Merge changes Ifc2ed99b,Ibd7fc78e

* changes:
  Integration of back gesture animation on Sysui (BackNav 2/n)
  Server infrastructure for back nav animation (BackNav 1/n)

4 files changed, 270 insertions, 2 deletions

diff --git a/core/java/android/app/IActivityTaskManager.aidl b/core/java/android/app/IActivityTaskManager.aidl
index a9ec11edd680..0801b2481f0c 100644
--- a/core/java/android/app/IActivityTaskManager.aidl
+++ b/core/java/android/app/IActivityTaskManager.aidl
@@ -72,6 +72,7 @@ import android.view.IRemoteAnimationRunner;
 import android.view.RemoteAnimationDefinition;
 import android.view.RemoteAnimationAdapter;
 import android.window.IWindowOrganizerController;
+import android.window.BackNavigationInfo;
 import android.window.SplashScreenView;
 import com.android.internal.app.IVoiceInteractor;
 import com.android.internal.os.IResultReceiver;
@@ -346,7 +347,8 @@ interface IActivityTaskManager {
     void setRunningRemoteTransitionDelegate(in IApplicationThread caller);
 
     /**
-     * Prepare the back preview in the server
+     * Prepare the back navigation in the server. This setups the leashed for sysui to animate
+     * the back gesture and returns the data needed for the animation.
      */
-    void startBackPreview(IRemoteAnimationRunner runner);
+    android.window.BackNavigationInfo startBackNavigation();
 }
diff --git a/core/java/android/window/BackNavigationInfo.aidl b/core/java/android/window/BackNavigationInfo.aidl
new file mode 100644
index 000000000000..1529902b9c20
--- /dev/null
+++ b/core/java/android/window/BackNavigationInfo.aidl
@@ -0,0 +1,22 @@
+/*
+ * 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;
+
+/**
+ * @hide
+ */
+parcelable BackNavigationInfo;
\ No newline at end of file
diff --git a/core/java/android/window/BackNavigationInfo.java b/core/java/android/window/BackNavigationInfo.java
new file mode 100644
index 000000000000..571714cc05d5
--- /dev/null
+++ b/core/java/android/window/BackNavigationInfo.java
@@ -0,0 +1,242 @@
+/*
+ * 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 java.util.Objects.requireNonNull;
+
+import android.annotation.IntDef;
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.app.WindowConfiguration;
+import android.hardware.HardwareBuffer;
+import android.os.Parcel;
+import android.os.Parcelable;
+import android.os.RemoteCallback;
+import android.view.SurfaceControl;
+
+/**
+ * Information to be sent to SysUI about a back event.
+ *
+ * @hide
+ */
+public final class BackNavigationInfo implements Parcelable {
+
+    /**
+     * The target of the back navigation is undefined.
+     */
+    public static final int TYPE_UNDEFINED = -1;
+
+    /**
+     * Navigating back will close the currently visible dialog
+     */
+    public static final int TYPE_DIALOG_CLOSE = 0;
+
+    /**
+     * Navigating back will bring the user back to the home screen
+     */
+    public static final int TYPE_RETURN_TO_HOME = 1;
+
+    /**
+     * Navigating back will bring the user to the previous activity in the same Task
+     */
+    public static final int TYPE_CROSS_ACTIVITY = 2;
+
+    /**
+     * Navigating back will bring the user to the previous activity in the previous Task
+     */
+    public static final int TYPE_CROSS_TASK = 3;
+
+    /**
+     * Defines the type of back destinations a back even can lead to. This is used to define the
+     * type of animation that need to be run on SystemUI.
+     */
+    @IntDef(prefix = "TYPE_", value = {
+            TYPE_UNDEFINED,
+            TYPE_DIALOG_CLOSE,
+            TYPE_RETURN_TO_HOME,
+            TYPE_CROSS_ACTIVITY,
+            TYPE_CROSS_TASK})
+    @interface BackTargetType {
+    }
+
+    private final int mType;
+    @Nullable
+    private final SurfaceControl mDepartingWindowContainer;
+    @Nullable
+    private final SurfaceControl mScreenshotSurface;
+    @Nullable
+    private final HardwareBuffer mScreenshotBuffer;
+    @Nullable
+    private final RemoteCallback mRemoteCallback;
+    @Nullable
+    private final WindowConfiguration mTaskWindowConfiguration;
+
+    /**
+     * Create a new {@link BackNavigationInfo} instance.
+     *
+     * @param type  The {@link BackTargetType} of the destination (what will be displayed after
+     *              the back action)
+     * @param topWindowLeash      The leash to animate away the current topWindow. The consumer
+     *                            of the leash is responsible for removing it.
+     * @param screenshotSurface The screenshot of the previous activity to be displayed.
+     * @param screenshotBuffer      A buffer containing a screenshot used to display the activity.
+     *                            See {@link  #getScreenshotHardwareBuffer()} for information
+     *                            about nullity.
+     * @param taskWindowConfiguration The window configuration of the Task being animated
+     *                            beneath.
+     * @param onBackNavigationDone   The callback to be called once the client is done with the back
+     *                           preview.
+     */
+    public BackNavigationInfo(@BackTargetType int type,
+            @Nullable SurfaceControl topWindowLeash,
+            @Nullable SurfaceControl screenshotSurface,
+            @Nullable HardwareBuffer screenshotBuffer,
+            @Nullable WindowConfiguration taskWindowConfiguration,
+            @NonNull RemoteCallback onBackNavigationDone) {
+        mType = type;
+        mDepartingWindowContainer = topWindowLeash;
+        mScreenshotSurface = screenshotSurface;
+        mScreenshotBuffer = screenshotBuffer;
+        mTaskWindowConfiguration = taskWindowConfiguration;
+        mRemoteCallback = onBackNavigationDone;
+    }
+
+    private BackNavigationInfo(@NonNull Parcel in) {
+        mType = in.readInt();
+        mDepartingWindowContainer = in.readTypedObject(SurfaceControl.CREATOR);
+        mScreenshotSurface = in.readTypedObject(SurfaceControl.CREATOR);
+        mScreenshotBuffer = in.readTypedObject(HardwareBuffer.CREATOR);
+        mTaskWindowConfiguration = in.readTypedObject(WindowConfiguration.CREATOR);
+        mRemoteCallback = requireNonNull(in.readTypedObject(RemoteCallback.CREATOR));
+    }
+
+    @Override
+    public void writeToParcel(@NonNull Parcel dest, int flags) {
+        dest.writeInt(mType);
+        dest.writeTypedObject(mDepartingWindowContainer, flags);
+        dest.writeTypedObject(mScreenshotSurface, flags);
+        dest.writeTypedObject(mScreenshotBuffer, flags);
+        dest.writeTypedObject(mTaskWindowConfiguration, flags);
+        dest.writeTypedObject(mRemoteCallback, flags);
+    }
+
+    /**
+     * Returns the type of back navigation that is about to happen.
+     * @see BackTargetType
+     */
+    public @BackTargetType int getType() {
+        return mType;
+    }
+
+    /**
+     * Returns a leash to the top window container that needs to be animated. This can be null if
+     * the back animation is controlled by the application.
+     */
+    @Nullable
+    public SurfaceControl getDepartingWindowContainer() {
+        return mDepartingWindowContainer;
+    }
+
+    /**
+     *  Returns the {@link SurfaceControl} that should be used to display a screenshot of the
+     *  previous activity.
+     */
+    @Nullable
+    public SurfaceControl getScreenshotSurface() {
+        return mScreenshotSurface;
+    }
+
+    /**
+     * Returns the {@link HardwareBuffer} containing the screenshot the activity about to be
+     * shown. This can be null if one of the following conditions is met:
+     * <ul>
+     *     <li>The screenshot is not available
+     *     <li> The previous activity is the home screen ( {@link  #TYPE_RETURN_TO_HOME}
+     *     <li> The current window is a dialog ({@link  #TYPE_DIALOG_CLOSE}
+     *     <li> The back animation is controlled by the application
+     * </ul>
+     */
+    @Nullable
+    public HardwareBuffer getScreenshotHardwareBuffer() {
+        return mScreenshotBuffer;
+    }
+
+    /**
+     * Returns the {@link WindowConfiguration} of the current task. This is null when the top
+     * application is controlling the back animation.
+     */
+    @Nullable
+    public WindowConfiguration getTaskWindowConfiguration() {
+        return mTaskWindowConfiguration;
+    }
+
+    /**
+     * Callback to be called when the back preview is finished in order to notify the server that
+     * it can clean up the resources created for the animation.
+     */
+    public void onBackNavigationFinished() {
+        mRemoteCallback.sendResult(null);
+    }
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    public static final Creator<BackNavigationInfo> CREATOR = new Creator<BackNavigationInfo>() {
+        @Override
+        public BackNavigationInfo createFromParcel(Parcel in) {
+            return new BackNavigationInfo(in);
+        }
+
+        @Override
+        public BackNavigationInfo[] newArray(int size) {
+            return new BackNavigationInfo[size];
+        }
+    };
+
+    @Override
+    public String toString() {
+        return "BackNavigationInfo{"
+                + "mType=" + typeToString(mType) + " (" + mType + ")"
+                + ", mDepartingWindowContainer=" + mDepartingWindowContainer
+                + ", mScreenshotSurface=" + mScreenshotSurface
+                + ", mTaskWindowConfiguration= " + mTaskWindowConfiguration
+                + ", mScreenshotBuffer=" + mScreenshotBuffer
+                + ", mRemoteCallback=" + mRemoteCallback
+                + '}';
+    }
+
+    /**
+     * Translates the {@link BackNavigationInfo} integer type to its String representation
+     */
+    public static String typeToString(@BackTargetType int type) {
+        switch (type) {
+            case  TYPE_UNDEFINED:
+                return "TYPE_UNDEFINED";
+            case TYPE_DIALOG_CLOSE:
+                return "TYPE_DIALOG_CLOSE";
+            case TYPE_RETURN_TO_HOME:
+                return "TYPE_RETURN_TO_HOME";
+            case TYPE_CROSS_ACTIVITY:
+                return "TYPE_CROSS_ACTIVITY";
+            case TYPE_CROSS_TASK:
+                return "TYPE_CROSS_TASK";
+        }
+        return String.valueOf(type);
+    }
+}
diff --git a/core/java/com/android/internal/protolog/ProtoLogGroup.java b/core/java/com/android/internal/protolog/ProtoLogGroup.java
index 5ac493637822..def598ca8724 100644
--- a/core/java/com/android/internal/protolog/ProtoLogGroup.java
+++ b/core/java/com/android/internal/protolog/ProtoLogGroup.java
@@ -85,6 +85,8 @@ public enum ProtoLogGroup implements IProtoLogGroup {
     WM_DEBUG_LAYER_MIRRORING(Consts.ENABLE_DEBUG, Consts.ENABLE_LOG_TO_PROTO_DEBUG, true,
             Consts.TAG_WM),
     WM_DEBUG_WALLPAPER(Consts.ENABLE_DEBUG, Consts.ENABLE_LOG_TO_PROTO_DEBUG, false, Consts.TAG_WM),
+    WM_DEBUG_BACK_PREVIEW(Consts.ENABLE_DEBUG, Consts.ENABLE_LOG_TO_PROTO_DEBUG, true,
+            "CoreBackPreview"),
     TEST_GROUP(true, true, false, "WindowManagerProtoLogTest");
 
     private final boolean mEnabled;