Implement OnBackInvokedDispatcher (54b9c9d6) · Commits · e / os / android_frameworks_base

core/java/android/view/IWindowSession.aidl

+9 −0

Original line number	Diff line number	Diff line
		@@ -37,6 +37,7 @@ import android.view.Surface;
		import android.view.SurfaceControl;
		import android.view.SurfaceControl.Transaction;
		import android.window.ClientWindowFrames;
		import android.window.IOnBackInvokedCallback;

		import java.util.List;

		@@ -328,4 +329,12 @@ interface IWindowSession {
		*/
		oneway void generateDisplayHash(IWindow window, in Rect boundsInWindow,
		in String hashAlgorithm, in RemoteCallback callback);

		/**
		* Sets the {@link IOnBackInvokedCallback} to be invoked for a window when back is triggered.
		*
		* @param window The token for the window to set the callback to.
		* @param callback The {@link IOnBackInvokedCallback} to set.
		*/
		oneway void setOnBackInvokedCallback(IWindow window, IOnBackInvokedCallback callback);
		}

core/java/android/view/WindowlessWindowManager.java

+5 −0

Original line number	Diff line number	Diff line
		@@ -28,6 +28,7 @@ import android.os.RemoteException;
		import android.util.Log;
		import android.util.MergedConfiguration;
		import android.window.ClientWindowFrames;
		import android.window.IOnBackInvokedCallback;

		import java.util.HashMap;
		import java.util.Objects;
		@@ -495,6 +496,10 @@ public class WindowlessWindowManager implements IWindowSession {
		RemoteCallback callback) {
		}

		@Override
		public void setOnBackInvokedCallback(IWindow iWindow,
		IOnBackInvokedCallback iOnBackInvokedCallback) throws RemoteException { }

		@Override
		public boolean dropForAccessibility(IWindow window, int x, int y) {
		return false;

core/java/android/window/IOnBackInvokedCallback.aidl

0 → 100644

+55 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2021 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.window;

		/**
		* Interface that wraps a {@link OnBackInvokedCallback} object, to be stored in window manager
		* and called from back handling process when back is invoked.
		*
		* @hide
		*/
		oneway interface IOnBackInvokedCallback {
		/**
		* Called when a back gesture has been started, or back button has been pressed down.
		* Wraps {@link OnBackInvokedCallback#onBackStarted()}.
		*/
		void onBackStarted();

		/**
		* Called on back gesture progress.
		* Wraps {@link OnBackInvokedCallback#onBackProgressed()}.
		*
		* @param touchX Absolute X location of the touch point.
		* @param touchY Absolute Y location of the touch point.
		* @param progress Value between 0 and 1 on how far along the back gesture is.
		*/
		void onBackProgressed(int touchX, int touchY, float progress);

		/**
		* Called when a back gesture or back button press has been cancelled.
		* Wraps {@link OnBackInvokedCallback#onBackCancelled()}.
		*/
		void onBackCancelled();

		/**
		* Called when a back gesture has been completed and committed, or back button pressed
		* has been released and committed.
		* Wraps {@link OnBackInvokedCallback#onBackInvoked()}.
		*/
		void onBackInvoked();
		}

core/java/android/window/WindowOnBackInvokedDispatcher.java

+132 −6

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		@@ -17,11 +17,19 @@
		package android.window;

		import android.annotation.NonNull;
		import android.annotation.Nullable;
		import android.os.Handler;
		import android.os.RemoteException;
		import android.util.Log;
		import android.view.IWindow;
		import android.view.IWindowSession;
		import android.view.OnBackInvokedCallback;
		import android.view.OnBackInvokedDispatcher;

		import java.util.ArrayList;
		import java.util.HashMap;
		import java.util.TreeMap;

		/**
		* Provides window based implementation of {@link OnBackInvokedDispatcher}.
		*
		@@ -39,6 +47,18 @@ import android.view.OnBackInvokedDispatcher;
		public class WindowOnBackInvokedDispatcher extends OnBackInvokedDispatcher {
		private IWindowSession mWindowSession;
		private IWindow mWindow;
		private static final String TAG = "WindowOnBackDispatcher";
		private static final boolean DEBUG = false;

		/** The currently most prioritized callback. */
		@Nullable
		private OnBackInvokedCallbackWrapper mTopCallback;

		/** Convenience hashmap to quickly decide if a callback has been added. */
		private final HashMap<OnBackInvokedCallback, Integer> mAllCallbacks = new HashMap<>();
		/** Holds all callbacks by priorities. */
		private final TreeMap<Integer, ArrayList<OnBackInvokedCallback>>
		mOnBackInvokedCallbacks = new TreeMap<>();

		/**
		* Sends the pending top callback (if one exists) to WM when the view root
		@@ -47,7 +67,9 @@ public class WindowOnBackInvokedDispatcher extends OnBackInvokedDispatcher {
		public void attachToWindow(@NonNull IWindowSession windowSession, @NonNull IWindow window) {
		mWindowSession = windowSession;
		mWindow = window;
		// TODO(b/209867448): Send the top callback to WM (if one exists).
		if (mTopCallback != null) {
		setTopOnBackInvokedCallback(mTopCallback);
		}
		}

		/** Detaches the dispatcher instance from its window. */
		@@ -56,20 +78,124 @@ public class WindowOnBackInvokedDispatcher extends OnBackInvokedDispatcher {
		mWindowSession = null;
		}

		// TODO: Take an Executor for the callback to run on.
		@Override
		public void registerOnBackInvokedCallback(
		@NonNull OnBackInvokedCallback callback, @Priority int priority) {
		// TODO(b/209867448): To be implemented.
		if (!mOnBackInvokedCallbacks.containsKey(priority)) {
		mOnBackInvokedCallbacks.put(priority, new ArrayList<>());
		}
		ArrayList<OnBackInvokedCallback> callbacks = mOnBackInvokedCallbacks.get(priority);

		// If callback has already been added, remove it and re-add it.
		if (mAllCallbacks.containsKey(callback)) {
		if (DEBUG) {
		Log.i(TAG, "Callback already added. Removing and re-adding it.");
		}
		Integer prevPriority = mAllCallbacks.get(callback);
		mOnBackInvokedCallbacks.get(prevPriority).remove(callback);
		}

		callbacks.add(callback);
		mAllCallbacks.put(callback, priority);
		if (mTopCallback == null \|\| (mTopCallback.getCallback() != callback
		&& mAllCallbacks.get(mTopCallback.getCallback()) <= priority)) {
		setTopOnBackInvokedCallback(new OnBackInvokedCallbackWrapper(callback, priority));
		}
		}

		@Override
		public void unregisterOnBackInvokedCallback(
		@NonNull OnBackInvokedCallback callback) {
		// TODO(b/209867448): To be implemented.
		public void unregisterOnBackInvokedCallback(@NonNull OnBackInvokedCallback callback) {
		if (!mAllCallbacks.containsKey(callback)) {
		if (DEBUG) {
		Log.i(TAG, "Callback not found. returning...");
		}
		return;
		}
		Integer priority = mAllCallbacks.get(callback);
		mOnBackInvokedCallbacks.get(priority).remove(callback);
		mAllCallbacks.remove(callback);
		if (mTopCallback != null && mTopCallback.getCallback() == callback) {
		findAndSetTopOnBackInvokedCallback();
		}
		}

		/** Clears all registered callbacks on the instance. */
		public void clear() {
		// TODO(b/209867448): To be implemented.
		mAllCallbacks.clear();
		mTopCallback = null;
		mOnBackInvokedCallbacks.clear();
		}

		/**
		* Iterates through all callbacks to find the most prioritized one and pushes it to
		* window manager.
		*/
		private void findAndSetTopOnBackInvokedCallback() {
		if (mAllCallbacks.isEmpty()) {
		setTopOnBackInvokedCallback(null);
		return;
		}

		for (Integer priority : mOnBackInvokedCallbacks.descendingKeySet()) {
		ArrayList<OnBackInvokedCallback> callbacks = mOnBackInvokedCallbacks.get(priority);
		if (!callbacks.isEmpty()) {
		OnBackInvokedCallbackWrapper callback = new OnBackInvokedCallbackWrapper(
		callbacks.get(callbacks.size() - 1), priority);
		setTopOnBackInvokedCallback(callback);
		return;
		}
		}
		setTopOnBackInvokedCallback(null);
		}

		// Pushes the top priority callback to window manager.
		private void setTopOnBackInvokedCallback(@Nullable OnBackInvokedCallbackWrapper callback) {
		mTopCallback = callback;
		if (mWindowSession == null \|\| mWindow == null) {
		return;
		}
		try {
		mWindowSession.setOnBackInvokedCallback(mWindow, mTopCallback);
		} catch (RemoteException e) {
		Log.e(TAG, "Failed to set OnBackInvokedCallback to WM. Error: " + e);
		}
		}

		private class OnBackInvokedCallbackWrapper extends IOnBackInvokedCallback.Stub {
		private final OnBackInvokedCallback mCallback;
		private final @Priority int mPriority;

		OnBackInvokedCallbackWrapper(
		@NonNull OnBackInvokedCallback callback, @Priority int priority) {
		mCallback = callback;
		mPriority = priority;
		}

		@NonNull
		public OnBackInvokedCallback getCallback() {
		return mCallback;
		}

		@Override
		public void onBackStarted() throws RemoteException {
		Handler.getMain().post(() -> mCallback.onBackStarted());
		}

		@Override
		public void onBackProgressed(int touchX, int touchY, float progress)
		throws RemoteException {
		Handler.getMain().post(() -> mCallback.onBackProgressed(touchX, touchY, progress));
		}

		@Override
		public void onBackCancelled() throws RemoteException {
		Handler.getMain().post(() -> mCallback.onBackCancelled());
		}

		@Override
		public void onBackInvoked() throws RemoteException {
		Handler.getMain().post(() -> mCallback.onBackInvoked());
		}
		}
		}

core/tests/coretests/src/android/window/WindowOnBackInvokedDispatcherTest.java

0 → 100644

+154 −0

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		/*
		* Copyright (C) 2021 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.window;

		import static org.mockito.ArgumentMatchers.isNull;
		import static org.mockito.Mockito.reset;
		import static org.mockito.Mockito.times;
		import static org.mockito.Mockito.verify;
		import static org.mockito.Mockito.verifyNoMoreInteractions;
		import static org.mockito.Mockito.verifyZeroInteractions;

		import android.os.RemoteException;
		import android.platform.test.annotations.Presubmit;
		import android.view.IWindow;
		import android.view.IWindowSession;
		import android.view.OnBackInvokedCallback;
		import android.view.OnBackInvokedDispatcher;

		import androidx.test.filters.SmallTest;
		import androidx.test.platform.app.InstrumentationRegistry;
		import androidx.test.runner.AndroidJUnit4;

		import org.junit.Before;
		import org.junit.Test;
		import org.junit.runner.RunWith;
		import org.mockito.ArgumentCaptor;
		import org.mockito.Mock;
		import org.mockito.Mockito;
		import org.mockito.MockitoAnnotations;

		/**
		* Tests for {@link WindowOnBackInvokedDispatcherTest}
		*
		* <p>Build/Install/Run:
		* atest FrameworksCoreTests:WindowOnBackInvokedDispatcherTest
		*/
		@RunWith(AndroidJUnit4.class)
		@SmallTest
		@Presubmit
		public class WindowOnBackInvokedDispatcherTest {
		@Mock
		private IWindowSession mWindowSession;
		@Mock
		private IWindow mWindow;
		private WindowOnBackInvokedDispatcher mDispatcher;
		@Mock
		private OnBackInvokedCallback mCallback1;
		@Mock
		private OnBackInvokedCallback mCallback2;

		@Before
		public void setUp() throws Exception {
		MockitoAnnotations.initMocks(this);
		mDispatcher = new WindowOnBackInvokedDispatcher();
		mDispatcher.attachToWindow(mWindowSession, mWindow);
		}

		private void waitForIdle() {
		InstrumentationRegistry.getInstrumentation().waitForIdleSync();
		}

		@Test
		public void propagatesTopCallback_samePriority() throws RemoteException {
		ArgumentCaptor<IOnBackInvokedCallback> captor =
		ArgumentCaptor.forClass(IOnBackInvokedCallback.class);

		mDispatcher.registerOnBackInvokedCallback(
		mCallback1, OnBackInvokedDispatcher.PRIORITY_DEFAULT);
		mDispatcher.registerOnBackInvokedCallback(
		mCallback2, OnBackInvokedDispatcher.PRIORITY_DEFAULT);

		verify(mWindowSession, times(2))
		.setOnBackInvokedCallback(Mockito.eq(mWindow), captor.capture());
		captor.getAllValues().get(0).onBackStarted();
		waitForIdle();
		verify(mCallback1).onBackStarted();
		verifyZeroInteractions(mCallback2);

		captor.getAllValues().get(1).onBackStarted();
		waitForIdle();
		verify(mCallback2).onBackStarted();
		verifyNoMoreInteractions(mCallback1);
		}

		@Test
		public void propagatesTopCallback_differentPriority() throws RemoteException {
		ArgumentCaptor<IOnBackInvokedCallback> captor =
		ArgumentCaptor.forClass(IOnBackInvokedCallback.class);

		mDispatcher.registerOnBackInvokedCallback(
		mCallback1, OnBackInvokedDispatcher.PRIORITY_OVERLAY);
		mDispatcher.registerOnBackInvokedCallback(
		mCallback2, OnBackInvokedDispatcher.PRIORITY_DEFAULT);

		verify(mWindowSession)
		.setOnBackInvokedCallback(Mockito.eq(mWindow), captor.capture());
		verifyNoMoreInteractions(mWindowSession);
		captor.getValue().onBackStarted();
		waitForIdle();
		verify(mCallback1).onBackStarted();
		}

		@Test
		public void propagatesTopCallback_withRemoval() throws RemoteException {
		mDispatcher.registerOnBackInvokedCallback(
		mCallback1, OnBackInvokedDispatcher.PRIORITY_DEFAULT);
		mDispatcher.registerOnBackInvokedCallback(
		mCallback2, OnBackInvokedDispatcher.PRIORITY_DEFAULT);

		reset(mWindowSession);
		mDispatcher.unregisterOnBackInvokedCallback(mCallback1);
		verifyZeroInteractions(mWindowSession);

		mDispatcher.unregisterOnBackInvokedCallback(mCallback2);
		verify(mWindowSession).setOnBackInvokedCallback(Mockito.eq(mWindow), isNull());
		}


		@Test
		public void propagatesTopCallback_sameInstanceAddedTwice() throws RemoteException {
		ArgumentCaptor<IOnBackInvokedCallback> captor =
		ArgumentCaptor.forClass(IOnBackInvokedCallback.class);

		mDispatcher.registerOnBackInvokedCallback(mCallback1,
		OnBackInvokedDispatcher.PRIORITY_OVERLAY);
		mDispatcher.registerOnBackInvokedCallback(
		mCallback2, OnBackInvokedDispatcher.PRIORITY_DEFAULT);
		mDispatcher.registerOnBackInvokedCallback(
		mCallback1, OnBackInvokedDispatcher.PRIORITY_DEFAULT);

		reset(mWindowSession);
		mDispatcher.registerOnBackInvokedCallback(
		mCallback2, OnBackInvokedDispatcher.PRIORITY_OVERLAY);
		verify(mWindowSession)
		.setOnBackInvokedCallback(Mockito.eq(mWindow), captor.capture());
		captor.getValue().onBackStarted();
		waitForIdle();
		verify(mCallback2).onBackStarted();
		}
		}