Add support to receive messages

app/src/main/java/com/duckduckgo/app/browser/BrowserTabFragment.kt

@@ -295,6 +295,7 @@ import com.duckduckgo.duckchat.api.inputscreen.InputScreenActivityResultCodes
 import com.duckduckgo.duckchat.api.inputscreen.InputScreenActivityResultParams
 import com.duckduckgo.duckplayer.api.DuckPlayer
 import com.duckduckgo.duckplayer.api.DuckPlayerSettingsNoParams
+import com.duckduckgo.js.messaging.api.AdsjsMessaging
 import com.duckduckgo.js.messaging.api.JsCallbackData
 import com.duckduckgo.js.messaging.api.JsMessageCallback
 import com.duckduckgo.js.messaging.api.JsMessaging
@@ -511,6 +512,10 @@ class BrowserTabFragment :
     @Named("DuckPlayer")
     lateinit var duckPlayerScripts: JsMessaging
 
+    @Inject
+    @Named("AdsjsContentScopeScripts")
+    lateinit var adsJsContentScopeScripts: AdsjsMessaging
+
     @Inject
     lateinit var webContentDebugging: WebContentDebugging
 
@@ -3006,7 +3011,25 @@ class BrowserTabFragment :
         webView?.let {
             it.isSafeWebViewEnabled = safeWebViewFeature.self().isEnabled()
             it.webViewClient = webViewClient
-            webViewClient.triggerJSInit(it)
+            lifecycleScope.launch(dispatchers.main()) {
+                webViewClient.triggerJSInit(it)
+                adsJsContentScopeScripts.register(
+                    it,
+                    object : JsMessageCallback() {
+                        override fun process(
+                            featureName: String,
+                            method: String,
+                            id: String?,
+                            data: JSONObject?,
+                        ) {
+                            viewModel.processJsCallbackMessage(featureName, method, id, data, isActiveCustomTab()) {
+                                it.url
+                            }
+                        }
+                    },
+                )
+            }
+
             it.webChromeClient = webChromeClient
             it.clearSslPreferences()
 

content-scope-scripts/content-scope-scripts-api/build.gradle

@@ -23,6 +23,7 @@ apply from: "$rootProject.projectDir/gradle/android-library.gradle"
 
 dependencies {
     implementation AndroidX.core.ktx
+    implementation AndroidX.webkit
     implementation project(':feature-toggles-api')
     implementation project(':js-messaging-api')
 }

content-scope-scripts/content-scope-scripts-api/src/main/java/com/duckduckgo/contentscopescripts/api/AdsjsContentScopeJsMessageHandlersPlugin.kt

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2025 DuckDuckGo
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.duckduckgo.contentscopescripts.api
+
+import com.duckduckgo.js.messaging.api.AdsjsMessageHandler
+
+/**
+ * Implement this interface and contribute it as a multibinding to manage JS Messages that are sent to C-S-S
+ */
+interface AdsjsContentScopeJsMessageHandlersPlugin {
+    /**
+     * @return a [AdsjsMessageHandler] that will be used to handle the JS messages
+     */
+    fun getJsMessageHandler(): AdsjsMessageHandler
+}

content-scope-scripts/content-scope-scripts-api/src/main/java/com/duckduckgo/contentscopescripts/api/GlobalContentScopeJsMessageHandlersPlugin.kt

@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2025 DuckDuckGo
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.duckduckgo.contentscopescripts.api
+
+import com.duckduckgo.js.messaging.api.JsMessage
+import com.duckduckgo.js.messaging.api.JsMessageCallback
+
+/**
+ * Plugin interface for global message handlers that should always be processed
+ * regardless of whether a specific feature handler matches the message.
+ * * Examples: addDebugFlag.
+ */
+interface GlobalContentScopeJsMessageHandlersPlugin {
+
+    /**
+     * @return a [GlobalJsMessageHandler] that will be used to handle global messages
+     */
+    fun getGlobalJsMessageHandler(): GlobalJsMessageHandler
+}
+
+/**
+ * Handler for global messages that should be processed for all features.
+ */
+interface GlobalJsMessageHandler {
+
+    /**
+     * Processes a global message.
+     */
+    fun process(
+        jsMessage: JsMessage,
+        jsMessageCallback: JsMessageCallback,
+    )
+
+    /**
+     * Method this handler can process.
+     */
+    val method: String
+}

content-scope-scripts/content-scope-scripts-impl/src/main/java/com/duckduckgo/contentscopescripts/impl/AdsjsContentScopeConfigPluginPoint.kt

@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2022 DuckDuckGo
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.duckduckgo.contentscopescripts.impl
+
+import com.duckduckgo.anvil.annotations.ContributesPluginPoint
+import com.duckduckgo.contentscopescripts.api.AdsjsContentScopeJsMessageHandlersPlugin
+import com.duckduckgo.di.scopes.AppScope
+
+@ContributesPluginPoint(
+    scope = AppScope::class,
+    boundType = AdsjsContentScopeJsMessageHandlersPlugin::class,
+)
+@Suppress("unused")
+interface AdsjsContentScopeJsMessageHandlersPluginPoint

content-scope-scripts/content-scope-scripts-impl/src/main/java/com/duckduckgo/contentscopescripts/impl/GlobalContentScopeJsMessageHandlersPluginPoint.kt

@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2025 DuckDuckGo
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.duckduckgo.contentscopescripts.impl
+
+import com.duckduckgo.anvil.annotations.ContributesPluginPoint
+import com.duckduckgo.contentscopescripts.api.GlobalContentScopeJsMessageHandlersPlugin
+import com.duckduckgo.di.scopes.AppScope
+
+@ContributesPluginPoint(
+    scope = AppScope::class,
+    boundType = GlobalContentScopeJsMessageHandlersPlugin::class,
+)
+@Suppress("unused")
+interface GlobalContentScopeJsMessageHandlersPluginPoint

content-scope-scripts/content-scope-scripts-impl/src/main/java/com/duckduckgo/contentscopescripts/impl/messaging/AdsjsContentScopeMessaging.kt

@@ -0,0 +1,108 @@
+/*
+ * Copyright (c) 2023 DuckDuckGo
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.duckduckgo.contentscopescripts.impl.messaging
+
+import android.annotation.SuppressLint
+import android.webkit.WebView
+import androidx.webkit.WebViewCompat
+import androidx.webkit.WebViewFeature
+import com.duckduckgo.common.utils.plugins.PluginPoint
+import com.duckduckgo.contentscopescripts.api.AdsjsContentScopeJsMessageHandlersPlugin
+import com.duckduckgo.contentscopescripts.api.GlobalContentScopeJsMessageHandlersPlugin
+import com.duckduckgo.di.scopes.ActivityScope
+import com.duckduckgo.js.messaging.api.AdsjsMessaging
+import com.duckduckgo.js.messaging.api.JsMessage
+import com.duckduckgo.js.messaging.api.JsMessageCallback
+import com.squareup.anvil.annotations.ContributesBinding
+import com.squareup.moshi.Moshi
+import javax.inject.Inject
+import javax.inject.Named
+import logcat.LogPriority.ERROR
+import logcat.asLog
+import logcat.logcat
+
+@ContributesBinding(ActivityScope::class)
+@Named("AdsjsContentScopeScripts")
+class AdsjsContentScopeMessaging @Inject constructor(
+    private val handlers: PluginPoint<AdsjsContentScopeJsMessageHandlersPlugin>,
+    private val globalHandlers: PluginPoint<GlobalContentScopeJsMessageHandlersPlugin>,
+) : AdsjsMessaging {
+
+    private val moshi = Moshi.Builder().add(JSONObjectAdapter()).build()
+
+    private lateinit var webView: WebView
+
+    override val context: String = "contentScopeScripts"
+    override val allowedDomains: Set<String> = setOf("*")
+
+    private fun process(
+        message: String,
+        jsMessageCallback: JsMessageCallback,
+    ) {
+        try {
+            val adapter = moshi.adapter(JsMessage::class.java)
+            val jsMessage = adapter.fromJson(message)
+
+            jsMessage?.let {
+                if (context == jsMessage.context) {
+                    // Process global handlers first (always processed regardless of feature handlers)
+                    globalHandlers.getPlugins()
+                        .map { it.getGlobalJsMessageHandler() }
+                        .filter { it.method == jsMessage.method }
+                        .forEach { handler ->
+                            handler.process(jsMessage, jsMessageCallback)
+                        }
+
+                    // Process with feature handlers
+                    handlers.getPlugins().map { it.getJsMessageHandler() }.firstOrNull {
+                        it.methods.contains(jsMessage.method) && it.featureName == jsMessage.featureName
+                    }?.process(jsMessage, jsMessageCallback)
+                }
+            }
+        } catch (e: Exception) {
+            logcat(ERROR) { "Exception is ${e.asLog()}" }
+        }
+    }
+
+    // TODO: A/B this, don't register if the feature is not enabled
+    @SuppressLint("AddWebMessageListenerUsage") // safeAddWebMessageListener belongs to app module
+    override fun register(webView: WebView, jsMessageCallback: JsMessageCallback?) {
+        if (jsMessageCallback == null) throw Exception("Callback cannot be null")
+        this.webView = webView
+
+        runCatching {
+            if (WebViewFeature.isFeatureSupported(WebViewFeature.WEB_MESSAGE_LISTENER)) {
+                WebViewCompat.addWebMessageListener(
+                    webView,
+                    "contentScopeAdsjs",
+                    allowedDomains,
+                ) { _, message, _, _, replyProxy ->
+                    process(
+                        message.data ?: "",
+                        jsMessageCallback,
+                    )
+                }
+                true
+            } else {
+                false
+            }
+        }.getOrElse { exception ->
+            logcat(ERROR) { "Error adding WebMessageListener for contentScopeAdsjs: ${exception.asLog()}" }
+            false
+        }
+    }
+}

content-scope-scripts/content-scope-scripts-impl/src/main/java/com/duckduckgo/contentscopescripts/impl/messaging/DebugFlagGlobalHandler.kt

@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2025 DuckDuckGo
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.duckduckgo.contentscopescripts.impl.messaging
+
+import com.duckduckgo.contentscopescripts.api.GlobalContentScopeJsMessageHandlersPlugin
+import com.duckduckgo.contentscopescripts.api.GlobalJsMessageHandler
+import com.duckduckgo.di.scopes.AppScope
+import com.duckduckgo.js.messaging.api.JsMessage
+import com.duckduckgo.js.messaging.api.JsMessageCallback
+import com.squareup.anvil.annotations.ContributesMultibinding
+import javax.inject.Inject
+import logcat.logcat
+
+@ContributesMultibinding(AppScope::class)
+class DebugFlagGlobalHandler @Inject constructor() : GlobalContentScopeJsMessageHandlersPlugin {
+
+    override fun getGlobalJsMessageHandler(): GlobalJsMessageHandler = object : GlobalJsMessageHandler {
+
+        override fun process(
+            jsMessage: JsMessage,
+            jsMessageCallback: JsMessageCallback,
+        ) {
+            if (jsMessage.method == method) {
+                logcat { "DebugFlagGlobalHandler addDebugFlag: ${jsMessage.featureName}" }
+                jsMessageCallback.process(
+                    featureName = jsMessage.featureName,
+                    method = jsMessage.method,
+                    id = jsMessage.id,
+                    data = jsMessage.params,
+                )
+            }
+        }
+
+        override val method: String = "addDebugFlag"
+    }
+}