src/com/android/launcher3/LauncherModel.java

/*
 * Copyright (C) 2008 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.launcher3;

import android.app.SearchManager;
import android.appwidget.AppWidgetManager;
import android.appwidget.AppWidgetProviderInfo;
import android.content.BroadcastReceiver;
import android.content.ComponentName;
import android.content.ContentProviderOperation;
import android.content.ContentResolver;
import android.content.ContentValues;
import android.content.Context;
import android.content.Intent;
import android.content.Intent.ShortcutIconResource;
import android.content.IntentFilter;
import android.content.pm.PackageManager;
import android.content.pm.ProviderInfo;
import android.content.pm.ResolveInfo;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Environment;
import android.os.Handler;
import android.os.HandlerThread;
import android.os.Looper;
import android.os.Parcelable;
import android.os.Process;
import android.os.SystemClock;
import android.os.TransactionTooLargeException;
import android.provider.BaseColumns;
import android.text.TextUtils;
import android.util.Log;
import android.util.LongSparseArray;
import android.util.Pair;

import com.android.launcher3.compat.AppWidgetManagerCompat;
import com.android.launcher3.compat.LauncherActivityInfoCompat;
import com.android.launcher3.compat.LauncherAppsCompat;
import com.android.launcher3.compat.PackageInstallerCompat;
import com.android.launcher3.compat.PackageInstallerCompat.PackageInstallInfo;
import com.android.launcher3.compat.UserHandleCompat;
import com.android.launcher3.compat.UserManagerCompat;
import com.android.launcher3.config.ProviderConfig;
import com.android.launcher3.model.MigrateFromRestoreTask;
import com.android.launcher3.model.WidgetsModel;
import com.android.launcher3.util.ComponentKey;
import com.android.launcher3.util.CursorIconInfo;
import com.android.launcher3.util.LongArrayMap;
import com.android.launcher3.util.ManagedProfileHeuristic;
import com.android.launcher3.util.Thunk;

import java.lang.ref.WeakReference;
import java.net.URISyntaxException;
import java.security.InvalidParameterException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map.Entry;
import java.util.Set;

/**
 * Maintains in-memory state of the Launcher. It is expected that there should be only one
 * LauncherModel object held in a static. Also provide APIs for updating the database state
 * for the Launcher.
 */
public class LauncherModel extends BroadcastReceiver
        implements LauncherAppsCompat.OnAppsChangedCallbackCompat {
    static final boolean DEBUG_LOADERS = false;
    private static final boolean DEBUG_RECEIVER = false;
    private static final boolean REMOVE_UNRESTORED_ICONS = true;

    static final String TAG = "Launcher.Model";

    public static final int LOADER_FLAG_NONE = 0;
    public static final int LOADER_FLAG_CLEAR_WORKSPACE = 1 << 0;
    public static final int LOADER_FLAG_MIGRATE_SHORTCUTS = 1 << 1;

    private static final int ITEMS_CHUNK = 6; // batch size for the workspace icons
    private static final long INVALID_SCREEN_ID = -1L;

    @Thunk final boolean mAppsCanBeOnRemoveableStorage;
    private final boolean mOldContentProviderExists;

    @Thunk final LauncherAppState mApp;
    @Thunk final Object mLock = new Object();
    @Thunk DeferredHandler mHandler = new DeferredHandler();
    @Thunk LoaderTask mLoaderTask;
    @Thunk boolean mIsLoaderTaskRunning;
    @Thunk boolean mHasLoaderCompletedOnce;

    private static final String MIGRATE_AUTHORITY = "com.android.launcher2.settings";

    @Thunk static final HandlerThread sWorkerThread = new HandlerThread("launcher-loader");
    static {
        sWorkerThread.start();
    }
    @Thunk static final Handler sWorker = new Handler(sWorkerThread.getLooper());

    // We start off with everything not loaded.  After that, we assume that
    // our monitoring of the package manager provides all updates and we never
    // need to do a requery.  These are only ever touched from the loader thread.
    @Thunk boolean mWorkspaceLoaded;
    @Thunk boolean mAllAppsLoaded;

    // When we are loading pages synchronously, we can't just post the binding of items on the side
    // pages as this delays the rotation process.  Instead, we wait for a callback from the first
    // draw (in Workspace) to initiate the binding of the remaining side pages.  Any time we start
    // a normal load, we also clear this set of Runnables.
    static final ArrayList<Runnable> mDeferredBindRunnables = new ArrayList<Runnable>();

    /**
     * Set of runnables to be called on the background thread after the workspace binding
     * is complete.
     */
    static final ArrayList<Runnable> mBindCompleteRunnables = new ArrayList<Runnable>();

    @Thunk WeakReference<Callbacks> mCallbacks;

    // < only access in worker thread >
    AllAppsList mBgAllAppsList;
    // Entire list of widgets.
    WidgetsModel mBgWidgetsModel;

    // The lock that must be acquired before referencing any static bg data structures.  Unlike
    // other locks, this one can generally be held long-term because we never expect any of these
    // static data structures to be referenced outside of the worker thread except on the first
    // load after configuration change.
    static final Object sBgLock = new Object();

    // sBgItemsIdMap maps *all* the ItemInfos (shortcuts, folders, and widgets) created by
    // LauncherModel to their ids
    static final LongArrayMap<ItemInfo> sBgItemsIdMap = new LongArrayMap<>();

    // sBgWorkspaceItems is passed to bindItems, which expects a list of all folders and shortcuts
    //       created by LauncherModel that are directly on the home screen (however, no widgets or
    //       shortcuts within folders).
    static final ArrayList<ItemInfo> sBgWorkspaceItems = new ArrayList<ItemInfo>();

    // sBgAppWidgets is all LauncherAppWidgetInfo created by LauncherModel. Passed to bindAppWidget()
    static final ArrayList<LauncherAppWidgetInfo> sBgAppWidgets =
        new ArrayList<LauncherAppWidgetInfo>();

    // sBgFolders is all FolderInfos created by LauncherModel. Passed to bindFolders()
    static final LongArrayMap<FolderInfo> sBgFolders = new LongArrayMap<>();

    // sBgWorkspaceScreens is the ordered set of workspace screens.
    static final ArrayList<Long> sBgWorkspaceScreens = new ArrayList<Long>();

    // sBgWidgetProviders is the set of widget providers including custom internal widgets
    public static HashMap<ComponentKey, LauncherAppWidgetProviderInfo> sBgWidgetProviders;

    // sPendingPackages is a set of packages which could be on sdcard and are not available yet
    static final HashMap<UserHandleCompat, HashSet<String>> sPendingPackages =
            new HashMap<UserHandleCompat, HashSet<String>>();

    // </ only access in worker thread >

    @Thunk IconCache mIconCache;

    @Thunk final LauncherAppsCompat mLauncherApps;
    @Thunk final UserManagerCompat mUserManager;

    public interface Callbacks {
        public boolean setLoadOnResume();
        public int getCurrentWorkspaceScreen();
        public void startBinding();
        public void bindItems(ArrayList<ItemInfo> shortcuts, int start, int end,
                              boolean forceAnimateIcons);
        public void bindScreens(ArrayList<Long> orderedScreenIds);
        public void bindAddScreens(ArrayList<Long> orderedScreenIds);
        public void bindFolders(LongArrayMap<FolderInfo> folders);
        public void finishBindingItems();
        public void bindAppWidget(LauncherAppWidgetInfo info);
        public void bindAllApplications(ArrayList<AppInfo> apps);
        public void bindAppsAdded(ArrayList<Long> newScreens,
                                  ArrayList<ItemInfo> addNotAnimated,
                                  ArrayList<ItemInfo> addAnimated,
                                  ArrayList<AppInfo> addedApps);
        public void bindAppsUpdated(ArrayList<AppInfo> apps);
        public void bindShortcutsChanged(ArrayList<ShortcutInfo> updated,
                ArrayList<ShortcutInfo> removed, UserHandleCompat user);
        public void bindWidgetsRestored(ArrayList<LauncherAppWidgetInfo> widgets);
        public void bindRestoreItemsChange(HashSet<ItemInfo> updates);
        public void bindComponentsRemoved(ArrayList<String> packageNames,
                        ArrayList<AppInfo> appInfos, UserHandleCompat user, int reason);
        public void bindAllPackages(WidgetsModel model);
        public void bindSearchProviderChanged();
        public boolean isAllAppsButtonRank(int rank);
        public void onPageBoundSynchronously(int page);
        public void dumpLogsToLocalData();
    }

    public interface ItemInfoFilter {
        public boolean filterItem(ItemInfo parent, ItemInfo info, ComponentName cn);
    }

    LauncherModel(LauncherAppState app, IconCache iconCache, AppFilter appFilter) {
        Context context = app.getContext();

        mAppsCanBeOnRemoveableStorage = Environment.isExternalStorageRemovable();
        String oldProvider = context.getString(R.string.old_launcher_provider_uri);
        // This may be the same as MIGRATE_AUTHORITY, or it may be replaced by a different
        // resource string.
        String redirectAuthority = Uri.parse(oldProvider).getAuthority();
        ProviderInfo providerInfo =
                context.getPackageManager().resolveContentProvider(MIGRATE_AUTHORITY, 0);
        ProviderInfo redirectProvider =
                context.getPackageManager().resolveContentProvider(redirectAuthority, 0);

        Log.d(TAG, "Old launcher provider: " + oldProvider);
        mOldContentProviderExists = (providerInfo != null) && (redirectProvider != null);

        if (mOldContentProviderExists) {
            Log.d(TAG, "Old launcher provider exists.");
        } else {
            Log.d(TAG, "Old launcher provider does not exist.");
        }

        mApp = app;
        mBgAllAppsList = new AllAppsList(iconCache, appFilter);
        mBgWidgetsModel = new WidgetsModel(context, iconCache, appFilter);
        mIconCache = iconCache;

        mLauncherApps = LauncherAppsCompat.getInstance(context);
        mUserManager = UserManagerCompat.getInstance(context);
    }

    /** Runs the specified runnable immediately if called from the main thread, otherwise it is
     * posted on the main thread handler. */
    @Thunk void runOnMainThread(Runnable r) {
        if (sWorkerThread.getThreadId() == Process.myTid()) {
            // If we are on the worker thread, post onto the main handler
            mHandler.post(r);
        } else {
            r.run();
        }
    }

    /** Runs the specified runnable immediately if called from the worker thread, otherwise it is
     * posted on the worker thread handler. */
    @Thunk static void runOnWorkerThread(Runnable r) {
        if (sWorkerThread.getThreadId() == Process.myTid()) {
            r.run();
        } else {
            // If we are not on the worker thread, then post to the worker handler
            sWorker.post(r);
        }
    }

    boolean canMigrateFromOldLauncherDb(Launcher launcher) {
        return mOldContentProviderExists && !launcher.isLauncherPreinstalled() ;
    }

    public void setPackageState(final PackageInstallInfo installInfo) {
        Runnable updateRunnable = new Runnable() {

            @Override
            public void run() {
                synchronized (sBgLock) {
                    final HashSet<ItemInfo> updates = new HashSet<>();

                    if (installInfo.state == PackageInstallerCompat.STATUS_INSTALLED) {
                        // Ignore install success events as they are handled by Package add events.
                        return;
                    }

                    for (ItemInfo info : sBgItemsIdMap) {
                        if (info instanceof ShortcutInfo) {
                            ShortcutInfo si = (ShortcutInfo) info;
                            ComponentName cn = si.getTargetComponent();
                            if (si.isPromise() && (cn != null)
                                    && installInfo.packageName.equals(cn.getPackageName())) {
                                si.setInstallProgress(installInfo.progress);

                                if (installInfo.state == PackageInstallerCompat.STATUS_FAILED) {
                                    // Mark this info as broken.
                                    si.status &= ~ShortcutInfo.FLAG_INSTALL_SESSION_ACTIVE;
                                }
                                updates.add(si);
                            }
                        }
                    }

                    for (LauncherAppWidgetInfo widget : sBgAppWidgets) {
                        if (widget.providerName.getPackageName().equals(installInfo.packageName)) {
                            widget.installProgress = installInfo.progress;
                            updates.add(widget);
                        }
                    }

                    if (!updates.isEmpty()) {
                        // Push changes to the callback.
                        Runnable r = new Runnable() {
                            public void run() {
                                Callbacks callbacks = getCallback();
                                if (callbacks != null) {
                                    callbacks.bindRestoreItemsChange(updates);
                                }
                            }
                        };
                        mHandler.post(r);
                    }
                }
            }
        };
        runOnWorkerThread(updateRunnable);
    }

    /**
     * Updates the icons and label of all pending icons for the provided package name.
     */
    public void updateSessionDisplayInfo(final String packageName) {
        Runnable updateRunnable = new Runnable() {

            @Override
            public void run() {
                synchronized (sBgLock) {
                    final ArrayList<ShortcutInfo> updates = new ArrayList<>();
                    final UserHandleCompat user = UserHandleCompat.myUserHandle();

                    for (ItemInfo info : sBgItemsIdMap) {
                        if (info instanceof ShortcutInfo) {
                            ShortcutInfo si = (ShortcutInfo) info;
                            ComponentName cn = si.getTargetComponent();
                            if (si.isPromise() && (cn != null)
                                    && packageName.equals(cn.getPackageName())) {
                                if (si.hasStatusFlag(ShortcutInfo.FLAG_AUTOINTALL_ICON)) {
                                    // For auto install apps update the icon as well as label.
                                    mIconCache.getTitleAndIcon(si,
                                            si.promisedIntent, user,
                                            si.shouldUseLowResIcon());
                                } else {
                                    // Only update the icon for restored apps.
                                    si.updateIcon(mIconCache);
                                }
                                updates.add(si);
                            }
                        }
                    }

                    if (!updates.isEmpty()) {
                        // Push changes to the callback.
                        Runnable r = new Runnable() {
                            public void run() {
                                Callbacks callbacks = getCallback();
                                if (callbacks != null) {
                                    callbacks.bindShortcutsChanged(updates,
                                            new ArrayList<ShortcutInfo>(), user);
                                }
                            }
                        };
                        mHandler.post(r);
                    }
                }
            }
        };
        runOnWorkerThread(updateRunnable);
    }

    public void addAppsToAllApps(final Context ctx, final ArrayList<AppInfo> allAppsApps) {
        final Callbacks callbacks = getCallback();

        if (allAppsApps == null) {
            throw new RuntimeException("allAppsApps must not be null");
        }
        if (allAppsApps.isEmpty()) {
            return;
        }

        // Process the newly added applications and add them to the database first
        Runnable r = new Runnable() {
            public void run() {
                runOnMainThread(new Runnable() {
                    public void run() {
                        Callbacks cb = getCallback();
                        if (callbacks == cb && cb != null) {
                            callbacks.bindAppsAdded(null, null, null, allAppsApps);
                        }
                    }
                });
            }
        };
        runOnWorkerThread(r);
    }

    private static boolean findNextAvailableIconSpaceInScreen(ArrayList<ItemInfo> occupiedPos,
            int[] xy, int spanX, int spanY) {
        LauncherAppState app = LauncherAppState.getInstance();
        InvariantDeviceProfile profile = app.getInvariantDeviceProfile();
        final int xCount = (int) profile.numColumns;
        final int yCount = (int) profile.numRows;
        boolean[][] occupied = new boolean[xCount][yCount];
        if (occupiedPos != null) {
            for (ItemInfo r : occupiedPos) {
                int right = r.cellX + r.spanX;
                int bottom = r.cellY + r.spanY;
                for (int x = r.cellX; 0 <= x && x < right && x < xCount; x++) {
                    for (int y = r.cellY; 0 <= y && y < bottom && y < yCount; y++) {
                        occupied[x][y] = true;
                    }
                }
            }
        }
        return Utilities.findVacantCell(xy, spanX, spanY, xCount, yCount, occupied);
    }

    /**
     * Find a position on the screen for the given size or adds a new screen.
     * @return screenId and the coordinates for the item.
     */
    @Thunk Pair<Long, int[]> findSpaceForItem(
            Context context,
            ArrayList<Long> workspaceScreens,
            ArrayList<Long> addedWorkspaceScreensFinal,
            int spanX, int spanY) {
        LongSparseArray<ArrayList<ItemInfo>> screenItems = new LongSparseArray<>();

        // Use sBgItemsIdMap as all the items are already loaded.
        assertWorkspaceLoaded();
        synchronized (sBgLock) {
            for (ItemInfo info : sBgItemsIdMap) {
                if (info.container == LauncherSettings.Favorites.CONTAINER_DESKTOP) {
                    ArrayList<ItemInfo> items = screenItems.get(info.screenId);
                    if (items == null) {
                        items = new ArrayList<>();
                        screenItems.put(info.screenId, items);
                    }
                    items.add(info);
                }
            }
        }

        // Find appropriate space for the item.
        long screenId = 0;
        int[] cordinates = new int[2];
        boolean found = false;

        int screenCount = workspaceScreens.size();
        // First check the preferred screen.
        int preferredScreenIndex = workspaceScreens.isEmpty() ? 0 : 1;
        if (preferredScreenIndex < screenCount) {
            screenId = workspaceScreens.get(preferredScreenIndex);
            found = findNextAvailableIconSpaceInScreen(
                    screenItems.get(screenId), cordinates, spanX, spanY);
        }

        if (!found) {
            // Search on any of the screens starting from the first screen.
            for (int screen = 1; screen < screenCount; screen++) {
                screenId = workspaceScreens.get(screen);
                if (findNextAvailableIconSpaceInScreen(
                        screenItems.get(screenId), cordinates, spanX, spanY)) {
                    // We found a space for it
                    found = true;
                    break;
                }
            }
        }

        if (!found) {
            // Still no position found. Add a new screen to the end.
            screenId = LauncherAppState.getLauncherProvider().generateNewScreenId();

            // Save the screen id for binding in the workspace
            workspaceScreens.add(screenId);
            addedWorkspaceScreensFinal.add(screenId);

            // If we still can't find an empty space, then God help us all!!!
            if (!findNextAvailableIconSpaceInScreen(
                    screenItems.get(screenId), cordinates, spanX, spanY)) {
                throw new RuntimeException("Can't find space to add the item");
            }
        }
        return Pair.create(screenId, cordinates);
    }

    /**
     * Adds the provided items to the workspace.
     */
    public void addAndBindAddedWorkspaceItems(final Context context,
            final ArrayList<? extends ItemInfo> workspaceApps) {
        final Callbacks callbacks = getCallback();
        if (workspaceApps.isEmpty()) {
            return;
        }
        // Process the newly added applications and add them to the database first
        Runnable r = new Runnable() {
            public void run() {
                final ArrayList<ItemInfo> addedShortcutsFinal = new ArrayList<ItemInfo>();
                final ArrayList<Long> addedWorkspaceScreensFinal = new ArrayList<Long>();

                // Get the list of workspace screens.  We need to append to this list and
                // can not use sBgWorkspaceScreens because loadWorkspace() may not have been
                // called.
                ArrayList<Long> workspaceScreens = loadWorkspaceScreensDb(context);
                synchronized(sBgLock) {
                    for (ItemInfo item : workspaceApps) {
                        if (item instanceof ShortcutInfo) {
                            // Short-circuit this logic if the icon exists somewhere on the workspace
                            if (shortcutExists(context, item.getIntent(), item.user)) {
                                continue;
                            }
                        }

                        // Find appropriate space for the item.
                        Pair<Long, int[]> coords = findSpaceForItem(context,
                                workspaceScreens, addedWorkspaceScreensFinal,
                                1, 1);
                        long screenId = coords.first;
                        int[] cordinates = coords.second;

                        ItemInfo itemInfo;
                        if (item instanceof ShortcutInfo || item instanceof FolderInfo) {
                            itemInfo = item;
                        } else if (item instanceof AppInfo) {
                            itemInfo = ((AppInfo) item).makeShortcut();
                        } else {
                            throw new RuntimeException("Unexpected info type");
                        }

                        // Add the shortcut to the db
                        addItemToDatabase(context, itemInfo,
                                LauncherSettings.Favorites.CONTAINER_DESKTOP,
                                screenId, cordinates[0], cordinates[1]);
                        // Save the ShortcutInfo for binding in the workspace
                        addedShortcutsFinal.add(itemInfo);
                    }
                }

                // Update the workspace screens
                updateWorkspaceScreenOrder(context, workspaceScreens);

                if (!addedShortcutsFinal.isEmpty()) {
                    runOnMainThread(new Runnable() {
                        public void run() {
                            Callbacks cb = getCallback();
                            if (callbacks == cb && cb != null) {
                                final ArrayList<ItemInfo> addAnimated = new ArrayList<ItemInfo>();
                                final ArrayList<ItemInfo> addNotAnimated = new ArrayList<ItemInfo>();
                                if (!addedShortcutsFinal.isEmpty()) {
                                    ItemInfo info = addedShortcutsFinal.get(addedShortcutsFinal.size() - 1);
                                    long lastScreenId = info.screenId;
                                    for (ItemInfo i : addedShortcutsFinal) {
                                        if (i.screenId == lastScreenId) {
                                            addAnimated.add(i);
                                        } else {
                                            addNotAnimated.add(i);
                                        }
                                    }
                                }
                                callbacks.bindAppsAdded(addedWorkspaceScreensFinal,
                                        addNotAnimated, addAnimated, null);
                            }
                        }
                    });
                }
            }
        };
        runOnWorkerThread(r);
    }

    private void unbindItemInfosAndClearQueuedBindRunnables() {
        if (sWorkerThread.getThreadId() == Process.myTid()) {
            throw new RuntimeException("Expected unbindLauncherItemInfos() to be called from the " +
                    "main thread");
        }

        // Clear any deferred bind runnables
        synchronized (mDeferredBindRunnables) {
            mDeferredBindRunnables.clear();
        }

        // Remove any queued UI runnables
        mHandler.cancelAll();
        // Unbind all the workspace items
        unbindWorkspaceItemsOnMainThread();
    }

    /** Unbinds all the sBgWorkspaceItems and sBgAppWidgets on the main thread */
    void unbindWorkspaceItemsOnMainThread() {
        // Ensure that we don't use the same workspace items data structure on the main thread
        // by making a copy of workspace items first.
        final ArrayList<ItemInfo> tmpItems = new ArrayList<ItemInfo>();
        synchronized (sBgLock) {
            tmpItems.addAll(sBgWorkspaceItems);
            tmpItems.addAll(sBgAppWidgets);
        }
        Runnable r = new Runnable() {
                @Override
                public void run() {
                   for (ItemInfo item : tmpItems) {
                       item.unbind();
                   }
                }
            };
        runOnMainThread(r);
    }

    /**
     * Adds an item to the DB if it was not created previously, or move it to a new
     * <container, screen, cellX, cellY>
     */
    static void addOrMoveItemInDatabase(Context context, ItemInfo item, long container,
            long screenId, int cellX, int cellY) {
        if (item.container == ItemInfo.NO_ID) {
            // From all apps
            addItemToDatabase(context, item, container, screenId, cellX, cellY);
        } else {
            // From somewhere else
            moveItemInDatabase(context, item, container, screenId, cellX, cellY);
        }
    }

    static void checkItemInfoLocked(
            final long itemId, final ItemInfo item, StackTraceElement[] stackTrace) {
        ItemInfo modelItem = sBgItemsIdMap.get(itemId);
        if (modelItem != null && item != modelItem) {
            // check all the data is consistent
            if (modelItem instanceof ShortcutInfo && item instanceof ShortcutInfo) {
                ShortcutInfo modelShortcut = (ShortcutInfo) modelItem;
                ShortcutInfo shortcut = (ShortcutInfo) item;
                if (modelShortcut.title.toString().equals(shortcut.title.toString()) &&
                        modelShortcut.intent.filterEquals(shortcut.intent) &&
                        modelShortcut.id == shortcut.id &&
                        modelShortcut.itemType == shortcut.itemType &&
                        modelShortcut.container == shortcut.container &&
                        modelShortcut.screenId == shortcut.screenId &&
                        modelShortcut.cellX == shortcut.cellX &&
                        modelShortcut.cellY == shortcut.cellY &&
                        modelShortcut.spanX == shortcut.spanX &&
                        modelShortcut.spanY == shortcut.spanY) {
                    // For all intents and purposes, this is the same object
                    return;
                }
            }

            // the modelItem needs to match up perfectly with item if our model is
            // to be consistent with the database-- for now, just require
            // modelItem == item or the equality check above
            String msg = "item: " + ((item != null) ? item.toString() : "null") +
                    "modelItem: " +
                    ((modelItem != null) ? modelItem.toString() : "null") +
                    "Error: ItemInfo passed to checkItemInfo doesn't match original";
            RuntimeException e = new RuntimeException(msg);
            if (stackTrace != null) {
                e.setStackTrace(stackTrace);
            }
            throw e;
        }
    }

    static void checkItemInfo(final ItemInfo item) {
        final StackTraceElement[] stackTrace = new Throwable().getStackTrace();
        final long itemId = item.id;
        Runnable r = new Runnable() {
            public void run() {
                synchronized (sBgLock) {
                    checkItemInfoLocked(itemId, item, stackTrace);
                }
            }
        };
        runOnWorkerThread(r);
    }

    static void updateItemInDatabaseHelper(Context context, final ContentValues values,
            final ItemInfo item, final String callingFunction) {
        final long itemId = item.id;
        final Uri uri = LauncherSettings.Favorites.getContentUri(itemId);
        final ContentResolver cr = context.getContentResolver();

        final StackTraceElement[] stackTrace = new Throwable().getStackTrace();
        Runnable r = new Runnable() {
            public void run() {
                cr.update(uri, values, null, null);
                updateItemArrays(item, itemId, stackTrace);
            }
        };
        runOnWorkerThread(r);
    }

    static void updateItemsInDatabaseHelper(Context context, final ArrayList<ContentValues> valuesList,
            final ArrayList<ItemInfo> items, final String callingFunction) {
        final ContentResolver cr = context.getContentResolver();

        final StackTraceElement[] stackTrace = new Throwable().getStackTrace();
        Runnable r = new Runnable() {
            public void run() {
                ArrayList<ContentProviderOperation> ops =
                        new ArrayList<ContentProviderOperation>();
                int count = items.size();
                for (int i = 0; i < count; i++) {
                    ItemInfo item = items.get(i);
                    final long itemId = item.id;
                    final Uri uri = LauncherSettings.Favorites.getContentUri(itemId);
                    ContentValues values = valuesList.get(i);

                    ops.add(ContentProviderOperation.newUpdate(uri).withValues(values).build());
                    updateItemArrays(item, itemId, stackTrace);

                }
                try {
                    cr.applyBatch(LauncherProvider.AUTHORITY, ops);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        };
        runOnWorkerThread(r);
    }

    static void updateItemArrays(ItemInfo item, long itemId, StackTraceElement[] stackTrace) {
        // Lock on mBgLock *after* the db operation
        synchronized (sBgLock) {
            checkItemInfoLocked(itemId, item, stackTrace);

            if (item.container != LauncherSettings.Favorites.CONTAINER_DESKTOP &&
                    item.container != LauncherSettings.Favorites.CONTAINER_HOTSEAT) {
                // Item is in a folder, make sure this folder exists
                if (!sBgFolders.containsKey(item.container)) {
                    // An items container is being set to a that of an item which is not in
                    // the list of Folders.
                    String msg = "item: " + item + " container being set to: " +
                            item.container + ", not in the list of folders";
                    Log.e(TAG, msg);
                }
            }

            // Items are added/removed from the corresponding FolderInfo elsewhere, such
            // as in Workspace.onDrop. Here, we just add/remove them from the list of items
            // that are on the desktop, as appropriate
            ItemInfo modelItem = sBgItemsIdMap.get(itemId);
            if (modelItem != null &&
                    (modelItem.container == LauncherSettings.Favorites.CONTAINER_DESKTOP ||
                     modelItem.container == LauncherSettings.Favorites.CONTAINER_HOTSEAT)) {
                switch (modelItem.itemType) {
                    case LauncherSettings.Favorites.ITEM_TYPE_APPLICATION:
                    case LauncherSettings.Favorites.ITEM_TYPE_SHORTCUT:
                    case LauncherSettings.Favorites.ITEM_TYPE_FOLDER:
                        if (!sBgWorkspaceItems.contains(modelItem)) {
                            sBgWorkspaceItems.add(modelItem);
                        }
                        break;
                    default:
                        break;
                }
            } else {
                sBgWorkspaceItems.remove(modelItem);
            }
        }
    }

    /**
     * Move an item in the DB to a new <container, screen, cellX, cellY>
     */
    public static void moveItemInDatabase(Context context, final ItemInfo item, final long container,
            final long screenId, final int cellX, final int cellY) {
        item.container = container;
        item.cellX = cellX;
        item.cellY = cellY;

        // We store hotseat items in canonical form which is this orientation invariant position
        // in the hotseat
        if (context instanceof Launcher && screenId < 0 &&
                container == LauncherSettings.Favorites.CONTAINER_HOTSEAT) {
            item.screenId = ((Launcher) context).getHotseat().getOrderInHotseat(cellX, cellY);
        } else {
            item.screenId = screenId;
        }

        final ContentValues values = new ContentValues();
        values.put(LauncherSettings.Favorites.CONTAINER, item.container);
        values.put(LauncherSettings.Favorites.CELLX, item.cellX);
        values.put(LauncherSettings.Favorites.CELLY, item.cellY);
        values.put(LauncherSettings.Favorites.RANK, item.rank);
        values.put(LauncherSettings.Favorites.SCREEN, item.screenId);

        updateItemInDatabaseHelper(context, values, item, "moveItemInDatabase");
    }

    /**
     * Move items in the DB to a new <container, screen, cellX, cellY>. We assume that the
     * cellX, cellY have already been updated on the ItemInfos.
     */
    static void moveItemsInDatabase(Context context, final ArrayList<ItemInfo> items,
            final long container, final int screen) {

        ArrayList<ContentValues> contentValues = new ArrayList<ContentValues>();
        int count = items.size();

        for (int i = 0; i < count; i++) {
            ItemInfo item = items.get(i);
            item.container = container;

            // We store hotseat items in canonical form which is this orientation invariant position
            // in the hotseat
            if (context instanceof Launcher && screen < 0 &&
                    container == LauncherSettings.Favorites.CONTAINER_HOTSEAT) {
                item.screenId = ((Launcher) context).getHotseat().getOrderInHotseat(item.cellX,
                        item.cellY);
            } else {
                item.screenId = screen;
            }

            final ContentValues values = new ContentValues();
            values.put(LauncherSettings.Favorites.CONTAINER, item.container);
            values.put(LauncherSettings.Favorites.CELLX, item.cellX);
            values.put(LauncherSettings.Favorites.CELLY, item.cellY);
            values.put(LauncherSettings.Favorites.RANK, item.rank);
            values.put(LauncherSettings.Favorites.SCREEN, item.screenId);

            contentValues.add(values);
        }
        updateItemsInDatabaseHelper(context, contentValues, items, "moveItemInDatabase");
    }

    /**
     * Move and/or resize item in the DB to a new <container, screen, cellX, cellY, spanX, spanY>
     */
    static void modifyItemInDatabase(Context context, final ItemInfo item, final long container,
            final long screenId, final int cellX, final int cellY, final int spanX, final int spanY) {
        item.container = container;
        item.cellX = cellX;
        item.cellY = cellY;
        item.spanX = spanX;
        item.spanY = spanY;

        // We store hotseat items in canonical form which is this orientation invariant position
        // in the hotseat
        if (context instanceof Launcher && screenId < 0 &&
                container == LauncherSettings.Favorites.CONTAINER_HOTSEAT) {
            item.screenId = ((Launcher) context).getHotseat().getOrderInHotseat(cellX, cellY);
        } else {
            item.screenId = screenId;
        }

        final ContentValues values = new ContentValues();
        values.put(LauncherSettings.Favorites.CONTAINER, item.container);
        values.put(LauncherSettings.Favorites.CELLX, item.cellX);
        values.put(LauncherSettings.Favorites.CELLY, item.cellY);
        values.put(LauncherSettings.Favorites.RANK, item.rank);
        values.put(LauncherSettings.Favorites.SPANX, item.spanX);
        values.put(LauncherSettings.Favorites.SPANY, item.spanY);
        values.put(LauncherSettings.Favorites.SCREEN, item.screenId);

        updateItemInDatabaseHelper(context, values, item, "modifyItemInDatabase");
    }

    /**
     * Update an item to the database in a specified container.
     */
    public static void updateItemInDatabase(Context context, final ItemInfo item) {
        final ContentValues values = new ContentValues();
        item.onAddToDatabase(context, values);
        updateItemInDatabaseHelper(context, values, item, "updateItemInDatabase");
    }

    private void assertWorkspaceLoaded() {
        if (ProviderConfig.IS_DOGFOOD_BUILD) {
            synchronized (mLock) {
                if (!mHasLoaderCompletedOnce ||
                        (mLoaderTask != null && mLoaderTask.mIsLoadingAndBindingWorkspace)) {
                    throw new RuntimeException("Trying to add shortcut while loader is running");
                }
            }
        }
    }

    /**
     * Returns true if the shortcuts already exists on the workspace. This must be called after
     * the workspace has been loaded. We identify a shortcut by its intent.
     */
    @Thunk boolean shortcutExists(Context context, Intent intent, UserHandleCompat user) {
        assertWorkspaceLoaded();
        final String intentWithPkg, intentWithoutPkg;
        if (intent.getComponent() != null) {
            // If component is not null, an intent with null package will produce
            // the same result and should also be a match.
            String packageName = intent.getComponent().getPackageName();
            if (intent.getPackage() != null) {
                intentWithPkg = intent.toUri(0);
                intentWithoutPkg = new Intent(intent).setPackage(null).toUri(0);
            } else {
                intentWithPkg = new Intent(intent).setPackage(packageName).toUri(0);
                intentWithoutPkg = intent.toUri(0);
            }
        } else {
            intentWithPkg = intent.toUri(0);
            intentWithoutPkg = intent.toUri(0);
        }

        synchronized (sBgLock) {
            for (ItemInfo item : sBgItemsIdMap) {
                if (item instanceof ShortcutInfo) {
                    ShortcutInfo info = (ShortcutInfo) item;
                    Intent targetIntent = info.promisedIntent == null
                            ? info.intent : info.promisedIntent;
                    if (targetIntent != null && info.user.equals(user)) {
                        String s = targetIntent.toUri(0);
                        if (intentWithPkg.equals(s) || intentWithoutPkg.equals(s)) {
                            return true;
                        }
                    }
                }
            }
        }
        return false;
    }

    /**
     * Find a folder in the db, creating the FolderInfo if necessary, and adding it to folderList.
     */
    FolderInfo getFolderById(Context context, LongArrayMap<FolderInfo> folderList, long id) {
        final ContentResolver cr = context.getContentResolver();
        Cursor c = cr.query(LauncherSettings.Favorites.CONTENT_URI, null,
                "_id=? and (itemType=? or itemType=?)",
                new String[] { String.valueOf(id),
                        String.valueOf(LauncherSettings.Favorites.ITEM_TYPE_FOLDER)}, null);

        try {
            if (c.moveToFirst()) {
                final int itemTypeIndex = c.getColumnIndexOrThrow(LauncherSettings.Favorites.ITEM_TYPE);
                final int titleIndex = c.getColumnIndexOrThrow(LauncherSettings.Favorites.TITLE);
                final int containerIndex = c.getColumnIndexOrThrow(LauncherSettings.Favorites.CONTAINER);
                final int screenIndex = c.getColumnIndexOrThrow(LauncherSettings.Favorites.SCREEN);
                final int cellXIndex = c.getColumnIndexOrThrow(LauncherSettings.Favorites.CELLX);
                final int cellYIndex = c.getColumnIndexOrThrow(LauncherSettings.Favorites.CELLY);
                final int optionsIndex = c.getColumnIndexOrThrow(LauncherSettings.Favorites.OPTIONS);

                FolderInfo folderInfo = null;
                switch (c.getInt(itemTypeIndex)) {
                    case LauncherSettings.Favorites.ITEM_TYPE_FOLDER:
                        folderInfo = findOrMakeFolder(folderList, id);
                        break;
                }

                // Do not trim the folder label, as is was set by the user.
                folderInfo.title = c.getString(titleIndex);
                folderInfo.id = id;
                folderInfo.container = c.getInt(containerIndex);
                folderInfo.screenId = c.getInt(screenIndex);
                folderInfo.cellX = c.getInt(cellXIndex);
                folderInfo.cellY = c.getInt(cellYIndex);
                folderInfo.options = c.getInt(optionsIndex);

                return folderInfo;
            }
        } finally {
            c.close();
        }

        return null;
    }

    /**
     * Add an item to the database in a specified container. Sets the container, screen, cellX and
     * cellY fields of the item. Also assigns an ID to the item.
     */
    public static void addItemToDatabase(Context context, final ItemInfo item, final long container,
            final long screenId, final int cellX, final int cellY) {
        item.container = container;
        item.cellX = cellX;
        item.cellY = cellY;
        // We store hotseat items in canonical form which is this orientation invariant position
        // in the hotseat
        if (context instanceof Launcher && screenId < 0 &&
                container == LauncherSettings.Favorites.CONTAINER_HOTSEAT) {
            item.screenId = ((Launcher) context).getHotseat().getOrderInHotseat(cellX, cellY);
        } else {
            item.screenId = screenId;
        }

        final ContentValues values = new ContentValues();
        final ContentResolver cr = context.getContentResolver();
        item.onAddToDatabase(context, values);

        item.id = LauncherAppState.getLauncherProvider().generateNewItemId();
        values.put(LauncherSettings.Favorites._ID, item.id);

        final StackTraceElement[] stackTrace = new Throwable().getStackTrace();
        Runnable r = new Runnable() {
            public void run() {
                cr.insert(LauncherSettings.Favorites.CONTENT_URI, values);

                // Lock on mBgLock *after* the db operation
                synchronized (sBgLock) {
                    checkItemInfoLocked(item.id, item, stackTrace);
                    sBgItemsIdMap.put(item.id, item);
                    switch (item.itemType) {
                        case LauncherSettings.Favorites.ITEM_TYPE_FOLDER:
                            sBgFolders.put(item.id, (FolderInfo) item);
                            // Fall through
                        case LauncherSettings.Favorites.ITEM_TYPE_APPLICATION:
                        case LauncherSettings.Favorites.ITEM_TYPE_SHORTCUT:
                            if (item.container == LauncherSettings.Favorites.CONTAINER_DESKTOP ||
                                    item.container == LauncherSettings.Favorites.CONTAINER_HOTSEAT) {
                                sBgWorkspaceItems.add(item);
                            } else {
                                if (!sBgFolders.containsKey(item.container)) {
                                    // Adding an item to a folder that doesn't exist.
                                    String msg = "adding item: " + item + " to a folder that " +
                                            " doesn't exist";
                                    Log.e(TAG, msg);
                                }
                            }
                            break;
                        case LauncherSettings.Favorites.ITEM_TYPE_APPWIDGET:
                            sBgAppWidgets.add((LauncherAppWidgetInfo) item);
                            break;
                    }
                }
            }
        };
        runOnWorkerThread(r);
    }

    /**
     * Creates a new unique child id, for a given cell span across all layouts.
     */
    static int getCellLayoutChildId(
            long container, long screen, int localCellX, int localCellY, int spanX, int spanY) {
        return (((int) container & 0xFF) << 24)
                | ((int) screen & 0xFF) << 16 | (localCellX & 0xFF) << 8 | (localCellY & 0xFF);
    }

    private static ArrayList<ItemInfo> getItemsByPackageName(
            final String pn, final UserHandleCompat user) {
        ItemInfoFilter filter  = new ItemInfoFilter() {
            @Override
            public boolean filterItem(ItemInfo parent, ItemInfo info, ComponentName cn) {
                return cn.getPackageName().equals(pn) && info.user.equals(user);
            }
        };
        return filterItemInfos(sBgItemsIdMap, filter);
    }

    /**
     * Removes all the items from the database corresponding to the specified package.
     */
    static void deletePackageFromDatabase(Context context, final String pn,
            final UserHandleCompat user) {
        deleteItemsFromDatabase(context, getItemsByPackageName(pn, user));
    }

    /**
     * Removes the specified item from the database
     * @param context
     * @param item
     */
    public static void deleteItemFromDatabase(Context context, final ItemInfo item) {
        ArrayList<ItemInfo> items = new ArrayList<ItemInfo>();
        items.add(item);
        deleteItemsFromDatabase(context, items);
    }

    /**
     * Removes the specified items from the database
     * @param context
     * @param item
     */
    static void deleteItemsFromDatabase(Context context, final ArrayList<? extends ItemInfo> items) {
        final ContentResolver cr = context.getContentResolver();
        Runnable r = new Runnable() {
            public void run() {
                for (ItemInfo item : items) {
                    final Uri uri = LauncherSettings.Favorites.getContentUri(item.id);
                    cr.delete(uri, null, null);

                    // Lock on mBgLock *after* the db operation
                    synchronized (sBgLock) {
                        switch (item.itemType) {
                            case LauncherSettings.Favorites.ITEM_TYPE_FOLDER:
                                sBgFolders.remove(item.id);
                                for (ItemInfo info: sBgItemsIdMap) {
                                    if (info.container == item.id) {
                                        // We are deleting a folder which still contains items that
                                        // think they are contained by that folder.
                                        String msg = "deleting a folder (" + item + ") which still " +
                                                "contains items (" + info + ")";
                                        Log.e(TAG, msg);
                                    }
                                }
                                sBgWorkspaceItems.remove(item);
                                break;
                            case LauncherSettings.Favorites.ITEM_TYPE_APPLICATION:
                            case LauncherSettings.Favorites.ITEM_TYPE_SHORTCUT:
                                sBgWorkspaceItems.remove(item);
                                break;
                            case LauncherSettings.Favorites.ITEM_TYPE_APPWIDGET:
                                sBgAppWidgets.remove((LauncherAppWidgetInfo) item);
                                break;
                        }
                        sBgItemsIdMap.remove(item.id);
                    }
                }
            }
        };
        runOnWorkerThread(r);
    }

    /**
     * Update the order of the workspace screens in the database. The array list contains
     * a list of screen ids in the order that they should appear.
     */
    public void updateWorkspaceScreenOrder(Context context, final ArrayList<Long> screens) {
        final ArrayList<Long> screensCopy = new ArrayList<Long>(screens);
        final ContentResolver cr = context.getContentResolver();
        final Uri uri = LauncherSettings.WorkspaceScreens.CONTENT_URI;

        // Remove any negative screen ids -- these aren't persisted
        Iterator<Long> iter = screensCopy.iterator();
        while (iter.hasNext()) {
            long id = iter.next();
            if (id < 0) {
                iter.remove();
            }
        }

        Runnable r = new Runnable() {
            @Override
            public void run() {
                ArrayList<ContentProviderOperation> ops = new ArrayList<ContentProviderOperation>();
                // Clear the table
                ops.add(ContentProviderOperation.newDelete(uri).build());
                int count = screensCopy.size();
                for (int i = 0; i < count; i++) {
                    ContentValues v = new ContentValues();
                    long screenId = screensCopy.get(i);
                    v.put(LauncherSettings.WorkspaceScreens._ID, screenId);
                    v.put(LauncherSettings.WorkspaceScreens.SCREEN_RANK, i);
                    ops.add(ContentProviderOperation.newInsert(uri).withValues(v).build());
                }

                try {
                    cr.applyBatch(LauncherProvider.AUTHORITY, ops);
                } catch (Exception ex) {
                    throw new RuntimeException(ex);
                }

                synchronized (sBgLock) {
                    sBgWorkspaceScreens.clear();
                    sBgWorkspaceScreens.addAll(screensCopy);
                }
            }
        };
        runOnWorkerThread(r);
    }

    /**
     * Remove the contents of the specified folder from the database
     */
    public static void deleteFolderContentsFromDatabase(Context context, final FolderInfo info) {
        final ContentResolver cr = context.getContentResolver();

        Runnable r = new Runnable() {
            public void run() {
                cr.delete(LauncherSettings.Favorites.getContentUri(info.id), null, null);
                // Lock on mBgLock *after* the db operation
                synchronized (sBgLock) {
                    sBgItemsIdMap.remove(info.id);
                    sBgFolders.remove(info.id);
                    sBgWorkspaceItems.remove(info);
                }

                cr.delete(LauncherSettings.Favorites.CONTENT_URI,
                        LauncherSettings.Favorites.CONTAINER + "=" + info.id, null);
                // Lock on mBgLock *after* the db operation
                synchronized (sBgLock) {
                    for (ItemInfo childInfo : info.contents) {
                        sBgItemsIdMap.remove(childInfo.id);
                    }
                }
            }
        };
        runOnWorkerThread(r);
    }

    /**
     * Set this as the current Launcher activity object for the loader.
     */
    public void initialize(Callbacks callbacks) {
        synchronized (mLock) {
            // Disconnect any of the callbacks and drawables associated with ItemInfos on the
            // workspace to prevent leaking Launcher activities on orientation change.
            unbindItemInfosAndClearQueuedBindRunnables();
            mCallbacks = new WeakReference<Callbacks>(callbacks);
        }
    }

    @Override
    public void onPackageChanged(String packageName, UserHandleCompat user) {
        int op = PackageUpdatedTask.OP_UPDATE;
        enqueuePackageUpdated(new PackageUpdatedTask(op, new String[] { packageName },
                user));
    }

    @Override
    public void onPackageRemoved(String packageName, UserHandleCompat user) {
        int op = PackageUpdatedTask.OP_REMOVE;
        enqueuePackageUpdated(new PackageUpdatedTask(op, new String[] { packageName },
                user));
    }

    @Override
    public void onPackageAdded(String packageName, UserHandleCompat user) {
        int op = PackageUpdatedTask.OP_ADD;
        enqueuePackageUpdated(new PackageUpdatedTask(op, new String[] { packageName },
                user));
    }

    @Override
    public void onPackagesAvailable(String[] packageNames, UserHandleCompat user,
            boolean replacing) {
        if (!replacing) {
            enqueuePackageUpdated(new PackageUpdatedTask(PackageUpdatedTask.OP_ADD, packageNames,
                    user));
            if (mAppsCanBeOnRemoveableStorage) {
                // Only rebind if we support removable storage. It catches the
                // case where
                // apps on the external sd card need to be reloaded
                startLoaderFromBackground();
            }
        } else {
            // If we are replacing then just update the packages in the list
            enqueuePackageUpdated(new PackageUpdatedTask(PackageUpdatedTask.OP_UPDATE,
                    packageNames, user));
        }
    }

    @Override
    public void onPackagesUnavailable(String[] packageNames, UserHandleCompat user,
            boolean replacing) {
        if (!replacing) {
            enqueuePackageUpdated(new PackageUpdatedTask(
                    PackageUpdatedTask.OP_UNAVAILABLE, packageNames,
                    user));
        }
    }

    /**
     * Call from the handler for ACTION_PACKAGE_ADDED, ACTION_PACKAGE_REMOVED and
     * ACTION_PACKAGE_CHANGED.
     */
    @Override
    public void onReceive(Context context, Intent intent) {
        if (DEBUG_RECEIVER) Log.d(TAG, "onReceive intent=" + intent);

        final String action = intent.getAction();
        if (Intent.ACTION_LOCALE_CHANGED.equals(action)) {
            // If we have changed locale we need to clear out the labels in all apps/workspace.
            forceReload();
        } else if (SearchManager.INTENT_GLOBAL_SEARCH_ACTIVITY_CHANGED.equals(action)) {
            Callbacks callbacks = getCallback();
            if (callbacks != null) {
                callbacks.bindSearchProviderChanged();
            }
        } else if (LauncherAppsCompat.ACTION_MANAGED_PROFILE_ADDED.equals(action)
                || LauncherAppsCompat.ACTION_MANAGED_PROFILE_REMOVED.equals(action)) {
            UserManagerCompat.getInstance(context).enableAndResetCache();
            forceReload();
        }
    }

    void forceReload() {
        resetLoadedState(true, true);

        // Do this here because if the launcher activity is running it will be restarted.
        // If it's not running startLoaderFromBackground will merely tell it that it needs
        // to reload.
        startLoaderFromBackground();
    }

    public void resetLoadedState(boolean resetAllAppsLoaded, boolean resetWorkspaceLoaded) {
        synchronized (mLock) {
            // Stop any existing loaders first, so they don't set mAllAppsLoaded or
            // mWorkspaceLoaded to true later
            stopLoaderLocked();
            if (resetAllAppsLoaded) mAllAppsLoaded = false;
            if (resetWorkspaceLoaded) mWorkspaceLoaded = false;
        }
    }

    /**
     * When the launcher is in the background, it's possible for it to miss paired
     * configuration changes.  So whenever we trigger the loader from the background
     * tell the launcher that it needs to re-run the loader when it comes back instead
     * of doing it now.
     */
    public void startLoaderFromBackground() {
        boolean runLoader = false;
        Callbacks callbacks = getCallback();
        if (callbacks != null) {
            // Only actually run the loader if they're not paused.
            if (!callbacks.setLoadOnResume()) {
                runLoader = true;
            }
        }
        if (runLoader) {
            startLoader(PagedView.INVALID_RESTORE_PAGE);
        }
    }

    /**
     * If there is already a loader task running, tell it to stop.
     */
    private void stopLoaderLocked() {
        LoaderTask oldTask = mLoaderTask;
        if (oldTask != null) {
            oldTask.stopLocked();
        }
    }

    public boolean isCurrentCallbacks(Callbacks callbacks) {
        return (mCallbacks != null && mCallbacks.get() == callbacks);
    }

    public void startLoader(int synchronousBindPage) {
        startLoader(synchronousBindPage, LOADER_FLAG_NONE);
    }

    public void startLoader(int synchronousBindPage, int loadFlags) {
        // Enable queue before starting loader. It will get disabled in Launcher#finishBindingItems
        InstallShortcutReceiver.enableInstallQueue();
        synchronized (mLock) {
            // Clear any deferred bind-runnables from the synchronized load process
            // We must do this before any loading/binding is scheduled below.
            synchronized (mDeferredBindRunnables) {
                mDeferredBindRunnables.clear();
            }

            // Don't bother to start the thread if we know it's not going to do anything
            if (mCallbacks != null && mCallbacks.get() != null) {
                // If there is already one running, tell it to stop.
                stopLoaderLocked();
                mLoaderTask = new LoaderTask(mApp.getContext(), loadFlags);
                if (synchronousBindPage != PagedView.INVALID_RESTORE_PAGE
                        && mAllAppsLoaded && mWorkspaceLoaded && !mIsLoaderTaskRunning) {
                    mLoaderTask.runBindSynchronousPage(synchronousBindPage);
                } else {
                    sWorkerThread.setPriority(Thread.NORM_PRIORITY);
                    sWorker.post(mLoaderTask);
                }
            }
        }
    }

    void bindRemainingSynchronousPages() {
        // Post the remaining side pages to be loaded
        if (!mDeferredBindRunnables.isEmpty()) {
            Runnable[] deferredBindRunnables = null;
            synchronized (mDeferredBindRunnables) {
                deferredBindRunnables = mDeferredBindRunnables.toArray(
                        new Runnable[mDeferredBindRunnables.size()]);
                mDeferredBindRunnables.clear();
            }
            for (final Runnable r : deferredBindRunnables) {
                mHandler.post(r);
            }
        }
    }

    public void stopLoader() {
        synchronized (mLock) {
            if (mLoaderTask != null) {
                mLoaderTask.stopLocked();
            }
        }
    }

    /**
     * Loads the workspace screen ids in an ordered list.
     */
    public static ArrayList<Long> loadWorkspaceScreensDb(Context context) {
        final ContentResolver contentResolver = context.getContentResolver();
        final Uri screensUri = LauncherSettings.WorkspaceScreens.CONTENT_URI;

        // Get screens ordered by rank.
        final Cursor sc = contentResolver.query(screensUri, null, null, null,
                LauncherSettings.WorkspaceScreens.SCREEN_RANK);
        ArrayList<Long> screenIds = new ArrayList<Long>();
        try {
            final int idIndex = sc.getColumnIndexOrThrow(LauncherSettings.WorkspaceScreens._ID);
            while (sc.moveToNext()) {
                try {
                    screenIds.add(sc.getLong(idIndex));
                } catch (Exception e) {
                    Launcher.addDumpLog(TAG, "Desktop items loading interrupted"
                            + " - invalid screens: " + e, true);
                }
            }
        } finally {
            sc.close();
        }
        return screenIds;
    }

    public boolean isAllAppsLoaded() {
        return mAllAppsLoaded;
    }

    /**
     * Runnable for the thread that loads the contents of the launcher:
     *   - workspace icons
     *   - widgets
     *   - all apps icons
     */
    private class LoaderTask implements Runnable {
        private Context mContext;
        @Thunk boolean mIsLoadingAndBindingWorkspace;
        private boolean mStopped;
        @Thunk boolean mLoadAndBindStepFinished;
        private int mFlags;

        LoaderTask(Context context, int flags) {
            mContext = context;
            mFlags = flags;
        }

        private void loadAndBindWorkspace() {
            mIsLoadingAndBindingWorkspace = true;

            // Load the workspace
            if (DEBUG_LOADERS) {
                Log.d(TAG, "loadAndBindWorkspace mWorkspaceLoaded=" + mWorkspaceLoaded);
            }

            if (!mWorkspaceLoaded) {
                loadWorkspace();
                synchronized (LoaderTask.this) {
                    if (mStopped) {
                        return;
                    }
                    mWorkspaceLoaded = true;
                }
            }

            // Bind the workspace
            bindWorkspace(-1);
        }

        private void waitForIdle() {
            // Wait until the either we're stopped or the other threads are done.
            // This way we don't start loading all apps until the workspace has settled
            // down.
            synchronized (LoaderTask.this) {
                final long workspaceWaitTime = DEBUG_LOADERS ? SystemClock.uptimeMillis() : 0;

                mHandler.postIdle(new Runnable() {
                        public void run() {
                            synchronized (LoaderTask.this) {
                                mLoadAndBindStepFinished = true;
                                if (DEBUG_LOADERS) {
                                    Log.d(TAG, "done with previous binding step");
                                }
                                LoaderTask.this.notify();
                            }
                        }
                    });

                while (!mStopped && !mLoadAndBindStepFinished) {
                    try {
                        // Just in case mFlushingWorkerThread changes but we aren't woken up,
                        // wait no longer than 1sec at a time
                        this.wait(1000);
                    } catch (InterruptedException ex) {
                        // Ignore
                    }
                }
                if (DEBUG_LOADERS) {
                    Log.d(TAG, "waited "
                            + (SystemClock.uptimeMillis()-workspaceWaitTime)
                            + "ms for previous step to finish binding");
                }
            }
        }

        void runBindSynchronousPage(int synchronousBindPage) {
            if (synchronousBindPage == PagedView.INVALID_RESTORE_PAGE) {
                // Ensure that we have a valid page index to load synchronously
                throw new RuntimeException("Should not call runBindSynchronousPage() without " +
                        "valid page index");
            }
            if (!mAllAppsLoaded || !mWorkspaceLoaded) {
                // Ensure that we don't try and bind a specified page when the pages have not been
                // loaded already (we should load everything asynchronously in that case)
                throw new RuntimeException("Expecting AllApps and Workspace to be loaded");
            }
            synchronized (mLock) {
                if (mIsLoaderTaskRunning) {
                    // Ensure that we are never running the background loading at this point since
                    // we also touch the background collections
                    throw new RuntimeException("Error! Background loading is already running");
                }
            }

            // XXX: Throw an exception if we are already loading (since we touch the worker thread
            //      data structures, we can't allow any other thread to touch that data, but because
            //      this call is synchronous, we can get away with not locking).

            // The LauncherModel is static in the LauncherAppState and mHandler may have queued
            // operations from the previous activity.  We need to ensure that all queued operations
            // are executed before any synchronous binding work is done.
            mHandler.flush();

            // Divide the set of loaded items into those that we are binding synchronously, and
            // everything else that is to be bound normally (asynchronously).
            bindWorkspace(synchronousBindPage);
            // XXX: For now, continue posting the binding of AllApps as there are other issues that
            //      arise from that.
            onlyBindAllApps();
        }

        public void run() {
            synchronized (mLock) {
                if (mStopped) {
                    return;
                }
                mIsLoaderTaskRunning = true;
            }
            // Optimize for end-user experience: if the Launcher is up and // running with the
            // All Apps interface in the foreground, load All Apps first. Otherwise, load the
            // workspace first (default).
            keep_running: {
                if (DEBUG_LOADERS) Log.d(TAG, "step 1: loading workspace");
                loadAndBindWorkspace();

                if (mStopped) {
                    break keep_running;
                }

                waitForIdle();

                // second step
                if (DEBUG_LOADERS) Log.d(TAG, "step 2: loading all apps");
                loadAndBindAllApps();
            }

            // Clear out this reference, otherwise we end up holding it until all of the
            // callback runnables are done.
            mContext = null;

            synchronized (mLock) {
                // If we are still the last one to be scheduled, remove ourselves.
                if (mLoaderTask == this) {
                    mLoaderTask = null;
                }
                mIsLoaderTaskRunning = false;
                mHasLoaderCompletedOnce = true;
            }
        }

        public void stopLocked() {
            synchronized (LoaderTask.this) {
                mStopped = true;
                this.notify();
            }
        }

        /**
         * Gets the callbacks object.  If we've been stopped, or if the launcher object
         * has somehow been garbage collected, return null instead.  Pass in the Callbacks
         * object that was around when the deferred message was scheduled, and if there's
         * a new Callbacks object around then also return null.  This will save us from
         * calling onto it with data that will be ignored.
         */
        Callbacks tryGetCallbacks(Callbacks oldCallbacks) {
            synchronized (mLock) {
                if (mStopped) {
                    return null;
                }

                if (mCallbacks == null) {
                    return null;
                }

                final Callbacks callbacks = mCallbacks.get();
                if (callbacks != oldCallbacks) {
                    return null;
                }
                if (callbacks == null) {
                    Log.w(TAG, "no mCallbacks");
                    return null;
                }

                return callbacks;
            }
        }

        // check & update map of what's occupied; used to discard overlapping/invalid items
        private boolean checkItemPlacement(LongArrayMap<ItemInfo[][]> occupied, ItemInfo item) {
            LauncherAppState app = LauncherAppState.getInstance();
            InvariantDeviceProfile profile = app.getInvariantDeviceProfile();
            final int countX = (int) profile.numColumns;
            final int countY = (int) profile.numRows;

            long containerIndex = item.screenId;
            if (item.container == LauncherSettings.Favorites.CONTAINER_HOTSEAT) {
                // Return early if we detect that an item is under the hotseat button
                if (mCallbacks == null ||
                        mCallbacks.get().isAllAppsButtonRank((int) item.screenId)) {
                    Log.e(TAG, "Error loading shortcut into hotseat " + item
                            + " into position (" + item.screenId + ":" + item.cellX + ","
                            + item.cellY + ") occupied by all apps");
                    return false;
                }

                final ItemInfo[][] hotseatItems =
                        occupied.get((long) LauncherSettings.Favorites.CONTAINER_HOTSEAT);

                if (item.screenId >= profile.numHotseatIcons) {
                    Log.e(TAG, "Error loading shortcut " + item
                            + " into hotseat position " + item.screenId
                            + ", position out of bounds: (0 to " + (profile.numHotseatIcons - 1)
                            + ")");
                    return false;
                }

                if (hotseatItems != null) {
                    if (hotseatItems[(int) item.screenId][0] != null) {
                        Log.e(TAG, "Error loading shortcut into hotseat " + item
                                + " into position (" + item.screenId + ":" + item.cellX + ","
                                + item.cellY + ") occupied by "
                                + occupied.get(LauncherSettings.Favorites.CONTAINER_HOTSEAT)
                                [(int) item.screenId][0]);
                            return false;
                    } else {
                        hotseatItems[(int) item.screenId][0] = item;
                        return true;
                    }
                } else {
                    final ItemInfo[][] items = new ItemInfo[(int) profile.numHotseatIcons][1];
                    items[(int) item.screenId][0] = item;
                    occupied.put((long) LauncherSettings.Favorites.CONTAINER_HOTSEAT, items);
                    return true;
                }
            } else if (item.container != LauncherSettings.Favorites.CONTAINER_DESKTOP) {
                // Skip further checking if it is not the hotseat or workspace container
                return true;
            }

            if (!occupied.containsKey(item.screenId)) {
                ItemInfo[][] items = new ItemInfo[countX + 1][countY + 1];
                occupied.put(item.screenId, items);
            }

            final ItemInfo[][] screens = occupied.get(item.screenId);
            if (item.container == LauncherSettings.Favorites.CONTAINER_DESKTOP &&
                    item.cellX < 0 || item.cellY < 0 ||
                    item.cellX + item.spanX > countX || item.cellY + item.spanY > countY) {
                Log.e(TAG, "Error loading shortcut " + item
                        + " into cell (" + containerIndex + "-" + item.screenId + ":"
                        + item.cellX + "," + item.cellY
                        + ") out of screen bounds ( " + countX + "x" + countY + ")");
                return false;
            }

            // Check if any workspace icons overlap with each other
            for (int x = item.cellX; x < (item.cellX+item.spanX); x++) {
                for (int y = item.cellY; y < (item.cellY+item.spanY); y++) {
                    if (screens[x][y] != null) {
                        Log.e(TAG, "Error loading shortcut " + item
                            + " into cell (" + containerIndex + "-" + item.screenId + ":"
                            + x + "," + y
                            + ") occupied by "
                            + screens[x][y]);
                        return false;
                    }
                }
            }
            for (int x = item.cellX; x < (item.cellX+item.spanX); x++) {
                for (int y = item.cellY; y < (item.cellY+item.spanY); y++) {
                    screens[x][y] = item;
                }
            }

            return true;
        }

        /** Clears all the sBg data structures */
        private void clearSBgDataStructures() {
            synchronized (sBgLock) {
                sBgWorkspaceItems.clear();
                sBgAppWidgets.clear();
                sBgFolders.clear();
                sBgItemsIdMap.clear();
                sBgWorkspaceScreens.clear();
            }
        }

        private void loadWorkspace() {
            final long t = DEBUG_LOADERS ? SystemClock.uptimeMillis() : 0;

            final Context context = mContext;
            final ContentResolver contentResolver = context.getContentResolver();
            final PackageManager manager = context.getPackageManager();
            final boolean isSafeMode = manager.isSafeMode();
            final LauncherAppsCompat launcherApps = LauncherAppsCompat.getInstance(context);
            final boolean isSdCardReady = Utilities.isBootCompleted();

            LauncherAppState app = LauncherAppState.getInstance();
            InvariantDeviceProfile profile = app.getInvariantDeviceProfile();
            int countX = (int) profile.numColumns;
            int countY = (int) profile.numRows;

            if (MigrateFromRestoreTask.ENABLED && MigrateFromRestoreTask.shouldRunTask(mContext)) {
                long migrationStartTime = System.currentTimeMillis();
                Log.v(TAG, "Starting workspace migration after restore");
                try {
                    MigrateFromRestoreTask task = new MigrateFromRestoreTask(mContext);
                    // Clear the flags before starting the task, so that we do not run the task
                    // again, in case there was an uncaught error.
                    MigrateFromRestoreTask.clearFlags(mContext);
                    task.execute();
                } catch (Exception e) {
                    Log.e(TAG, "Error during grid migration", e);

                    // Clear workspace.
                    mFlags = mFlags | LOADER_FLAG_CLEAR_WORKSPACE;
                }
                Log.v(TAG, "Workspace migration completed in "
                        + (System.currentTimeMillis() - migrationStartTime));
            }

            if ((mFlags & LOADER_FLAG_CLEAR_WORKSPACE) != 0) {
                Launcher.addDumpLog(TAG, "loadWorkspace: resetting launcher database", true);
                LauncherAppState.getLauncherProvider().deleteDatabase();
            }

            if ((mFlags & LOADER_FLAG_MIGRATE_SHORTCUTS) != 0) {
                // append the user's Launcher2 shortcuts
                Launcher.addDumpLog(TAG, "loadWorkspace: migrating from launcher2", true);
                LauncherAppState.getLauncherProvider().migrateLauncher2Shortcuts();
            } else {
                // Make sure the default workspace is loaded
                Launcher.addDumpLog(TAG, "loadWorkspace: loading default favorites", false);
                LauncherAppState.getLauncherProvider().loadDefaultFavoritesIfNecessary();
            }

            synchronized (sBgLock) {
                clearSBgDataStructures();
                final HashMap<String, Integer> installingPkgs = PackageInstallerCompat
                        .getInstance(mContext).updateAndGetActiveSessionCache();

                final ArrayList<Long> itemsToRemove = new ArrayList<Long>();
                final ArrayList<Long> restoredRows = new ArrayList<Long>();
                final Uri contentUri = LauncherSettings.Favorites.CONTENT_URI;
                if (DEBUG_LOADERS) Log.d(TAG, "loading model from " + contentUri);
                final Cursor c = contentResolver.query(contentUri, null, null, null, null);

                // +1 for the hotseat (it can be larger than the workspace)
                // Load workspace in reverse order to ensure that latest items are loaded first (and
                // before any earlier duplicates)
                final LongArrayMap<ItemInfo[][]> occupied = new LongArrayMap<>();

                try {
                    final int idIndex = c.getColumnIndexOrThrow(LauncherSettings.Favorites._ID);
                    final int intentIndex = c.getColumnIndexOrThrow
                            (LauncherSettings.Favorites.INTENT);
                    final int titleIndex = c.getColumnIndexOrThrow
                            (LauncherSettings.Favorites.TITLE);
                    final int containerIndex = c.getColumnIndexOrThrow(
                            LauncherSettings.Favorites.CONTAINER);
                    final int itemTypeIndex = c.getColumnIndexOrThrow(
                            LauncherSettings.Favorites.ITEM_TYPE);
                    final int appWidgetIdIndex = c.getColumnIndexOrThrow(
                            LauncherSettings.Favorites.APPWIDGET_ID);
                    final int appWidgetProviderIndex = c.getColumnIndexOrThrow(
                            LauncherSettings.Favorites.APPWIDGET_PROVIDER);
                    final int screenIndex = c.getColumnIndexOrThrow(
                            LauncherSettings.Favorites.SCREEN);
                    final int cellXIndex = c.getColumnIndexOrThrow
                            (LauncherSettings.Favorites.CELLX);
                    final int cellYIndex = c.getColumnIndexOrThrow
                            (LauncherSettings.Favorites.CELLY);
                    final int spanXIndex = c.getColumnIndexOrThrow
                            (LauncherSettings.Favorites.SPANX);
                    final int spanYIndex = c.getColumnIndexOrThrow(
                            LauncherSettings.Favorites.SPANY);
                    final int rankIndex = c.getColumnIndexOrThrow(
                            LauncherSettings.Favorites.RANK);
                    final int restoredIndex = c.getColumnIndexOrThrow(
                            LauncherSettings.Favorites.RESTORED);
                    final int profileIdIndex = c.getColumnIndexOrThrow(
                            LauncherSettings.Favorites.PROFILE_ID);
                    final int optionsIndex = c.getColumnIndexOrThrow(
                            LauncherSettings.Favorites.OPTIONS);
                    final CursorIconInfo cursorIconInfo = new CursorIconInfo(c);

                    final LongSparseArray<UserHandleCompat> allUsers = new LongSparseArray<>();
                    for (UserHandleCompat user : mUserManager.getUserProfiles()) {
                        allUsers.put(mUserManager.getSerialNumberForUser(user), user);
                    }

                    ShortcutInfo info;
                    String intentDescription;
                    LauncherAppWidgetInfo appWidgetInfo;
                    int container;
                    long id;
                    long serialNumber;
                    Intent intent;
                    UserHandleCompat user;

                    while (!mStopped && c.moveToNext()) {
                        try {
                            int itemType = c.getInt(itemTypeIndex);
                            boolean restored = 0 != c.getInt(restoredIndex);
                            boolean allowMissingTarget = false;
                            container = c.getInt(containerIndex);

                            switch (itemType) {
                            case LauncherSettings.Favorites.ITEM_TYPE_APPLICATION:
                            case LauncherSettings.Favorites.ITEM_TYPE_SHORTCUT:
                                id = c.getLong(idIndex);
                                intentDescription = c.getString(intentIndex);
                                serialNumber = c.getInt(profileIdIndex);
                                user = allUsers.get(serialNumber);
                                int promiseType = c.getInt(restoredIndex);
                                int disabledState = 0;
                                boolean itemReplaced = false;
                                if (user == null) {
                                    // User has been deleted remove the item.
                                    itemsToRemove.add(id);
                                    continue;
                                }
                                try {
                                    intent = Intent.parseUri(intentDescription, 0);
                                    ComponentName cn = intent.getComponent();
                                    if (cn != null && cn.getPackageName() != null) {
                                        boolean validPkg = launcherApps.isPackageEnabledForProfile(
                                                cn.getPackageName(), user);
                                        boolean validComponent = validPkg &&
                                                launcherApps.isActivityEnabledForProfile(cn, user);

                                        if (validComponent) {
                                            if (restored) {
                                                // no special handling necessary for this item
                                                restoredRows.add(id);
                                                restored = false;
                                            }
                                        } else if (validPkg) {
                                            intent = null;
                                            if ((promiseType & ShortcutInfo.FLAG_AUTOINTALL_ICON) != 0) {
                                                // We allow auto install apps to have their intent
                                                // updated after an install.
                                                intent = manager.getLaunchIntentForPackage(
                                                        cn.getPackageName());
                                                if (intent != null) {
                                                    ContentValues values = new ContentValues();
                                                    values.put(LauncherSettings.Favorites.INTENT,
                                                            intent.toUri(0));
                                                    updateItem(id, values);
                                                }
                                            }

                                            if (intent == null) {
                                                // The app is installed but the component is no
                                                // longer available.
                                                Launcher.addDumpLog(TAG,
                                                        "Invalid component removed: " + cn, true);
                                                itemsToRemove.add(id);
                                                continue;
                                            } else {
                                                // no special handling necessary for this item
                                                restoredRows.add(id);
                                                restored = false;
                                            }
                                        } else if (restored) {
                                            // Package is not yet available but might be
                                            // installed later.
                                            Launcher.addDumpLog(TAG,
                                                    "package not yet restored: " + cn, true);

                                            if ((promiseType & ShortcutInfo.FLAG_RESTORE_STARTED) != 0) {
                                                // Restore has started once.
                                            } else if (installingPkgs.containsKey(cn.getPackageName())) {
                                                // App restore has started. Update the flag
                                                promiseType |= ShortcutInfo.FLAG_RESTORE_STARTED;
                                                ContentValues values = new ContentValues();
                                                values.put(LauncherSettings.Favorites.RESTORED,
                                                        promiseType);
                                                updateItem(id, values);
                                            } else if ((promiseType & ShortcutInfo.FLAG_RESTORED_APP_TYPE) != 0) {
                                                // This is a common app. Try to replace this.
                                                int appType = CommonAppTypeParser.decodeItemTypeFromFlag(promiseType);
                                                CommonAppTypeParser parser = new CommonAppTypeParser(id, appType, context);
                                                if (parser.findDefaultApp()) {
                                                    // Default app found. Replace it.
                                                    intent = parser.parsedIntent;
                                                    cn = intent.getComponent();
                                                    ContentValues values = parser.parsedValues;
                                                    values.put(LauncherSettings.Favorites.RESTORED, 0);
                                                    updateItem(id, values);
                                                    restored = false;
                                                    itemReplaced = true;

                                                } else if (REMOVE_UNRESTORED_ICONS) {
                                                    Launcher.addDumpLog(TAG,
                                                            "Unrestored package removed: " + cn, true);
                                                    itemsToRemove.add(id);
                                                    continue;
                                                }
                                            } else if (REMOVE_UNRESTORED_ICONS) {
                                                Launcher.addDumpLog(TAG,
                                                        "Unrestored package removed: " + cn, true);
                                                itemsToRemove.add(id);
                                                continue;
                                            }
                                        } else if (launcherApps.isAppEnabled(
                                                manager, cn.getPackageName(),
                                                PackageManager.GET_UNINSTALLED_PACKAGES)) {
                                            // Package is present but not available.
                                            allowMissingTarget = true;
                                            disabledState = ShortcutInfo.FLAG_DISABLED_NOT_AVAILABLE;
                                        } else if (!isSdCardReady) {
                                            // SdCard is not ready yet. Package might get available,
                                            // once it is ready.
                                            Launcher.addDumpLog(TAG, "Invalid package: " + cn
                                                    + " (check again later)", true);
                                            HashSet<String> pkgs = sPendingPackages.get(user);
                                            if (pkgs == null) {
                                                pkgs = new HashSet<String>();
                                                sPendingPackages.put(user, pkgs);
                                            }
                                            pkgs.add(cn.getPackageName());
                                            allowMissingTarget = true;
                                            // Add the icon on the workspace anyway.

                                        } else {
                                            // Do not wait for external media load anymore.
                                            // Log the invalid package, and remove it
                                            Launcher.addDumpLog(TAG,
                                                    "Invalid package removed: " + cn, true);
                                            itemsToRemove.add(id);
                                            continue;
                                        }
                                    } else if (cn == null) {
                                        // For shortcuts with no component, keep them as they are
                                        restoredRows.add(id);
                                        restored = false;
                                    }
                                } catch (URISyntaxException e) {
                                    Launcher.addDumpLog(TAG,
                                            "Invalid uri: " + intentDescription, true);
                                    continue;
                                }

                                boolean useLowResIcon = container >= 0 &&
                                        c.getInt(rankIndex) >= FolderIcon.NUM_ITEMS_IN_PREVIEW;

                                if (itemReplaced) {
                                    if (user.equals(UserHandleCompat.myUserHandle())) {
                                        info = getAppShortcutInfo(manager, intent, user, context, null,
                                                cursorIconInfo.iconIndex, titleIndex,
                                                false, useLowResIcon);
                                    } else {
                                        // Don't replace items for other profiles.
                                        itemsToRemove.add(id);
                                        continue;
                                    }
                                } else if (restored) {
                                    if (user.equals(UserHandleCompat.myUserHandle())) {
                                        Launcher.addDumpLog(TAG,
                                                "constructing info for partially restored package",
                                                true);
                                        info = getRestoredItemInfo(c, titleIndex, intent,
                                                promiseType, itemType, cursorIconInfo, context);
                                        intent = getRestoredItemIntent(c, context, intent);
                                    } else {
                                        // Don't restore items for other profiles.
                                        itemsToRemove.add(id);
                                        continue;
                                    }
                                } else if (itemType ==
                                        LauncherSettings.Favorites.ITEM_TYPE_APPLICATION) {
                                    info = getAppShortcutInfo(manager, intent, user, context, c,
                                            cursorIconInfo.iconIndex, titleIndex,
                                            allowMissingTarget, useLowResIcon);
                                } else {
                                    info = getShortcutInfo(c, context, titleIndex, cursorIconInfo);

                                    // App shortcuts that used to be automatically added to Launcher
                                    // didn't always have the correct intent flags set, so do that
                                    // here
                                    if (intent.getAction() != null &&
                                        intent.getCategories() != null &&
                                        intent.getAction().equals(Intent.ACTION_MAIN) &&
                                        intent.getCategories().contains(Intent.CATEGORY_LAUNCHER)) {
                                        intent.addFlags(
                                            Intent.FLAG_ACTIVITY_NEW_TASK |
                                            Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);
                                    }
                                }

                                if (info != null) {
                                    info.id = id;
                                    info.intent = intent;
                                    info.container = container;
                                    info.screenId = c.getInt(screenIndex);
                                    info.cellX = c.getInt(cellXIndex);
                                    info.cellY = c.getInt(cellYIndex);
                                    info.rank = c.getInt(rankIndex);
                                    info.spanX = 1;
                                    info.spanY = 1;
                                    info.intent.putExtra(ItemInfo.EXTRA_PROFILE, serialNumber);
                                    if (info.promisedIntent != null) {
                                        info.promisedIntent.putExtra(ItemInfo.EXTRA_PROFILE, serialNumber);
                                    }
                                    info.isDisabled = disabledState;
                                    if (isSafeMode && !Utilities.isSystemApp(context, intent)) {
                                        info.isDisabled |= ShortcutInfo.FLAG_DISABLED_SAFEMODE;
                                    }

                                    // check & update map of what's occupied
                                    if (!checkItemPlacement(occupied, info)) {
                                        itemsToRemove.add(id);
                                        break;
                                    }

                                    if (restored) {
                                        ComponentName cn = info.getTargetComponent();
                                        if (cn != null) {
                                            Integer progress = installingPkgs.get(cn.getPackageName());
                                            if (progress != null) {
                                                info.setInstallProgress(progress);
                                            } else {
                                                info.status &= ~ShortcutInfo.FLAG_INSTALL_SESSION_ACTIVE;
                                            }
                                        }
                                    }

                                    switch (container) {
                                    case LauncherSettings.Favorites.CONTAINER_DESKTOP:
                                    case LauncherSettings.Favorites.CONTAINER_HOTSEAT:
                                        sBgWorkspaceItems.add(info);
                                        break;
                                    default:
                                        // Item is in a user folder
                                        FolderInfo folderInfo =
                                                findOrMakeFolder(sBgFolders, container);
                                        folderInfo.add(info);
                                        break;
                                    }
                                    sBgItemsIdMap.put(info.id, info);
                                } else {
                                    throw new RuntimeException("Unexpected null ShortcutInfo");
                                }
                                break;

                            case LauncherSettings.Favorites.ITEM_TYPE_FOLDER:
                                id = c.getLong(idIndex);
                                FolderInfo folderInfo = findOrMakeFolder(sBgFolders, id);

                                // Do not trim the folder label, as is was set by the user.
                                folderInfo.title = c.getString(titleIndex);
                                folderInfo.id = id;
                                folderInfo.container = container;
                                folderInfo.screenId = c.getInt(screenIndex);
                                folderInfo.cellX = c.getInt(cellXIndex);
                                folderInfo.cellY = c.getInt(cellYIndex);
                                folderInfo.spanX = 1;
                                folderInfo.spanY = 1;
                                folderInfo.options = c.getInt(optionsIndex);

                                // check & update map of what's occupied
                                if (!checkItemPlacement(occupied, folderInfo)) {
                                    itemsToRemove.add(id);
                                    break;
                                }

                                switch (container) {
                                    case LauncherSettings.Favorites.CONTAINER_DESKTOP:
                                    case LauncherSettings.Favorites.CONTAINER_HOTSEAT:
                                        sBgWorkspaceItems.add(folderInfo);
                                        break;
                                }

                                if (restored) {
                                    // no special handling required for restored folders
                                    restoredRows.add(id);
                                }

                                sBgItemsIdMap.put(folderInfo.id, folderInfo);
                                sBgFolders.put(folderInfo.id, folderInfo);
                                break;

                            case LauncherSettings.Favorites.ITEM_TYPE_APPWIDGET:
                            case LauncherSettings.Favorites.ITEM_TYPE_CUSTOM_APPWIDGET:
                                // Read all Launcher-specific widget details
                                boolean customWidget = itemType ==
                                    LauncherSettings.Favorites.ITEM_TYPE_CUSTOM_APPWIDGET;

                                int appWidgetId = c.getInt(appWidgetIdIndex);
                                serialNumber = c.getLong(profileIdIndex);
                                String savedProvider = c.getString(appWidgetProviderIndex);
                                id = c.getLong(idIndex);
                                user = allUsers.get(serialNumber);
                                if (user == null) {
                                    itemsToRemove.add(id);
                                    continue;
                                }

                                final ComponentName component =
                                        ComponentName.unflattenFromString(savedProvider);

                                final int restoreStatus = c.getInt(restoredIndex);
                                final boolean isIdValid = (restoreStatus &
                                        LauncherAppWidgetInfo.FLAG_ID_NOT_VALID) == 0;
                                final boolean wasProviderReady = (restoreStatus &
                                        LauncherAppWidgetInfo.FLAG_PROVIDER_NOT_READY) == 0;

                                final LauncherAppWidgetProviderInfo provider =
                                        LauncherModel.getProviderInfo(context,
                                                ComponentName.unflattenFromString(savedProvider),
                                                user);

                                final boolean isProviderReady = isValidProvider(provider);
                                if (!isSafeMode && !customWidget &&
                                        wasProviderReady && !isProviderReady) {
                                    String log = "Deleting widget that isn't installed anymore: "
                                            + "id=" + id + " appWidgetId=" + appWidgetId;

                                    Log.e(TAG, log);
                                    Launcher.addDumpLog(TAG, log, false);
                                    itemsToRemove.add(id);
                                } else {
                                    if (isProviderReady) {
                                        appWidgetInfo = new LauncherAppWidgetInfo(appWidgetId,
                                                provider.provider);

                                        // The provider is available. So the widget is either
                                        // available or not available. We do not need to track
                                        // any future restore updates.
                                        int status = restoreStatus &
                                                ~LauncherAppWidgetInfo.FLAG_RESTORE_STARTED;
                                        if (!wasProviderReady) {
                                            // If provider was not previously ready, update the
                                            // status and UI flag.

                                            // Id would be valid only if the widget restore broadcast was received.
                                            if (isIdValid) {
                                                status = LauncherAppWidgetInfo.FLAG_UI_NOT_READY;
                                            } else {
                                                status &= ~LauncherAppWidgetInfo
                                                        .FLAG_PROVIDER_NOT_READY;
                                            }
                                        }
                                        appWidgetInfo.restoreStatus = status;
                                    } else {
                                        Log.v(TAG, "Widget restore pending id=" + id
                                                + " appWidgetId=" + appWidgetId
                                                + " status =" + restoreStatus);
                                        appWidgetInfo = new LauncherAppWidgetInfo(appWidgetId,
                                                component);
                                        appWidgetInfo.restoreStatus = restoreStatus;
                                        Integer installProgress = installingPkgs.get(component.getPackageName());

                                        if ((restoreStatus & LauncherAppWidgetInfo.FLAG_RESTORE_STARTED) != 0) {
                                            // Restore has started once.
                                        } else if (installProgress != null) {
                                            // App restore has started. Update the flag
                                            appWidgetInfo.restoreStatus |=
                                                    LauncherAppWidgetInfo.FLAG_RESTORE_STARTED;
                                        } else if (REMOVE_UNRESTORED_ICONS && !isSafeMode) {
                                            Launcher.addDumpLog(TAG,
                                                    "Unrestored widget removed: " + component, true);
                                            itemsToRemove.add(id);
                                            continue;
                                        }

                                        appWidgetInfo.installProgress =
                                                installProgress == null ? 0 : installProgress;
                                    }

                                    appWidgetInfo.id = id;
                                    appWidgetInfo.screenId = c.getInt(screenIndex);
                                    appWidgetInfo.cellX = c.getInt(cellXIndex);
                                    appWidgetInfo.cellY = c.getInt(cellYIndex);
                                    appWidgetInfo.spanX = c.getInt(spanXIndex);
                                    appWidgetInfo.spanY = c.getInt(spanYIndex);
                                    appWidgetInfo.user = user;

                                    if (container != LauncherSettings.Favorites.CONTAINER_DESKTOP &&
                                        container != LauncherSettings.Favorites.CONTAINER_HOTSEAT) {
                                        Log.e(TAG, "Widget found where container != " +
                                            "CONTAINER_DESKTOP nor CONTAINER_HOTSEAT - ignoring!");
                                        continue;
                                    }

                                    appWidgetInfo.container = container;
                                    // check & update map of what's occupied
                                    if (!checkItemPlacement(occupied, appWidgetInfo)) {
                                        itemsToRemove.add(id);
                                        break;
                                    }

                                    if (!customWidget) {
                                        String providerName =
                                                appWidgetInfo.providerName.flattenToString();
                                        if (!providerName.equals(savedProvider) ||
                                                (appWidgetInfo.restoreStatus != restoreStatus)) {
                                            ContentValues values = new ContentValues();
                                            values.put(
                                                    LauncherSettings.Favorites.APPWIDGET_PROVIDER,
                                                    providerName);
                                            values.put(LauncherSettings.Favorites.RESTORED,
                                                    appWidgetInfo.restoreStatus);
                                            updateItem(id, values);
                                        }
                                    }
                                    sBgItemsIdMap.put(appWidgetInfo.id, appWidgetInfo);
                                    sBgAppWidgets.add(appWidgetInfo);
                                }
                                break;
                            }
                        } catch (Exception e) {
                            Launcher.addDumpLog(TAG, "Desktop items loading interrupted", e, true);
                        }
                    }
                } finally {
                    if (c != null) {
                        c.close();
                    }
                }

                // Break early if we've stopped loading
                if (mStopped) {
                    clearSBgDataStructures();
                    return;
                }

                if (itemsToRemove.size() > 0) {
                    // Remove dead items
                    contentResolver.delete(LauncherSettings.Favorites.CONTENT_URI,
                            Utilities.createDbSelectionQuery(
                                    LauncherSettings.Favorites._ID, itemsToRemove), null);
                    if (DEBUG_LOADERS) {
                        Log.d(TAG, "Removed = " + Utilities.createDbSelectionQuery(
                                LauncherSettings.Favorites._ID, itemsToRemove));
                    }

                    // Remove any empty folder
                    for (long folderId : LauncherAppState.getLauncherProvider()
                            .deleteEmptyFolders()) {
                        sBgWorkspaceItems.remove(sBgFolders.get(folderId));
                        sBgFolders.remove(folderId);
                        sBgItemsIdMap.remove(folderId);
                    }
                }

                // Sort all the folder items and make sure the first 3 items are high resolution.
                for (FolderInfo folder : sBgFolders) {
                    Collections.sort(folder.contents, Folder.ITEM_POS_COMPARATOR);
                    int pos = 0;
                    for (ShortcutInfo info : folder.contents) {
                        if (info.usingLowResIcon) {
                            info.updateIcon(mIconCache, false);
                        }
                        pos ++;
                        if (pos >= FolderIcon.NUM_ITEMS_IN_PREVIEW) {
                            break;
                        }
                    }
                }

                if (restoredRows.size() > 0) {
                    // Update restored items that no longer require special handling
                    ContentValues values = new ContentValues();
                    values.put(LauncherSettings.Favorites.RESTORED, 0);
                    contentResolver.update(LauncherSettings.Favorites.CONTENT_URI, values,
                            Utilities.createDbSelectionQuery(
                                    LauncherSettings.Favorites._ID, restoredRows), null);
                }

                if (!isSdCardReady && !sPendingPackages.isEmpty()) {
                    context.registerReceiver(new AppsAvailabilityCheck(),
                            new IntentFilter(Intent.ACTION_BOOT_COMPLETED),
                            null, sWorker);
                }

                sBgWorkspaceScreens.addAll(loadWorkspaceScreensDb(mContext));

                // Remove any empty screens
                ArrayList<Long> unusedScreens = new ArrayList<Long>(sBgWorkspaceScreens);
                for (ItemInfo item: sBgItemsIdMap) {
                    long screenId = item.screenId;
                    if (item.container == LauncherSettings.Favorites.CONTAINER_DESKTOP &&
                            unusedScreens.contains(screenId)) {
                        unusedScreens.remove(screenId);
                    }
                }

                // If there are any empty screens remove them, and update.
                if (unusedScreens.size() != 0) {
                    sBgWorkspaceScreens.removeAll(unusedScreens);
                    updateWorkspaceScreenOrder(context, sBgWorkspaceScreens);
                }

                if (DEBUG_LOADERS) {
                    Log.d(TAG, "loaded workspace in " + (SystemClock.uptimeMillis()-t) + "ms");
                    Log.d(TAG, "workspace layout: ");
                    int nScreens = occupied.size();
                    for (int y = 0; y < countY; y++) {
                        String line = "";

                        for (int i = 0; i < nScreens; i++) {
                            long screenId = occupied.keyAt(i);
                            if (screenId > 0) {
                                line += " | ";
                            }
                            ItemInfo[][] screen = occupied.valueAt(i);
                            for (int x = 0; x < countX; x++) {
                                if (x < screen.length && y < screen[x].length) {
                                    line += (screen[x][y] != null) ? "#" : ".";
                                } else {
                                    line += "!";
                                }
                            }
                        }
                        Log.d(TAG, "[ " + line + " ]");
                    }
                }
            }
        }

        /**
         * Partially updates the item without any notification. Must be called on the worker thread.
         */
        private void updateItem(long itemId, ContentValues update) {
            mContext.getContentResolver().update(
                    LauncherSettings.Favorites.CONTENT_URI,
                    update,
                    BaseColumns._ID + "= ?",
                    new String[]{Long.toString(itemId)});
        }

        /** Filters the set of items who are directly or indirectly (via another container) on the
         * specified screen. */
        private void filterCurrentWorkspaceItems(long currentScreenId,
                ArrayList<ItemInfo> allWorkspaceItems,
                ArrayList<ItemInfo> currentScreenItems,
                ArrayList<ItemInfo> otherScreenItems) {
            // Purge any null ItemInfos
            Iterator<ItemInfo> iter = allWorkspaceItems.iterator();
            while (iter.hasNext()) {
                ItemInfo i = iter.next();
                if (i == null) {
                    iter.remove();
                }
            }

            // Order the set of items by their containers first, this allows use to walk through the
            // list sequentially, build up a list of containers that are in the specified screen,
            // as well as all items in those containers.
            Set<Long> itemsOnScreen = new HashSet<Long>();
            Collections.sort(allWorkspaceItems, new Comparator<ItemInfo>() {
                @Override
                public int compare(ItemInfo lhs, ItemInfo rhs) {
                    return (int) (lhs.container - rhs.container);
                }
            });
            for (ItemInfo info : allWorkspaceItems) {
                if (info.container == LauncherSettings.Favorites.CONTAINER_DESKTOP) {
                    if (info.screenId == currentScreenId) {
                        currentScreenItems.add(info);
                        itemsOnScreen.add(info.id);
                    } else {
                        otherScreenItems.add(info);
                    }
                } else if (info.container == LauncherSettings.Favorites.CONTAINER_HOTSEAT) {
                    currentScreenItems.add(info);
                    itemsOnScreen.add(info.id);
                } else {
                    if (itemsOnScreen.contains(info.container)) {
                        currentScreenItems.add(info);
                        itemsOnScreen.add(info.id);
                    } else {
                        otherScreenItems.add(info);
                    }
                }
            }
        }

        /** Filters the set of widgets which are on the specified screen. */
        private void filterCurrentAppWidgets(long currentScreenId,
                ArrayList<LauncherAppWidgetInfo> appWidgets,
                ArrayList<LauncherAppWidgetInfo> currentScreenWidgets,
                ArrayList<LauncherAppWidgetInfo> otherScreenWidgets) {

            for (LauncherAppWidgetInfo widget : appWidgets) {
                if (widget == null) continue;
                if (widget.container == LauncherSettings.Favorites.CONTAINER_DESKTOP &&
                        widget.screenId == currentScreenId) {
                    currentScreenWidgets.add(widget);
                } else {
                    otherScreenWidgets.add(widget);
                }
            }
        }

        /** Filters the set of folders which are on the specified screen. */
        private void filterCurrentFolders(long currentScreenId,
                LongArrayMap<ItemInfo> itemsIdMap,
                LongArrayMap<FolderInfo> folders,
                LongArrayMap<FolderInfo> currentScreenFolders,
                LongArrayMap<FolderInfo> otherScreenFolders) {

            int total = folders.size();
            for (int i = 0; i < total; i++) {
                long id = folders.keyAt(i);
                FolderInfo folder = folders.valueAt(i);

                ItemInfo info = itemsIdMap.get(id);
                if (info == null || folder == null) continue;
                if (info.container == LauncherSettings.Favorites.CONTAINER_DESKTOP &&
                        info.screenId == currentScreenId) {
                    currentScreenFolders.put(id, folder);
                } else {
                    otherScreenFolders.put(id, folder);
                }
            }
        }

        /** Sorts the set of items by hotseat, workspace (spatially from top to bottom, left to
         * right) */
        private void sortWorkspaceItemsSpatially(ArrayList<ItemInfo> workspaceItems) {
            final LauncherAppState app = LauncherAppState.getInstance();
            final InvariantDeviceProfile profile = app.getInvariantDeviceProfile();
            final int screenCols = profile.numColumns;
            final int screenCellCount = profile.numColumns * profile.numRows;
            Collections.sort(workspaceItems, new Comparator<ItemInfo>() {
                @Override
                public int compare(ItemInfo lhs, ItemInfo rhs) {
                    if (lhs.container == rhs.container) {
                        // Within containers, order by their spatial position in that container
                        switch ((int) lhs.container) {
                            case LauncherSettings.Favorites.CONTAINER_DESKTOP: {
                                long lr = (lhs.screenId * screenCellCount +
                                        lhs.cellY * screenCols + lhs.cellX);
                                long rr = (rhs.screenId * screenCellCount +
                                        rhs.cellY * screenCols + rhs.cellX);
                                return (int) (lr - rr);
                            }
                            case LauncherSettings.Favorites.CONTAINER_HOTSEAT: {
                                // We currently use the screen id as the rank
                                return (int) (lhs.screenId - rhs.screenId);
                            }
                            default:
                                if (ProviderConfig.IS_DOGFOOD_BUILD) {
                                    throw new RuntimeException("Unexpected container type when " +
                                            "sorting workspace items.");
                                }
                                return 0;
                        }
                    } else {
                        // Between containers, order by hotseat, desktop
                        return (int) (lhs.container - rhs.container);
                    }
                }
            });
        }

        private void bindWorkspaceScreens(final Callbacks oldCallbacks,
                final ArrayList<Long> orderedScreens) {
            final Runnable r = new Runnable() {
                @Override
                public void run() {
                    Callbacks callbacks = tryGetCallbacks(oldCallbacks);
                    if (callbacks != null) {
                        callbacks.bindScreens(orderedScreens);
                    }
                }
            };
            runOnMainThread(r);
        }

        private void bindWorkspaceItems(final Callbacks oldCallbacks,
                final ArrayList<ItemInfo> workspaceItems,
                final ArrayList<LauncherAppWidgetInfo> appWidgets,
                final LongArrayMap<FolderInfo> folders,
                ArrayList<Runnable> deferredBindRunnables) {

            final boolean postOnMainThread = (deferredBindRunnables != null);

            // Bind the workspace items
            int N = workspaceItems.size();
            for (int i = 0; i < N; i += ITEMS_CHUNK) {
                final int start = i;
                final int chunkSize = (i+ITEMS_CHUNK <= N) ? ITEMS_CHUNK : (N-i);
                final Runnable r = new Runnable() {
                    @Override
                    public void run() {
                        Callbacks callbacks = tryGetCallbacks(oldCallbacks);
                        if (callbacks != null) {
                            callbacks.bindItems(workspaceItems, start, start+chunkSize,
                                    false);
                        }
                    }
                };
                if (postOnMainThread) {
                    synchronized (deferredBindRunnables) {
                        deferredBindRunnables.add(r);
                    }
                } else {
                    runOnMainThread(r);
                }
            }

            // Bind the folders
            if (!folders.isEmpty()) {
                final Runnable r = new Runnable() {
                    public void run() {
                        Callbacks callbacks = tryGetCallbacks(oldCallbacks);
                        if (callbacks != null) {
                            callbacks.bindFolders(folders);
                        }
                    }
                };
                if (postOnMainThread) {
                    synchronized (deferredBindRunnables) {
                        deferredBindRunnables.add(r);
                    }
                } else {
                    runOnMainThread(r);
                }
            }

            // Bind the widgets, one at a time
            N = appWidgets.size();
            for (int i = 0; i < N; i++) {
                final LauncherAppWidgetInfo widget = appWidgets.get(i);
                final Runnable r = new Runnable() {
                    public void run() {
                        Callbacks callbacks = tryGetCallbacks(oldCallbacks);
                        if (callbacks != null) {
                            callbacks.bindAppWidget(widget);
                        }
                    }
                };
                if (postOnMainThread) {
                    deferredBindRunnables.add(r);
                } else {
                    runOnMainThread(r);
                }
            }
        }

        /**
         * Binds all loaded data to actual views on the main thread.
         */
        private void bindWorkspace(int synchronizeBindPage) {
            final long t = SystemClock.uptimeMillis();
            Runnable r;

            // Don't use these two variables in any of the callback runnables.
            // Otherwise we hold a reference to them.
            final Callbacks oldCallbacks = mCallbacks.get();
            if (oldCallbacks == null) {
                // This launcher has exited and nobody bothered to tell us.  Just bail.
                Log.w(TAG, "LoaderTask running with no launcher");
                return;
            }

            // Save a copy of all the bg-thread collections
            ArrayList<ItemInfo> workspaceItems = new ArrayList<ItemInfo>();
            ArrayList<LauncherAppWidgetInfo> appWidgets =
                    new ArrayList<LauncherAppWidgetInfo>();
            ArrayList<Long> orderedScreenIds = new ArrayList<Long>();

            final LongArrayMap<FolderInfo> folders;
            final LongArrayMap<ItemInfo> itemsIdMap;

            synchronized (sBgLock) {
                workspaceItems.addAll(sBgWorkspaceItems);
                appWidgets.addAll(sBgAppWidgets);
                orderedScreenIds.addAll(sBgWorkspaceScreens);

                folders = sBgFolders.clone();
                itemsIdMap = sBgItemsIdMap.clone();
            }

            final boolean isLoadingSynchronously =
                    synchronizeBindPage != PagedView.INVALID_RESTORE_PAGE;
            int currScreen = isLoadingSynchronously ? synchronizeBindPage :
                oldCallbacks.getCurrentWorkspaceScreen();
            if (currScreen >= orderedScreenIds.size()) {
                // There may be no workspace screens (just hotseat items and an empty page).
                currScreen = PagedView.INVALID_RESTORE_PAGE;
            }
            final int currentScreen = currScreen;
            final long currentScreenId = currentScreen < 0
                    ? INVALID_SCREEN_ID : orderedScreenIds.get(currentScreen);

            // Load all the items that are on the current page first (and in the process, unbind
            // all the existing workspace items before we call startBinding() below.
            unbindWorkspaceItemsOnMainThread();

            // Separate the items that are on the current screen, and all the other remaining items
            ArrayList<ItemInfo> currentWorkspaceItems = new ArrayList<ItemInfo>();
            ArrayList<ItemInfo> otherWorkspaceItems = new ArrayList<ItemInfo>();
            ArrayList<LauncherAppWidgetInfo> currentAppWidgets =
                    new ArrayList<LauncherAppWidgetInfo>();
            ArrayList<LauncherAppWidgetInfo> otherAppWidgets =
                    new ArrayList<LauncherAppWidgetInfo>();
            LongArrayMap<FolderInfo> currentFolders = new LongArrayMap<>();
            LongArrayMap<FolderInfo> otherFolders = new LongArrayMap<>();

            filterCurrentWorkspaceItems(currentScreenId, workspaceItems, currentWorkspaceItems,
                    otherWorkspaceItems);
            filterCurrentAppWidgets(currentScreenId, appWidgets, currentAppWidgets,
                    otherAppWidgets);
            filterCurrentFolders(currentScreenId, itemsIdMap, folders, currentFolders,
                    otherFolders);
            sortWorkspaceItemsSpatially(currentWorkspaceItems);
            sortWorkspaceItemsSpatially(otherWorkspaceItems);

            // Tell the workspace that we're about to start binding items
            r = new Runnable() {
                public void run() {
                    Callbacks callbacks = tryGetCallbacks(oldCallbacks);
                    if (callbacks != null) {
                        callbacks.startBinding();
                    }
                }
            };
            runOnMainThread(r);

            bindWorkspaceScreens(oldCallbacks, orderedScreenIds);

            // Load items on the current page
            bindWorkspaceItems(oldCallbacks, currentWorkspaceItems, currentAppWidgets,
                    currentFolders, null);
            if (isLoadingSynchronously) {
                r = new Runnable() {
                    public void run() {
                        Callbacks callbacks = tryGetCallbacks(oldCallbacks);
                        if (callbacks != null && currentScreen != PagedView.INVALID_RESTORE_PAGE) {
                            callbacks.onPageBoundSynchronously(currentScreen);
                        }
                    }
                };
                runOnMainThread(r);
            }

            // Load all the remaining pages (if we are loading synchronously, we want to defer this
            // work until after the first render)
            synchronized (mDeferredBindRunnables) {
                mDeferredBindRunnables.clear();
            }
            bindWorkspaceItems(oldCallbacks, otherWorkspaceItems, otherAppWidgets, otherFolders,
                    (isLoadingSynchronously ? mDeferredBindRunnables : null));

            // Tell the workspace that we're done binding items
            r = new Runnable() {
                public void run() {
                    Callbacks callbacks = tryGetCallbacks(oldCallbacks);
                    if (callbacks != null) {
                        callbacks.finishBindingItems();
                    }

                    mIsLoadingAndBindingWorkspace = false;

                    // Run all the bind complete runnables after workspace is bound.
                    if (!mBindCompleteRunnables.isEmpty()) {
                        synchronized (mBindCompleteRunnables) {
                            for (final Runnable r : mBindCompleteRunnables) {
                                runOnWorkerThread(r);
                            }
                            mBindCompleteRunnables.clear();
                        }
                    }

                    // If we're profiling, ensure this is the last thing in the queue.
                    if (DEBUG_LOADERS) {
                        Log.d(TAG, "bound workspace in "
                            + (SystemClock.uptimeMillis()-t) + "ms");
                    }

                }
            };
            if (isLoadingSynchronously) {
                synchronized (mDeferredBindRunnables) {
                    mDeferredBindRunnables.add(r);
                }
            } else {
                runOnMainThread(r);
            }
        }

        private void loadAndBindAllApps() {
            if (DEBUG_LOADERS) {
                Log.d(TAG, "loadAndBindAllApps mAllAppsLoaded=" + mAllAppsLoaded);
            }
            if (!mAllAppsLoaded) {
                loadAllApps();
                synchronized (LoaderTask.this) {
                    if (mStopped) {
                        return;
                    }
                }
                updateIconCache();
                synchronized (LoaderTask.this) {
                    if (mStopped) {
                        return;
                    }
                    mAllAppsLoaded = true;
                }
            } else {
                onlyBindAllApps();
            }
        }

        private void updateIconCache() {
            // Ignore packages which have a promise icon.
            HashSet<String> packagesToIgnore = new HashSet<>();
            synchronized (sBgLock) {
                for (ItemInfo info : sBgItemsIdMap) {
                    if (info instanceof ShortcutInfo) {
                        ShortcutInfo si = (ShortcutInfo) info;
                        if (si.isPromise() && si.getTargetComponent() != null) {
                            packagesToIgnore.add(si.getTargetComponent().getPackageName());
                        }
                    } else if (info instanceof LauncherAppWidgetInfo) {
                        LauncherAppWidgetInfo lawi = (LauncherAppWidgetInfo) info;
                        if (lawi.hasRestoreFlag(LauncherAppWidgetInfo.FLAG_PROVIDER_NOT_READY)) {
                            packagesToIgnore.add(lawi.providerName.getPackageName());
                        }
                    }
                }
            }
            mIconCache.updateDbIcons(packagesToIgnore);
        }

        private void onlyBindAllApps() {
            final Callbacks oldCallbacks = mCallbacks.get();
            if (oldCallbacks == null) {
                // This launcher has exited and nobody bothered to tell us.  Just bail.
                Log.w(TAG, "LoaderTask running with no launcher (onlyBindAllApps)");
                return;
            }

            // shallow copy
            @SuppressWarnings("unchecked")
            final ArrayList<AppInfo> list
                    = (ArrayList<AppInfo>) mBgAllAppsList.data.clone();
            final WidgetsModel widgetList = mBgWidgetsModel.clone();
            Runnable r = new Runnable() {
                public void run() {
                    final long t = SystemClock.uptimeMillis();
                    final Callbacks callbacks = tryGetCallbacks(oldCallbacks);
                    if (callbacks != null) {
                        callbacks.bindAllApplications(list);
                        callbacks.bindAllPackages(widgetList);
                    }
                    if (DEBUG_LOADERS) {
                        Log.d(TAG, "bound all " + list.size() + " apps from cache in "
                                + (SystemClock.uptimeMillis()-t) + "ms");
                    }
                }
            };
            boolean isRunningOnMainThread = !(sWorkerThread.getThreadId() == Process.myTid());
            if (isRunningOnMainThread) {
                r.run();
            } else {
                mHandler.post(r);
            }
        }

        private void loadAllApps() {
            final long loadTime = DEBUG_LOADERS ? SystemClock.uptimeMillis() : 0;

            final Callbacks oldCallbacks = mCallbacks.get();
            if (oldCallbacks == null) {
                // This launcher has exited and nobody bothered to tell us.  Just bail.
                Log.w(TAG, "LoaderTask running with no launcher (loadAllApps)");
                return;
            }

            final List<UserHandleCompat> profiles = mUserManager.getUserProfiles();

            // Clear the list of apps
            mBgAllAppsList.clear();
            for (UserHandleCompat user : profiles) {
                // Query for the set of apps
                final long qiaTime = DEBUG_LOADERS ? SystemClock.uptimeMillis() : 0;
                final List<LauncherActivityInfoCompat> apps = mLauncherApps.getActivityList(null, user);
                if (DEBUG_LOADERS) {
                    Log.d(TAG, "getActivityList took "
                            + (SystemClock.uptimeMillis()-qiaTime) + "ms for user " + user);
                    Log.d(TAG, "getActivityList got " + apps.size() + " apps for user " + user);
                }
                // Fail if we don't have any apps
                // TODO: Fix this. Only fail for the current user.
                if (apps == null || apps.isEmpty()) {
                    return;
                }

                // Create the ApplicationInfos
                for (int i = 0; i < apps.size(); i++) {
                    LauncherActivityInfoCompat app = apps.get(i);
                    // This builds the icon bitmaps.
                    mBgAllAppsList.add(new AppInfo(mContext, app, user, mIconCache));
                }

                final ManagedProfileHeuristic heuristic = ManagedProfileHeuristic.get(mContext, user);
                if (heuristic != null) {
                    final Runnable r = new Runnable() {

                        @Override
                        public void run() {
                            heuristic.processUserApps(apps);
                        }
                    };
                    runOnMainThread(new Runnable() {

                        @Override
                        public void run() {
                            // Check isLoadingWorkspace on the UI thread, as it is updated on
                            // the UI thread.
                            if (mIsLoadingAndBindingWorkspace) {
                                synchronized (mBindCompleteRunnables) {
                                    mBindCompleteRunnables.add(r);
                                }
                            } else {
                                runOnWorkerThread(r);
                            }
                        }
                    });
                }
            }
            // Huh? Shouldn't this be inside the Runnable below?
            final ArrayList<AppInfo> added = mBgAllAppsList.added;
            mBgAllAppsList.added = new ArrayList<AppInfo>();

            // Post callback on main thread
            mHandler.post(new Runnable() {
                public void run() {

                    final long bindTime = SystemClock.uptimeMillis();
                    final Callbacks callbacks = tryGetCallbacks(oldCallbacks);
                    if (callbacks != null) {
                        callbacks.bindAllApplications(added);
                        if (DEBUG_LOADERS) {
                            Log.d(TAG, "bound " + added.size() + " apps in "
                                + (SystemClock.uptimeMillis() - bindTime) + "ms");
                        }
                    } else {
                        Log.i(TAG, "not binding apps: no Launcher activity");
                    }
                }
            });
            // Cleanup any data stored for a deleted user.
            ManagedProfileHeuristic.processAllUsers(profiles, mContext);

            loadAndBindWidgetsAndShortcuts(tryGetCallbacks(oldCallbacks), true /* refresh */);
            if (DEBUG_LOADERS) {
                Log.d(TAG, "Icons processed in "
                        + (SystemClock.uptimeMillis() - loadTime) + "ms");
            }
        }

        public void dumpState() {
            synchronized (sBgLock) {
                Log.d(TAG, "mLoaderTask.mContext=" + mContext);
                Log.d(TAG, "mLoaderTask.mStopped=" + mStopped);
                Log.d(TAG, "mLoaderTask.mLoadAndBindStepFinished=" + mLoadAndBindStepFinished);
                Log.d(TAG, "mItems size=" + sBgWorkspaceItems.size());
            }
        }
    }

    /**
     * Called when the icons for packages have been updated in the icon cache.
     */
    public void onPackageIconsUpdated(HashSet<String> updatedPackages, UserHandleCompat user) {
        final Callbacks callbacks = getCallback();
        final ArrayList<AppInfo> updatedApps = new ArrayList<>();
        final ArrayList<ShortcutInfo> updatedShortcuts = new ArrayList<>();

        // If any package icon has changed (app was updated while launcher was dead),
        // update the corresponding shortcuts.
        synchronized (sBgLock) {
            for (ItemInfo info : sBgItemsIdMap) {
                if (info instanceof ShortcutInfo && user.equals(info.user)
                        && info.itemType == LauncherSettings.Favorites.ITEM_TYPE_APPLICATION) {
                    ShortcutInfo si = (ShortcutInfo) info;
                    ComponentName cn = si.getTargetComponent();
                    if (cn != null && updatedPackages.contains(cn.getPackageName())) {
                        si.updateIcon(mIconCache);
                        updatedShortcuts.add(si);
                    }
                }
            }
            mBgAllAppsList.updateIconsAndLabels(updatedPackages, user, updatedApps);
        }

        if (!updatedShortcuts.isEmpty()) {
            final UserHandleCompat userFinal = user;
            mHandler.post(new Runnable() {

                public void run() {
                    Callbacks cb = getCallback();
                    if (cb != null && callbacks == cb) {
                        cb.bindShortcutsChanged(updatedShortcuts,
                                new ArrayList<ShortcutInfo>(), userFinal);
                    }
                }
            });
        }

        if (!updatedApps.isEmpty()) {
            mHandler.post(new Runnable() {

                public void run() {
                    Callbacks cb = getCallback();
                    if (cb != null && callbacks == cb) {
                        cb.bindAppsUpdated(updatedApps);
                    }
                }
            });
        }

        // Reload widget list. No need to refresh, as we only want to update the icons and labels.
        loadAndBindWidgetsAndShortcuts(callbacks, false);
    }

    void enqueuePackageUpdated(PackageUpdatedTask task) {
        sWorker.post(task);
    }

    @Thunk class AppsAvailabilityCheck extends BroadcastReceiver {

        @Override
        public void onReceive(Context context, Intent intent) {
            synchronized (sBgLock) {
                final LauncherAppsCompat launcherApps = LauncherAppsCompat
                        .getInstance(mApp.getContext());
                final PackageManager manager = context.getPackageManager();
                final ArrayList<String> packagesRemoved = new ArrayList<String>();
                final ArrayList<String> packagesUnavailable = new ArrayList<String>();
                for (Entry<UserHandleCompat, HashSet<String>> entry : sPendingPackages.entrySet()) {
                    UserHandleCompat user = entry.getKey();
                    packagesRemoved.clear();
                    packagesUnavailable.clear();
                    for (String pkg : entry.getValue()) {
                        if (!launcherApps.isPackageEnabledForProfile(pkg, user)) {
                            boolean packageOnSdcard = launcherApps.isAppEnabled(
                                    manager, pkg, PackageManager.GET_UNINSTALLED_PACKAGES);
                            if (packageOnSdcard) {
                                Launcher.addDumpLog(TAG, "Package found on sd-card: " + pkg, true);
                                packagesUnavailable.add(pkg);
                            } else {
                                Launcher.addDumpLog(TAG, "Package not found: " + pkg, true);
                                packagesRemoved.add(pkg);
                            }
                        }
                    }
                    if (!packagesRemoved.isEmpty()) {
                        enqueuePackageUpdated(new PackageUpdatedTask(PackageUpdatedTask.OP_REMOVE,
                                packagesRemoved.toArray(new String[packagesRemoved.size()]), user));
                    }
                    if (!packagesUnavailable.isEmpty()) {
                        enqueuePackageUpdated(new PackageUpdatedTask(PackageUpdatedTask.OP_UNAVAILABLE,
                                packagesUnavailable.toArray(new String[packagesUnavailable.size()]), user));
                    }
                }
                sPendingPackages.clear();
            }
        }
    }

    private class PackageUpdatedTask implements Runnable {
        int mOp;
        String[] mPackages;
        UserHandleCompat mUser;

        public static final int OP_NONE = 0;
        public static final int OP_ADD = 1;
        public static final int OP_UPDATE = 2;
        public static final int OP_REMOVE = 3; // uninstlled
        public static final int OP_UNAVAILABLE = 4; // external media unmounted


        public PackageUpdatedTask(int op, String[] packages, UserHandleCompat user) {
            mOp = op;
            mPackages = packages;
            mUser = user;
        }

        public void run() {
            if (!mHasLoaderCompletedOnce) {
                // Loader has not yet run.
                return;
            }
            final Context context = mApp.getContext();

            final String[] packages = mPackages;
            final int N = packages.length;
            switch (mOp) {
                case OP_ADD: {
                    for (int i=0; i<N; i++) {
                        if (DEBUG_LOADERS) Log.d(TAG, "mAllAppsList.addPackage " + packages[i]);
                        mIconCache.updateIconsForPkg(packages[i], mUser);
                        mBgAllAppsList.addPackage(context, packages[i], mUser);
                    }

                    ManagedProfileHeuristic heuristic = ManagedProfileHeuristic.get(context, mUser);
                    if (heuristic != null) {
                        heuristic.processPackageAdd(mPackages);
                    }
                    break;
                }
                case OP_UPDATE:
                    for (int i=0; i<N; i++) {
                        if (DEBUG_LOADERS) Log.d(TAG, "mAllAppsList.updatePackage " + packages[i]);
                        mIconCache.updateIconsForPkg(packages[i], mUser);
                        mBgAllAppsList.updatePackage(context, packages[i], mUser);
                        mApp.getWidgetCache().removePackage(packages[i], mUser);
                    }
                    break;
                case OP_REMOVE: {
                    ManagedProfileHeuristic heuristic = ManagedProfileHeuristic.get(context, mUser);
                    if (heuristic != null) {
                        heuristic.processPackageRemoved(mPackages);
                    }
                    for (int i=0; i<N; i++) {
                        if (DEBUG_LOADERS) Log.d(TAG, "mAllAppsList.removePackage " + packages[i]);
                        mIconCache.removeIconsForPkg(packages[i], mUser);
                    }
                    // Fall through
                }
                case OP_UNAVAILABLE:
                    for (int i=0; i<N; i++) {
                        if (DEBUG_LOADERS) Log.d(TAG, "mAllAppsList.removePackage " + packages[i]);
                        mBgAllAppsList.removePackage(packages[i], mUser);
                        mApp.getWidgetCache().removePackage(packages[i], mUser);
                    }
                    break;
            }

            ArrayList<AppInfo> added = null;
            ArrayList<AppInfo> modified = null;
            final ArrayList<AppInfo> removedApps = new ArrayList<AppInfo>();

            if (mBgAllAppsList.added.size() > 0) {
                added = new ArrayList<AppInfo>(mBgAllAppsList.added);
                mBgAllAppsList.added.clear();
            }
            if (mBgAllAppsList.modified.size() > 0) {
                modified = new ArrayList<AppInfo>(mBgAllAppsList.modified);
                mBgAllAppsList.modified.clear();
            }
            if (mBgAllAppsList.removed.size() > 0) {
                removedApps.addAll(mBgAllAppsList.removed);
                mBgAllAppsList.removed.clear();
            }

            final Callbacks callbacks = getCallback();
            if (callbacks == null) {
                Log.w(TAG, "Nobody to tell about the new app.  Launcher is probably loading.");
                return;
            }

            final HashMap<ComponentName, AppInfo> addedOrUpdatedApps =
                    new HashMap<ComponentName, AppInfo>();

            if (added != null) {
                addAppsToAllApps(context, added);
                for (AppInfo ai : added) {
                    addedOrUpdatedApps.put(ai.componentName, ai);
                }
            }

            if (modified != null) {
                final ArrayList<AppInfo> modifiedFinal = modified;
                for (AppInfo ai : modified) {
                    addedOrUpdatedApps.put(ai.componentName, ai);
                }

                mHandler.post(new Runnable() {
                    public void run() {
                        Callbacks cb = getCallback();
                        if (callbacks == cb && cb != null) {
                            callbacks.bindAppsUpdated(modifiedFinal);
                        }
                    }
                });
            }

            // Update shortcut infos
            if (mOp == OP_ADD || mOp == OP_UPDATE) {
                final ArrayList<ShortcutInfo> updatedShortcuts = new ArrayList<ShortcutInfo>();
                final ArrayList<ShortcutInfo> removedShortcuts = new ArrayList<ShortcutInfo>();
                final ArrayList<LauncherAppWidgetInfo> widgets = new ArrayList<LauncherAppWidgetInfo>();

                HashSet<String> packageSet = new HashSet<String>(Arrays.asList(packages));
                synchronized (sBgLock) {
                    for (ItemInfo info : sBgItemsIdMap) {
                        if (info instanceof ShortcutInfo && mUser.equals(info.user)) {
                            ShortcutInfo si = (ShortcutInfo) info;
                            boolean infoUpdated = false;
                            boolean shortcutUpdated = false;

                            // Update shortcuts which use iconResource.
                            if ((si.iconResource != null)
                                    && packageSet.contains(si.iconResource.packageName)) {
                                Bitmap icon = Utilities.createIconBitmap(
                                        si.iconResource.packageName,
                                        si.iconResource.resourceName, context);
                                if (icon != null) {
                                    si.setIcon(icon);
                                    si.usingFallbackIcon = false;
                                    infoUpdated = true;
                                }
                            }

                            ComponentName cn = si.getTargetComponent();
                            if (cn != null && packageSet.contains(cn.getPackageName())) {
                                AppInfo appInfo = addedOrUpdatedApps.get(cn);

                                if (si.isPromise()) {
                                    if (si.hasStatusFlag(ShortcutInfo.FLAG_AUTOINTALL_ICON)) {
                                        // Auto install icon
                                        PackageManager pm = context.getPackageManager();
                                        ResolveInfo matched = pm.resolveActivity(
                                                new Intent(Intent.ACTION_MAIN)
                                                .setComponent(cn).addCategory(Intent.CATEGORY_LAUNCHER),
                                                PackageManager.MATCH_DEFAULT_ONLY);
                                        if (matched == null) {
                                            // Try to find the best match activity.
                                            Intent intent = pm.getLaunchIntentForPackage(
                                                    cn.getPackageName());
                                            if (intent != null) {
                                                cn = intent.getComponent();
                                                appInfo = addedOrUpdatedApps.get(cn);
                                            }

                                            if ((intent == null) || (appInfo == null)) {
                                                removedShortcuts.add(si);
                                                continue;
                                            }
                                            si.promisedIntent = intent;
                                        }
                                    }

                                    // Restore the shortcut.
                                    if (appInfo != null) {
                                        si.flags = appInfo.flags;
                                    }

                                    si.intent = si.promisedIntent;
                                    si.promisedIntent = null;
                                    si.status = ShortcutInfo.DEFAULT;
                                    infoUpdated = true;
                                    si.updateIcon(mIconCache);
                                }

                                if (appInfo != null && Intent.ACTION_MAIN.equals(si.intent.getAction())
                                        && si.itemType == LauncherSettings.Favorites.ITEM_TYPE_APPLICATION) {
                                    si.updateIcon(mIconCache);
                                    si.title = Utilities.trim(appInfo.title);
                                    si.contentDescription = appInfo.contentDescription;
                                    infoUpdated = true;
                                }

                                if ((si.isDisabled & ShortcutInfo.FLAG_DISABLED_NOT_AVAILABLE) != 0) {
                                    // Since package was just updated, the target must be available now.
                                    si.isDisabled &= ~ShortcutInfo.FLAG_DISABLED_NOT_AVAILABLE;
                                    shortcutUpdated = true;
                                }
                            }

                            if (infoUpdated || shortcutUpdated) {
                                updatedShortcuts.add(si);
                            }
                            if (infoUpdated) {
                                updateItemInDatabase(context, si);
                            }
                        } else if (info instanceof LauncherAppWidgetInfo) {
                            LauncherAppWidgetInfo widgetInfo = (LauncherAppWidgetInfo) info;
                            if (mUser.equals(widgetInfo.user)
                                    && widgetInfo.hasRestoreFlag(LauncherAppWidgetInfo.FLAG_PROVIDER_NOT_READY)
                                    && packageSet.contains(widgetInfo.providerName.getPackageName())) {
                                widgetInfo.restoreStatus &=
                                        ~LauncherAppWidgetInfo.FLAG_PROVIDER_NOT_READY &
                                        ~LauncherAppWidgetInfo.FLAG_RESTORE_STARTED;

                                // adding this flag ensures that launcher shows 'click to setup'
                                // if the widget has a config activity. In case there is no config
                                // activity, it will be marked as 'restored' during bind.
                                widgetInfo.restoreStatus |= LauncherAppWidgetInfo.FLAG_UI_NOT_READY;

                                widgets.add(widgetInfo);
                                updateItemInDatabase(context, widgetInfo);
                            }
                        }
                    }
                }

                if (!updatedShortcuts.isEmpty() || !removedShortcuts.isEmpty()) {
                    mHandler.post(new Runnable() {

                        public void run() {
                            Callbacks cb = getCallback();
                            if (callbacks == cb && cb != null) {
                                callbacks.bindShortcutsChanged(
                                        updatedShortcuts, removedShortcuts, mUser);
                            }
                        }
                    });
                    if (!removedShortcuts.isEmpty()) {
                        deleteItemsFromDatabase(context, removedShortcuts);
                    }
                }
                if (!widgets.isEmpty()) {
                    mHandler.post(new Runnable() {
                        public void run() {
                            Callbacks cb = getCallback();
                            if (callbacks == cb && cb != null) {
                                callbacks.bindWidgetsRestored(widgets);
                            }
                        }
                    });
                }
            }

            final ArrayList<String> removedPackageNames =
                    new ArrayList<String>();
            if (mOp == OP_REMOVE || mOp == OP_UNAVAILABLE) {
                // Mark all packages in the broadcast to be removed
                removedPackageNames.addAll(Arrays.asList(packages));
            } else if (mOp == OP_UPDATE) {
                // Mark disabled packages in the broadcast to be removed
                for (int i=0; i<N; i++) {
                    if (isPackageDisabled(context, packages[i], mUser)) {
                        removedPackageNames.add(packages[i]);
                    }
                }
            }

            if (!removedPackageNames.isEmpty() || !removedApps.isEmpty()) {
                final int removeReason;
                if (mOp == OP_UNAVAILABLE) {
                    removeReason = ShortcutInfo.FLAG_DISABLED_NOT_AVAILABLE;
                } else {
                    // Remove all the components associated with this package
                    for (String pn : removedPackageNames) {
                        deletePackageFromDatabase(context, pn, mUser);
                    }
                    // Remove all the specific components
                    for (AppInfo a : removedApps) {
                        ArrayList<ItemInfo> infos = getItemInfoForComponentName(a.componentName, mUser);
                        deleteItemsFromDatabase(context, infos);
                    }
                    removeReason = 0;
                }

                // Remove any queued items from the install queue
                InstallShortcutReceiver.removeFromInstallQueue(context, removedPackageNames, mUser);
                // Call the components-removed callback
                mHandler.post(new Runnable() {
                    public void run() {
                        Callbacks cb = getCallback();
                        if (callbacks == cb && cb != null) {
                            callbacks.bindComponentsRemoved(
                                    removedPackageNames, removedApps, mUser, removeReason);
                        }
                    }
                });
            }

            // Update widgets
            if (mOp == OP_ADD || mOp == OP_REMOVE || mOp == OP_UPDATE) {
                // Always refresh for a package event on secondary user
                boolean needToRefresh = !mUser.equals(UserHandleCompat.myUserHandle());

                // Refresh widget list, if the package already had a widget.
                synchronized (sBgLock) {
                    if (sBgWidgetProviders != null) {
                        HashSet<String> pkgSet = new HashSet<>();
                        Collections.addAll(pkgSet, mPackages);

                        for (ComponentKey key : sBgWidgetProviders.keySet()) {
                            needToRefresh |= key.user.equals(mUser) &&
                                    pkgSet.contains(key.componentName.getPackageName());
                        }
                    }
                }

                if (!needToRefresh && mOp != OP_REMOVE) {
                    // Refresh widget list, if there is any newly added widget
                    PackageManager pm = context.getPackageManager();
                    for (String pkg : mPackages) {
                        needToRefresh |= !pm.queryBroadcastReceivers(
                                new Intent(AppWidgetManager.ACTION_APPWIDGET_UPDATE)
                                    .setPackage(pkg), 0).isEmpty();
                    }
                }

                loadAndBindWidgetsAndShortcuts(callbacks, needToRefresh);
            }

            // Write all the logs to disk
            mHandler.post(new Runnable() {
                public void run() {
                    Callbacks cb = getCallback();
                    if (callbacks == cb && cb != null) {
                        callbacks.dumpLogsToLocalData();
                    }
                }
            });
        }
    }

    public static List<LauncherAppWidgetProviderInfo> getWidgetProviders(Context context,
            boolean refresh) {
        ArrayList<LauncherAppWidgetProviderInfo> results =
                new ArrayList<LauncherAppWidgetProviderInfo>();
        try {
            synchronized (sBgLock) {
                if (sBgWidgetProviders == null || refresh) {
                    HashMap<ComponentKey, LauncherAppWidgetProviderInfo> tmpWidgetProviders
                            = new HashMap<>();
                    AppWidgetManagerCompat wm = AppWidgetManagerCompat.getInstance(context);
                    LauncherAppWidgetProviderInfo info;

                    List<AppWidgetProviderInfo> widgets = wm.getAllProviders();
                    for (AppWidgetProviderInfo pInfo : widgets) {
                        info = LauncherAppWidgetProviderInfo.fromProviderInfo(context, pInfo);
                        UserHandleCompat user = wm.getUser(info);
                        tmpWidgetProviders.put(new ComponentKey(info.provider, user), info);
                    }

                    Collection<CustomAppWidget> customWidgets = Launcher.getCustomAppWidgets().values();
                    for (CustomAppWidget widget : customWidgets) {
                        info = new LauncherAppWidgetProviderInfo(context, widget);
                        UserHandleCompat user = wm.getUser(info);
                        tmpWidgetProviders.put(new ComponentKey(info.provider, user), info);
                    }
                    // Replace the global list at the very end, so that if there is an exception,
                    // previously loaded provider list is used.
                    sBgWidgetProviders = tmpWidgetProviders;
                }
                results.addAll(sBgWidgetProviders.values());
                return results;
            }
        } catch (Exception e) {
            if (e.getCause() instanceof TransactionTooLargeException) {
                // the returned value may be incomplete and will not be refreshed until the next
                // time Launcher starts.
                // TODO: after figuring out a repro step, introduce a dirty bit to check when
                // onResume is called to refresh the widget provider list.
                synchronized (sBgLock) {
                    if (sBgWidgetProviders != null) {
                        results.addAll(sBgWidgetProviders.values());
                    }
                    return results;
                }
            } else {
                throw e;
            }
        }
    }

    public static LauncherAppWidgetProviderInfo getProviderInfo(Context ctx, ComponentName name,
            UserHandleCompat user) {
        synchronized (sBgLock) {
            if (sBgWidgetProviders == null) {
                getWidgetProviders(ctx, false /* refresh */);
            }
            return sBgWidgetProviders.get(new ComponentKey(name, user));
        }
    }

    public void loadAndBindWidgetsAndShortcuts(final Callbacks callbacks, final boolean refresh) {

        runOnWorkerThread(new Runnable() {
            @Override
            public void run() {
                updateWidgetsModel(refresh);
                final WidgetsModel model = mBgWidgetsModel.clone();

                mHandler.post(new Runnable() {
                    @Override
                    public void run() {
                        Callbacks cb = getCallback();
                        if (callbacks == cb && cb != null) {
                            callbacks.bindAllPackages(model);
                        }
                    }
                });
                // update the Widget entries inside DB on the worker thread.
                LauncherAppState.getInstance().getWidgetCache().removeObsoletePreviews(
                        model.getRawList());
            }
        });
    }

    /**
     * Returns a list of ResolveInfos/AppWidgetInfos.
     *
     * @see #loadAndBindWidgetsAndShortcuts
     */
    @Thunk void updateWidgetsModel(boolean refresh) {
        PackageManager packageManager = mApp.getContext().getPackageManager();
        final ArrayList<Object> widgetsAndShortcuts = new ArrayList<Object>();
        widgetsAndShortcuts.addAll(getWidgetProviders(mApp.getContext(), refresh));
        Intent shortcutsIntent = new Intent(Intent.ACTION_CREATE_SHORTCUT);
        widgetsAndShortcuts.addAll(packageManager.queryIntentActivities(shortcutsIntent, 0));
        mBgWidgetsModel.setWidgetsAndShortcuts(widgetsAndShortcuts);
    }

    @Thunk static boolean isPackageDisabled(Context context, String packageName,
            UserHandleCompat user) {
        final LauncherAppsCompat launcherApps = LauncherAppsCompat.getInstance(context);
        return !launcherApps.isPackageEnabledForProfile(packageName, user);
    }

    public static boolean isValidPackageActivity(Context context, ComponentName cn,
            UserHandleCompat user) {
        if (cn == null) {
            return false;
        }
        final LauncherAppsCompat launcherApps = LauncherAppsCompat.getInstance(context);
        if (!launcherApps.isPackageEnabledForProfile(cn.getPackageName(), user)) {
            return false;
        }
        return launcherApps.isActivityEnabledForProfile(cn, user);
    }

    public static boolean isValidPackage(Context context, String packageName,
            UserHandleCompat user) {
        if (packageName == null) {
            return false;
        }
        final LauncherAppsCompat launcherApps = LauncherAppsCompat.getInstance(context);
        return launcherApps.isPackageEnabledForProfile(packageName, user);
    }

    /**
     * Make an ShortcutInfo object for a restored application or shortcut item that points
     * to a package that is not yet installed on the system.
     */
    public ShortcutInfo getRestoredItemInfo(Cursor c, int titleIndex, Intent intent,
            int promiseType, int itemType, CursorIconInfo iconInfo, Context context) {
        final ShortcutInfo info = new ShortcutInfo();
        info.user = UserHandleCompat.myUserHandle();

        Bitmap icon = iconInfo.loadIcon(c, info, context);
        // the fallback icon
        if (icon == null) {
            mIconCache.getTitleAndIcon(info, intent, info.user, false /* useLowResIcon */);
        } else {
            info.setIcon(icon);
        }

        if ((promiseType & ShortcutInfo.FLAG_RESTORED_ICON) != 0) {
            String title = (c != null) ? c.getString(titleIndex) : null;
            if (!TextUtils.isEmpty(title)) {
                info.title = Utilities.trim(title);
            }
        } else if  ((promiseType & ShortcutInfo.FLAG_AUTOINTALL_ICON) != 0) {
            if (TextUtils.isEmpty(info.title)) {
                info.title = (c != null) ? Utilities.trim(c.getString(titleIndex)) : "";
            }
        } else {
            throw new InvalidParameterException("Invalid restoreType " + promiseType);
        }

        info.contentDescription = mUserManager.getBadgedLabelForUser(info.title, info.user);
        info.itemType = itemType;
        info.promisedIntent = intent;
        info.status = promiseType;
        return info;
    }

    /**
     * Make an Intent object for a restored application or shortcut item that points
     * to the market page for the item.
     */
    @Thunk Intent getRestoredItemIntent(Cursor c, Context context, Intent intent) {
        ComponentName componentName = intent.getComponent();
        return getMarketIntent(componentName.getPackageName());
    }

    static Intent getMarketIntent(String packageName) {
        return new Intent(Intent.ACTION_VIEW)
            .setData(new Uri.Builder()
                .scheme("market")
                .authority("details")
                .appendQueryParameter("id", packageName)
                .build());
    }

    /**
     * Make an ShortcutInfo object for a shortcut that is an application.
     *
     * If c is not null, then it will be used to fill in missing data like the title and icon.
     */
    public ShortcutInfo getAppShortcutInfo(PackageManager manager, Intent intent,
            UserHandleCompat user, Context context, Cursor c, int iconIndex, int titleIndex,
            boolean allowMissingTarget, boolean useLowResIcon) {
        if (user == null) {
            Log.d(TAG, "Null user found in getShortcutInfo");
            return null;
        }

        ComponentName componentName = intent.getComponent();
        if (componentName == null) {
            Log.d(TAG, "Missing component found in getShortcutInfo: " + componentName);
            return null;
        }

        Intent newIntent = new Intent(intent.getAction(), null);
        newIntent.addCategory(Intent.CATEGORY_LAUNCHER);
        newIntent.setComponent(componentName);
        LauncherActivityInfoCompat lai = mLauncherApps.resolveActivity(newIntent, user);
        if ((lai == null) && !allowMissingTarget) {
            Log.d(TAG, "Missing activity found in getShortcutInfo: " + componentName);
            return null;
        }

        final ShortcutInfo info = new ShortcutInfo();
        mIconCache.getTitleAndIcon(info, componentName, lai, user, false, useLowResIcon);
        if (mIconCache.isDefaultIcon(info.getIcon(mIconCache), user) && c != null) {
            Bitmap icon = Utilities.createIconBitmap(c, iconIndex, context);
            info.setIcon(icon == null ? mIconCache.getDefaultIcon(user) : icon);
        }

        // from the db
        if (TextUtils.isEmpty(info.title) && c != null) {
            info.title =  Utilities.trim(c.getString(titleIndex));
        }

        // fall back to the class name of the activity
        if (info.title == null) {
            info.title = componentName.getClassName();
        }

        info.itemType = LauncherSettings.Favorites.ITEM_TYPE_APPLICATION;
        info.user = user;
        info.contentDescription = mUserManager.getBadgedLabelForUser(info.title, info.user);
        if (lai != null) {
            info.flags = AppInfo.initFlags(lai);
        }
        return info;
    }

    static ArrayList<ItemInfo> filterItemInfos(Iterable<ItemInfo> infos,
            ItemInfoFilter f) {
        HashSet<ItemInfo> filtered = new HashSet<ItemInfo>();
        for (ItemInfo i : infos) {
            if (i instanceof ShortcutInfo) {
                ShortcutInfo info = (ShortcutInfo) i;
                ComponentName cn = info.getTargetComponent();
                if (cn != null && f.filterItem(null, info, cn)) {
                    filtered.add(info);
                }
            } else if (i instanceof FolderInfo) {
                FolderInfo info = (FolderInfo) i;
                for (ShortcutInfo s : info.contents) {
                    ComponentName cn = s.getTargetComponent();
                    if (cn != null && f.filterItem(info, s, cn)) {
                        filtered.add(s);
                    }
                }
            } else if (i instanceof LauncherAppWidgetInfo) {
                LauncherAppWidgetInfo info = (LauncherAppWidgetInfo) i;
                ComponentName cn = info.providerName;
                if (cn != null && f.filterItem(null, info, cn)) {
                    filtered.add(info);
                }
            }
        }
        return new ArrayList<ItemInfo>(filtered);
    }

    @Thunk ArrayList<ItemInfo> getItemInfoForComponentName(final ComponentName cname,
            final UserHandleCompat user) {
        ItemInfoFilter filter  = new ItemInfoFilter() {
            @Override
            public boolean filterItem(ItemInfo parent, ItemInfo info, ComponentName cn) {
                if (info.user == null) {
                    return cn.equals(cname);
                } else {
                    return cn.equals(cname) && info.user.equals(user);
                }
            }
        };
        return filterItemInfos(sBgItemsIdMap, filter);
    }

    /**
     * Make an ShortcutInfo object for a shortcut that isn't an application.
     */
    @Thunk ShortcutInfo getShortcutInfo(Cursor c, Context context,
            int titleIndex, CursorIconInfo iconInfo) {
        final ShortcutInfo info = new ShortcutInfo();
        // Non-app shortcuts are only supported for current user.
        info.user = UserHandleCompat.myUserHandle();
        info.itemType = LauncherSettings.Favorites.ITEM_TYPE_SHORTCUT;

        // TODO: If there's an explicit component and we can't install that, delete it.

        info.title = Utilities.trim(c.getString(titleIndex));

        Bitmap icon = iconInfo.loadIcon(c, info, context);
        // the fallback icon
        if (icon == null) {
            icon = mIconCache.getDefaultIcon(info.user);
            info.usingFallbackIcon = true;
        }
        info.setIcon(icon);
        return info;
    }

    ShortcutInfo infoFromShortcutIntent(Context context, Intent data) {
        Intent intent = data.getParcelableExtra(Intent.EXTRA_SHORTCUT_INTENT);
        String name = data.getStringExtra(Intent.EXTRA_SHORTCUT_NAME);
        Parcelable bitmap = data.getParcelableExtra(Intent.EXTRA_SHORTCUT_ICON);

        if (intent == null) {
            // If the intent is null, we can't construct a valid ShortcutInfo, so we return null
            Log.e(TAG, "Can't construct ShorcutInfo with null intent");
            return null;
        }

        Bitmap icon = null;
        boolean customIcon = false;
        ShortcutIconResource iconResource = null;

        if (bitmap instanceof Bitmap) {
            icon = Utilities.createIconBitmap((Bitmap) bitmap, context);
            customIcon = true;
        } else {
            Parcelable extra = data.getParcelableExtra(Intent.EXTRA_SHORTCUT_ICON_RESOURCE);
            if (extra instanceof ShortcutIconResource) {
                iconResource = (ShortcutIconResource) extra;
                icon = Utilities.createIconBitmap(iconResource.packageName,
                        iconResource.resourceName, context);
            }
        }

        final ShortcutInfo info = new ShortcutInfo();

        // Only support intents for current user for now. Intents sent from other
        // users wouldn't get here without intent forwarding anyway.
        info.user = UserHandleCompat.myUserHandle();
        if (icon == null) {
            icon = mIconCache.getDefaultIcon(info.user);
            info.usingFallbackIcon = true;
        }
        info.setIcon(icon);

        info.title = Utilities.trim(name);
        info.contentDescription = mUserManager.getBadgedLabelForUser(info.title, info.user);
        info.intent = intent;
        info.customIcon = customIcon;
        info.iconResource = iconResource;

        return info;
    }

    /**
     * Return an existing FolderInfo object if we have encountered this ID previously,
     * or make a new one.
     */
    @Thunk static FolderInfo findOrMakeFolder(LongArrayMap<FolderInfo> folders, long id) {
        // See if a placeholder was created for us already
        FolderInfo folderInfo = folders.get(id);
        if (folderInfo == null) {
            // No placeholder -- create a new instance
            folderInfo = new FolderInfo();
            folders.put(id, folderInfo);
        }
        return folderInfo;
    }


    static boolean isValidProvider(AppWidgetProviderInfo provider) {
        return (provider != null) && (provider.provider != null)
                && (provider.provider.getPackageName() != null);
    }

    public void dumpState() {
        Log.d(TAG, "mCallbacks=" + mCallbacks);
        AppInfo.dumpApplicationInfoList(TAG, "mAllAppsList.data", mBgAllAppsList.data);
        AppInfo.dumpApplicationInfoList(TAG, "mAllAppsList.added", mBgAllAppsList.added);
        AppInfo.dumpApplicationInfoList(TAG, "mAllAppsList.removed", mBgAllAppsList.removed);
        AppInfo.dumpApplicationInfoList(TAG, "mAllAppsList.modified", mBgAllAppsList.modified);
        if (mLoaderTask != null) {
            mLoaderTask.dumpState();
        } else {
            Log.d(TAG, "mLoaderTask=null");
        }
    }

    public Callbacks getCallback() {
        return mCallbacks != null ? mCallbacks.get() : null;
    }

    /**
     * @return {@link FolderInfo} if its already loaded.
     */
    public FolderInfo findFolderById(Long folderId) {
        synchronized (sBgLock) {
            return sBgFolders.get(folderId);
        }
    }

    /**
     * @return the looper for the worker thread which can be used to start background tasks.
     */
    public static Looper getWorkerLooper() {
        return sWorkerThread.getLooper();
    }
}