For #19813: Invalidate tab tray adapter structure on screen rotation. (#20044)

app/src/main/java/org/mozilla/fenix/tabstray/TabsTrayFragment.kt

@@ -271,6 +271,10 @@ class TabsTrayFragment : AppCompatDialogFragment() {
         super.onConfigurationChanged(newConfig)
 
         trayBehaviorManager.updateDependingOnOrientation(newConfig.orientation)
+
+        if (requireContext().settings().gridTabView) {
+            tabsTray.adapter?.notifyDataSetChanged()
+        }
     }
 
     @VisibleForTesting
@@ -287,9 +291,11 @@ class TabsTrayFragment : AppCompatDialogFragment() {
             getString(R.string.snackbar_deleted_undo),
             {
                 requireComponents.useCases.tabsUseCases.undo.invoke()
-                tabLayoutMediator.withFeature { it.selectTabAtPosition(
-                    if (isPrivate) Page.PrivateTabs.ordinal else Page.NormalTabs.ordinal
-                ) }
+                tabLayoutMediator.withFeature {
+                    it.selectTabAtPosition(
+                        if (isPrivate) Page.PrivateTabs.ordinal else Page.NormalTabs.ordinal
+                    )
+                }
             },
             operation = { },
             elevation = ELEVATION,

app/src/test/java/org/mozilla/fenix/tabstray/TabsTrayFragmentTest.kt

@@ -49,6 +49,7 @@ import org.mozilla.fenix.components.metrics.Event
 import org.mozilla.fenix.components.metrics.MetricController
 import org.mozilla.fenix.ext.components
 import org.mozilla.fenix.ext.navigateBlockingForAsyncNavGraph
+import org.mozilla.fenix.ext.settings
 import org.mozilla.fenix.helpers.FenixRobolectricTestRunner
 import org.mozilla.fenix.home.HomeScreenViewModel
 import org.mozilla.fenix.tabstray.browser.BrowserTrayInteractor
@@ -354,6 +355,7 @@ class TabsTrayFragmentTest {
         val trayBehaviorManager: TabSheetBehaviorManager = mockk(relaxed = true)
         fragment.trayBehaviorManager = trayBehaviorManager
         val newConfiguration = Configuration()
+        every { context.settings().gridTabView } returns false
 
         fragment.onConfigurationChanged(newConfiguration)
 
@@ -370,4 +372,58 @@ class TabsTrayFragmentTest {
         Assert.assertFalse(behavior.skipCollapsed)
         assert(behavior.halfExpandedRatio <= 0.001f)
     }
+
+    @Test
+    fun `GIVEN a grid TabView WHEN onConfigurationChanged is called THEN the adapter structure is updated`() {
+        val tray: ViewPager2 = mockk(relaxed = true)
+        val store: TabsTrayStore = mockk()
+        val trayInteractor: TabsTrayInteractor = mockk()
+        val browserInteractor: BrowserTrayInteractor = mockk()
+        val navigationInteractor: NavigationInteractor = mockk()
+        val browserStore: BrowserStore = mockk()
+
+        every { fragment.tabsTray } returns tray
+        every { context.components.core.store } returns browserStore
+        every { context.settings().gridTabView } returns true
+
+        fragment.setupPager(
+            context, store, trayInteractor, browserInteractor, navigationInteractor
+        )
+
+        val trayBehaviorManager: TabSheetBehaviorManager = mockk(relaxed = true)
+        fragment.trayBehaviorManager = trayBehaviorManager
+
+        val newConfiguration = Configuration()
+
+        fragment.onConfigurationChanged(newConfiguration)
+
+        verify { tray.adapter?.notifyDataSetChanged() }
+    }
+
+    @Test
+    fun `GIVEN a list TabView WHEN onConfigurationChanged is called THEN the adapter structure is NOT updated`() {
+        val tray: ViewPager2 = mockk(relaxed = true)
+        val store: TabsTrayStore = mockk()
+        val trayInteractor: TabsTrayInteractor = mockk()
+        val browserInteractor: BrowserTrayInteractor = mockk()
+        val navigationInteractor: NavigationInteractor = mockk()
+        val browserStore: BrowserStore = mockk()
+
+        every { fragment.tabsTray } returns tray
+        every { context.components.core.store } returns browserStore
+        every { context.settings().gridTabView } returns false
+
+        fragment.setupPager(
+            context, store, trayInteractor, browserInteractor, navigationInteractor
+        )
+
+        val trayBehaviorManager: TabSheetBehaviorManager = mockk(relaxed = true)
+        fragment.trayBehaviorManager = trayBehaviorManager
+
+        val newConfiguration = Configuration()
+
+        fragment.onConfigurationChanged(newConfiguration)
+
+        verify(exactly = 0) { tray.adapter?.notifyDataSetChanged() }
+    }
 }