Track falsing touches on UserSwitcherActivity

UserSwitcherActivity uses the FalsingManager, but the FalsingManager
wasn't being told about touches happening on its surface. Therefore,
the FalsingManager was relying on whatever the most recent touch
was elsewhere.

If this touch was a swipe (such as on the shade) it would not let an
owner change users because a swipe is not a tap.

Test: manual
Fixes: 238598985
Change-Id: Ic1f86d6f4b55b5a28d7db5d56afe72136dbdcef9

packages/SystemUI/res/layout/user_switcher_fullscreen.xml

@@ -14,7 +14,7 @@
      See the License for the specific language governing permissions and
      limitations under the License.
 -->
-<androidx.constraintlayout.widget.ConstraintLayout
+<com.android.systemui.user.UserSwitcherRootView
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:androidprv="http://schemas.android.com/apk/prv/res/android"
@@ -68,4 +68,4 @@
       app:layout_constraintBottom_toBottomOf="parent"
       app:layout_constraintEnd_toEndOf="parent"
       app:layout_constraintHeight_min="48dp" />
-</androidx.constraintlayout.widget.ConstraintLayout>
+</com.android.systemui.user.UserSwitcherRootView>

packages/SystemUI/src/com/android/systemui/Gefingerpoken.java

@@ -20,6 +20,13 @@ import android.view.MotionEvent;
 
 // ACHTUNG!
 public interface Gefingerpoken {
-    boolean onInterceptTouchEvent(MotionEvent ev);
-    boolean onTouchEvent(MotionEvent ev);
+    /** Called when a touch is being intercepted in a ViewGroup. */
+    default boolean onInterceptTouchEvent(MotionEvent ev) {
+        return false;
+    }
+
+    /** Called when a touch is being handled by a view. */
+    default boolean onTouchEvent(MotionEvent ev) {
+        return false;
+    }
 }

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

@@ -28,6 +28,7 @@ import android.os.Bundle
 import android.os.UserManager
 import android.provider.Settings
 import android.view.LayoutInflater
+import android.view.MotionEvent
 import android.view.View
 import android.view.ViewGroup
 import android.widget.AdapterView
@@ -38,8 +39,10 @@ import androidx.constraintlayout.helper.widget.Flow
 import com.android.internal.annotations.VisibleForTesting
 import com.android.internal.util.UserIcons
 import com.android.settingslib.Utils
+import com.android.systemui.Gefingerpoken
 import com.android.systemui.R
 import com.android.systemui.broadcast.BroadcastDispatcher
+import com.android.systemui.classifier.FalsingCollector
 import com.android.systemui.plugins.FalsingManager
 import com.android.systemui.plugins.FalsingManager.LOW_PENALTY
 import com.android.systemui.settings.UserTracker
@@ -61,12 +64,13 @@ class UserSwitcherActivity @Inject constructor(
     private val userSwitcherController: UserSwitcherController,
     private val broadcastDispatcher: BroadcastDispatcher,
     private val layoutInflater: LayoutInflater,
+    private val falsingCollector: FalsingCollector,
     private val falsingManager: FalsingManager,
     private val userManager: UserManager,
     private val userTracker: UserTracker
 ) : LifecycleActivity() {
 
-    private lateinit var parent: ViewGroup
+    private lateinit var parent: UserSwitcherRootView
     private lateinit var broadcastReceiver: BroadcastReceiver
     private var popupMenu: UserSwitcherPopupMenu? = null
     private lateinit var addButton: View
@@ -202,7 +206,14 @@ class UserSwitcherActivity @Inject constructor(
             or View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
             or View.SYSTEM_UI_FLAG_HIDE_NAVIGATION)
 
-        parent = requireViewById<ViewGroup>(R.id.user_switcher_root)
+        parent = requireViewById<UserSwitcherRootView>(R.id.user_switcher_root)
+
+        parent.touchHandler = object : Gefingerpoken {
+            override fun onTouchEvent(ev: MotionEvent?): Boolean {
+                falsingCollector.onTouchEvent(ev)
+                return false
+            }
+        }
 
         requireViewById<View>(R.id.cancel).apply {
             setOnClickListener {
@@ -241,7 +252,7 @@ class UserSwitcherActivity @Inject constructor(
         )
         popupMenuAdapter.addAll(items)
 
-        popupMenu = UserSwitcherPopupMenu(this, falsingManager).apply {
+        popupMenu = UserSwitcherPopupMenu(this).apply {
             setAnchorView(addButton)
             setAdapter(popupMenuAdapter)
             setOnItemClickListener {

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

@@ -23,16 +23,13 @@ import android.view.View.MeasureSpec
 import android.widget.ListAdapter
 import android.widget.ListPopupWindow
 import android.widget.ListView
-
 import com.android.systemui.R
-import com.android.systemui.plugins.FalsingManager
 
 /**
  * Popup menu for displaying items on the fullscreen user switcher.
  */
 class UserSwitcherPopupMenu(
-    private val context: Context,
-    private val falsingManager: FalsingManager
+    private val context: Context
 ) : ListPopupWindow(context) {
 
     private val res = context.resources

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

@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * 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.android.systemui.user
+
+import android.content.Context
+import android.util.AttributeSet
+import android.view.MotionEvent
+import androidx.constraintlayout.widget.ConstraintLayout
+import com.android.systemui.Gefingerpoken
+
+/** A simple subclass that allows for observing touch events as they happen. */
+class UserSwitcherRootView(
+    context: Context,
+    attrs: AttributeSet?
+) : ConstraintLayout(context, attrs) {
+
+    /** Assign this field to observer touch events. */
+    var touchHandler: Gefingerpoken? = null
+
+    override fun dispatchTouchEvent(ev: MotionEvent): Boolean {
+        touchHandler?.onTouchEvent(ev)
+        return super.dispatchTouchEvent(ev)
+    }
+}

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

@@ -23,6 +23,7 @@ import android.view.LayoutInflater
 import androidx.test.filters.SmallTest
 import com.android.systemui.SysuiTestCase
 import com.android.systemui.broadcast.BroadcastDispatcher
+import com.android.systemui.classifier.FalsingCollector
 import com.android.systemui.plugins.FalsingManager
 import com.android.systemui.settings.UserTracker
 import com.android.systemui.statusbar.policy.UserSwitcherController
@@ -46,6 +47,8 @@ class UserSwitcherActivityTest : SysuiTestCase() {
     @Mock
     private lateinit var layoutInflater: LayoutInflater
     @Mock
+    private lateinit var falsingCollector: FalsingCollector
+    @Mock
     private lateinit var falsingManager: FalsingManager
     @Mock
     private lateinit var userManager: UserManager
@@ -59,6 +62,7 @@ class UserSwitcherActivityTest : SysuiTestCase() {
             userSwitcherController,
             broadcastDispatcher,
             layoutInflater,
+            falsingCollector,
             falsingManager,
             userManager,
             userTracker