Keeping task list stable across multiple task switches (849d7e6c) · Commits · e / os / android_packages_apps_Trebuchet

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

+2 −1

Original line number	Diff line number	Diff line
		@@ -44,6 +44,7 @@ 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;
		@@ -83,7 +84,7 @@ public class RecentTasksList extends TaskStackChangeListener {
		final int requestLoadId = mChangeId;
		Runnable resultCallback = callback == null
		? () -> { }
		: () -> callback.accept(mTasks);
		: () -> callback.accept(mStabilizer.reorder(mTasks));

		if (mLastLoadedId == mChangeId && (!mLastLoadHadKeysOnly \|\| loadKeysOnly)) {
		// The list is up to date, callback with the same list

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

0 → 100644

+95 −0

Original line number	Diff line number	Diff line
		/*
		* 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 static com.android.launcher3.config.FeatureFlags.ENABLE_TASK_STABILIZER;

		import android.os.SystemClock;
		import android.util.SparseArray;

		import com.android.launcher3.util.IntArray;
		import com.android.launcher3.util.IntSet;
		import com.android.systemui.shared.recents.model.Task;

		import java.util.ArrayList;

		public class TaskListStabilizer {

		private static final long TASK_CACHE_TIMEOUT_MS = 5000;

		private final SparseArray<Task> mTempMap = new SparseArray<>();
		private final IntArray mTempArray = new IntArray();
		private final IntSet mTempSet = new IntSet();

		private final IntArray mLastStableOrder = new IntArray();
		private final IntSet mLastSet = new IntSet();
		private final IntArray mLastUnstableOrder = new IntArray();

		private long mLastReorderTime;

		public ArrayList<Task> reorder(ArrayList<Task> tasks) {
		if (!ENABLE_TASK_STABILIZER.get()) {
		return tasks;
		}

		// Create task id array
		int count = tasks.size();
		mTempArray.clear();
		mTempSet.clear();
		mTempMap.clear();

		for (int i = 0; i < count; i++) {
		Task t = tasks.get(i);
		mTempMap.put(t.key.id, t);

		mTempSet.add(t.key.id);
		mTempArray.add(t.key.id);
		}

		if (mLastSet.equals(mTempSet) && isStabilizationQuickEnough()) {
		if (mLastStableOrder.equals(mTempArray)) {
		// Everything is same
		return tasks;
		}

		if (!mLastUnstableOrder.equals(mTempArray)) {
		// Fast reordering, record the current time.
		mLastUnstableOrder.copyFrom(mTempArray);
		mLastReorderTime = SystemClock.uptimeMillis();
		}

		// Reorder the tasks based on the last stable order.
		ArrayList<Task> sorted = new ArrayList<>(count);
		for (int i = 0; i < count; i++) {
		sorted.add(mTempMap.get(mLastStableOrder.get(i)));
		}
		return sorted;
		}

		// Cache the data
		mLastStableOrder.copyFrom(mTempArray);
		mLastUnstableOrder.copyFrom(mTempArray);
		mLastSet.copyFrom(mTempSet);

		mLastReorderTime = SystemClock.uptimeMillis();

		return tasks;
		}

		private boolean isStabilizationQuickEnough() {
		return (SystemClock.uptimeMillis() - mLastReorderTime) < TASK_CACHE_TIMEOUT_MS;
		}
		}

quickstep/src/com/android/quickstep/views/RecentsView.java

+2 −1

Original line number	Diff line number	Diff line
		@@ -749,7 +749,8 @@ public abstract class RecentsView<T extends BaseActivity> extends PagedView impl
		setRunningTaskIconScaledDown(runningTaskIconScaledDown);
		setRunningTaskHidden(runningTaskTileHidden);

		setCurrentPage(0);
		TaskView tv = getRunningTaskView();
		setCurrentPage(tv == null ? 0 : indexOfChild(tv));

		// Load the tasks (if the loading is already
		mTaskListChangeId = mModel.getTasks(this::applyLoadPlan);

src/com/android/launcher3/config/BaseFlags.java

+3 −0

Original line number	Diff line number	Diff line
		@@ -95,6 +95,9 @@ abstract class BaseFlags {
		public static final TogglableFlag APPLY_CONFIG_AT_RUNTIME = new TogglableFlag(
		"APPLY_CONFIG_AT_RUNTIME", false, "Apply display changes dynamically");

		public static final TogglableFlag ENABLE_TASK_STABILIZER = new TogglableFlag(
		"ENABLE_TASK_STABILIZER", true, "Stable task list across fast task switches");

		public static void initialize(Context context) {
		// Avoid the disk read for user builds
		if (Utilities.IS_DEBUG_DEVICE) {

src/com/android/launcher3/util/IntArray.java

+27 −0

Original line number	Diff line number	Diff line
		@@ -99,6 +99,14 @@ public class IntArray implements Cloneable {
		mSize += count;
		}

		/**
		* Sets the array to be same as {@param other}
		*/
		public void copyFrom(IntArray other) {
		clear();
		addAll(other);
		}

		/**
		* Ensures capacity to append at least <code>count</code> values.
		*/
		@@ -127,6 +135,25 @@ public class IntArray implements Cloneable {
		return wrap(toArray());
		}

		@Override
		public boolean equals(Object obj) {
		if (obj == this) {
		return true;
		}
		if (obj instanceof IntArray) {
		IntArray arr = (IntArray) obj;
		if (mSize == arr.mSize) {
		for (int i = 0; i < mSize; i++) {
		if (arr.mValues[i] != mValues[i]) {
		return false;
		}
		}
		return true;
		}
		}
		return false;
		}

		/**
		* Returns the value at the specified position in this array.
		*/