Add no-op WebMessageListener (#4551)

duckduckgo · May 20, 2024 · 5c1d919 · 5c1d919
1 parent b89e969
commit 5c1d919
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diff --git a/app/src/main/java/com/duckduckgo/app/browser/BrowserTabFragment.kt b/app/src/main/java/com/duckduckgo/app/browser/BrowserTabFragment.kt
@@ -79,6 +79,8 @@ import androidx.recyclerview.widget.GridLayoutManager
 import androidx.recyclerview.widget.ItemTouchHelper
 import androidx.recyclerview.widget.LinearLayoutManager
 import androidx.recyclerview.widget.RecyclerView
+import androidx.webkit.WebViewCompat
+import androidx.webkit.WebViewFeature
 import com.duckduckgo.anvil.annotations.InjectWith
 import com.duckduckgo.app.accessibility.data.AccessibilitySettingsDataStore
 import com.duckduckgo.app.autocomplete.api.AutoComplete.AutoCompleteSuggestion
@@ -161,6 +163,7 @@ import com.duckduckgo.app.browser.viewstate.OmnibarViewState
 import com.duckduckgo.app.browser.viewstate.PrivacyShieldViewState
 import com.duckduckgo.app.browser.viewstate.SavedSiteChangedViewState
 import com.duckduckgo.app.browser.webshare.WebShareChooser
+import com.duckduckgo.app.browser.webview.DummyWebMessageListenerFeature
 import com.duckduckgo.app.browser.webview.WebContentDebugging
 import com.duckduckgo.app.cta.ui.*
 import com.duckduckgo.app.cta.ui.DaxDialogCta.*
@@ -482,6 +485,9 @@ class BrowserTabFragment :
     @Inject
     lateinit var subscriptions: Subscriptions
 
+    @Inject
+    lateinit var dummyWebMessageListenerFeature: DummyWebMessageListenerFeature
+
     /**
      * We use this to monitor whether the user was seeing the in-context Email Protection signup prompt
      * This is needed because the activity stack will be cleared if an external link is opened in our browser
@@ -2344,11 +2350,35 @@ class BrowserTabFragment :
                     }
                 },
             )
+            addNoOpWebMessageListener(it)
         }
 
         WebView.setWebContentsDebuggingEnabled(webContentDebugging.isEnabled())
     }
 
+    // See https://app.asana.com/0/1200204095367872/1207300292572452/f (WebMessageListener debugging)
+    private fun addNoOpWebMessageListener(webView: DuckDuckGoWebView) {
+        lifecycleScope.launch(dispatchers.main()) {
+            val isFeatureEnabled = withContext(dispatchers.io()) {
+                dummyWebMessageListenerFeature.self().isEnabled()
+            }
+
+            if (WebViewFeature.isFeatureSupported(WebViewFeature.WEB_MESSAGE_LISTENER) &&
+                isFeatureEnabled &&
+                !webView.isDestroyed
+            ) {
+                Timber.d("Adding no-op WebMessageListener")
+                WebViewCompat.addWebMessageListener(
+                    webView,
+                    "testObj",
+                    setOf("*"),
+                ) { _, _, _, _, _ ->
+                    // no-op
+                }
+            }
+        }
+    }
+
     private fun screenLock(data: JsCallbackData) {
         val returnData = jsOrientationHandler.updateOrientation(data, this)
         contentScopeScripts.onResponse(returnData)

diff --git a/app/src/main/java/com/duckduckgo/app/browser/DuckDuckGoWebView.kt b/app/src/main/java/com/duckduckgo/app/browser/DuckDuckGoWebView.kt
@@ -49,6 +49,8 @@ class DuckDuckGoWebView : WebView, NestedScrollingChild3 {
     private var nestedScrollHelper: NestedScrollingChildHelper = NestedScrollingChildHelper(this)
     private val helper = CoordinatorLayoutHelper()
 
+    var isDestroyed: Boolean = false
+
     constructor(context: Context) : this(context, null)
     constructor(
         context: Context,
@@ -62,6 +64,11 @@ class DuckDuckGoWebView : WebView, NestedScrollingChild3 {
         helper.onViewAttached(this)
     }
 
+    override fun destroy() {
+        isDestroyed = true
+        super.destroy()
+    }
+
     fun setBottomMatchingBehaviourEnabled(value: Boolean) {
         helper.setBottomMatchingBehaviourEnabled(value)
     }

diff --git a/app/src/main/java/com/duckduckgo/app/browser/webview/DummyWebMessageListenerFeature.kt b/app/src/main/java/com/duckduckgo/app/browser/webview/DummyWebMessageListenerFeature.kt
@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2024 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.app.browser.webview
+
+import com.duckduckgo.anvil.annotations.ContributesRemoteFeature
+import com.duckduckgo.di.scopes.AppScope
+import com.duckduckgo.feature.toggles.api.Toggle
+
+@ContributesRemoteFeature(
+    scope = AppScope::class,
+    featureName = "dummyWebMessageListener",
+)
+
+interface DummyWebMessageListenerFeature {
+
+    @Toggle.DefaultValue(false)
+    fun self(): Toggle
+}