the common case where the delegate is set after
+            // construction but before the editor finishes loading.
+            if (value != null) {
+                startUploadServer()
+            }
+        }
+
+    private var uploadServer: MediaUploadServer? = null
+    private val uploadHttpClient: okhttp3.OkHttpClient by lazy { okhttp3.OkHttpClient() }
+
     private var onFileChooserRequested: ((Intent, Int) -> Unit)? = null
     private var contentChangeListener: ContentChangeListener? = null
     private var historyChangeListener: HistoryChangeListener? = null
@@ -432,7 +450,12 @@ class GutenbergView : WebView {
     }
 
     private fun setGlobalJavaScriptVariables() {
-        val gbKit = GBKitGlobal.fromConfiguration(configuration, dependencies)
+        val gbKit = GBKitGlobal.fromConfiguration(
+            configuration,
+            dependencies,
+            nativeUploadPort = uploadServer?.port,
+            nativeUploadToken = uploadServer?.token
+        )
         val gbKitJson = gbKit.toJsonString()
         val gbKitConfig = """
             window.GBKit = $gbKitJson;
@@ -443,6 +466,24 @@ class GutenbergView : WebView {
     }
 
 
+    private fun startUploadServer() {
+        if (configuration.siteApiRoot.isEmpty() || configuration.authHeader.isEmpty()) return
+
+        try {
+            val defaultUploader = DefaultMediaUploader(
+                httpClient = uploadHttpClient,
+                siteApiRoot = configuration.siteApiRoot,
+                authHeader = configuration.authHeader
+            )
+            uploadServer = MediaUploadServer(
+                uploadDelegate = mediaUploadDelegate,
+                defaultUploader = defaultUploader
+            )
+        } catch (e: Exception) {
+            Log.w(TAG, "Failed to start upload server", e)
+        }
+    }
+
     fun clearConfig() {
         val jsCode = """
             delete window.GBKit;
@@ -861,6 +902,8 @@ class GutenbergView : WebView {
 
     override fun onDetachedFromWindow() {
         super.onDetachedFromWindow()
+        uploadServer?.stop()
+        uploadServer = null
         clearConfig()
         this.stopLoading()
         FileCache.clearCache(context)
@@ -881,6 +924,8 @@ class GutenbergView : WebView {
     }
 
     companion object {
+        private const val TAG = "GutenbergView"
+
         /** Hosts that are safe to serve assets over HTTP (local development only). */
         private val LOCAL_HOSTS = setOf("localhost", "127.0.0.1", "10.0.2.2")