Improve startBackNavigation stability

  - Use the focused window instead of the topApp window
    - Instead we now rely on WindowManagerService to get
     the focused window.
    - SystemUI does not have ActivityRecord so we can't rely
     on the top window of the Task to find the correct
      window on which the callback will be called.

  - Introduce a Builder for BackNavigationInfo
    - This reduces the number of variable needed outside the synchonized
    block.
    - It also reduces the number of early return of BackNavigationInfo
    instances

  - Adding log messages to help further debug the method.

Test: BackNavigationControllerTests
Test: Manual dismiss of SystemUi dialog in QS
Bug: 216604581
Fixes: 221458292
Change-Id: I9ba2c7f89956f34d6338824502c210b3e58dc076

Introduce builder for BackNavigationInfo

Change-Id: I14b4a4b3abc8f417998b7b32831cb3d5c4faa491

3 files changed, 108 insertions, 8 deletions

diff --git a/core/java/android/view/ViewRootImpl.java b/core/java/android/view/ViewRootImpl.java
index 172cd03900e7..17e3914ab24b 100644
--- a/core/java/android/view/ViewRootImpl.java
+++ b/core/java/android/view/ViewRootImpl.java
@@ -147,6 +147,7 @@ import android.os.SystemProperties;
 import android.os.Trace;
 import android.os.UserHandle;
 import android.sysprop.DisplayProperties;
+import android.text.TextUtils;
 import android.util.AndroidRuntimeException;
 import android.util.DisplayMetrics;
 import android.util.EventLog;
@@ -10885,6 +10886,12 @@ public final class ViewRootImpl implements ViewParent,
      * {@link OnBackInvokedCallback} to be called to the server.
      */
     private void registerBackCallbackOnWindow() {
+        if (OnBackInvokedDispatcher.DEBUG) {
+            Log.d(OnBackInvokedDispatcher.TAG, TextUtils.formatSimple(
+                    "ViewRootImpl.registerBackCallbackOnWindow. Callback:%s Package:%s "
+                            + "IWindow:%s Session:%s",
+                    mOnBackInvokedDispatcher, mBasePackageName, mWindow, mWindowSession));
+        }
         mOnBackInvokedDispatcher.attachToWindow(mWindowSession, mWindow);
     }
 
diff --git a/core/java/android/window/BackNavigationInfo.java b/core/java/android/window/BackNavigationInfo.java
index 6653758e6c50..0ab6db58ab4b 100644
--- a/core/java/android/window/BackNavigationInfo.java
+++ b/core/java/android/window/BackNavigationInfo.java
@@ -81,7 +81,9 @@ public final class BackNavigationInfo implements Parcelable {
             TYPE_DIALOG_CLOSE,
             TYPE_RETURN_TO_HOME,
             TYPE_CROSS_ACTIVITY,
-            TYPE_CROSS_TASK})
+            TYPE_CROSS_TASK,
+            TYPE_CALLBACK
+    })
     @interface BackTargetType {
     }
 
@@ -121,8 +123,8 @@ public final class BackNavigationInfo implements Parcelable {
             @Nullable SurfaceControl screenshotSurface,
             @Nullable HardwareBuffer screenshotBuffer,
             @Nullable WindowConfiguration taskWindowConfiguration,
-            @NonNull RemoteCallback onBackNavigationDone,
-            @NonNull IOnBackInvokedCallback onBackInvokedCallback) {
+            @Nullable RemoteCallback onBackNavigationDone,
+            @Nullable IOnBackInvokedCallback onBackInvokedCallback) {
         mType = type;
         mDepartingAnimationTarget = departingAnimationTarget;
         mScreenshotSurface = screenshotSurface;
@@ -278,7 +280,98 @@ public final class BackNavigationInfo implements Parcelable {
                 return "TYPE_CROSS_ACTIVITY";
             case TYPE_CROSS_TASK:
                 return "TYPE_CROSS_TASK";
+            case TYPE_CALLBACK:
+                return "TYPE_CALLBACK";
         }
         return String.valueOf(type);
     }
+
+    /**
+     * @hide
+     */
+    @SuppressWarnings("UnusedReturnValue") // Builder pattern
+    public static class Builder {
+
+        private int mType = TYPE_UNDEFINED;
+        @Nullable
+        private RemoteAnimationTarget mDepartingAnimationTarget = null;
+        @Nullable
+        private SurfaceControl mScreenshotSurface = null;
+        @Nullable
+        private HardwareBuffer mScreenshotBuffer = null;
+        @Nullable
+        private WindowConfiguration mTaskWindowConfiguration = null;
+        @Nullable
+        private RemoteCallback mOnBackNavigationDone = null;
+        @Nullable
+        private IOnBackInvokedCallback mOnBackInvokedCallback = null;
+
+        /**
+         * @see BackNavigationInfo#getType()
+         */
+        public Builder setType(@BackTargetType int type) {
+            mType = type;
+            return this;
+        }
+
+        /**
+         * @see BackNavigationInfo#getDepartingAnimationTarget
+         */
+        public Builder setDepartingAnimationTarget(
+                @Nullable RemoteAnimationTarget departingAnimationTarget) {
+            mDepartingAnimationTarget = departingAnimationTarget;
+            return this;
+        }
+
+        /**
+         * @see BackNavigationInfo#getScreenshotSurface
+         */
+        public Builder setScreenshotSurface(@Nullable SurfaceControl screenshotSurface) {
+            mScreenshotSurface = screenshotSurface;
+            return this;
+        }
+
+        /**
+         * @see BackNavigationInfo#getScreenshotHardwareBuffer()
+         */
+        public Builder setScreenshotBuffer(@Nullable HardwareBuffer screenshotBuffer) {
+            mScreenshotBuffer = screenshotBuffer;
+            return this;
+        }
+
+        /**
+         * @see BackNavigationInfo#getTaskWindowConfiguration
+         */
+        public Builder setTaskWindowConfiguration(
+                @Nullable WindowConfiguration taskWindowConfiguration) {
+            mTaskWindowConfiguration = taskWindowConfiguration;
+            return this;
+        }
+
+        /**
+         * @see BackNavigationInfo#onBackNavigationFinished(boolean)
+         */
+        public Builder setOnBackNavigationDone(@Nullable RemoteCallback onBackNavigationDone) {
+            mOnBackNavigationDone = onBackNavigationDone;
+            return this;
+        }
+
+        /**
+         * @see BackNavigationInfo#getOnBackInvokedCallback
+         */
+        public Builder setOnBackInvokedCallback(
+                @Nullable IOnBackInvokedCallback onBackInvokedCallback) {
+            mOnBackInvokedCallback = onBackInvokedCallback;
+            return this;
+        }
+
+        /**
+         * Builds and returns an instance of {@link BackNavigationInfo}
+         */
+        public BackNavigationInfo build() {
+            return new BackNavigationInfo(mType, mDepartingAnimationTarget, mScreenshotSurface,
+                    mScreenshotBuffer, mTaskWindowConfiguration, mOnBackNavigationDone,
+                    mOnBackInvokedCallback);
+        }
+    }
 }
diff --git a/core/java/android/window/ProxyOnBackInvokedDispatcher.java b/core/java/android/window/ProxyOnBackInvokedDispatcher.java
index 2b2f5e945710..eb776310b8bb 100644
--- a/core/java/android/window/ProxyOnBackInvokedDispatcher.java
+++ b/core/java/android/window/ProxyOnBackInvokedDispatcher.java
@@ -73,7 +73,7 @@ public class ProxyOnBackInvokedDispatcher implements OnBackInvokedDispatcher {
     public void unregisterOnBackInvokedCallback(
             @NonNull OnBackInvokedCallback callback) {
         if (DEBUG) {
-            Log.v(TAG, String.format("Pending unregister %s. Actual=%s", callback,
+            Log.v(TAG, String.format("Proxy unregister %s. Actual=%s", callback,
                     mActualDispatcherOwner));
         }
         synchronized (mLock) {
@@ -109,8 +109,8 @@ public class ProxyOnBackInvokedDispatcher implements OnBackInvokedDispatcher {
         OnBackInvokedDispatcher dispatcher =
                 mActualDispatcherOwner.getOnBackInvokedDispatcher();
         if (DEBUG) {
-            Log.v(TAG, String.format("Pending transferring %d callbacks to %s", mCallbacks.size(),
-                    dispatcher));
+            Log.v(TAG, String.format("Proxy: transferring %d pending callbacks to %s",
+                    mCallbacks.size(), dispatcher));
         }
         for (Pair<OnBackInvokedCallback, Integer> callbackPair : mCallbacks) {
             int priority = callbackPair.second;
@@ -144,7 +144,7 @@ public class ProxyOnBackInvokedDispatcher implements OnBackInvokedDispatcher {
      */
     public void reset() {
         if (DEBUG) {
-            Log.v(TAG, "Pending reset callbacks");
+            Log.v(TAG, "Proxy: reset callbacks");
         }
         synchronized (mLock) {
             mCallbacks.clear();
@@ -165,7 +165,7 @@ public class ProxyOnBackInvokedDispatcher implements OnBackInvokedDispatcher {
     public void setActualDispatcherOwner(
             @Nullable OnBackInvokedDispatcherOwner actualDispatcherOwner) {
         if (DEBUG) {
-            Log.v(TAG, String.format("Pending setActual %s. Current %s",
+            Log.v(TAG, String.format("Proxy setActual %s. Current %s",
                             actualDispatcherOwner, mActualDispatcherOwner));
         }
         synchronized (mLock) {