Migrate UserSwitcherActivity to new back API

Test: atest UserSwitcherActivityTest
Bug: 238358031
Change-Id: I6173f0c70de3e975cff34471ae24126bcd9de3ef

packages/SystemUI/src/com/android/systemui/user/UserSwitcherActivity.kt

@@ -36,6 +36,8 @@ import android.widget.AdapterView
 import android.widget.ArrayAdapter
 import android.widget.ImageView
 import android.widget.TextView
+import android.window.OnBackInvokedCallback
+import android.window.OnBackInvokedDispatcher
 import androidx.activity.ComponentActivity
 import androidx.constraintlayout.helper.widget.Flow
 import androidx.lifecycle.ViewModelProvider
@@ -67,7 +69,7 @@ private const val USER_VIEW = "user_view"
 /**
  * Support a fullscreen user switcher
  */
-class UserSwitcherActivity @Inject constructor(
+open class UserSwitcherActivity @Inject constructor(
     private val userSwitcherController: UserSwitcherController,
     private val broadcastDispatcher: BroadcastDispatcher,
     private val falsingCollector: FalsingCollector,
@@ -83,6 +85,7 @@ class UserSwitcherActivity @Inject constructor(
     private var popupMenu: UserSwitcherPopupMenu? = null
     private lateinit var addButton: View
     private var addUserRecords = mutableListOf<UserRecord>()
+    private val onBackCallback = OnBackInvokedCallback { finish() }
     private val userSwitchedCallback: UserTracker.Callback = object : UserTracker.Callback {
         override fun onUserChanged(newUser: Int, userContext: Context) {
             finish()
@@ -105,7 +108,11 @@ class UserSwitcherActivity @Inject constructor(
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
+        createActivity()
+    }
 
+    @VisibleForTesting
+    fun createActivity() {
         setContentView(R.layout.user_switcher_fullscreen)
         window.decorView.systemUiVisibility = (View.SYSTEM_UI_FLAG_LAYOUT_STABLE
                 or View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
@@ -148,6 +155,9 @@ class UserSwitcherActivity @Inject constructor(
             }
         }
 
+        onBackInvokedDispatcher.registerOnBackInvokedCallback(
+                OnBackInvokedDispatcher.PRIORITY_DEFAULT, onBackCallback)
+
         userSwitcherController.init(parent)
         initBroadcastReceiver()
 
@@ -278,7 +288,12 @@ class UserSwitcherActivity @Inject constructor(
         if (isUsingModernArchitecture()) {
             return
         }
+        destroyActivity()
+    }
 
+    @VisibleForTesting
+    fun destroyActivity() {
+        onBackInvokedDispatcher.unregisterOnBackInvokedCallback(onBackCallback)
         broadcastDispatcher.unregisterReceiver(broadcastReceiver)
         userTracker.removeCallback(userSwitchedCallback)
     }

packages/SystemUI/tests/src/com/android/systemui/user/UserSwitcherActivityTest.kt

@@ -16,11 +16,17 @@
 
 package com.android.systemui.user
 
+import android.app.Application
 import android.os.UserManager
 import android.testing.AndroidTestingRunner
 import android.testing.TestableLooper.RunWithLooper
 import android.view.LayoutInflater
+import android.view.View
+import android.view.Window
+import android.window.OnBackInvokedCallback
+import android.window.OnBackInvokedDispatcher
 import androidx.test.filters.SmallTest
+import com.android.systemui.R
 import com.android.systemui.SysuiTestCase
 import com.android.systemui.broadcast.BroadcastDispatcher
 import com.android.systemui.classifier.FalsingCollector
@@ -29,12 +35,25 @@ import com.android.systemui.plugins.FalsingManager
 import com.android.systemui.settings.UserTracker
 import com.android.systemui.statusbar.policy.UserSwitcherController
 import com.android.systemui.user.ui.viewmodel.UserSwitcherViewModel
+import com.android.systemui.util.concurrency.FakeExecutor
+import com.android.systemui.util.time.FakeSystemClock
 import com.google.common.truth.Truth.assertThat
 import org.junit.Before
 import org.junit.Test
 import org.junit.runner.RunWith
+import org.mockito.ArgumentCaptor
+import org.mockito.Captor
 import org.mockito.Mock
+import org.mockito.Mockito.`when`
+import org.mockito.Mockito.any
+import org.mockito.Mockito.anyInt
+import org.mockito.Mockito.doNothing
+import org.mockito.Mockito.eq
+import org.mockito.Mockito.mock
+import org.mockito.Mockito.spy
+import org.mockito.Mockito.verify
 import org.mockito.MockitoAnnotations
+import java.util.concurrent.Executor
 
 @SmallTest
 @RunWith(AndroidTestingRunner::class)
@@ -60,11 +79,22 @@ class UserSwitcherActivityTest : SysuiTestCase() {
     private lateinit var flags: FeatureFlags
     @Mock
     private lateinit var viewModelFactoryLazy: dagger.Lazy<UserSwitcherViewModel.Factory>
+    @Mock
+    private lateinit var onBackDispatcher: OnBackInvokedDispatcher
+    @Mock
+    private lateinit var decorView: View
+    @Mock
+    private lateinit var window: Window
+    @Mock
+    private lateinit var userSwitcherRootView: UserSwitcherRootView
+    @Captor
+    private lateinit var onBackInvokedCallback: ArgumentCaptor<OnBackInvokedCallback>
+    var isFinished = false
 
     @Before
     fun setUp() {
         MockitoAnnotations.initMocks(this)
-        activity = UserSwitcherActivity(
+        activity = spy(object : UserSwitcherActivity(
             userSwitcherController,
             broadcastDispatcher,
             falsingCollector,
@@ -73,7 +103,21 @@ class UserSwitcherActivityTest : SysuiTestCase() {
             userTracker,
             flags,
             viewModelFactoryLazy,
-        )
+        ) {
+            override fun getOnBackInvokedDispatcher() = onBackDispatcher
+            override fun getMainExecutor(): Executor = FakeExecutor(FakeSystemClock())
+            override fun finish() {
+                isFinished = true
+            }
+        })
+        `when`(activity.window).thenReturn(window)
+        `when`(window.decorView).thenReturn(decorView)
+        `when`(activity.findViewById<UserSwitcherRootView>(R.id.user_switcher_root))
+                .thenReturn(userSwitcherRootView)
+        `when`(activity.findViewById<View>(R.id.cancel)).thenReturn(mock(View::class.java))
+        `when`(activity.findViewById<View>(R.id.add)).thenReturn(mock(View::class.java))
+        `when`(activity.application).thenReturn(mock(Application::class.java))
+        doNothing().`when`(activity).setContentView(anyInt())
     }
 
     @Test
@@ -85,4 +129,24 @@ class UserSwitcherActivityTest : SysuiTestCase() {
         assertThat(activity.getMaxColumns(7)).isEqualTo(4)
         assertThat(activity.getMaxColumns(9)).isEqualTo(5)
     }
+
+    @Test
+    fun onCreate_callbackRegistration() {
+        activity.createActivity()
+        verify(onBackDispatcher).registerOnBackInvokedCallback(
+                eq(OnBackInvokedDispatcher.PRIORITY_DEFAULT), any())
+
+        activity.destroyActivity()
+        verify(onBackDispatcher).unregisterOnBackInvokedCallback(any())
+    }
+
+    @Test
+    fun onBackInvokedCallback_finishesActivity() {
+        activity.createActivity()
+        verify(onBackDispatcher).registerOnBackInvokedCallback(
+                eq(OnBackInvokedDispatcher.PRIORITY_DEFAULT), onBackInvokedCallback.capture())
+
+        onBackInvokedCallback.value.onBackInvoked()
+        assertThat(isFinished).isTrue()
+    }
 }