Add a listener to know when the list of root views changes. (f8d9ad19) · Commits · e / os / android_frameworks_base

core/api/current.txt

+2 −0

Original line number	Diff line number	Diff line
		@@ -58287,7 +58287,9 @@ package android.view.inspector {
		}

		public final class WindowInspector {
		method @FlaggedApi("android.view.flags.root_view_changed_listener") public static void addGlobalWindowViewsListener(@NonNull java.util.concurrent.Executor, @NonNull java.util.function.Consumer<java.util.List<android.view.View>>);
		method @NonNull public static java.util.List<android.view.View> getGlobalWindowViews();
		method @FlaggedApi("android.view.flags.root_view_changed_listener") public static void removeGlobalWindowViewsListener(@NonNull java.util.function.Consumer<java.util.List<android.view.View>>);
		}

		}

core/java/android/view/ListenerWrapper.java

0 → 100644

+56 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2025 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 android.view;

		import android.annotation.NonNull;

		import java.util.Objects;
		import java.util.concurrent.Executor;
		import java.util.function.Consumer;

		/**
		* A utilty class to bundle a {@link Consumer} and an {@link Executor}
		* @param <T> the type of value to be reported.
		* @hide
		*/
		public class ListenerWrapper<T> {

		@NonNull
		private final Consumer<T> mConsumer;
		@NonNull
		private final Executor mExecutor;

		public ListenerWrapper(@NonNull Executor executor, @NonNull Consumer<T> consumer) {
		mExecutor = Objects.requireNonNull(executor);
		mConsumer = Objects.requireNonNull(consumer);
		}

		/**
		* Relays the new value to the {@link Consumer} using the {@link Executor}
		*/
		public void accept(@NonNull T value) {
		mExecutor.execute(() -> mConsumer.accept(value));
		}

		/**
		* Returns {@code true} if the consumer matches the one provided in the constructor,
		* {@code false} otherwise.
		*/
		public boolean isConsumerSame(@NonNull Consumer<T> consumer) {
		return mConsumer.equals(consumer);
		}
		}

core/java/android/view/WindowManagerGlobal.java

+33 −0

Original line number	Diff line number	Diff line
		@@ -44,6 +44,7 @@ import android.util.Log;
		import android.util.Pair;
		import android.util.SparseArray;
		import android.view.inputmethod.InputMethodManager;
		import android.view.translation.ListenerGroup;
		import android.window.ITrustedPresentationListener;
		import android.window.InputTransferToken;
		import android.window.TrustedPresentationThresholds;
		@@ -58,6 +59,7 @@ import java.io.FileOutputStream;
		import java.io.PrintWriter;
		import java.lang.ref.WeakReference;
		import java.util.ArrayList;
		import java.util.List;
		import java.util.WeakHashMap;
		import java.util.concurrent.Executor;
		import java.util.function.Consumer;
		@@ -147,6 +149,12 @@ public final class WindowManagerGlobal {

		@UnsupportedAppUsage
		private final ArrayList<View> mViews = new ArrayList<View>();
		/**
		* The {@link ListenerGroup} that is associated to {@link #mViews}.
		* @hide
		*/
		@GuardedBy("mLock")
		private final ListenerGroup<List<View>> mWindowViewsListenerGroup = new ListenerGroup<>();
		@UnsupportedAppUsage
		private final ArrayList<ViewRootImpl> mRoots = new ArrayList<ViewRootImpl>();
		@UnsupportedAppUsage
		@@ -319,6 +327,29 @@ public final class WindowManagerGlobal {
		}
		}

		/**
		* Adds a listener that will be notified whenever {@link #getWindowViews()} changes. The
		* current value is provided immediately. If it was registered previously then this is ano op.
		*/
		public void addWindowViewsListener(@NonNull Executor executor,
		@NonNull Consumer<List<View>> consumer) {
		synchronized (mLock) {
		mWindowViewsListenerGroup.addListener(executor, consumer);
		mWindowViewsListenerGroup.accept(getWindowViews());
		}
		}

		/**
		* Removes a listener that was registered in
		* {@link #addWindowViewsListener(Executor, Consumer)}. If it was not registered previously,
		* then this is a no op.
		*/
		public void removeWindowViewsListener(@NonNull Consumer<List<View>> consumer) {
		synchronized (mLock) {
		mWindowViewsListenerGroup.removeListener(consumer);
		}
		}

		public View getWindowView(IBinder windowToken) {
		synchronized (mLock) {
		final int numViews = mViews.size();
		@@ -454,6 +485,7 @@ public final class WindowManagerGlobal {
		// do this last because it fires off messages to start doing things
		try {
		root.setView(view, wparams, panelParentView, userId);
		mWindowViewsListenerGroup.accept(getWindowViews());
		} catch (RuntimeException e) {
		Log.e(TAG, "Couldn't add view: " + view, e);
		final int viewIndex = (index >= 0) ? index : (mViews.size() - 1);
		@@ -575,6 +607,7 @@ public final class WindowManagerGlobal {
		mDyingViews.remove(view);
		}
		allViewsRemoved = mRoots.isEmpty();
		mWindowViewsListenerGroup.accept(getWindowViews());
		}

		// If we don't have any views anymore in our process, we no longer need the

core/java/android/view/flags/view_flags.aconfig

+8 −0

Original line number	Diff line number	Diff line
		@@ -159,3 +159,11 @@ flag {
		bug: "364653005"
		is_fixed_read_only: true
		}

		flag {
		name: "root_view_changed_listener"
		namespace: "windowing_sdk"
		description: "Implement listener pattern for WindowInspector#getGlobalWindowViews."
		bug: "394397033"
		is_fixed_read_only: false
		}

core/java/android/view/inspector/WindowInspector.java

+24 −0

Original line number	Diff line number	Diff line
		@@ -16,11 +16,14 @@

		package android.view.inspector;

		import android.annotation.FlaggedApi;
		import android.annotation.NonNull;
		import android.view.View;
		import android.view.WindowManagerGlobal;

		import java.util.List;
		import java.util.concurrent.Executor;
		import java.util.function.Consumer;

		/**
		* Provides access to window inspection information.
		@@ -37,4 +40,25 @@ public final class WindowInspector {
		public static List<View> getGlobalWindowViews() {
		return WindowManagerGlobal.getInstance().getWindowViews();
		}

		/**
		* Adds a listener that is notified whenever the list of global window views changes. If a
		* {@link Consumer} is already registered this method is a no op.
		* @see #getGlobalWindowViews()
		*/
		@FlaggedApi(android.view.flags.Flags.FLAG_ROOT_VIEW_CHANGED_LISTENER)
		public static void addGlobalWindowViewsListener(@NonNull Executor executor,
		@NonNull Consumer<List<View>> consumer) {
		WindowManagerGlobal.getInstance().addWindowViewsListener(executor, consumer);
		}

		/**
		* Removes a listener from getting notifications of global window views changes. If the
		* {@link Consumer} is not registered this method is a no op.
		* @see #addGlobalWindowViewsListener(Executor, Consumer)
		*/
		@FlaggedApi(android.view.flags.Flags.FLAG_ROOT_VIEW_CHANGED_LISTENER)
		public static void removeGlobalWindowViewsListener(@NonNull Consumer<List<View>> consumer) {
		WindowManagerGlobal.getInstance().removeWindowViewsListener(consumer);
		}
		}