android/launcher2/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.launcher2;

import java.lang.ref.WeakReference;
import java.net.URISyntaxException;
import java.text.Collator;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;

import android.appwidget.AppWidgetManager;
import android.appwidget.AppWidgetProviderInfo;
import android.content.BroadcastReceiver;
import android.content.ComponentName;
import android.content.ContentProviderClient;
import android.content.ContentResolver;
import android.content.ContentValues;
import android.content.Context;
import android.content.Intent;
import android.content.Intent.ShortcutIconResource;
import android.content.pm.ActivityInfo;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.content.res.Resources;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Environment;
import android.os.Handler;
import android.os.HandlerThread;
import android.os.Parcelable;
import android.os.Process;
import android.os.RemoteException;
import android.os.SystemClock;
import android.util.Log;

import com.android.launcher.R;
import com.android.launcher2.InstallWidgetReceiver.WidgetMimeTypeHandlerData;

/**
 * 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 {
    static final boolean DEBUG_LOADERS = false;
    static final String TAG = "Launcher.Model";

    private static final int ITEMS_CHUNK = 6; // batch size for the workspace icons
    private final boolean mAppsCanBeOnExternalStorage;
    private int mBatchSize; // 0 is all apps at once
    private int mAllAppsLoadDelay; // milliseconds between batches

    private final LauncherApplication mApp;
    private final Object mLock = new Object();
    private DeferredHandler mHandler = new DeferredHandler();
    private LoaderTask mLoaderTask;

    private static final HandlerThread sWorkerThread = new HandlerThread("launcher-loader");
    static {
        sWorkerThread.start();
    }
    private 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.
    private boolean mWorkspaceLoaded;
    private boolean mAllAppsLoaded;

    private WeakReference<Callbacks> mCallbacks;

    private AllAppsList mAllAppsList; // only access in worker thread
    private IconCache mIconCache;

    private Bitmap mDefaultIcon;

    private static int mCellCountX;
    private static int mCellCountY;

    public interface Callbacks {
        public boolean setLoadOnResume();
        public int getCurrentWorkspaceScreen();
        public void startBinding();
        public void bindItems(ArrayList<ItemInfo> shortcuts, int start, int end);
        public void bindFolders(HashMap<Long,FolderInfo> folders);
        public void finishBindingItems();
        public void bindAppWidget(LauncherAppWidgetInfo info);
        public void bindAllApplications(ArrayList<ApplicationInfo> apps);
        public void bindAppsAdded(ArrayList<ApplicationInfo> apps);
        public void bindAppsUpdated(ArrayList<ApplicationInfo> apps);
        public void bindAppsRemoved(ArrayList<ApplicationInfo> apps, boolean permanent);
        public void bindPackagesUpdated();
        public boolean isAllAppsVisible();
    }

    LauncherModel(LauncherApplication app, IconCache iconCache) {
        mAppsCanBeOnExternalStorage = !Environment.isExternalStorageEmulated();
        mApp = app;
        mAllAppsList = new AllAppsList(iconCache);
        mIconCache = iconCache;

        mDefaultIcon = Utilities.createIconBitmap(
                mIconCache.getFullResDefaultActivityIcon(), app);

        mAllAppsLoadDelay = app.getResources().getInteger(R.integer.config_allAppsBatchLoadDelay);

        mBatchSize = app.getResources().getInteger(R.integer.config_allAppsBatchSize);
    }

    public Bitmap getFallbackIcon() {
        return Bitmap.createBitmap(mDefaultIcon);
    }

    /**
     * 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,
            int screen, int cellX, int cellY) {
        if (item.container == ItemInfo.NO_ID) {
            // From all apps
            addItemToDatabase(context, item, container, screen, cellX, cellY, false);
        } else {
            // From somewhere else
            moveItemInDatabase(context, item, container, screen, cellX, cellY);
        }
    }

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

        item.container = container;
        item.screen = screen;
        item.cellX = cellX;
        item.cellY = cellY;

        final Uri uri = LauncherSettings.Favorites.getContentUri(item.id, false);
        final ContentValues values = new ContentValues();
        final ContentResolver cr = context.getContentResolver();

        values.put(LauncherSettings.Favorites.CONTAINER, item.container);
        values.put(LauncherSettings.Favorites.CELLX, cellX);
        values.put(LauncherSettings.Favorites.CELLY, cellY);
        values.put(LauncherSettings.Favorites.SCREEN, item.screen);

        sWorker.post(new Runnable() {
                public void run() {
                    cr.update(uri, values, null, null);
                }
            });
    }

    /**
     * Resize an item in the DB to a new <spanX, spanY, cellX, cellY>
     */
    static void resizeItemInDatabase(Context context, ItemInfo item, int cellX, int cellY,
            int spanX, int spanY) {
        item.spanX = spanX;
        item.spanY = spanY;
        item.cellX = cellX;
        item.cellY = cellY;

        final Uri uri = LauncherSettings.Favorites.getContentUri(item.id, false);
        final ContentValues values = new ContentValues();
        final ContentResolver cr = context.getContentResolver();

        values.put(LauncherSettings.Favorites.CONTAINER, item.container);
        values.put(LauncherSettings.Favorites.SPANX, spanX);
        values.put(LauncherSettings.Favorites.SPANY, spanY);
        values.put(LauncherSettings.Favorites.CELLX, cellX);
        values.put(LauncherSettings.Favorites.CELLY, cellY);

        sWorker.post(new Runnable() {
                public void run() {
                    cr.update(uri, values, null, null);
                }
            });
    }

    /**
     * Returns true if the shortcuts already exists in the database.
     * we identify a shortcut by its title and intent.
     */
    static boolean shortcutExists(Context context, String title, Intent intent) {
        final ContentResolver cr = context.getContentResolver();
        Cursor c = cr.query(LauncherSettings.Favorites.CONTENT_URI,
            new String[] { "title", "intent" }, "title=? and intent=?",
            new String[] { title, intent.toUri(0) }, null);
        boolean result = false;
        try {
            result = c.moveToFirst();
        } finally {
            c.close();
        }
        return result;
    }

    /**
     * Returns an ItemInfo array containing all the items in the LauncherModel.
     * The ItemInfo.id is not set through this function.
     */
    static ArrayList<ItemInfo> getItemsInLocalCoordinates(Context context) {
        ArrayList<ItemInfo> items = new ArrayList<ItemInfo>();
        final ContentResolver cr = context.getContentResolver();
        Cursor c = cr.query(LauncherSettings.Favorites.CONTENT_URI, new String[] {
                LauncherSettings.Favorites.ITEM_TYPE, LauncherSettings.Favorites.CONTAINER,
                LauncherSettings.Favorites.SCREEN, LauncherSettings.Favorites.CELLX, LauncherSettings.Favorites.CELLY,
                LauncherSettings.Favorites.SPANX, LauncherSettings.Favorites.SPANY }, null, null, null);

        final int itemTypeIndex = c.getColumnIndexOrThrow(LauncherSettings.Favorites.ITEM_TYPE);
        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 spanXIndex = c.getColumnIndexOrThrow(LauncherSettings.Favorites.SPANX);
        final int spanYIndex = c.getColumnIndexOrThrow(LauncherSettings.Favorites.SPANY);

        try {
            while (c.moveToNext()) {
                ItemInfo item = new ItemInfo();
                item.cellX = c.getInt(cellXIndex);
                item.cellY = c.getInt(cellYIndex);
                item.spanX = c.getInt(spanXIndex);
                item.spanY = c.getInt(spanYIndex);
                item.container = c.getInt(containerIndex);
                item.itemType = c.getInt(itemTypeIndex);
                item.screen = c.getInt(screenIndex);

                items.add(item);
            }
        } catch (Exception e) {
            items.clear();
        } finally {
            c.close();
        }

        return items;
    }

    /**
     * Find a folder in the db, creating the FolderInfo if necessary, and adding it to folderList.
     */
    FolderInfo getFolderById(Context context, HashMap<Long,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);

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

                folderInfo.title = c.getString(titleIndex);
                folderInfo.id = id;
                folderInfo.container = c.getInt(containerIndex);
                folderInfo.screen = c.getInt(screenIndex);
                folderInfo.cellX = c.getInt(cellXIndex);
                folderInfo.cellY = c.getInt(cellYIndex);

                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.
     */
    static void addItemToDatabase(Context context, ItemInfo item, long container,
            int screen, int cellX, int cellY, boolean notify) {
        item.container = container;
        item.screen = screen;
        item.cellX = cellX;
        item.cellY = cellY;

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

        item.updateValuesWithCoordinates(values, cellX, cellY);

        Uri result = cr.insert(notify ? LauncherSettings.Favorites.CONTENT_URI :
                LauncherSettings.Favorites.CONTENT_URI_NO_NOTIFICATION, values);

        if (result != null) {
            item.id = Integer.parseInt(result.getPathSegments().get(1));
        }
    }

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

    static int getCellCountX() {
        return mCellCountX;
    }

    static int getCellCountY() {
        return mCellCountY;
    }

    /**
     * Updates the model orientation helper to take into account the current layout dimensions
     * when performing local/canonical coordinate transformations.
     */
    static void updateWorkspaceLayoutCells(int shortAxisCellCount, int longAxisCellCount) {
        mCellCountX = shortAxisCellCount;
        mCellCountY = longAxisCellCount;
    }

    /**
     * Update an item to the database in a specified container.
     */
    static void updateItemInDatabase(Context context, ItemInfo item) {
        final ContentValues values = new ContentValues();
        final ContentResolver cr = context.getContentResolver();

        item.onAddToDatabase(values);
        item.updateValuesWithCoordinates(values, item.cellX, item.cellY);

        cr.update(LauncherSettings.Favorites.getContentUri(item.id, false), values, null, null);
    }

    /**
     * Removes the specified item from the database
     * @param context
     * @param item
     */
    static void deleteItemFromDatabase(Context context, ItemInfo item) {
        final ContentResolver cr = context.getContentResolver();
        final Uri uriToDelete = LauncherSettings.Favorites.getContentUri(item.id, false);
        sWorker.post(new Runnable() {
                public void run() {
                    cr.delete(uriToDelete, null, null);
                }
            });
    }

    static void deleteFolderContentsFromDatabase(Context context, final FolderInfo info) {
        deleteFolderContentsFromDatabase(context, info, false);
    }

    /**
     * Remove the contents of the specified folder from the database
     */
    static void deleteFolderContentsFromDatabase(Context context, final FolderInfo info,
            boolean post) {
        // TODO: this post flag is temporary to fix an ordering of commands issue. In future,
        // all db operations will be moved to the worker thread, so this can be discarded at
        // that time.
        final ContentResolver cr = context.getContentResolver();

        if (!post) {
            cr.delete(LauncherSettings.Favorites.getContentUri(info.id, false), null, null);
            cr.delete(LauncherSettings.Favorites.CONTENT_URI,
                    LauncherSettings.Favorites.CONTAINER + "=" + info.id, null);
        } else {
            sWorker.post(new Runnable() {
                public void run() {
                    cr.delete(LauncherSettings.Favorites.getContentUri(info.id, false), null, null);
                    cr.delete(LauncherSettings.Favorites.CONTENT_URI,
                            LauncherSettings.Favorites.CONTAINER + "=" + info.id, null);
                }
            });
        }
    }

    /**
     * Set this as the current Launcher activity object for the loader.
     */
    public void initialize(Callbacks callbacks) {
        synchronized (mLock) {
            mCallbacks = new WeakReference<Callbacks>(callbacks);
        }
    }

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

        final String action = intent.getAction();

        if (Intent.ACTION_PACKAGE_CHANGED.equals(action)
                || Intent.ACTION_PACKAGE_REMOVED.equals(action)
                || Intent.ACTION_PACKAGE_ADDED.equals(action)) {
            final String packageName = intent.getData().getSchemeSpecificPart();
            final boolean replacing = intent.getBooleanExtra(Intent.EXTRA_REPLACING, false);

            int op = PackageUpdatedTask.OP_NONE;

            if (packageName == null || packageName.length() == 0) {
                // they sent us a bad intent
                return;
            }

            if (Intent.ACTION_PACKAGE_CHANGED.equals(action)) {
                op = PackageUpdatedTask.OP_UPDATE;
            } else if (Intent.ACTION_PACKAGE_REMOVED.equals(action)) {
                if (!replacing) {
                    op = PackageUpdatedTask.OP_REMOVE;
                }
                // else, we are replacing the package, so a PACKAGE_ADDED will be sent
                // later, we will update the package at this time
            } else if (Intent.ACTION_PACKAGE_ADDED.equals(action)) {
                if (!replacing) {
                    op = PackageUpdatedTask.OP_ADD;
                } else {
                    op = PackageUpdatedTask.OP_UPDATE;
                }
            }

            if (op != PackageUpdatedTask.OP_NONE) {
                enqueuePackageUpdated(new PackageUpdatedTask(op, new String[] { packageName }));
            }

        } else if (Intent.ACTION_EXTERNAL_APPLICATIONS_AVAILABLE.equals(action)) {
            // First, schedule to add these apps back in.
            String[] packages = intent.getStringArrayExtra(Intent.EXTRA_CHANGED_PACKAGE_LIST);
            enqueuePackageUpdated(new PackageUpdatedTask(PackageUpdatedTask.OP_ADD, packages));
            // Then, rebind everything.
            startLoaderFromBackground();
        } else if (Intent.ACTION_EXTERNAL_APPLICATIONS_UNAVAILABLE.equals(action)) {
            String[] packages = intent.getStringArrayExtra(Intent.EXTRA_CHANGED_PACKAGE_LIST);
            enqueuePackageUpdated(new PackageUpdatedTask(
                        PackageUpdatedTask.OP_UNAVAILABLE, packages));
        } else if (Intent.ACTION_LOCALE_CHANGED.equals(action)) {
            // If we have changed locale we need to clear out the labels in all apps.
            // 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.  Either way, mAllAppsLoaded will be cleared so it re-reads everything
            // next time.
            mAllAppsLoaded = false;
            startLoaderFromBackground();
        }
    }

    /**
     * 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;
        if (mCallbacks != null) {
            Callbacks callbacks = mCallbacks.get();
            if (callbacks != null) {
                // Only actually run the loader if they're not paused.
                if (!callbacks.setLoadOnResume()) {
                    runLoader = true;
                }
            }
        }
        if (runLoader) {
            startLoader(mApp, false);
        }
    }

    public void startLoader(Context context, boolean isLaunching) {
        synchronized (mLock) {
            if (DEBUG_LOADERS) {
                Log.d(TAG, "startLoader isLaunching=" + isLaunching);
            }

            // 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.
                LoaderTask oldTask = mLoaderTask;
                if (oldTask != null) {
                    if (oldTask.isLaunching()) {
                        // don't downgrade isLaunching if we're already running
                        isLaunching = true;
                    }
                    oldTask.stopLocked();
                }
                mLoaderTask = new LoaderTask(context, isLaunching);
                sWorker.post(mLoaderTask);
            }
        }
    }

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

    /**
     * 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;
        private Thread mWaitThread;
        private boolean mIsLaunching;
        private boolean mStopped;
        private boolean mLoadAndBindStepFinished;

        final ArrayList<ItemInfo> mItems = new ArrayList<ItemInfo>();
        final ArrayList<LauncherAppWidgetInfo> mAppWidgets = new ArrayList<LauncherAppWidgetInfo>();
        final HashMap<Long, FolderInfo> mFolders = new HashMap<Long, FolderInfo>();

        LoaderTask(Context context, boolean isLaunching) {
            mContext = context;
            mIsLaunching = isLaunching;
        }

        boolean isLaunching() {
            return mIsLaunching;
        }

        private void loadAndBindWorkspace() {
            // Load the workspace

            // For now, just always reload the workspace.  It's ~100 ms vs. the
            // binding which takes many hundreds of ms.
            // We can reconsider.
            if (DEBUG_LOADERS) {
                Log.d(TAG, "loadAndBindWorkspace mWorkspaceLoaded=" + mWorkspaceLoaded);
            }
            if (true || !mWorkspaceLoaded) {
                loadWorkspace();
                if (mStopped) {
                    return;
                }
                mWorkspaceLoaded = true;
            }

            // Bind the workspace
            bindWorkspace();
        }

        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 {
                        this.wait();
                    } catch (InterruptedException ex) {
                        // Ignore
                    }
                }
                if (DEBUG_LOADERS) {
                    Log.d(TAG, "waited "
                            + (SystemClock.uptimeMillis()-workspaceWaitTime)
                            + "ms for previous step to finish binding");
                }
            }
        }

        public void run() {
            // 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).
            final Callbacks cbk = mCallbacks.get();
            final boolean loadWorkspaceFirst = cbk != null ? (!cbk.isAllAppsVisible()) : true;

            keep_running: {
                // Elevate priority when Home launches for the first time to avoid
                // starving at boot time. Staring at a blank home is not cool.
                synchronized (mLock) {
                    android.os.Process.setThreadPriority(mIsLaunching
                            ? Process.THREAD_PRIORITY_DEFAULT : Process.THREAD_PRIORITY_BACKGROUND);
                }
                if (loadWorkspaceFirst) {
                    if (DEBUG_LOADERS) Log.d(TAG, "step 1: loading workspace");
                    loadAndBindWorkspace();
                } else {
                    if (DEBUG_LOADERS) Log.d(TAG, "step 1: special: loading all apps");
                    loadAndBindAllApps();
                }

                if (mStopped) {
                    break keep_running;
                }

                // Whew! Hard work done.  Slow us down, and wait until the UI thread has
                // settled down.
                synchronized (mLock) {
                    if (mIsLaunching) {
                        android.os.Process.setThreadPriority(Process.THREAD_PRIORITY_BACKGROUND);
                    }
                }
                waitForIdle();

                // second step
                if (loadWorkspaceFirst) {
                    if (DEBUG_LOADERS) Log.d(TAG, "step 2: loading all apps");
                    loadAndBindAllApps();
                } else {
                    if (DEBUG_LOADERS) Log.d(TAG, "step 2: special: loading workspace");
                    loadAndBindWorkspace();
                }
            }

            // 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;
                }
            }
        }

        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(ItemInfo occupied[][][], ItemInfo item) {
            if (item.container != LauncherSettings.Favorites.CONTAINER_DESKTOP) {
                return true;
            }
            for (int x = item.cellX; x < (item.cellX+item.spanX); x++) {
                for (int y = item.cellY; y < (item.cellY+item.spanY); y++) {
                    if (occupied[item.screen][x][y] != null) {
                        Log.e(TAG, "Error loading shortcut " + item
                            + " into cell (" + item.screen + ":"
                            + x + "," + y
                            + ") occupied by "
                            + occupied[item.screen][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++) {
                    occupied[item.screen][x][y] = item;
                }
            }
            return true;
        }

        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 AppWidgetManager widgets = AppWidgetManager.getInstance(context);
            final boolean isSafeMode = manager.isSafeMode();

            mItems.clear();
            mAppWidgets.clear();
            mFolders.clear();

            final ArrayList<Long> itemsToRemove = new ArrayList<Long>();

            final Cursor c = contentResolver.query(
                    LauncherSettings.Favorites.CONTENT_URI, null, null, null, null);

            final ItemInfo occupied[][][] =
                    new ItemInfo[Launcher.SCREEN_COUNT][mCellCountX][mCellCountY];

            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 iconTypeIndex = c.getColumnIndexOrThrow(
                        LauncherSettings.Favorites.ICON_TYPE);
                final int iconIndex = c.getColumnIndexOrThrow(LauncherSettings.Favorites.ICON);
                final int iconPackageIndex = c.getColumnIndexOrThrow(
                        LauncherSettings.Favorites.ICON_PACKAGE);
                final int iconResourceIndex = c.getColumnIndexOrThrow(
                        LauncherSettings.Favorites.ICON_RESOURCE);
                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 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 uriIndex = c.getColumnIndexOrThrow(LauncherSettings.Favorites.URI);
                final int displayModeIndex = c.getColumnIndexOrThrow(
                        LauncherSettings.Favorites.DISPLAY_MODE);

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

                while (!mStopped && c.moveToNext()) {
                    try {
                        int itemType = c.getInt(itemTypeIndex);

                        switch (itemType) {
                        case LauncherSettings.Favorites.ITEM_TYPE_APPLICATION:
                        case LauncherSettings.Favorites.ITEM_TYPE_SHORTCUT:
                            intentDescription = c.getString(intentIndex);
                            try {
                                intent = Intent.parseUri(intentDescription, 0);
                            } catch (URISyntaxException e) {
                                continue;
                            }

                            if (itemType == LauncherSettings.Favorites.ITEM_TYPE_APPLICATION) {
                                info = getShortcutInfo(manager, intent, context, c, iconIndex,
                                        titleIndex);
                            } else {
                                info = getShortcutInfo(c, context, iconTypeIndex,
                                        iconPackageIndex, iconResourceIndex, iconIndex,
                                        titleIndex);
                            }

                            if (info != null) {
                                info.intent = intent;
                                info.id = c.getLong(idIndex);
                                container = c.getInt(containerIndex);
                                info.container = container;
                                info.screen = c.getInt(screenIndex);
                                info.cellX = c.getInt(cellXIndex);
                                info.cellY = c.getInt(cellYIndex);

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

                                switch (container) {
                                case LauncherSettings.Favorites.CONTAINER_DESKTOP:
                                    mItems.add(info);
                                    break;
                                default:
                                    // Item is in a user folder
                                    FolderInfo folderInfo =
                                            findOrMakeFolder(mFolders, container);
                                    folderInfo.add(info);
                                    break;
                                }

                                // now that we've loaded everthing re-save it with the
                                // icon in case it disappears somehow.
                                updateSavedIcon(context, info, c, iconIndex);
                            } else {
                                // Failed to load the shortcut, probably because the
                                // activity manager couldn't resolve it (maybe the app
                                // was uninstalled), or the db row was somehow screwed up.
                                // Delete it.
                                id = c.getLong(idIndex);
                                Log.e(TAG, "Error loading shortcut " + id + ", removing it");
                                contentResolver.delete(LauncherSettings.Favorites.getContentUri(
                                            id, false), null, null);
                            }
                            break;

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

                            folderInfo.title = c.getString(titleIndex);
                            folderInfo.id = id;
                            container = c.getInt(containerIndex);
                            folderInfo.container = container;
                            folderInfo.screen = c.getInt(screenIndex);
                            folderInfo.cellX = c.getInt(cellXIndex);
                            folderInfo.cellY = c.getInt(cellYIndex);

                            // check & update map of what's occupied
                            if (!checkItemPlacement(occupied, folderInfo)) {
                                break;
                            }
                            switch (container) {
                                case LauncherSettings.Favorites.CONTAINER_DESKTOP:
                                    mItems.add(folderInfo);
                                    break;
                            }

                            mFolders.put(folderInfo.id, folderInfo);
                            break;

                        case LauncherSettings.Favorites.ITEM_TYPE_APPWIDGET:
                            // Read all Launcher-specific widget details
                            int appWidgetId = c.getInt(appWidgetIdIndex);
                            id = c.getLong(idIndex);

                            final AppWidgetProviderInfo provider =
                                    widgets.getAppWidgetInfo(appWidgetId);

                            if (!isSafeMode && (provider == null || provider.provider == null ||
                                    provider.provider.getPackageName() == null)) {
                                Log.e(TAG, "Deleting widget that isn't installed anymore: id="
                                        + id + " appWidgetId=" + appWidgetId);
                                itemsToRemove.add(id);
                            } else {
                                appWidgetInfo = new LauncherAppWidgetInfo(appWidgetId);
                                appWidgetInfo.id = id;
                                appWidgetInfo.screen = c.getInt(screenIndex);
                                appWidgetInfo.cellX = c.getInt(cellXIndex);
                                appWidgetInfo.cellY = c.getInt(cellYIndex);
                                appWidgetInfo.spanX = c.getInt(spanXIndex);
                                appWidgetInfo.spanY = c.getInt(spanYIndex);

                                container = c.getInt(containerIndex);
                                if (container != LauncherSettings.Favorites.CONTAINER_DESKTOP) {
                                    Log.e(TAG, "Widget found where container "
                                            + "!= CONTAINER_DESKTOP -- ignoring!");
                                    continue;
                                }
                                appWidgetInfo.container = c.getInt(containerIndex);

                                // check & update map of what's occupied
                                if (!checkItemPlacement(occupied, appWidgetInfo)) {
                                    break;
                                }

                                mAppWidgets.add(appWidgetInfo);
                            }
                            break;
                        }
                    } catch (Exception e) {
                        Log.w(TAG, "Desktop items loading interrupted:", e);
                    }
                }
            } finally {
                c.close();
            }

            if (itemsToRemove.size() > 0) {
                ContentProviderClient client = contentResolver.acquireContentProviderClient(
                                LauncherSettings.Favorites.CONTENT_URI);
                // Remove dead items
                for (long id : itemsToRemove) {
                    if (DEBUG_LOADERS) {
                        Log.d(TAG, "Removed id = " + id);
                    }
                    // Don't notify content observers
                    try {
                        client.delete(LauncherSettings.Favorites.getContentUri(id, false),
                                null, null);
                    } catch (RemoteException e) {
                        Log.w(TAG, "Could not remove id = " + id);
                    }
                }
            }

            if (DEBUG_LOADERS) {
                Log.d(TAG, "loaded workspace in " + (SystemClock.uptimeMillis()-t) + "ms");
                Log.d(TAG, "workspace layout: ");
                for (int y = 0; y < mCellCountY; y++) {
                    String line = "";
                    for (int s = 0; s < Launcher.SCREEN_COUNT; s++) {
                        if (s > 0) {
                            line += " | ";
                        }
                        for (int x = 0; x < mCellCountX; x++) {
                            line += ((occupied[s][x][y] != null) ? "#" : ".");
                        }
                    }
                    Log.d(TAG, "[ " + line + " ]");
                }
            }
        }

        /**
         * Read everything out of our database.
         */
        private void bindWorkspace() {
            final long t = SystemClock.uptimeMillis();

            // 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;
            }

            int N;
            // Tell the workspace that we're about to start firing items at it
            mHandler.post(new Runnable() {
                public void run() {
                    Callbacks callbacks = tryGetCallbacks(oldCallbacks);
                    if (callbacks != null) {
                        callbacks.startBinding();
                    }
                }
            });
            // Add the items to the workspace.
            N = mItems.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);
                mHandler.post(new Runnable() {
                    public void run() {
                        Callbacks callbacks = tryGetCallbacks(oldCallbacks);
                        if (callbacks != null) {
                            callbacks.bindItems(mItems, start, start+chunkSize);
                        }
                    }
                });
            }
            mHandler.post(new Runnable() {
                public void run() {
                    Callbacks callbacks = tryGetCallbacks(oldCallbacks);
                    if (callbacks != null) {
                        callbacks.bindFolders(mFolders);
                    }
                }
            });
            // Wait until the queue goes empty.
            mHandler.post(new Runnable() {
                public void run() {
                    if (DEBUG_LOADERS) {
                        Log.d(TAG, "Going to start binding widgets soon.");
                    }
                }
            });
            // Bind the widgets, one at a time.
            // WARNING: this is calling into the workspace from the background thread,
            // but since getCurrentScreen() just returns the int, we should be okay.  This
            // is just a hint for the order, and if it's wrong, we'll be okay.
            // TODO: instead, we should have that push the current screen into here.
            final int currentScreen = oldCallbacks.getCurrentWorkspaceScreen();
            N = mAppWidgets.size();
            // once for the current screen
            for (int i=0; i<N; i++) {
                final LauncherAppWidgetInfo widget = mAppWidgets.get(i);
                if (widget.screen == currentScreen) {
                    mHandler.post(new Runnable() {
                        public void run() {
                            Callbacks callbacks = tryGetCallbacks(oldCallbacks);
                            if (callbacks != null) {
                                callbacks.bindAppWidget(widget);
                            }
                        }
                    });
                }
            }
            // once for the other screens
            for (int i=0; i<N; i++) {
                final LauncherAppWidgetInfo widget = mAppWidgets.get(i);
                if (widget.screen != currentScreen) {
                    mHandler.post(new Runnable() {
                        public void run() {
                            Callbacks callbacks = tryGetCallbacks(oldCallbacks);
                            if (callbacks != null) {
                                callbacks.bindAppWidget(widget);
                            }
                        }
                    });
                }
            }
            // Tell the workspace that we're done.
            mHandler.post(new Runnable() {
                public void run() {
                    Callbacks callbacks = tryGetCallbacks(oldCallbacks);
                    if (callbacks != null) {
                        callbacks.finishBindingItems();
                    }
                }
            });
            // If we're profiling, this is the last thing in the queue.
            mHandler.post(new Runnable() {
                public void run() {
                    if (DEBUG_LOADERS) {
                        Log.d(TAG, "bound workspace in "
                            + (SystemClock.uptimeMillis()-t) + "ms");
                    }
                }
            });
        }

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

        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
            final ArrayList<ApplicationInfo> list
                    = (ArrayList<ApplicationInfo>)mAllAppsList.data.clone();
            mHandler.post(new Runnable() {
                public void run() {
                    final long t = SystemClock.uptimeMillis();
                    final Callbacks callbacks = tryGetCallbacks(oldCallbacks);
                    if (callbacks != null) {
                        callbacks.bindAllApplications(list);
                    }
                    if (DEBUG_LOADERS) {
                        Log.d(TAG, "bound all " + list.size() + " apps from cache in "
                                + (SystemClock.uptimeMillis()-t) + "ms");
                    }
                }
            });

        }

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

            // 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 (loadAllAppsByBatch)");
                return;
            }

            final Intent mainIntent = new Intent(Intent.ACTION_MAIN, null);
            mainIntent.addCategory(Intent.CATEGORY_LAUNCHER);

            final PackageManager packageManager = mContext.getPackageManager();
            List<ResolveInfo> apps = null;

            int N = Integer.MAX_VALUE;

            int startIndex;
            int i=0;
            int batchSize = -1;
            while (i < N && !mStopped) {
                if (i == 0) {
                    mAllAppsList.clear();
                    final long qiaTime = DEBUG_LOADERS ? SystemClock.uptimeMillis() : 0;
                    apps = packageManager.queryIntentActivities(mainIntent, 0);
                    if (DEBUG_LOADERS) {
                        Log.d(TAG, "queryIntentActivities took "
                                + (SystemClock.uptimeMillis()-qiaTime) + "ms");
                    }
                    if (apps == null) {
                        return;
                    }
                    N = apps.size();
                    if (DEBUG_LOADERS) {
                        Log.d(TAG, "queryIntentActivities got " + N + " apps");
                    }
                    if (N == 0) {
                        // There are no apps?!?
                        return;
                    }
                    if (mBatchSize == 0) {
                        batchSize = N;
                    } else {
                        batchSize = mBatchSize;
                    }

                    final long sortTime = DEBUG_LOADERS ? SystemClock.uptimeMillis() : 0;
                    Collections.sort(apps,
                            new ResolveInfo.DisplayNameComparator(packageManager));
                    if (DEBUG_LOADERS) {
                        Log.d(TAG, "sort took "
                                + (SystemClock.uptimeMillis()-sortTime) + "ms");
                    }
                }

                final long t2 = DEBUG_LOADERS ? SystemClock.uptimeMillis() : 0;

                startIndex = i;
                for (int j=0; i<N && j<batchSize; j++) {
                    // This builds the icon bitmaps.
                    mAllAppsList.add(new ApplicationInfo(packageManager, apps.get(i), mIconCache));
                    i++;
                }

                final boolean first = i <= batchSize;
                final Callbacks callbacks = tryGetCallbacks(oldCallbacks);
                final ArrayList<ApplicationInfo> added = mAllAppsList.added;
                mAllAppsList.added = new ArrayList<ApplicationInfo>();

                mHandler.post(new Runnable() {
                    public void run() {
                        final long t = SystemClock.uptimeMillis();
                        if (callbacks != null) {
                            if (first) {
                                callbacks.bindAllApplications(added);
                            } else {
                                callbacks.bindAppsAdded(added);
                            }
                            if (DEBUG_LOADERS) {
                                Log.d(TAG, "bound " + added.size() + " apps in "
                                    + (SystemClock.uptimeMillis() - t) + "ms");
                            }
                        } else {
                            Log.i(TAG, "not binding apps: no Launcher activity");
                        }
                    }
                });

                if (DEBUG_LOADERS) {
                    Log.d(TAG, "batch of " + (i-startIndex) + " icons processed in "
                            + (SystemClock.uptimeMillis()-t2) + "ms");
                }

                if (mAllAppsLoadDelay > 0 && i < N) {
                    try {
                        if (DEBUG_LOADERS) {
                            Log.d(TAG, "sleeping for " + mAllAppsLoadDelay + "ms");
                        }
                        Thread.sleep(mAllAppsLoadDelay);
                    } catch (InterruptedException exc) { }
                }
            }

            if (DEBUG_LOADERS) {
                Log.d(TAG, "cached all " + N + " apps in "
                        + (SystemClock.uptimeMillis()-t) + "ms"
                        + (mAllAppsLoadDelay > 0 ? " (including delay)" : ""));
            }
        }

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

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

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

        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) {
            mOp = op;
            mPackages = packages;
        }

        public void run() {
            final Context context = mApp;

            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]);
                        mAllAppsList.addPackage(context, packages[i]);
                    }
                    break;
                case OP_UPDATE:
                    for (int i=0; i<N; i++) {
                        if (DEBUG_LOADERS) Log.d(TAG, "mAllAppsList.updatePackage " + packages[i]);
                        mAllAppsList.updatePackage(context, packages[i]);
                    }
                    break;
                case OP_REMOVE:
                case OP_UNAVAILABLE:
                    for (int i=0; i<N; i++) {
                        if (DEBUG_LOADERS) Log.d(TAG, "mAllAppsList.removePackage " + packages[i]);
                        mAllAppsList.removePackage(packages[i]);
                    }
                    break;
            }

            ArrayList<ApplicationInfo> added = null;
            ArrayList<ApplicationInfo> removed = null;
            ArrayList<ApplicationInfo> modified = null;

            if (mAllAppsList.added.size() > 0) {
                added = mAllAppsList.added;
                mAllAppsList.added = new ArrayList<ApplicationInfo>();
            }
            if (mAllAppsList.removed.size() > 0) {
                removed = mAllAppsList.removed;
                mAllAppsList.removed = new ArrayList<ApplicationInfo>();
                for (ApplicationInfo info: removed) {
                    mIconCache.remove(info.intent.getComponent());
                }
            }
            if (mAllAppsList.modified.size() > 0) {
                modified = mAllAppsList.modified;
                mAllAppsList.modified = new ArrayList<ApplicationInfo>();
            }

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

            if (added != null) {
                final ArrayList<ApplicationInfo> addedFinal = added;
                mHandler.post(new Runnable() {
                    public void run() {
                        Callbacks cb = mCallbacks != null ? mCallbacks.get() : null;
                        if (callbacks == cb && cb != null) {
                            callbacks.bindAppsAdded(addedFinal);
                        }
                    }
                });
            }
            if (modified != null) {
                final ArrayList<ApplicationInfo> modifiedFinal = modified;
                mHandler.post(new Runnable() {
                    public void run() {
                        Callbacks cb = mCallbacks != null ? mCallbacks.get() : null;
                        if (callbacks == cb && cb != null) {
                            callbacks.bindAppsUpdated(modifiedFinal);
                        }
                    }
                });
            }
            if (removed != null) {
                final boolean permanent = mOp != OP_UNAVAILABLE;
                final ArrayList<ApplicationInfo> removedFinal = removed;
                mHandler.post(new Runnable() {
                    public void run() {
                        Callbacks cb = mCallbacks != null ? mCallbacks.get() : null;
                        if (callbacks == cb && cb != null) {
                            callbacks.bindAppsRemoved(removedFinal, permanent);
                        }
                    }
                });
            }

            mHandler.post(new Runnable() {
                @Override
                public void run() {
                    Callbacks cb = mCallbacks != null ? mCallbacks.get() : null;
                    if (callbacks == cb && cb != null) {
                        callbacks.bindPackagesUpdated();
                    }
                }
            });
        }
    }

    /**
     * This is called from the code that adds shortcuts from the intent receiver.  This
     * doesn't have a Cursor, but
     */
    public ShortcutInfo getShortcutInfo(PackageManager manager, Intent intent, Context context) {
        return getShortcutInfo(manager, intent, context, null, -1, -1);
    }

    /**
     * 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 getShortcutInfo(PackageManager manager, Intent intent, Context context,
            Cursor c, int iconIndex, int titleIndex) {
        Bitmap icon = null;
        final ShortcutInfo info = new ShortcutInfo();

        ComponentName componentName = intent.getComponent();
        if (componentName == null) {
            return null;
        }

        // TODO: See if the PackageManager knows about this case.  If it doesn't
        // then return null & delete this.

        // the resource -- This may implicitly give us back the fallback icon,
        // but don't worry about that.  All we're doing with usingFallbackIcon is
        // to avoid saving lots of copies of that in the database, and most apps
        // have icons anyway.
        final ResolveInfo resolveInfo = manager.resolveActivity(intent, 0);
        if (resolveInfo != null) {
            icon = mIconCache.getIcon(componentName, resolveInfo);
        }
        // the db
        if (icon == null) {
            if (c != null) {
                icon = getIconFromCursor(c, iconIndex);
            }
        }
        // the fallback icon
        if (icon == null) {
            icon = getFallbackIcon();
            info.usingFallbackIcon = true;
        }
        info.setIcon(icon);

        // from the resource
        if (resolveInfo != null) {
            info.title = resolveInfo.activityInfo.loadLabel(manager);
        }
        // from the db
        if (info.title == null) {
            if (c != null) {
                info.title =  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;
        return info;
    }

    /**
     * Make an ShortcutInfo object for a shortcut that isn't an application.
     */
    private ShortcutInfo getShortcutInfo(Cursor c, Context context,
            int iconTypeIndex, int iconPackageIndex, int iconResourceIndex, int iconIndex,
            int titleIndex) {

        Bitmap icon = null;
        final ShortcutInfo info = new ShortcutInfo();
        info.itemType = LauncherSettings.Favorites.ITEM_TYPE_SHORTCUT;

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

        info.title = c.getString(titleIndex);

        int iconType = c.getInt(iconTypeIndex);
        switch (iconType) {
        case LauncherSettings.Favorites.ICON_TYPE_RESOURCE:
            String packageName = c.getString(iconPackageIndex);
            String resourceName = c.getString(iconResourceIndex);
            PackageManager packageManager = context.getPackageManager();
            info.customIcon = false;
            // the resource
            try {
                Resources resources = packageManager.getResourcesForApplication(packageName);
                if (resources != null) {
                    final int id = resources.getIdentifier(resourceName, null, null);
                    icon = Utilities.createIconBitmap(
                            mIconCache.getFullResIcon(resources, id), context);
                }
            } catch (Exception e) {
                // drop this.  we have other places to look for icons
            }
            // the db
            if (icon == null) {
                icon = getIconFromCursor(c, iconIndex);
            }
            // the fallback icon
            if (icon == null) {
                icon = getFallbackIcon();
                info.usingFallbackIcon = true;
            }
            break;
        case LauncherSettings.Favorites.ICON_TYPE_BITMAP:
            icon = getIconFromCursor(c, iconIndex);
            if (icon == null) {
                icon = getFallbackIcon();
                info.customIcon = false;
                info.usingFallbackIcon = true;
            } else {
                info.customIcon = true;
            }
            break;
        default:
            icon = getFallbackIcon();
            info.usingFallbackIcon = true;
            info.customIcon = false;
            break;
        }
        info.setIcon(icon);
        return info;
    }

    Bitmap getIconFromCursor(Cursor c, int iconIndex) {
        if (false) {
            Log.d(TAG, "getIconFromCursor app="
                    + c.getString(c.getColumnIndexOrThrow(LauncherSettings.Favorites.TITLE)));
        }
        byte[] data = c.getBlob(iconIndex);
        try {
            return BitmapFactory.decodeByteArray(data, 0, data.length);
        } catch (Exception e) {
            return null;
        }
    }

    ShortcutInfo addShortcut(Context context, Intent data,
            int screen, int cellX, int cellY, boolean notify) {

        final ShortcutInfo info = infoFromShortcutIntent(context, data, null);
        addItemToDatabase(context, info, LauncherSettings.Favorites.CONTAINER_DESKTOP,
                screen, cellX, cellY, notify);

        return info;
    }

    /**
     * Attempts to find an AppWidgetProviderInfo that matches the given component.
     */
    AppWidgetProviderInfo findAppWidgetProviderInfoWithComponent(Context context,
            ComponentName component) {
        List<AppWidgetProviderInfo> widgets =
            AppWidgetManager.getInstance(context).getInstalledProviders();
        for (AppWidgetProviderInfo info : widgets) {
            if (info.provider.equals(component)) {
                return info;
            }
        }
        return null;
    }

    /**
     * Returns a list of all the widgets that can handle configuration with a particular mimeType.
     */
    List<WidgetMimeTypeHandlerData> resolveWidgetsForMimeType(Context context, String mimeType) {
        final PackageManager packageManager = context.getPackageManager();
        final List<WidgetMimeTypeHandlerData> supportedConfigurationActivities =
            new ArrayList<WidgetMimeTypeHandlerData>();

        final Intent supportsIntent =
            new Intent(InstallWidgetReceiver.ACTION_SUPPORTS_CLIPDATA_MIMETYPE);
        supportsIntent.setType(mimeType);

        // Create a set of widget configuration components that we can test against
        final List<AppWidgetProviderInfo> widgets =
            AppWidgetManager.getInstance(context).getInstalledProviders();
        final HashMap<ComponentName, AppWidgetProviderInfo> configurationComponentToWidget =
            new HashMap<ComponentName, AppWidgetProviderInfo>();
        for (AppWidgetProviderInfo info : widgets) {
            configurationComponentToWidget.put(info.configure, info);
        }

        // Run through each of the intents that can handle this type of clip data, and cross
        // reference them with the components that are actual configuration components
        final List<ResolveInfo> activities = packageManager.queryIntentActivities(supportsIntent,
                PackageManager.MATCH_DEFAULT_ONLY);
        for (ResolveInfo info : activities) {
            final ActivityInfo activityInfo = info.activityInfo;
            final ComponentName infoComponent = new ComponentName(activityInfo.packageName,
                    activityInfo.name);
            if (configurationComponentToWidget.containsKey(infoComponent)) {
                supportedConfigurationActivities.add(
                        new InstallWidgetReceiver.WidgetMimeTypeHandlerData(info,
                                configurationComponentToWidget.get(infoComponent)));
            }
        }
        return supportedConfigurationActivities;
    }

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

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

        if (bitmap != null && bitmap instanceof Bitmap) {
            icon = Utilities.createIconBitmap(new FastBitmapDrawable((Bitmap)bitmap), context);
            customIcon = true;
        } else {
            Parcelable extra = data.getParcelableExtra(Intent.EXTRA_SHORTCUT_ICON_RESOURCE);
            if (extra != null && extra instanceof ShortcutIconResource) {
                try {
                    iconResource = (ShortcutIconResource) extra;
                    final PackageManager packageManager = context.getPackageManager();
                    Resources resources = packageManager.getResourcesForApplication(
                            iconResource.packageName);
                    final int id = resources.getIdentifier(iconResource.resourceName, null, null);
                    icon = Utilities.createIconBitmap(
                            mIconCache.getFullResIcon(resources, id), context);
                } catch (Exception e) {
                    Log.w(TAG, "Could not load shortcut icon: " + extra);
                }
            }
        }

        final ShortcutInfo info = new ShortcutInfo();

        if (icon == null) {
            if (fallbackIcon != null) {
                icon = fallbackIcon;
            } else {
                icon = getFallbackIcon();
                info.usingFallbackIcon = true;
            }
        }
        info.setIcon(icon);

        info.title = name;
        info.intent = intent;
        info.customIcon = customIcon;
        info.iconResource = iconResource;

        return info;
    }

    void updateSavedIcon(Context context, ShortcutInfo info, Cursor c, int iconIndex) {
        // If apps can't be on SD, don't even bother.
        if (!mAppsCanBeOnExternalStorage) {
            return;
        }
        // If this icon doesn't have a custom icon, check to see
        // what's stored in the DB, and if it doesn't match what
        // we're going to show, store what we are going to show back
        // into the DB.  We do this so when we're loading, if the
        // package manager can't find an icon (for example because
        // the app is on SD) then we can use that instead.
        if (!info.customIcon && !info.usingFallbackIcon) {
            boolean needSave;
            byte[] data = c.getBlob(iconIndex);
            try {
                if (data != null) {
                    Bitmap saved = BitmapFactory.decodeByteArray(data, 0, data.length);
                    Bitmap loaded = info.getIcon(mIconCache);
                    needSave = !saved.sameAs(loaded);
                } else {
                    needSave = true;
                }
            } catch (Exception e) {
                needSave = true;
            }
            if (needSave) {
                Log.d(TAG, "going to save icon bitmap for info=" + info);
                // This is slower than is ideal, but this only happens once
                // or when the app is updated with a new icon.
                updateItemInDatabase(context, info);
            }
        }
    }

    /**
     * Return an existing FolderInfo object if we have encountered this ID previously,
     * or make a new one.
     */
    private static FolderInfo findOrMakeFolder(HashMap<Long, 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;
    }

    private static final Collator sCollator = Collator.getInstance();
    public static final Comparator<ApplicationInfo> APP_NAME_COMPARATOR
            = new Comparator<ApplicationInfo>() {
        public final int compare(ApplicationInfo a, ApplicationInfo b) {
            return sCollator.compare(a.title.toString(), b.title.toString());
        }
    };
    public static final Comparator<ApplicationInfo> APP_INSTALL_TIME_COMPARATOR
            = new Comparator<ApplicationInfo>() {
        public final int compare(ApplicationInfo a, ApplicationInfo b) {
            if (a.firstInstallTime < b.firstInstallTime) return 1;
            if (a.firstInstallTime > b.firstInstallTime) return -1;
            return 0;
        }
    };
    public static final Comparator<AppWidgetProviderInfo> WIDGET_NAME_COMPARATOR
            = new Comparator<AppWidgetProviderInfo>() {
        public final int compare(AppWidgetProviderInfo a, AppWidgetProviderInfo b) {
            return sCollator.compare(a.label.toString(), b.label.toString());
        }
    };
    public static class ShortcutNameComparator implements Comparator<ResolveInfo> {
        private PackageManager mPackageManager;
        private HashMap<Object, String> mLabelCache;
        ShortcutNameComparator(PackageManager pm) {
            mPackageManager = pm;
            mLabelCache = new HashMap<Object, String>();
        }
        public final int compare(ResolveInfo a, ResolveInfo b) {
            String labelA, labelB;
            if (mLabelCache.containsKey(a)) labelA = mLabelCache.get(a);
            else labelA = a.loadLabel(mPackageManager).toString();
            if (mLabelCache.containsKey(b)) labelB = mLabelCache.get(b);
            else labelB = b.loadLabel(mPackageManager).toString();
            return sCollator.compare(labelA, labelB);
        }
    };
    public static class WidgetAndShortcutNameComparator implements Comparator<Object> {
        private PackageManager mPackageManager;
        private HashMap<Object, String> mLabelCache;
        WidgetAndShortcutNameComparator(PackageManager pm) {
            mPackageManager = pm;
            mLabelCache = new HashMap<Object, String>();
        }
        public final int compare(Object a, Object b) {
            String labelA, labelB;
            if (mLabelCache.containsKey(a)) labelA = mLabelCache.get(a);
            else labelA = (a instanceof AppWidgetProviderInfo) ?
                    ((AppWidgetProviderInfo) a).label :
                    ((ResolveInfo) a).loadLabel(mPackageManager).toString();
            if (mLabelCache.containsKey(b)) labelB = mLabelCache.get(b);
            else labelB = (b instanceof AppWidgetProviderInfo) ?
                    ((AppWidgetProviderInfo) b).label :
                    ((ResolveInfo) b).loadLabel(mPackageManager).toString();
            return sCollator.compare(labelA, labelB);
        }
    };

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