From ad89a821450e9a61bd85225fbcf921f8ca51e94b Mon Sep 17 00:00:00 2001
From: Shan Huang <shanh@google.com>
Date: Wed, 2 Mar 2022 00:04:13 +0000
Subject: [PATCH] Turn off predictive back

Test: m -j. Test back in apps that opt-in, opt-out & sysUI
Bug: 222170518

Change-Id: I97ae7769ff2e04eb7fb39c49e025b255cdba057f
---
 .../android/window/WindowOnBackInvokedDispatcher.java    | 2 +-
 .../android/wm/shell/back/BackAnimationController.java   | 3 +++
 .../com/android/wm/shell/dagger/WMShellBaseModule.java   | 7 +++++--
 .../navigationbar/gestural/EdgeBackGestureHandler.java   | 9 +++++++++
 .../com/android/server/wm/BackNavigationController.java  | 2 +-
 5 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/core/java/android/window/WindowOnBackInvokedDispatcher.java b/core/java/android/window/WindowOnBackInvokedDispatcher.java
index 94e5ea960f4fe..909e2770ddccd 100644
--- a/core/java/android/window/WindowOnBackInvokedDispatcher.java
+++ b/core/java/android/window/WindowOnBackInvokedDispatcher.java
@@ -54,7 +54,7 @@ public class WindowOnBackInvokedDispatcher implements OnBackInvokedDispatcher {
     private static final String TAG = "WindowOnBackDispatcher";
     private static final String BACK_PREDICTABILITY_PROP = "persist.debug.back_predictability";
     private static final boolean IS_BACK_PREDICTABILITY_ENABLED = SystemProperties
-            .getInt(BACK_PREDICTABILITY_PROP, 1) > 0;
+            .getInt(BACK_PREDICTABILITY_PROP, 0) > 0;
 
     /** Convenience hashmap to quickly decide if a callback has been added. */
     private final HashMap<OnBackInvokedCallback, Integer> mAllCallbacks = new HashMap<>();
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/back/BackAnimationController.java b/libs/WindowManager/Shell/src/com/android/wm/shell/back/BackAnimationController.java
index 9b414681c0fa8..8d5fdfbc8cb08 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/back/BackAnimationController.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/back/BackAnimationController.java
@@ -52,6 +52,9 @@ import com.android.wm.shell.common.annotations.ShellMainThread;
  */
 public class BackAnimationController implements RemoteCallable<BackAnimationController> {
 
+    private static final String BACK_PREDICTABILITY_PROP = "persist.debug.back_predictability";
+    public static final boolean IS_ENABLED = SystemProperties
+            .getInt(BACK_PREDICTABILITY_PROP, 0) > 0;
     private static final String BACK_PREDICTABILITY_PROGRESS_THRESHOLD_PROP =
             "persist.debug.back_predictability_progress_threshold";
     private static final int PROGRESS_THRESHOLD = SystemProperties
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/dagger/WMShellBaseModule.java b/libs/WindowManager/Shell/src/com/android/wm/shell/dagger/WMShellBaseModule.java
index c94f3d197dea1..0362b3fba36b8 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/dagger/WMShellBaseModule.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/dagger/WMShellBaseModule.java
@@ -699,7 +699,10 @@ public abstract class WMShellBaseModule {
             Context context,
             @ShellMainThread ShellExecutor shellExecutor
     ) {
-        return Optional.of(
-                new BackAnimationController(shellExecutor, context));
+        if (BackAnimationController.IS_ENABLED) {
+            return Optional.of(
+                    new BackAnimationController(shellExecutor, context));
+        }
+        return Optional.empty();
     }
 }
diff --git a/packages/SystemUI/src/com/android/systemui/navigationbar/gestural/EdgeBackGestureHandler.java b/packages/SystemUI/src/com/android/systemui/navigationbar/gestural/EdgeBackGestureHandler.java
index 9ea27634df6ae..9199911896760 100644
--- a/packages/SystemUI/src/com/android/systemui/navigationbar/gestural/EdgeBackGestureHandler.java
+++ b/packages/SystemUI/src/com/android/systemui/navigationbar/gestural/EdgeBackGestureHandler.java
@@ -263,6 +263,15 @@ public class EdgeBackGestureHandler extends CurrentUserTracker
                     // Notify FalsingManager that an intentional gesture has occurred.
                     // TODO(b/186519446): use a different method than isFalseTouch
                     mFalsingManager.isFalseTouch(BACK_GESTURE);
+                    // Only inject back keycodes when ahead-of-time back dispatching is disabled.
+                    if (mBackAnimation == null) {
+                        boolean sendDown = sendEvent(KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_BACK);
+                        boolean sendUp = sendEvent(KeyEvent.ACTION_UP, KeyEvent.KEYCODE_BACK);
+                        if (DEBUG_MISSING_GESTURE) {
+                            Log.d(DEBUG_MISSING_GESTURE_TAG, "Triggered back: down="
+                                    + sendDown + ", up=" + sendUp);
+                        }
+                    }
 
                     mOverviewProxyService.notifyBackAction(true, (int) mDownPoint.x,
                             (int) mDownPoint.y, false /* isButton */, !mIsOnLeftEdge);
diff --git a/services/core/java/com/android/server/wm/BackNavigationController.java b/services/core/java/com/android/server/wm/BackNavigationController.java
index 487aff63b555d..23f14a7b7a163 100644
--- a/services/core/java/com/android/server/wm/BackNavigationController.java
+++ b/services/core/java/com/android/server/wm/BackNavigationController.java
@@ -53,7 +53,7 @@ class BackNavigationController {
      * Returns true if the back predictability feature is enabled
      */
     static boolean isEnabled() {
-        return SystemProperties.getInt(BACK_PREDICTABILITY_PROP, 1) > 0;
+        return SystemProperties.getInt(BACK_PREDICTABILITY_PROP, 0) > 0;
     }
 
     static boolean isScreenshotEnabled() {