For #6313 - On first load, hides engineView until firstContentfulPaint

app/src/androidTest/java/org/mozilla/fenix/ui/robots/BrowserRobot.kt

@@ -44,12 +44,6 @@ import org.mozilla.fenix.helpers.click
 import org.mozilla.fenix.helpers.ext.waitNotNull
 
 class BrowserRobot {
-
-    fun verifyBrowserScreen() {
-        onView(ViewMatchers.withResourceName("browserLayout"))
-            .check(matches(withEffectiveVisibility(ViewMatchers.Visibility.VISIBLE)))
-    }
-
     fun verifyCurrentPrivateSession(context: Context) {
         val session = context.components.core.sessionManager.selectedSession
         assertTrue("Current session is private", session?.private!!)
@@ -84,6 +78,10 @@ class BrowserRobot {
     */
 
     fun verifyPageContent(expectedText: String) {
+        mDevice.waitNotNull(
+            Until.findObject(By.res("org.mozilla.fenix.debug:id/engineView")),
+            waitingTime
+        )
         assertTrue(mDevice.findObject(UiSelector().text(expectedText)).waitForExists(waitingTime))
     }
 
@@ -145,7 +143,8 @@ class BrowserRobot {
 
     fun verifyEnhancedTrackingProtectionSwitch() = assertEnhancedTrackingProtectionSwitch()
 
-    fun clickEnhancedTrackingProtectionSwitchOffOn() = onView(withResourceName("switch_widget")).click()
+    fun clickEnhancedTrackingProtectionSwitchOffOn() =
+        onView(withResourceName("switch_widget")).click()
 
     fun verifyProtectionSettingsButton() = assertProtectionSettingsButton()
 
@@ -191,7 +190,8 @@ class BrowserRobot {
 
     fun clickEnhancedTrackingProtectionPanel() = enhancedTrackingProtectionPanel().click()
 
-    fun verifyEnhancedTrackingProtectionPanelNotVisible() = assertEnhancedTrackingProtectionPanelNotVisible()
+    fun verifyEnhancedTrackingProtectionPanelNotVisible() =
+        assertEnhancedTrackingProtectionPanelNotVisible()
 
     fun clickContextOpenLinkInNewTab() {
         val mDevice = UiDevice.getInstance(InstrumentationRegistry.getInstrumentation())
@@ -423,7 +423,8 @@ fun navURLBar() = onView(withId(R.id.mozac_browser_toolbar_url_view))
 private fun assertNavURLBar() = navURLBar()
     .check(matches(withEffectiveVisibility(Visibility.VISIBLE)))
 
-fun enhancedTrackingProtectionPanel() = onView(withId(R.id.mozac_browser_toolbar_tracking_protection_indicator))
+fun enhancedTrackingProtectionPanel() =
+    onView(withId(R.id.mozac_browser_toolbar_tracking_protection_indicator))
 
 private fun assertEnhancedTrackingProtectionPanelNotVisible() {
     enhancedTrackingProtectionPanel()

app/src/main/java/org/mozilla/fenix/FeatureFlags.kt

@@ -43,4 +43,9 @@ object FeatureFlags {
      * Enables the new search experience
      */
     val newSearchExperience = Config.channel.isDebug
+
+    /**
+     * Enables wait til first contentful paint
+     */
+    val waitUntilPaintToDraw = Config.channel.isDebug
 }

app/src/main/java/org/mozilla/fenix/browser/BaseBrowserFragment.kt

@@ -144,9 +144,11 @@ abstract class BaseBrowserFragment : Fragment(), UserInteractionHandler, Session
     private val fullScreenFeature = ViewBoundFeatureWrapper<FullScreenFeature>()
     private val swipeRefreshFeature = ViewBoundFeatureWrapper<SwipeRefreshFeature>()
     private val webchannelIntegration = ViewBoundFeatureWrapper<FxaWebChannelFeature>()
-    private val sitePermissionWifiIntegration = ViewBoundFeatureWrapper<SitePermissionsWifiIntegration>()
+    private val sitePermissionWifiIntegration =
+        ViewBoundFeatureWrapper<SitePermissionsWifiIntegration>()
     private val secureWindowFeature = ViewBoundFeatureWrapper<SecureWindowFeature>()
-    private var fullScreenMediaFeature = ViewBoundFeatureWrapper<MediaFullscreenOrientationFeature>()
+    private var fullScreenMediaFeature =
+        ViewBoundFeatureWrapper<MediaFullscreenOrientationFeature>()
     private var pipFeature: PictureInPictureFeature? = null
 
     var customTabSessionId: String? = null
@@ -202,7 +204,8 @@ abstract class BaseBrowserFragment : Fragment(), UserInteractionHandler, Session
             engineView = WeakReference(engineView),
             swipeRefresh = WeakReference(swipeRefresh),
             viewLifecycleScope = WeakReference(viewLifecycleOwner.lifecycleScope),
-            arguments = requireArguments()
+            arguments = requireArguments(),
+            firstContentfulHappened = ::didFirstContentfulHappen
         ).apply {
             beginAnimateInIfNecessary()
         }
@@ -412,8 +415,10 @@ abstract class BaseBrowserFragment : Fragment(), UserInteractionHandler, Session
                 }
             }
 
-            resumeDownloadDialogState(sessionManager.selectedSession?.id,
+            resumeDownloadDialogState(
-                store, view, context, toolbarHeight)
+                sessionManager.selectedSession?.id,
+                store, view, context, toolbarHeight
+            )
 
             downloadsFeature.set(
                 downloadFeature,
@@ -506,7 +511,11 @@ abstract class BaseBrowserFragment : Fragment(), UserInteractionHandler, Session
                     onNeedToRequestPermissions = { permissions ->
                         requestPermissions(permissions, REQUEST_CODE_APP_PERMISSIONS)
                     },
-                    onShouldShowRequestPermissionRationale = { shouldShowRequestPermissionRationale(it) }),
+                    onShouldShowRequestPermissionRationale = {
+                        shouldShowRequestPermissionRationale(
+                            it
+                        )
+                    }),
                 owner = this,
                 view = view
             )
@@ -568,6 +577,21 @@ abstract class BaseBrowserFragment : Fragment(), UserInteractionHandler, Session
                     .collect { tab -> pipModeChanged(tab) }
             }
 
+            if (context.settings().waitToShowPageUntilFirstPaint) {
+                store.flowScoped(viewLifecycleOwner) { flow ->
+                    flow.mapNotNull { state ->
+                        state.findTabOrCustomTabOrSelectedTab(
+                            customTabSessionId
+                        )
+                    }
+                        .ifChanged { it.content.firstContentfulPaint }
+                        .collect {
+                            engineView?.asView()?.isVisible =
+                                it.content.firstContentfulPaint || it.content.progress == 100
+                        }
+                }
+            }
+
             @Suppress("ConstantConditionIf")
             if (FeatureFlags.pullToRefreshEnabled) {
                 val primaryTextColor =
@@ -687,7 +711,12 @@ abstract class BaseBrowserFragment : Fragment(), UserInteractionHandler, Session
         val context = requireContext()
         val behavior = when (context.settings().toolbarPosition) {
             ToolbarPosition.BOTTOM -> EngineViewBottomBehavior(context, null)
-            ToolbarPosition.TOP -> SwipeRefreshScrollingViewBehavior(context, null, engineView, browserToolbarView)
+            ToolbarPosition.TOP -> SwipeRefreshScrollingViewBehavior(
+                context,
+                null,
+                engineView,
+                browserToolbarView
+            )
         }
 
         (swipeRefresh.layoutParams as CoordinatorLayout.LayoutParams).behavior = behavior
@@ -751,12 +780,13 @@ abstract class BaseBrowserFragment : Fragment(), UserInteractionHandler, Session
         super.onStop()
         initUIJob?.cancel()
 
-        requireComponents.core.store.state.findTabOrCustomTabOrSelectedTab(customTabSessionId)?.let { session ->
+        requireComponents.core.store.state.findTabOrCustomTabOrSelectedTab(customTabSessionId)
-            // If we didn't enter PiP, exit full screen on stop
+            ?.let { session ->
-            if (!session.content.pictureInPictureEnabled && fullScreenFeature.onBackPressed()) {
+                // If we didn't enter PiP, exit full screen on stop
-                fullScreenChanged(false)
+                if (!session.content.pictureInPictureEnabled && fullScreenFeature.onBackPressed()) {
+                    fullScreenChanged(false)
+                }
             }
-        }
     }
 
     @CallSuper
@@ -950,7 +980,10 @@ abstract class BaseBrowserFragment : Fragment(), UserInteractionHandler, Session
                         .setAction(getString(R.string.edit_bookmark_snackbar_action)) {
                             nav(
                                 R.id.browserFragment,
-                                BrowserFragmentDirections.actionGlobalBookmarkEditFragment(guid, true)
+                                BrowserFragmentDirections.actionGlobalBookmarkEditFragment(
+                                    guid,
+                                    true
+                                )
                             )
                         }
                         .show()
@@ -988,10 +1021,10 @@ abstract class BaseBrowserFragment : Fragment(), UserInteractionHandler, Session
             // Close find in page bar if opened
             findInPageIntegration.onBackPressed()
             FenixSnackbar.make(
-                    view = requireView().browserLayout,
+                view = requireView().browserLayout,
-                    duration = Snackbar.LENGTH_SHORT,
+                duration = Snackbar.LENGTH_SHORT,
-                    isDisplayedWithBrowserToolbar = false
+                isDisplayedWithBrowserToolbar = false
-                )
+            )
                 .setText(getString(R.string.full_screen_notification))
                 .show()
             activity?.enterToImmersiveMode()
@@ -1014,6 +1047,12 @@ abstract class BaseBrowserFragment : Fragment(), UserInteractionHandler, Session
         }
     }
 
+    private fun didFirstContentfulHappen() =
+        if (!requireContext().settings().waitToShowPageUntilFirstPaint) true else
+            context?.components?.core?.store?.state?.findTabOrCustomTabOrSelectedTab(
+                customTabSessionId
+            )?.content?.firstContentfulPaint ?: false
+
     /*
      * Dereference these views when the fragment view is destroyed to prevent memory leaks
      */

app/src/main/java/org/mozilla/fenix/browser/BrowserAnimator.kt

@@ -34,7 +34,8 @@ class BrowserAnimator(
     private val engineView: WeakReference<EngineView>,
     private val swipeRefresh: WeakReference<View>,
     private val viewLifecycleScope: WeakReference<LifecycleCoroutineScope>,
-    private val arguments: Bundle
+    private val arguments: Bundle,
+    private val firstContentfulHappened: () -> Boolean
 ) {
 
     private val unwrappedEngineView: EngineView?
@@ -53,22 +54,9 @@ class BrowserAnimator(
         }
 
         doOnEnd {
-            unwrappedEngineView?.asView()?.visibility = View.VISIBLE
+            if (firstContentfulHappened()) {
-            unwrappedSwipeRefresh?.background = null
+                unwrappedEngineView?.asView()?.visibility = View.VISIBLE
-            arguments.putBoolean(SHOULD_ANIMATE_FLAG, false)
+            }
-        }
-
-        interpolator = DecelerateInterpolator()
-        duration = ANIMATION_DURATION
-    }
-
-    private val browserFadeInValueAnimator = ValueAnimator.ofFloat(0f, END_ANIMATOR_VALUE).apply {
-        addUpdateListener {
-            unwrappedSwipeRefresh?.alpha = it.animatedFraction
-        }
-
-        doOnEnd {
-            unwrappedEngineView?.asView()?.visibility = View.VISIBLE
             unwrappedSwipeRefresh?.background = null
             arguments.putBoolean(SHOULD_ANIMATE_FLAG, false)
         }
@@ -93,20 +81,10 @@ class BrowserAnimator(
             }
         } else {
             unwrappedSwipeRefresh?.alpha = 1f
-            unwrappedEngineView?.asView()?.visibility = View.VISIBLE
+            if (firstContentfulHappened()) {
-            unwrappedSwipeRefresh?.background = null
+                unwrappedEngineView?.asView()?.visibility = View.VISIBLE
-        }
-    }
-
-    /**
-     * Triggers the *zoom out* browser animation to run.
-     */
-    fun beginAnimateOut() {
-        viewLifecycleScope.get()?.launch(Dispatchers.Main) {
-            captureEngineViewAndDrawStatically {
-                unwrappedEngineView?.asView()?.visibility = View.GONE
-                browserZoomInValueAnimator.reverse()
             }
+            unwrappedSwipeRefresh?.background = null
         }
     }
 

app/src/main/java/org/mozilla/fenix/settings/SecretSettingsFragment.kt

@@ -30,5 +30,11 @@ class SecretSettingsFragment : PreferenceFragmentCompat() {
             isChecked = context.settings().useNewSearchExperience
             onPreferenceChangeListener = SharedPreferenceUpdater()
         }
+
+        requirePreference<SwitchPreference>(R.string.pref_key_wait_first_paint).apply {
+            isVisible = FeatureFlags.waitUntilPaintToDraw
+            isChecked = context.settings().waitToShowPageUntilFirstPaint
+            onPreferenceChangeListener = SharedPreferenceUpdater()
+        }
     }
 }

app/src/main/java/org/mozilla/fenix/utils/Settings.kt

@@ -103,6 +103,12 @@ class Settings(private val appContext: Context) : PreferencesHolder {
         featureFlag = FeatureFlags.newSearchExperience
     )
 
+    var waitToShowPageUntilFirstPaint by featureFlagPreference(
+        appContext.getPreferenceKey(R.string.pref_key_wait_first_paint),
+        default = false,
+        featureFlag = FeatureFlags.waitUntilPaintToDraw
+    )
+
     var forceEnableZoom by booleanPreference(
         appContext.getPreferenceKey(R.string.pref_key_accessibility_force_enable_zoom),
         default = false

app/src/main/res/values/preference_keys.xml

@@ -175,6 +175,8 @@
 
     <string name="pref_key_use_new_search_experience" translatable="false">pref_key_use_new_search_experience</string>
 
+    <string name="pref_key_wait_first_paint" translatable="false">pref_key_wait_first_paint</string>
+
     <string name="pref_key_debug_settings" translatable="false">pref_key_debug_settings</string>
 
     <string name="pref_key_open_tabs_count" translatable="false">pref_key_open_tabs_count</string>

app/src/main/res/values/static_strings.xml

@@ -34,6 +34,8 @@
     <string name="preferences_debug_settings">Secret Settings</string>
     <!-- Label for the new search experience preference -->
     <string name="preferences_debug_settings_use_new_search_experience">Use New Search Experience</string>
+    <!-- Label for the wait until first paint preference -->
+    <string name="preferences_debug_settings_wait_first_paint">Wait Until First Paint To Show Page Content</string>
 
     <!-- Content description (not visible, for screen readers etc.) used to announce [LinkTextView]. -->
     <string name="link_text_view_type_announcement" translatable="false">link</string>

app/src/main/res/xml/secret_settings_preferences.xml

@@ -9,4 +9,9 @@
         android:key="@string/pref_key_use_new_search_experience"
         android:title="@string/preferences_debug_settings_use_new_search_experience"
         app:iconSpaceReserved="false" />
+    <SwitchPreference
+        android:defaultValue="false"
+        android:key="@string/pref_key_wait_first_paint"
+        android:title="@string/preferences_debug_settings_wait_first_paint"
+        app:iconSpaceReserved="false" />
 </PreferenceScreen>