Use system recent tasks stabilization

Bug: 111926330
Test: Swipe to last task, ensure it resets task list on timeout or interaction

Change-Id: Id09215a4cfdea63a4be6fb69fced163ad3bc10bd

quickstep/src/com/android/quickstep/NavBarModeOverlayResourceObserver.java

@@ -70,6 +70,11 @@ public class NavBarModeOverlayResourceObserver extends BroadcastReceiver {
                 NAV_BAR_INTERACTION_MODE_RES_NAME));
     }
 
+    public static boolean isLegacyModeEnabled(Context context) {
+        return QuickStepContract.isLegacyMode(getSystemIntegerRes(context,
+                NAV_BAR_INTERACTION_MODE_RES_NAME));
+    }
+
     private static int getSystemIntegerRes(Context context, String resName) {
         Resources res = context.getResources();
         int resId = res.getIdentifier(resName, "integer", "android");
@@ -81,4 +86,4 @@ public class NavBarModeOverlayResourceObserver extends BroadcastReceiver {
             return -1;
         }
     }
-}
+}

quickstep/src/com/android/quickstep/RecentTasksList.java

@@ -44,7 +44,6 @@ public class RecentTasksList extends TaskStackChangeListener {
     private final KeyguardManagerCompat mKeyguardManager;
     private final MainThreadExecutor mMainThreadExecutor;
     private final BackgroundExecutor mBgThreadExecutor;
-    private final TaskListStabilizer mStabilizer = new TaskListStabilizer();
 
     // The list change id, increments as the task list changes in the system
     private int mChangeId;
@@ -74,14 +73,6 @@ public class RecentTasksList extends TaskStackChangeListener {
         });
     }
 
-    public void startStabilizationSession() {
-        mStabilizer.startStabilizationSession();
-    }
-
-    public void endStabilizationSession() {
-        mStabilizer.endStabilizationSession();
-    }
-
     /**
      * Asynchronously fetches the list of recent tasks, reusing cached list if available.
      *
@@ -93,7 +84,7 @@ public class RecentTasksList extends TaskStackChangeListener {
         final int requestLoadId = mChangeId;
         Runnable resultCallback = callback == null
                 ? () -> { }
-                : () -> callback.accept(mStabilizer.reorder(mTasks));
+                : () -> callback.accept(mTasks);
 
         if (mLastLoadedId == mChangeId && (!mLastLoadHadKeysOnly || loadKeysOnly)) {
             // The list is up to date, callback with the same list

quickstep/src/com/android/quickstep/RecentsModel.java

@@ -90,14 +90,6 @@ public class RecentsModel extends TaskStackChangeListener {
         return mThumbnailCache;
     }
 
-    public void startStabilizationSession() {
-        mTaskList.startStabilizationSession();
-    }
-
-    public void endStabilizationSession() {
-        mTaskList.endStabilizationSession();
-    }
-
     /**
      * Fetches the list of recent tasks.
      *

quickstep/src/com/android/quickstep/TaskListStabilizer.java

@@ -1,145 +0,0 @@
-/*
- * Copyright (C) 2019 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 com.android.quickstep;
-
-import android.app.ActivityManager.RecentTaskInfo;
-import android.content.ComponentName;
-import android.os.Process;
-import android.os.SystemClock;
-
-import com.android.launcher3.util.IntArray;
-import com.android.systemui.shared.recents.model.Task;
-import com.android.systemui.shared.recents.model.Task.TaskKey;
-import com.android.systemui.shared.system.ActivityManagerWrapper;
-import com.android.systemui.shared.system.TaskStackChangeListener;
-
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-
-/**
- * Keeps the task list stable during quick switch gestures. So if you swipe right to switch from app
- * A to B, you can then swipe right again to get to app C or left to get back to A.
- */
-public class TaskListStabilizer {
-
-    private static final long TASK_CACHE_TIMEOUT_MS = 5000;
-
-    private final TaskStackChangeListener mTaskStackListener = new TaskStackChangeListener() {
-
-        @Override
-        public void onTaskCreated(int taskId, ComponentName componentName) {
-            endStabilizationSession();
-        }
-
-        @Override
-        public void onTaskRemoved(int taskId) {
-            endStabilizationSession();
-        }
-    };
-
-    // Task ids ordered based on recency, 0th index is the least recent task
-    private final IntArray mSystemOrder;
-    private final IntArray mStabilizedOrder;
-
-    // Wrapper objects used for sorting tasks
-    private final ArrayList<TaskWrapper> mTaskWrappers = new ArrayList<>();
-
-    private boolean mInStabilizationSession;
-    private long mSessionStartTime;
-
-    public TaskListStabilizer() {
-        // Initialize the task ids map
-        List<RecentTaskInfo> rawTasks = ActivityManagerWrapper.getInstance().getRecentTasks(
-                Integer.MAX_VALUE, Process.myUserHandle().getIdentifier());
-        mSystemOrder = new IntArray(rawTasks.size());
-        for (RecentTaskInfo info : rawTasks) {
-            mSystemOrder.add(new TaskKey(info).id);
-        }
-        // We will lazily copy the task id's from mSystemOrder when a stabilization session starts.
-        mStabilizedOrder = new IntArray(rawTasks.size());
-
-        ActivityManagerWrapper.getInstance().registerTaskStackListener(mTaskStackListener);
-    }
-
-    public synchronized void startStabilizationSession() {
-        if (!mInStabilizationSession) {
-            mStabilizedOrder.clear();
-            mStabilizedOrder.addAll(mSystemOrder);
-        }
-        mInStabilizationSession = true;
-        mSessionStartTime = SystemClock.uptimeMillis();
-    }
-
-    public synchronized void endStabilizationSession() {
-        mInStabilizationSession = false;
-    }
-
-    public synchronized ArrayList<Task> reorder(ArrayList<Task> tasks) {
-        mSystemOrder.clear();
-        for (Task task : tasks) {
-            mSystemOrder.add(task.key.id);
-        }
-
-        if ((SystemClock.uptimeMillis() - mSessionStartTime) > TASK_CACHE_TIMEOUT_MS) {
-            endStabilizationSession();
-        }
-
-        if (!mInStabilizationSession) {
-            return tasks;
-        }
-
-        // Ensure that we have enough wrappers
-        int taskCount = tasks.size();
-        for (int i = taskCount - mTaskWrappers.size(); i > 0; i--) {
-            mTaskWrappers.add(new TaskWrapper());
-        }
-
-        List<TaskWrapper> listToSort = mTaskWrappers.size() == taskCount
-                ? mTaskWrappers : mTaskWrappers.subList(0, taskCount);
-        int missingTaskIndex = -taskCount;
-
-        for (int i = 0; i < taskCount; i++){
-            TaskWrapper wrapper = listToSort.get(i);
-            wrapper.task = tasks.get(i);
-            wrapper.index = mStabilizedOrder.indexOf(wrapper.task.key.id);
-
-            // Ensure that missing tasks are put in the front, in the order they appear in the
-            // original list
-            if (wrapper.index < 0) {
-                wrapper.index = missingTaskIndex;
-                missingTaskIndex++;
-            }
-        }
-        Collections.sort(listToSort);
-
-        ArrayList<Task> result = new ArrayList<>(taskCount);
-        for (int i = 0; i < taskCount; i++) {
-            result.add(listToSort.get(i).task);
-        }
-        return result;
-    }
-
-    private static class TaskWrapper implements Comparable<TaskWrapper> {
-        Task task;
-        int index;
-
-        @Override
-        public int compareTo(TaskWrapper other) {
-            return Integer.compare(index, other.index);
-        }
-    }
-}