Fixes concurrent display test flakiness am: c3b80dc70b

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/22656860

Change-Id: I3deee71a0e007a5e59cddfe8fb1d5e697753bbeb
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

libs/WindowManager/Jetpack/src/androidx/window/extensions/area/RearDisplayPresentationController.java

@@ -20,9 +20,6 @@ import static androidx.window.extensions.area.WindowAreaComponent.SESSION_STATE_
 import static androidx.window.extensions.area.WindowAreaComponent.SESSION_STATE_INACTIVE;
 
 import android.content.Context;
-import android.hardware.devicestate.DeviceStateRequest;
-import android.hardware.display.DisplayManager;
-import android.util.Log;
 import android.view.Display;
 
 import androidx.annotation.NonNull;
@@ -32,17 +29,12 @@ import androidx.window.extensions.core.util.function.Consumer;
 import java.util.Objects;
 
 /**
- * Controller class that keeps track of the status of the device state request
- * to enable the rear display presentation feature. This controller notifies the session callback
- * when the state request is active, and notifies the callback when the request is canceled.
- *
- * Clients are notified via {@link Consumer} provided with
- * {@link androidx.window.extensions.area.WindowAreaComponent.WindowAreaStatus} values to signify
- * when the request becomes active and cancelled.
+ * Controller class that manages the creation of the {@link android.app.Presentation} object used
+ * to show content on the rear facing display. This controller notifies the session callback with
+ * {@link androidx.window.extensions.area.WindowAreaComponent.WindowAreaStatus} values when the
+ * feature is active, or when the feature has been ended.
  */
-class RearDisplayPresentationController implements DeviceStateRequest.Callback {
-
-    private static final String TAG = "RearDisplayPresentationController";
+class RearDisplayPresentationController {
 
     // Original context that requested to enable rear display presentation mode
     @NonNull
@@ -51,8 +43,6 @@ class RearDisplayPresentationController implements DeviceStateRequest.Callback {
     private final Consumer<@WindowAreaComponent.WindowAreaSessionState Integer> mStateConsumer;
     @Nullable
     private ExtensionWindowAreaPresentation mExtensionWindowAreaPresentation;
-    @NonNull
-    private final DisplayManager mDisplayManager;
 
     /**
      * Creates the RearDisplayPresentationController
@@ -71,25 +61,15 @@ class RearDisplayPresentationController implements DeviceStateRequest.Callback {
 
         mContext = context;
         mStateConsumer = stateConsumer;
-        mDisplayManager = context.getSystemService(DisplayManager.class);
     }
 
-    @Override
-    public void onRequestActivated(@NonNull DeviceStateRequest request) {
-        Display[] rearDisplays = mDisplayManager.getDisplays(DisplayManager.DISPLAY_CATEGORY_REAR);
-        if (rearDisplays.length == 0) {
-            mStateConsumer.accept(SESSION_STATE_INACTIVE);
-            Log.e(TAG, "Rear display list should not be empty");
-            return;
-        }
-
+    public void startSession(@NonNull Display rearDisplay) {
         mExtensionWindowAreaPresentation =
-                new RearDisplayPresentation(mContext, rearDisplays[0], mStateConsumer);
+                new RearDisplayPresentation(mContext, rearDisplay, mStateConsumer);
         mStateConsumer.accept(SESSION_STATE_ACTIVE);
     }
 
-    @Override
-    public void onRequestCanceled(@NonNull DeviceStateRequest request) {
+    public void endSession() {
         mStateConsumer.accept(SESSION_STATE_INACTIVE);
     }
 

libs/WindowManager/Jetpack/src/androidx/window/extensions/area/RearDisplayPresentationRequestCallback.java

@@ -0,0 +1,115 @@
+/*
+ * Copyright (C) 2023 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 androidx.window.extensions.area;
+
+import android.content.Context;
+import android.hardware.devicestate.DeviceStateRequest;
+import android.hardware.display.DisplayManager;
+import android.view.Display;
+
+import androidx.annotation.NonNull;
+
+/**
+ * Callback class to be notified of updates to a {@link DeviceStateRequest} for the rear display
+ * presentation state. This class notifies the {@link RearDisplayPresentationController} when the
+ * device is ready to enable the rear display presentation feature.
+ */
+public class RearDisplayPresentationRequestCallback implements DeviceStateRequest.Callback {
+
+    private static final String TAG = RearDisplayPresentationRequestCallback.class.getSimpleName();
+
+    @NonNull
+    private final DisplayManager mDisplayManager;
+    @NonNull
+    private final DisplayManager.DisplayListener mRearDisplayListener = new RearDisplayListener();
+    @NonNull
+    private final RearDisplayPresentationController mRearDisplayPresentationController;
+    private boolean mWaitingForRearDisplay = false;
+
+    public RearDisplayPresentationRequestCallback(@NonNull Context context,
+            @NonNull RearDisplayPresentationController rearDisplayPresentationController) {
+        mDisplayManager = context.getSystemService(DisplayManager.class);
+        mDisplayManager.registerDisplayListener(mRearDisplayListener,
+                context.getMainThreadHandler(), DisplayManager.EVENT_FLAG_DISPLAY_ADDED
+                        | DisplayManager.EVENT_FLAG_DISPLAY_CHANGED);
+
+        mRearDisplayPresentationController = rearDisplayPresentationController;
+    }
+
+    @Override
+    public void onRequestActivated(@NonNull DeviceStateRequest request) {
+        Display[] rearDisplays = mDisplayManager.getDisplays(DisplayManager.DISPLAY_CATEGORY_REAR);
+        if (rearDisplays.length == 0) {
+            // No rear facing display found, marking waiting for display flag as true.
+            mWaitingForRearDisplay = true;
+            return;
+        }
+        mDisplayManager.unregisterDisplayListener(mRearDisplayListener);
+        mRearDisplayPresentationController.startSession(rearDisplays[0]);
+    }
+
+    @Override
+    public void onRequestCanceled(@NonNull DeviceStateRequest request) {
+        mDisplayManager.unregisterDisplayListener(mRearDisplayListener);
+        mRearDisplayPresentationController.endSession();
+    }
+
+    /**
+     * {@link DisplayManager.DisplayListener} to be used if a rear facing {@link Display} isn't
+     * available synchronously when the device is entered into the rear display presentation state.
+     * A rear facing {@link Display} is a {@link Display} that is categorized as
+     * {@link DisplayManager#DISPLAY_CATEGORY_REAR}. This can occur if {@link DisplayManager} is
+     * still in the process of configuring itself for this state when
+     * {@link DeviceStateRequest.Callback#onRequestActivated} is called.
+     *
+     * The {@link DisplayManager.DisplayListener} removes itself when a rear facing display is
+     * found.
+     */
+    private class RearDisplayListener implements DisplayManager.DisplayListener {
+        @Override
+        public void onDisplayAdded(int displayId) {
+            Display display = mDisplayManager.getDisplay(displayId);
+            if (mWaitingForRearDisplay && (display.getFlags() & Display.FLAG_REAR) != 0) {
+                startRearDisplayPresentation(display);
+            }
+        }
+
+        @Override
+        public void onDisplayRemoved(int displayId) {}
+
+        @Override
+        public void onDisplayChanged(int displayId) {
+            Display display = mDisplayManager.getDisplay(displayId);
+            if (mWaitingForRearDisplay && (display.getFlags() & Display.FLAG_REAR) != 0) {
+                startRearDisplayPresentation(display);
+            }
+        }
+
+        /**
+         * Starts a new {@link RearDisplayPresentation} with the updated {@link Display} with a
+         * category of {@link DisplayManager#DISPLAY_CATEGORY_REAR}.
+         */
+        private void startRearDisplayPresentation(Display rearDisplay) {
+            // We have been notified of a change to a rear display, we can unregister the
+            // callback and stop waiting for a display
+            mDisplayManager.unregisterDisplayListener(this);
+            mWaitingForRearDisplay = false;
+
+            mRearDisplayPresentationController.startSession(rearDisplay);
+        }
+    }
+}

libs/WindowManager/Jetpack/src/androidx/window/extensions/area/WindowAreaComponentImpl.java

@@ -337,13 +337,15 @@ public class WindowAreaComponentImpl implements WindowAreaComponent,
                             consumer.accept(stateStatus);
                         }
                     });
-
+            RearDisplayPresentationRequestCallback deviceStateCallback =
+                    new RearDisplayPresentationRequestCallback(activity,
+                            mRearDisplayPresentationController);
             DeviceStateRequest concurrentDisplayStateRequest = DeviceStateRequest.newBuilder(
                     mConcurrentDisplayState).build();
             mDeviceStateManager.requestState(
                     concurrentDisplayStateRequest,
                     mExecutor,
-                    mRearDisplayPresentationController
+                    deviceStateCallback
             );
         }
     }