try mitigate initialization race condition

packages/flutter_mozilla_components/android/src/main/kotlin/eu/weblibre/flutter_mozilla_components/BaseBrowserFragment.kt

@@ -21,12 +21,18 @@ import androidx.activity.result.ActivityResultLauncher
 import androidx.activity.result.contract.ActivityResultContracts
 import androidx.annotation.CallSuper
 import androidx.fragment.app.Fragment
+import eu.weblibre.flutter_mozilla_components.addons.WebExtensionActionPopupActivity
 import eu.weblibre.flutter_mozilla_components.addons.WebExtensionPromptFeature
 import eu.weblibre.flutter_mozilla_components.databinding.FragmentBrowserBinding
 import eu.weblibre.flutter_mozilla_components.ext.getPreferenceKey
+import eu.weblibre.flutter_mozilla_components.feature.ReadabilityExtractFeature
+import eu.weblibre.flutter_mozilla_components.feature.WebExtensionToolbarFeature
+import eu.weblibre.flutter_mozilla_components.integration.ReaderViewIntegration
 import eu.weblibre.flutter_mozilla_components.services.DownloadService
 import io.flutter.Log
 import mozilla.components.browser.state.selector.selectedTab
+import mozilla.components.browser.state.state.WebExtensionState
+import mozilla.components.browser.thumbnails.BrowserThumbnails
 import mozilla.components.concept.engine.EngineView
 import mozilla.components.feature.app.links.AppLinksFeature
 import mozilla.components.feature.downloads.DownloadsFeature
@@ -43,6 +49,7 @@ import mozilla.components.feature.session.SwipeRefreshFeature
 import mozilla.components.feature.sitepermissions.SitePermissionsFeature
 import mozilla.components.feature.sitepermissions.SitePermissionsRules
 import mozilla.components.feature.sitepermissions.SitePermissionsRules.AutoplayAction
+import mozilla.components.feature.tabs.WindowFeature
 import mozilla.components.feature.webauthn.WebAuthnFeature
 import mozilla.components.support.base.feature.ActivityResultHandler
 import mozilla.components.support.base.feature.PermissionsFeature
@@ -52,6 +59,7 @@ import mozilla.components.support.base.log.logger.Logger
 import mozilla.components.support.ktx.android.view.enterImmersiveMode
 import mozilla.components.support.ktx.android.view.exitImmersiveMode
 import mozilla.components.support.locale.ActivityContextWrapper
+import mozilla.components.support.webextensions.WebExtensionPopupObserver
 
 /**
  * Base fragment extended by [BrowserFragment] and [ExternalAppBrowserFragment].
@@ -77,6 +85,13 @@ abstract class BaseBrowserFragment : Fragment(), UserInteractionHandler, Activit
 
     private var pictureInPictureFeature: PictureInPictureFeature? = null
 
+    private val windowFeature = ViewBoundFeatureWrapper<WindowFeature>()
+    private val thumbnailsFeature = ViewBoundFeatureWrapper<BrowserThumbnails>()
+    val readerViewFeature = ViewBoundFeatureWrapper<ReaderViewIntegration>()
+    private val readabilityExtractFeature = ViewBoundFeatureWrapper<ReadabilityExtractFeature>()
+    private val webExtensionPopupObserver = ViewBoundFeatureWrapper<WebExtensionPopupObserver>()
+    private val webExtToolbarFeature = ViewBoundFeatureWrapper<WebExtensionToolbarFeature>()
+
     // Registers a photo picker activity launcher in single-select mode.
     private val singleMediaPicker =
         AndroidPhotoPicker.singleMediaPicker(
@@ -160,6 +175,49 @@ abstract class BaseBrowserFragment : Fragment(), UserInteractionHandler, Activit
     @CallSuper
     @Suppress("LongMethod")
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+        view.post {
+            if (GlobalComponents.components != null) {
+                createAndSetupEngine(view)
+            } else {
+                // Retry or handle error
+                view.postDelayed({ createAndSetupEngine(view) }, 100)
+            }
+        }
+    }
+
+    private fun restartApp(context: Context) {
+        val packageManager = context.packageManager
+        val intent = packageManager.getLaunchIntentForPackage(context.packageName)
+        intent?.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)
+        intent?.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
+        context.startActivity(intent)
+
+        if (context is Activity) {
+            context.finish()
+        }
+
+        Runtime.getRuntime().exit(0)
+    }
+
+    private fun createAndSetupEngine(view: View) {
+        try {
+            // Set layout parameters
+            val layoutParams = FrameLayout.LayoutParams(
+                FrameLayout.LayoutParams.MATCH_PARENT,
+                FrameLayout.LayoutParams.MATCH_PARENT
+            )
+
+            val engineView = createEngine(components)
+            val originalContext = ActivityContextWrapper.getOriginalContext(requireActivity())
+            val engineNativeView = engineView.asView()
+            engineNativeView.layoutParams = layoutParams
+
+            engineView.setActivityContext(originalContext)
+
+            binding.swipeToRefresh.addView(engineNativeView)
+
+            components.engineView = engineView
+
             sessionFeature.set(
                 feature = SessionFeature(
                     components.core.store,
@@ -338,53 +396,70 @@ abstract class BaseBrowserFragment : Fragment(), UserInteractionHandler, Activit
                 owner = this,
                 view = view
             )
-    }
 
-    private fun restartApp(context: Context) {
+            readerViewFeature.set(
-        val packageManager = context.packageManager
+                feature = ReaderViewIntegration(
-        val intent = packageManager.getLaunchIntentForPackage(context.packageName)
+                    requireContext(),
-        intent?.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)
+                    components.core.engine,
-        intent?.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
+                    components.core.store,
-        context.startActivity(intent)
+                    binding.readerViewBar,
-
+                    components.events.readerViewEvents,
-        if (context is Activity) {
+                    components.readerViewController,
-            context.finish()
+                ),
-        }
+                owner = this,
-
+                view = view,
-        Runtime.getRuntime().exit(0)
-    }
-
-    private fun createAndSetupEngine() {
-        try {
-            // Set layout parameters
-            val layoutParams = FrameLayout.LayoutParams(
-                FrameLayout.LayoutParams.MATCH_PARENT,
-                FrameLayout.LayoutParams.MATCH_PARENT
             )
 
-            val engineView = createEngine(components)
+            readabilityExtractFeature.set(
-            val originalContext = ActivityContextWrapper.getOriginalContext(requireActivity())
+                feature = components.features.readabilityExtractFeature,
-            val engineNativeView = engineView.asView()
+                owner = this,
-            engineNativeView.layoutParams = layoutParams
+                view = view,
+            )
 
-            engineView.setActivityContext(originalContext)
+            windowFeature.set(
+                feature = WindowFeature(components.core.store, components.useCases.tabsUseCases),
+                owner = this,
+                view = view,
+            )
 
-            binding.swipeToRefresh.addView(engineNativeView)
+            thumbnailsFeature.set(
+                feature = BrowserThumbnails(requireContext(), components.engineView!!, components.core.store),
+                owner = this,
+                view = view,
+            )
+
+            webExtensionPopupObserver.set(
+                feature = WebExtensionPopupObserver(components.core.store, ::openPopup),
+                owner = this,
+                view = view,
+            )
+
+            webExtToolbarFeature.set(
+                feature = components.features.webExtensionToolbarFeature,
+                owner = this,
+                view = view,
+            )
+
+            components.core.historyStorage.registerStorageMaintenanceWorker()
 
-            components.engineView = engineView
         } catch (e: Exception) {
             Log.e("EngineCreation", "Failed to create engine: ${e.message}", e)
             context?.let { restartApp(it) }
         }
     }
 
+    private fun openPopup(webExtensionState: WebExtensionState) {
+        val intent = Intent(requireContext().applicationContext, WebExtensionActionPopupActivity::class.java)
+        intent.putExtra("web_extension_id", webExtensionState.id)
+        intent.putExtra("web_extension_name", webExtensionState.name)
+        intent.flags = Intent.FLAG_ACTIVITY_NEW_TASK
+        startActivity(intent)
+    }
+
     @CallSuper
     @Suppress("LongMethod")
     override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View {
         _binding = FragmentBrowserBinding.inflate(inflater, container, false)
-
-        createAndSetupEngine()
-
         return binding.root
     }
 

packages/flutter_mozilla_components/android/src/main/kotlin/eu/weblibre/flutter_mozilla_components/BrowserFragment.kt

@@ -27,13 +27,6 @@ import mozilla.components.support.webextensions.WebExtensionPopupObserver
  * Fragment used for browsing the web within the main app.
  */
 class BrowserFragment() : BaseBrowserFragment(), UserInteractionHandler {
-    private val windowFeature = ViewBoundFeatureWrapper<WindowFeature>()
-    private val thumbnailsFeature = ViewBoundFeatureWrapper<BrowserThumbnails>()
-    private val readerViewFeature = ViewBoundFeatureWrapper<ReaderViewIntegration>()
-    private val readabilityExtractFeature = ViewBoundFeatureWrapper<ReadabilityExtractFeature>()
-    private val webExtensionPopupObserver = ViewBoundFeatureWrapper<WebExtensionPopupObserver>()
-    private val webExtToolbarFeature = ViewBoundFeatureWrapper<WebExtensionToolbarFeature>()
-
     override fun createEngine(components: Components): EngineView {
         return components.core.engine.createView(requireContext()).apply {
            selectionActionDelegate = components.selectionAction
@@ -49,63 +42,10 @@ class BrowserFragment() : BaseBrowserFragment(), UserInteractionHandler {
     @Suppress("LongMethod")
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         super.onViewCreated(view, savedInstanceState)
-
-        readerViewFeature.set(
-            feature = ReaderViewIntegration(
-                requireContext(),
-                components.core.engine,
-                components.core.store,
-                binding.readerViewBar,
-                components.events.readerViewEvents,
-                components.readerViewController,
-            ),
-            owner = this,
-            view = view,
-        )
-
-        readabilityExtractFeature.set(
-            feature = components.features.readabilityExtractFeature,
-            owner = this,
-            view = view,
-        )
-
-        windowFeature.set(
-            feature = WindowFeature(components.core.store, components.useCases.tabsUseCases),
-            owner = this,
-            view = view,
-        )
-
-        thumbnailsFeature.set(
-            feature = BrowserThumbnails(requireContext(), components.engineView!!, components.core.store),
-            owner = this,
-            view = view,
-        )
-
-        webExtensionPopupObserver.set(
-            feature = WebExtensionPopupObserver(components.core.store, ::openPopup),
-            owner = this,
-            view = view,
-        )
-
-        webExtToolbarFeature.set(
-            feature = components.features.webExtensionToolbarFeature,
-            owner = this,
-            view = view,
-        )
-
-        components.core.historyStorage.registerStorageMaintenanceWorker()
-    }
-
-    private fun openPopup(webExtensionState: WebExtensionState) {
-        val intent = Intent(requireContext().applicationContext, WebExtensionActionPopupActivity::class.java)
-        intent.putExtra("web_extension_id", webExtensionState.id)
-        intent.putExtra("web_extension_name", webExtensionState.name)
-        intent.flags = Intent.FLAG_ACTIVITY_NEW_TASK
-        startActivity(intent)
     }
 
     override fun onBackPressed(): Boolean =
-        readerViewFeature.onBackPressed() || super.onBackPressed()
+        super.readerViewFeature.onBackPressed() || super.onBackPressed()
 
     companion object {
         fun create(sessionId: String? = null) = BrowserFragment().apply {