Add listeners for the creation and destruction of virtual displays.

This will be used later by VibrationSettings to keep record of active
virtual displays.

Test: VirtualDeviceManagerServiceTest

bug:189474679

Change-Id: I8d39dccc194cac7aab08446fbdeea2ded7e1030f

services/companion/java/com/android/server/companion/virtual/VirtualDeviceManagerService.java

@@ -56,6 +56,7 @@ import com.android.server.wm.ActivityTaskManagerInternal;
 
 import java.io.FileDescriptor;
 import java.io.PrintWriter;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.ConcurrentHashMap;
 
@@ -208,6 +209,10 @@ public class VirtualDeviceManagerService extends SystemService {
     }
 
     @VisibleForTesting
+    VirtualDeviceManagerInternal getLocalServiceInstance() {
+        return mLocalService;
+    }
+
     class VirtualDeviceManagerImpl extends IVirtualDeviceManager.Stub implements
             VirtualDeviceImpl.PendingTrampolineCallback {
 
@@ -308,10 +313,11 @@ public class VirtualDeviceManagerService extends SystemService {
             final long tokenTwo = Binder.clearCallingIdentity();
             try {
                 virtualDeviceImpl.onVirtualDisplayCreatedLocked(gwpc, displayId);
-                return displayId;
             } finally {
                 Binder.restoreCallingIdentity(tokenTwo);
             }
+            mLocalService.onVirtualDisplayCreated(displayId);
+            return displayId;
         }
 
         @Nullable
@@ -378,6 +384,10 @@ public class VirtualDeviceManagerService extends SystemService {
     }
 
     private final class LocalService extends VirtualDeviceManagerInternal {
+        @GuardedBy("mVirtualDeviceManagerLock")
+        private final ArrayList<VirtualDeviceManagerInternal.VirtualDisplayListener>
+                mVirtualDisplayListeners = new ArrayList<>();
+
         @Override
         public boolean isValidVirtualDevice(IVirtualDevice virtualDevice) {
             synchronized (mVirtualDeviceManagerLock) {
@@ -385,11 +395,31 @@ public class VirtualDeviceManagerService extends SystemService {
             }
         }
 
+        @Override
+        public void onVirtualDisplayCreated(int displayId) {
+            final VirtualDisplayListener[] listeners;
+            synchronized (mVirtualDeviceManagerLock) {
+                listeners = mVirtualDisplayListeners.toArray(new VirtualDisplayListener[0]);
+            }
+            mHandler.post(() -> {
+                for (VirtualDisplayListener listener : listeners) {
+                    listener.onVirtualDisplayCreated(displayId);
+                }
+            });
+        }
+
         @Override
         public void onVirtualDisplayRemoved(IVirtualDevice virtualDevice, int displayId) {
+            final VirtualDisplayListener[] listeners;
             synchronized (mVirtualDeviceManagerLock) {
                 ((VirtualDeviceImpl) virtualDevice).onVirtualDisplayRemovedLocked(displayId);
+                listeners = mVirtualDisplayListeners.toArray(new VirtualDisplayListener[0]);
             }
+            mHandler.post(() -> {
+                for (VirtualDisplayListener listener : listeners) {
+                    listener.onVirtualDisplayRemoved(displayId);
+                }
+            });
         }
 
         @Override
@@ -435,6 +465,22 @@ public class VirtualDeviceManagerService extends SystemService {
             }
             return false;
         }
+
+        @Override
+        public void registerVirtualDisplayListener(
+                @NonNull VirtualDisplayListener listener) {
+            synchronized (mVirtualDeviceManagerLock) {
+                mVirtualDisplayListeners.add(listener);
+            }
+        }
+
+        @Override
+        public void unregisterVirtualDisplayListener(
+                @NonNull VirtualDisplayListener listener) {
+            synchronized (mVirtualDeviceManagerLock) {
+                mVirtualDisplayListeners.remove(listener);
+            }
+        }
     }
 
     private static final class PendingTrampolineMap {

services/core/java/com/android/server/companion/virtual/VirtualDeviceManagerInternal.java

@@ -16,6 +16,7 @@
 
 package com.android.server.companion.virtual;
 
+import android.annotation.NonNull;
 import android.companion.virtual.IVirtualDevice;
 
 /**
@@ -24,16 +25,41 @@ import android.companion.virtual.IVirtualDevice;
  */
 public abstract class VirtualDeviceManagerInternal {
 
+    /** Interface to listen to the creation and destruction of virtual displays. */
+    public interface VirtualDisplayListener {
+        /** Notifies that a virtual display was created. */
+        void onVirtualDisplayCreated(int displayId);
+
+        /** Notifies that a virtual display was removed. */
+        void onVirtualDisplayRemoved(int displayId);
+    }
+
+    /** Register a listener for the creation and destruction of virtual displays. */
+    public abstract void registerVirtualDisplayListener(
+            @NonNull VirtualDisplayListener listener);
+
+    /** Unregister a listener for the creation and  destruction of virtual displays. */
+    public abstract void unregisterVirtualDisplayListener(
+            @NonNull VirtualDisplayListener listener);
+
+
     /**
      * Validate the virtual device.
      */
     public abstract boolean isValidVirtualDevice(IVirtualDevice virtualDevice);
 
     /**
-     * Notify a virtual display is removed.
+     * Notifies that a virtual display is created.
+     *
+     * @param displayId The display id of the created virtual display.
+     */
+    public abstract void onVirtualDisplayCreated(int displayId);
+
+    /**
+     * Notifies that a virtual display is removed.
      *
      * @param virtualDevice The virtual device where the virtual display located.
-     * @param displayId The display id of the removed virtual display.
+     * @param displayId     The display id of the removed virtual display.
      */
     public abstract void onVirtualDisplayRemoved(IVirtualDevice virtualDevice, int displayId);
 

services/tests/servicestests/src/com/android/server/companion/virtual/VirtualDeviceManagerServiceTest.java

@@ -124,6 +124,8 @@ public class VirtualDeviceManagerServiceTest {
     private VirtualDeviceImpl mDeviceImpl;
     private InputController mInputController;
     private AssociationInfo mAssociationInfo;
+    private VirtualDeviceManagerService mVdms;
+    private VirtualDeviceManagerInternal mLocalService;
     @Mock
     private InputController.NativeWrapper mNativeWrapperMock;
     @Mock
@@ -139,6 +141,8 @@ public class VirtualDeviceManagerServiceTest {
     @Mock
     private Consumer<ArraySet<Integer>> mRunningAppsChangedCallback;
     @Mock
+    private VirtualDeviceManagerInternal.VirtualDisplayListener mDisplayListener;
+    @Mock
     IPowerManager mIPowerManagerMock;
     @Mock
     IThermalService mIThermalServiceMock;
@@ -215,6 +219,9 @@ public class VirtualDeviceManagerServiceTest {
         mAssociationInfo = new AssociationInfo(1, 0, null,
                 MacAddress.BROADCAST_ADDRESS, "", null, true, false, false, 0, 0);
 
+        mVdms = new VirtualDeviceManagerService(mContext);
+        mLocalService = mVdms.getLocalServiceInstance();
+
         VirtualDeviceParams params = new VirtualDeviceParams
                 .Builder()
                 .setBlockedActivities(getBlockedActivities())
@@ -234,6 +241,28 @@ public class VirtualDeviceManagerServiceTest {
         mDeviceImpl.onVirtualDisplayRemovedLocked(DISPLAY_ID);
     }
 
+    @Test
+    public void onVirtualDisplayCreatedLocked_listenersNotified() throws RemoteException {
+        mLocalService.registerVirtualDisplayListener(mDisplayListener);
+
+        mLocalService.onVirtualDisplayCreated(DISPLAY_ID);
+        TestableLooper.get(this).processAllMessages();
+
+        verify(mDisplayListener).onVirtualDisplayCreated(DISPLAY_ID);
+    }
+
+    @Test
+    public void onVirtualDisplayRemovedLocked_listenersNotified() throws RemoteException {
+        mLocalService.registerVirtualDisplayListener(mDisplayListener);
+        mDeviceImpl.onVirtualDisplayCreatedLocked(
+                mDeviceImpl.createWindowPolicyController(), DISPLAY_ID);
+
+        mLocalService.onVirtualDisplayRemoved(mDeviceImpl, DISPLAY_ID);
+        TestableLooper.get(this).processAllMessages();
+
+        verify(mDisplayListener).onVirtualDisplayRemoved(DISPLAY_ID);
+    }
+
     @Test
     public void onVirtualDisplayCreatedLocked_wakeLockIsAcquired() throws RemoteException {
         verify(mIPowerManagerMock, never()).acquireWakeLock(any(Binder.class), anyInt(),