js injection

OpacityCore/src/main/cpp/OpacityCore.cpp

@@ -376,6 +376,27 @@ extern "C" const char *android_get_browser_cookies_for_current_url() {
   return val_str;
 }
 
+extern "C" const char *android_eval_js(const char *js,
+                                       double timeout_in_seconds) {
+  JNIEnv *env = GetJniEnv();
+  jclass jOpacityCore = env->GetObjectClass(java_object);
+  jmethodID method = env->GetMethodID(
+      jOpacityCore, "evalJs", "(Ljava/lang/String;J)Ljava/lang/String;");
+  jstring jjs = env->NewStringUTF(js);
+  jlong timeout_ms = (jlong)(timeout_in_seconds * 1000.0);
+  auto result =
+      (jstring)env->CallObjectMethod(java_object, method, jjs, timeout_ms);
+  env->DeleteLocalRef(jjs);
+  if (result == nullptr) {
+    return strdup("{\"result\":null}");
+  }
+  const char *str = env->GetStringUTFChars(result, nullptr);
+  char *copy = strdup(str);
+  env->ReleaseStringUTFChars(result, str);
+  env->DeleteLocalRef(result);
+  return copy;
+}
+
 extern "C" const char *
 android_get_browser_cookies_for_domain(const char *domain) {
   JNIEnv *env = GetJniEnv();

OpacityCore/src/main/jni/include/sdk.h

@@ -84,6 +84,8 @@ typedef const char *(*GetDeviceCodenameFn)(void);
 
 typedef void (*IosWebviewChangeUrlFn)(const char*);
 
+typedef const char *(*IosEvalJsFn)(const char*, double);
+
 
 
 
@@ -240,7 +242,8 @@ void register_ios_callbacks(IosPrepareRequestFn ios_prepare_request,
                             GetScreenDpiFn get_screen_dpi,
                             GetDeviceCpuFn get_device_cpu,
                             GetDeviceCodenameFn get_device_codename,
-                            IosWebviewChangeUrlFn ios_webview_change_url);
+                            IosWebviewChangeUrlFn ios_webview_change_url,
+                            IosEvalJsFn ios_eval_js);
 
 extern void secure_set(const char *key, const char *value);
 
@@ -262,6 +265,8 @@ extern const char *android_get_browser_cookies_for_domain(const char *domain);
 
 extern void android_webview_change_url(const char *url);
 
+extern const char *android_eval_js(const char *js, double timeout_in_seconds);
+
 #ifdef __cplusplus
 }  // extern "C"
 #endif  // __cplusplus

OpacityCore/src/main/kotlin/com/opacitylabs/opacitycore/InAppBrowserActivity.kt

@@ -6,6 +6,8 @@ import android.content.Context
 import android.content.Intent
 import android.content.IntentFilter
 import android.os.Bundle
+import android.os.Handler
+import android.os.Looper
 import android.util.Log
 import android.view.Gravity
 import android.view.ViewGroup
@@ -126,6 +128,11 @@ class InAppBrowserActivity : AppCompatActivity() {
             Log.d("Opacity SDK", "storePostBody: url=$url (${body.length} bytes)")
             pendingPostBodies[url] = body
         }
+
+        @JavascriptInterface
+        fun notifyEvalResult(id: String, json: String) {
+            OpacityCore.notifyWebViewEvalResult(id, json)
+        }
     }
 
     @SuppressLint("WrongThread", "SetJavaScriptEnabled")
@@ -182,6 +189,7 @@ class InAppBrowserActivity : AppCompatActivity() {
         supportActionBar?.setCustomView(closeButton, actionBarLayoutParams)
         supportActionBar?.setDisplayShowCustomEnabled(true)
 
+        OpacityCore.setActiveWebViewActivity(this)
         interceptExtensionEnabled = intent.getBooleanExtra("enableInterceptRequests", false)
         // Clear cookies for private-mode-like behavior
         CookieManager.getInstance().removeAllCookies(null)
@@ -593,9 +601,36 @@ class InAppBrowserActivity : AppCompatActivity() {
 
         CookieManager.getInstance().removeAllCookies(null)
         webView.destroy()
+        OpacityCore.setActiveWebViewActivity(null)
         OpacityCore.onBrowserDestroyed()
     }
 
+    /**
+     * Injects [js] into the standard WebView as an AsyncFunction (mirrors the GeckoView eval
+     * extension behaviour). When [fireAndForget] is false the result is delivered back via
+     * [OpacityJsBridge.notifyEvalResult] → [OpacityCore.notifyWebViewEvalResult].
+     */
+    fun dispatchWebViewEval(id: String, js: String, fireAndForget: Boolean) {
+        val escapedJs = org.json.JSONObject.quote(js)
+        val wrappedJs = if (fireAndForget) {
+            "(function(){var AF=Object.getPrototypeOf(async function(){}).constructor;new AF($escapedJs)();})()"
+        } else {
+            val escapedId = org.json.JSONObject.quote(id)
+            "(function(){" +
+                "var AF=Object.getPrototypeOf(async function(){}).constructor;" +
+                "new AF($escapedJs)().then(function(__r){" +
+                    "var __val=(__r!==undefined&&__r!==null)?__r:null;" +
+                    "OpacityNative.notifyEvalResult($escapedId,JSON.stringify({result:__val}));" +
+                "}).catch(function(e){" +
+                    "OpacityNative.notifyEvalResult($escapedId,JSON.stringify({error:String(e)}));" +
+                "});" +
+            "})()"
+        }
+        Handler(Looper.getMainLooper()).post {
+            webView.evaluateJavascript(wrappedJs, null)
+        }
+    }
+
     companion object {
         private const val INTERCEPT_SCRIPT = """
 (function() {

OpacityCore/src/main/kotlin/com/opacitylabs/opacitycore/OpacityCore.kt

@@ -4,7 +4,13 @@ import android.content.Context
 import android.content.Intent
 import android.os.Build
 import android.os.Bundle
+import android.os.Handler
+import android.os.Looper
 import androidx.localbroadcastmanager.content.LocalBroadcastManager
+import java.util.concurrent.ConcurrentHashMap
+import java.util.concurrent.CountDownLatch
+import java.util.concurrent.TimeUnit
+import java.util.concurrent.atomic.AtomicInteger
 import com.opacitylabs.opacitycore.JsonConverter.Companion.mapToJsonElement
 import com.opacitylabs.opacitycore.JsonConverter.Companion.parseJsonElementToAny
 import kotlinx.coroutines.Dispatchers
@@ -28,6 +34,16 @@ object OpacityCore {
     private var pendingCookies: MutableList<Pair<String, String>> = mutableListOf()
     private var isBrowserActive = false
 
+    // --- eval state ---
+    private val pendingEvals = ConcurrentHashMap<String, PendingEval>()
+    private val evalIdCounter = AtomicInteger(0)
+    private var activeWebViewActivity: java.lang.ref.WeakReference<InAppBrowserActivity>? = null
+
+    private data class PendingEval(
+        val latch: CountDownLatch = CountDownLatch(1),
+        var result: String = "{\"result\":null}"
+    )
+
     init {
         System.loadLibrary("OpacityCore")
     }
@@ -192,6 +208,37 @@ object OpacityCore {
         isBrowserActive = false
     }
 
+    fun setActiveWebViewActivity(activity: InAppBrowserActivity?) {
+        activeWebViewActivity = activity?.let { java.lang.ref.WeakReference(it) }
+    }
+
+    fun notifyWebViewEvalResult(id: String, json: String) {
+        val pending = pendingEvals[id] ?: return
+        pending.result = json
+        pending.latch.countDown()
+    }
+
+    fun evalJs(js: String, timeoutMs: Long): String {
+        val activity = activeWebViewActivity?.get()
+        if (activity == null || activity.isFinishing || activity.isDestroyed) {
+            return "{\"error\":\"no active webview\"}"
+        }
+
+        val id = "eval_${evalIdCounter.incrementAndGet()}"
+
+        if (timeoutMs == 0L) {
+            activity.dispatchWebViewEval(id, js, fireAndForget = true)
+            return "{\"result\":null}"
+        }
+
+        val pending = PendingEval()
+        pendingEvals[id] = pending
+        activity.dispatchWebViewEval(id, js, fireAndForget = false)
+        pending.latch.await(timeoutMs, TimeUnit.MILLISECONDS)
+        pendingEvals.remove(id)
+        return pending.result
+    }
+
     private fun parseOpacityError(error: String?): OpacityError {
         if (error == null) {
             return OpacityError("UnknownError", "No Message")

app/src/main/java/com/opacitylabs/opacitycoreexample/MainActivity.kt

@@ -74,7 +74,7 @@ class MainActivity : ComponentActivity() {
         requireNotNull(opacityApiKey) { "Opacity API key is null" }
 
         OpacityCore.setContext(this)
-        OpacityCore.initialize(opacityApiKey, false, OpacityCore.Environment.PRODUCTION, false)
+        OpacityCore.initialize(opacityApiKey, false, OpacityCore.Environment.LOCAL, false)
 
         Log.d("MainActivity", "Opacity SDK initialized and MainActivity loaded")
 
@@ -177,7 +177,7 @@ class MainActivity : ComponentActivity() {
                                         OpacityCore.initialize(
                                             opacityApiKey,
                                             false,
-                                            OpacityCore.Environment.PRODUCTION,
+                                            OpacityCore.Environment.LOCAL,
                                             true
                                         )
                                         Log.d("MainActivity", "Opacity SDK re-initialized")