Migrate CentralSurfacesImpl to Predictive Back api

This moves the CentralSurfacesImpl over to use the ahead-of-time
Predictive Back Api, which relies on callback registration and
unregistration.

Test: atest CentralSurfacesImplTest#testPredictiveBackCallback_registration and atest CentralSurfacesImplTest#testPredictiveBackCallback_invocationCollapsesPanel
Bug: 243586904
Change-Id: If7628a3375236a199025aa27cba0352ac61e747d

2 files changed, 120 insertions, 4 deletions

diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/phone/CentralSurfacesImpl.java b/packages/SystemUI/src/com/android/systemui/statusbar/phone/CentralSurfacesImpl.java
index 7da1d6c085b0..7d2928b12c72 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/phone/CentralSurfacesImpl.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/phone/CentralSurfacesImpl.java
@@ -101,11 +101,14 @@ import android.view.MotionEvent;
 import android.view.ThreadedRenderer;
 import android.view.View;
 import android.view.ViewGroup;
+import android.view.ViewRootImpl;
 import android.view.WindowInsetsController.Appearance;
 import android.view.WindowManager;
 import android.view.WindowManagerGlobal;
 import android.view.accessibility.AccessibilityManager;
 import android.widget.DateTimeView;
+import android.window.OnBackInvokedCallback;
+import android.window.OnBackInvokedDispatcher;
 
 import androidx.annotation.NonNull;
 import androidx.lifecycle.Lifecycle;
@@ -528,10 +531,17 @@ public class CentralSurfacesImpl extends CoreStartable implements
     private CentralSurfacesComponent mCentralSurfacesComponent;
 
     // Flags for disabling the status bar
-    // Two variables becaseu the first one evidently ran out of room for new flags.
+    // Two variables because the first one evidently ran out of room for new flags.
     private int mDisabled1 = 0;
     private int mDisabled2 = 0;
 
+    /**
+     * This keeps track of whether we have (or haven't) registered the predictive back callback.
+     * Since we can have visible -> visible transitions, we need to avoid
+     * double-registering (or double-unregistering) our callback.
+     */
+    private boolean mIsBackCallbackRegistered = false;
+
     /** @see android.view.WindowInsetsController#setSystemBarsAppearance(int, int) */
     private @Appearance int mAppearance;
 
@@ -657,6 +667,12 @@ public class CentralSurfacesImpl extends CoreStartable implements
 
     private final InteractionJankMonitor mJankMonitor;
 
+    private final OnBackInvokedCallback mOnBackInvokedCallback = () -> {
+        if (DEBUG) {
+            Log.d(TAG, "mOnBackInvokedCallback() called");
+        }
+        onBackPressed();
+    };
 
     /**
      * Public constructor for CentralSurfaces.
@@ -2775,9 +2791,38 @@ public class CentralSurfacesImpl extends CoreStartable implements
         if (visibleToUser) {
             handleVisibleToUserChangedImpl(visibleToUser);
             mNotificationLogger.startNotificationLogging();
+
+            if (!mIsBackCallbackRegistered) {
+                ViewRootImpl viewRootImpl = getViewRootImpl();
+                if (viewRootImpl != null) {
+                    viewRootImpl.getOnBackInvokedDispatcher()
+                            .registerOnBackInvokedCallback(OnBackInvokedDispatcher.PRIORITY_DEFAULT,
+                                    mOnBackInvokedCallback);
+                    mIsBackCallbackRegistered = true;
+                    if (DEBUG) Log.d(TAG, "is now VISIBLE to user AND callback registered");
+                }
+            } else {
+                if (DEBUG) Log.d(TAG, "is now VISIBLE to user, BUT callback ALREADY unregistered");
+            }
         } else {
             mNotificationLogger.stopNotificationLogging();
             handleVisibleToUserChangedImpl(visibleToUser);
+
+            if (mIsBackCallbackRegistered) {
+                ViewRootImpl viewRootImpl = getViewRootImpl();
+                if (viewRootImpl != null) {
+                    viewRootImpl.getOnBackInvokedDispatcher()
+                            .unregisterOnBackInvokedCallback(mOnBackInvokedCallback);
+                    mIsBackCallbackRegistered = false;
+                    if (DEBUG) Log.d(TAG, "is NOT VISIBLE to user, AND callback unregistered");
+                }
+            } else {
+                if (DEBUG) {
+                    Log.d(TAG,
+                            "is NOT VISIBLE to user, BUT NO callback (or callback ALREADY "
+                                    + "unregistered)");
+                }
+            }
         }
     }
 
@@ -3503,6 +3548,12 @@ public class CentralSurfacesImpl extends CoreStartable implements
         return mNotificationPanelViewController.getKeyguardBottomAreaView();
     }
 
+    protected ViewRootImpl getViewRootImpl()  {
+        NotificationShadeWindowView nswv = getNotificationShadeWindowView();
+        if (nswv != null) return nswv.getViewRootImpl();
+
+        return null;
+    }
     /**
      * Propagation of the bouncer state, indicating that it's fully visible.
      */
@@ -3821,6 +3872,12 @@ public class CentralSurfacesImpl extends CoreStartable implements
         updateScrimController();
     }
 
+    @VisibleForTesting
+    public void setNotificationShadeWindowViewController(
+            NotificationShadeWindowViewController nswvc) {
+        mNotificationShadeWindowViewController = nswvc;
+    }
+
     /**
      * Set the amount of progress we are currently in if we're transitioning to the full shade.
      * 0.0f means we're not transitioning yet, while 1 means we're all the way in the full
diff --git a/packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/CentralSurfacesImplTest.java b/packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/CentralSurfacesImplTest.java
index a0f7087ddb9e..ced2dbd751c1 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/CentralSurfacesImplTest.java
+++ b/packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/CentralSurfacesImplTest.java
@@ -35,6 +35,7 @@ import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.reset;
+import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
@@ -69,7 +70,11 @@ import android.util.DisplayMetrics;
 import android.util.SparseArray;
 import android.view.ViewGroup;
 import android.view.ViewGroup.LayoutParams;
+import android.view.ViewRootImpl;
 import android.view.WindowManager;
+import android.window.OnBackInvokedCallback;
+import android.window.OnBackInvokedDispatcher;
+import android.window.WindowOnBackInvokedDispatcher;
 
 import androidx.test.filters.SmallTest;
 
@@ -170,6 +175,7 @@ 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.MockitoAnnotations;
 
@@ -283,6 +289,15 @@ public class CentralSurfacesImplTest extends SysuiTestCase {
     @Mock private InteractionJankMonitor mJankMonitor;
     @Mock private DeviceStateManager mDeviceStateManager;
     @Mock private WiredChargingRippleController mWiredChargingRippleController;
+    /**
+     * The process of registering/unregistering a predictive back callback requires a
+     * ViewRootImpl, which is present IRL, but may be missing during a Mockito unit test.
+     * To prevent an NPE during test execution, we explicitly craft and provide a fake ViewRootImpl.
+     */
+    @Mock private ViewRootImpl mViewRootImpl;
+    @Mock private WindowOnBackInvokedDispatcher mOnBackInvokedDispatcher;
+    @Captor private ArgumentCaptor<OnBackInvokedCallback> mOnBackInvokedCallback;
+
     private ShadeController mShadeController;
     private final FakeSystemClock mFakeSystemClock = new FakeSystemClock();
     private FakeExecutor mMainExecutor = new FakeExecutor(mFakeSystemClock);
@@ -372,10 +387,10 @@ public class CentralSurfacesImplTest extends SysuiTestCase {
             return null;
         }).when(mNotificationShadeWindowController).batchApplyWindowLayoutParams(any());
 
-        mShadeController = new ShadeControllerImpl(mCommandQueue,
+        mShadeController = spy(new ShadeControllerImpl(mCommandQueue,
                 mStatusBarStateController, mNotificationShadeWindowController,
                 mStatusBarKeyguardViewManager, mContext.getSystemService(WindowManager.class),
-                () -> Optional.of(mCentralSurfaces), () -> mAssistManager);
+                () -> Optional.of(mCentralSurfaces), () -> mAssistManager));
 
         when(mOperatorNameViewControllerFactory.create(any()))
                 .thenReturn(mOperatorNameViewController);
@@ -465,7 +480,14 @@ public class CentralSurfacesImplTest extends SysuiTestCase {
                 mActivityLaunchAnimator,
                 mJankMonitor,
                 mDeviceStateManager,
-                mWiredChargingRippleController, mDreamManager);
+                mWiredChargingRippleController, mDreamManager) {
+            @Override
+            protected ViewRootImpl getViewRootImpl() {
+                return mViewRootImpl;
+            }
+        };
+        when(mViewRootImpl.getOnBackInvokedDispatcher())
+                .thenReturn(mOnBackInvokedDispatcher);
         when(mKeyguardViewMediator.registerCentralSurfaces(
                 any(CentralSurfacesImpl.class),
                 any(NotificationPanelViewController.class),
@@ -743,6 +765,43 @@ public class CentralSurfacesImplTest extends SysuiTestCase {
         }
     }
 
+    /**
+     * Do the following:
+     * 1. verify that a predictive back callback is registered when CSurf becomes visible
+     * 2. verify that the same callback is unregistered when CSurf becomes invisible
+     */
+    @Test
+    public void testPredictiveBackCallback_registration() {
+        mCentralSurfaces.handleVisibleToUserChanged(true);
+        verify(mOnBackInvokedDispatcher).registerOnBackInvokedCallback(
+                eq(OnBackInvokedDispatcher.PRIORITY_DEFAULT),
+                mOnBackInvokedCallback.capture());
+
+        mCentralSurfaces.handleVisibleToUserChanged(false);
+        verify(mOnBackInvokedDispatcher).unregisterOnBackInvokedCallback(
+                eq(mOnBackInvokedCallback.getValue()));
+    }
+
+    /**
+     * Do the following:
+     * 1. capture the predictive back callback during registration
+     * 2. call the callback directly
+     * 3. verify that the ShadeController's panel collapse animation is invoked
+     */
+    @Test
+    public void testPredictiveBackCallback_invocationCollapsesPanel() {
+        mCentralSurfaces.setNotificationShadeWindowViewController(
+                mNotificationShadeWindowViewController);
+        mCentralSurfaces.handleVisibleToUserChanged(true);
+        verify(mOnBackInvokedDispatcher).registerOnBackInvokedCallback(
+                eq(OnBackInvokedDispatcher.PRIORITY_DEFAULT),
+                mOnBackInvokedCallback.capture());
+
+        when(mNotificationPanelViewController.canPanelBeCollapsed()).thenReturn(true);
+        mOnBackInvokedCallback.getValue().onBackInvoked();
+        verify(mShadeController).animateCollapsePanels();
+    }
+
     @Test
     public void testPanelOpenForHeadsUp() {
         when(mDeviceProvisionedController.isDeviceProvisioned()).thenReturn(true);