Android 4.0 Launcher2源码分析——Launcher内容加载详细过程

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Launcher在应用启动的时候，需要加载AppWidget，shortcut等内容项，通过调用LauncherModel.startLoader()，开始加载的工作。launcherModel中加载好的内容会通过

LauncherModel.Callbacks接口的回调函数将数据传给需要的组件，那先来看看Callbacks的定义：

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();        public void bindSearchablesChanged();    }

简单的了解下每个方法的用途：

setLoadOnResume()     由于Launcher继承自Activity，因此Launcher可能会处于paused状态（onPause()被调用），则有可能在这段时间内资源可能

发生了改变，如应用被删除或新应用安装，因此需要在onResume()中调用此方法进行重新加载。

getCurrentWorkspace()    获取当前屏幕的序号

startBinding()     通知Launcher加载开始，并更新Workspace上的shortcuts

bindItems(ArrayList<ItemInfo> shortcuts, int start, int end)     加载一批内容项到Workspace，加载的内容项包括，Application、shortcut、folder。

bindFolders(HashMap<Long, FolderInfo> folders)    加载folder的内容

finishBindingItems()    通知Launcher加载结束。

bindAppWidget(LauncherAppWidgetInfo item)    加载AppWidget到Workspace

bindAllApplications(final ArrayList<ApplicationInfo> apps)   在All Apps页加载所有应用的Icon

bindAppsAdded(ArrayList<ApplicationInfo> apps)   通知Launcher一个新的应用被安装，并加载这个应用

bindAppsUpdated(ArrayList<ApplicationInfo> apps)  通知Launcher一个应用发生了更新

bindAppsRemoved(ArrayList<ApplicationInfo> apps, boolean permanent)    通知Launcher一个应用被删除了

bindPackagesUpdated()   通知Launcher多个应用发生了更新

isAllAppsVisible()用于在加载的过程中记录当前Launcher的状态，返回true则当前显示的All Apps

bindSearchablesChanged()当搜索/删除框状态发生改变时调用

了解了每个方法的作用之后，就可以开始进一步的分析了。

首先让我们回顾一下整个加载过程的流程是怎样的

通过在Launcher中调用LauncherModel.startLoader()方法，开始加载内容。

public void startLoader(Context context, boolean isLaunching) {        synchronized (mLock) {            ......            // Don't bother to start the thread if we know it's not going to do anything            if (mCallbacks != null && mCallbacks.get() != null) {                ......                mLoaderTask = new LoaderTask(context, isLaunching);                sWorkerThread.setPriority(Thread.NORM_PRIORITY);                sWorker.post(mLoaderTask);            }        }    }

mLoaderTask是一个Runnable，被添加到消息队列之后，它的run() 方法会被调用。

public void run() {            ......            keep_running: {                ......                if (loadWorkspaceFirst) {                    ......                    loadAndBindWorkspace();                } else {                    ......                }                if (mStopped) {                    break keep_running;                }                ......                waitForIdle();                // second step                if (loadWorkspaceFirst) {                    ......                    loadAndBindAllApps();                } else {                    ......                }                ......            }            ......        }

加载的工作由两部分组成，第一部分是为Workspace加载内容，第二部分则是为AllApps加载内容。每一部分的加载又可以分为两个步骤：1、由LauncherModel完成，主要

工作是从数据库中读取信息，并且按类别将内容项分装到不同的数据结构中。2、由Launcher来完成，通过LauncherModel.Callbacks接口定义的回调方法，从LauncherModel

中获取的数据，将其显示到桌面。

一、Workspace内容加载

run()中首先会调用loadAndBindWorkspace()方法开始Workspace的加载工作。

private void loadAndBindWorkspace() {            ...            if (!mWorkspaceLoaded) {                loadWorkspace();                synchronized (LoaderTask.this) {                    if (mStopped) {                        return;                    }                    mWorkspaceLoaded = true;                }            }            // Bind the workspace            bindWorkspace();        }

因为WorkspaceLoaded=false，所以会调用loadWorkspace()读取内容数据，等数据读取完毕之后，再调用bindWorkspace()将数据

加载到Workspace中。

private void loadWorkspace() {            ......            //存放container为CONTAINER_DESKTOP和CONTAINER_HOTSEAT类型的item            sWorkspaceItems.clear();                        //存放所有的AppWidget类型            sAppWidgets.clear();            //存放的FolderInfo.id和FolderInfo组成的映射对            sFolders.clear();            //所有的item的id和ItemInfo组成的映射对            sItemsIdMap.clear();            sDbIconCache.clear();            final ArrayList<Long> itemsToRemove = new ArrayList<Long>();            final Cursor c = contentResolver.query(                    LauncherSettings.Favorites.CONTENT_URI, 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)            //代表屏幕中的每一个单位的方格是否被占用。            //第一维表示分屏的序号，其中最后一个代表Hotseat            //第二维表示x方向方格的序号            //第三维表示y方向方格的序号            final ItemInfo occupied[][][] =                    new ItemInfo[Launcher.SCREEN_COUNT + 1][mCellCountX + 1][mCellCountY + 1];            try {                ......                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, mLabelCache);                            } else {                                info = getShortcutInfo(c, context, iconTypeIndex,                                        iconPackageIndex, iconResourceIndex, iconIndex,                                        titleIndex);                            }                            if (info != null) {                                ......                                // check & update map of what's occupied                                //检查这个item所占的空间是否空闲，true表示空闲                                if (!checkItemPlacement(occupied, info)) {                                    break;                                }                                switch (container) {                                case LauncherSettings.Favorites.CONTAINER_DESKTOP:                                case LauncherSettings.Favorites.CONTAINER_HOTSEAT:                                    //当加载的item类型为ITEM_TYPE_APPLICATION或者ITEM_TYPE_SHORTCUT                                    //并且所属的container为CONTAINER_DESKTOP或者CONTAINER_HOTSEAT时                                    //将其添加到sWorkspaceItems中                                    sWorkspaceItems.add(info);                                    break;                                default:                                    // Item is in a user folder                                    //如果item的container不是上述两者，则代表它处于一个folder中                                    //将其添加到所属的folderInfo中                                    FolderInfo folderInfo =                                            findOrMakeFolder(sFolders, container);                                    folderInfo.add(info);                                    break;                                }                                //所有的ITEM_TYPE_APPLICATION和ITEM_TYPE_SHORTCUT类型的item都需要                                //加入到sItemsIdMap的映射对中。                                sItemsIdMap.put(info.id, info);                                // now that we've loaded everthing re-save it with the                                // icon in case it disappears somehow.                                queueIconToBeChecked(sDbIconCache, 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(sFolders, id);                            .....                            // check & update map of what's occupied                            if (!checkItemPlacement(occupied, folderInfo)) {                                break;                            }                            switch (container) {                                case LauncherSettings.Favorites.CONTAINER_DESKTOP:                                case LauncherSettings.Favorites.CONTAINER_HOTSEAT:                                    //folderInfo类型的item也需要添加到sWorkspaceItems中                                    sWorkspaceItems.add(folderInfo);                                    break;                            }                            //添加到sItemsIdMap映射对中                            sItemsIdMap.put(folderInfo.id, folderInfo);                            //添加到sFolder映射对中                            sFolders.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)) {                                ......                                itemsToRemove.add(id);                            } else {                                appWidgetInfo = new LauncherAppWidgetInfo(appWidgetId);                                ......                                container = c.getInt(containerIndex);                                ......                                appWidgetInfo.container = c.getInt(containerIndex);                                // check & update map of what's occupied                                if (!checkItemPlacement(occupied, appWidgetInfo)) {                                    break;                                }                                //添加到sItemsIdMap映射对                                sItemsIdMap.put(appWidgetInfo.id, appWidgetInfo);                                //添加到sAppWidgets                                sAppWidgets.add(appWidgetInfo);                            }                            break;                        }                    } catch (Exception e) {                        ......                    }                }            } finally {                c.close();            }            ......        }

loadWorkspace的工作就是从ContentProvider获取指定URI中的数据，并将它们分类存放到指定的数据结构中。分类的标准有两条：1、item的类型。包括ITEM_TYPE_APPLICATION  ,ITEM_TYPE_SHORTCUT  ,ITEM_TYPE_FOLDER,ITEM_TYPE_APPWIDGET四类。2、item所属的容器。包括CONTAINER_DESKTOP，

CONTAINER_HOTSEAT以及其它（主要指文件夹）。LauncherModel在读取完数据之后，通过LauncherModel.bindWorkspace()将数据传给到Launcher。进入LauncherModel.bindWorkspace()中：

 private void bindWorkspace() {            ......            mHandler.post(new Runnable() {                public void run() {                    Callbacks callbacks = tryGetCallbacks(oldCallbacks);                    if (callbacks != null) {                        //开始绑定                        callbacks.startBinding();                    }                }            });            ......            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) {                            //绑定application、shortcut、folder三种内容                            callbacks.bindItems(workspaceItems, start, start+chunkSize);                        }                    }                });            }            ......            mHandler.post(new Runnable() {                public void run() {                    Callbacks callbacks = tryGetCallbacks(oldCallbacks);                    if (callbacks != null) {                        //绑定folder                        callbacks.bindFolders(folders);                    }                }            });            ......            for (int i=0; i<N; i++) {                final LauncherAppWidgetInfo widget = sAppWidgets.get(i);                if (widget.screen == currentScreen) {                    mHandler.post(new Runnable() {                        public void run() {                            Callbacks callbacks = tryGetCallbacks(oldCallbacks);                            if (callbacks != null) {                                //绑定当前屏的AppWidget                                callbacks.bindAppWidget(widget);                            }                        }                    });                }            }                       for (int i=0; i<N; i++) {                final LauncherAppWidgetInfo widget = sAppWidgets.get(i);                if (widget.screen != currentScreen) {                    mHandler.post(new Runnable() {                        public void run() {                            Callbacks callbacks = tryGetCallbacks(oldCallbacks);                            if (callbacks != null) {                                //绑定其它屏的AppWidget                                callbacks.bindAppWidget(widget);                            }                        }                    });                }            }                       mHandler.post(new Runnable() {                public void run() {                    Callbacks callbacks = tryGetCallbacks(oldCallbacks);                    if (callbacks != null) {                        //结束绑定                        callbacks.finishBindingItems();                    }                }            });            ......        }

可以看到，Launcher的内容绑定分为五步：分别对应着startBinding()、bindItems()、bindFolders()、bindAppWidgets()、finishBindingItems()的调用

Step1:调用Callbacks.startBinding()

由于Launcher实现了Callbacks接口，Launcher中的startBinding()被调用，进入Launcher.startBinding();

    /**     * Refreshes the shortcuts shown on the workspace.     *     * Implementation of the method from LauncherModel.Callbacks.     */    public void startBinding() {        final Workspace workspace = mWorkspace;        mWorkspace.clearDropTargets();        int count = workspace.getChildCount();        for (int i = 0; i < count; i++) {            // Use removeAllViewsInLayout() to avoid an extra requestLayout() and invalidate().            final CellLayout layoutParent = (CellLayout) workspace.getChildAt(i);            layoutParent.removeAllViewsInLayout();        }        if (mHotseat != null) {            mHotseat.resetLayout();        }    }

从方法中的内容我们可以看到，当被通知开始加载Workspace中内容时，Launcher重置了Workspace中的内容，Hotseat也通过resetLayout方法进行重置。

    void resetLayout() {        mContent.removeAllViewsInLayout();        // Add the Apps button        Context context = getContext();        LayoutInflater inflater = LayoutInflater.from(context);        BubbleTextView allAppsButton = (BubbleTextView)                inflater.inflate(R.layout.application, mContent, false);        ......        // Note: We do this to ensure that the hotseat is always laid out in the orientation of        // the hotseat in order regardless of which orientation they were added        int x = getCellXFromOrder(sAllAppsButtonRank);        int y = getCellYFromOrder(sAllAppsButtonRank);        mContent.addViewToCellLayout(allAppsButton, -1, 0, new CellLayout.LayoutParams(x,y,1,1),                true);    }

Hotseat中清空了装载的内容，然后重新加载allAppsButton。从这里也可以看到allAppsButton是固定到了Hotseat中，不同于Hotseat中的其他控件。

Step2:调用Callbacks.bindItems(ArrayList<ItemInfo> shortcuts, int start, int end)

准备工作完成之后，现在可以开始正式的加载工作了，首先被调用的是bindItems()方法

     /**     * Bind the items start-end from the list.     *     * Implementation of the method from LauncherModel.Callbacks.     */    public void bindItems(ArrayList<ItemInfo> shortcuts, int start, int end) {        setLoadOnResume();        final Workspace workspace = mWorkspace;        for (int i=start; i<end; i++) {            final ItemInfo item = shortcuts.get(i);            ......            switch (item.itemType) {                case LauncherSettings.Favorites.ITEM_TYPE_APPLICATION:                case LauncherSettings.Favorites.ITEM_TYPE_SHORTCUT:                    View shortcut = createShortcut((ShortcutInfo)item);                    workspace.addInScreen(shortcut, item.container, item.screen, item.cellX,                            item.cellY, 1, 1, false);                    break;                case LauncherSettings.Favorites.ITEM_TYPE_FOLDER:                    FolderIcon newFolder = FolderIcon.fromXml(R.layout.folder_icon, this,                            (ViewGroup) workspace.getChildAt(workspace.getCurrentPage()),                            (FolderInfo) item, mIconCache);                    workspace.addInScreen(newFolder, item.container, item.screen, item.cellX,                            item.cellY, 1, 1, false);                    break;            }        }        workspace.requestLayout();    }

通过这个方法，将application、shortcut、folder三种item通过Workspace.addInScreen()添加到Workspace中

    /**     * Adds the specified child in the specified screen. The position and dimension of     * the child are defined by x, y, spanX and spanY.     *     * @param child The child to add in one of the workspace's screens.     * @param screen The screen in which to add the child.     * @param x The X position of the child in the screen's grid.     * @param y The Y position of the child in the screen's grid.     * @param spanX The number of cells spanned horizontally by the child.     * @param spanY The number of cells spanned vertically by the child.     * @param insert When true, the child is inserted at the beginning of the children list.     */    void addInScreen(View child, long container, int screen, int x, int y, int spanX, int spanY,            boolean insert) {        ......        //Workspace一共有五个分屏，每个分屏是一个CellLayout        final CellLayout layout;        if (container == LauncherSettings.Favorites.CONTAINER_HOTSEAT) {            layout = mLauncher.getHotseat().getLayout();            child.setOnKeyListener(null);            ......            if (screen < 0) {                screen = mLauncher.getHotseat().getOrderInHotseat(x, y);            } else {                // Note: We do this to ensure that the hotseat is always laid out in the orientation                // of the hotseat in order regardless of which orientation they were added                //获取child的位置，返回true添加成功，false失败                x = mLauncher.getHotseat().getCellXFromOrder(screen);                y = mLauncher.getHotseat().getCellYFromOrder(screen);            }        } else {            // Show folder title if not in the hotseat            if (child instanceof FolderIcon) {                ((FolderIcon) child).setTextVisible(true);            }            layout = (CellLayout) getChildAt(screen);            child.setOnKeyListener(new IconKeyEventListener());        }        CellLayout.LayoutParams lp = (CellLayout.LayoutParams) child.getLayoutParams();        if (lp == null) {            lp = new CellLayout.LayoutParams(x, y, spanX, spanY);        } else {            lp.cellX = x;            lp.cellY = y;            lp.cellHSpan = spanX;            lp.cellVSpan = spanY;        }        if (spanX < 0 && spanY < 0) {            lp.isLockedToGrid = false;        }        // Get the canonical child id to uniquely represent this view in this screen        int childId = LauncherModel.getCellLayoutChildId(container, screen, x, y, spanX, spanY);        boolean markCellsAsOccupied = !(child instanceof Folder);        //将child添加到CellLayout中去        if (!layout.addViewToCellLayout(child, insert ? 0 : -1, childId, lp, markCellsAsOccupied)) {            ......        }        if (!(child instanceof Folder)) {            child.setHapticFeedbackEnabled(false);            child.setOnLongClickListener(mLongClickListener);        }        if (child instanceof DropTarget) {            mDragController.addDropTarget((DropTarget) child);        }    }

通过addInScreen()就能将child添加到指定的CellLayout中去。CellLayout共有六个，Workspace中五个，Hotseat一个。

Step3:调用Callbacks.bindFolders(HashMap<Long, FolderInfo> folders)

Launcher.bindFolders()中的代码只有三行：

public void bindFolders(HashMap<Long, FolderInfo> folders) {        setLoadOnResume();        sFolders.clear();        sFolders.putAll(folders);    }

获取到当前的Folder的映射表。

Step4:调用Callbacks.bindAppWidgets(LauncherAppWidgetInfo item)

现在开始加载AppWidget到Workspace：

     /**     * Add the views for a widget to the workspace.     *     * Implementation of the method from LauncherModel.Callbacks.     */    public void bindAppWidget(LauncherAppWidgetInfo item) {        setLoadOnResume();        ......        final Workspace workspace = mWorkspace;        final int appWidgetId = item.appWidgetId;        final AppWidgetProviderInfo appWidgetInfo = mAppWidgetManager.getAppWidgetInfo(appWidgetId);        ......        item.hostView = mAppWidgetHost.createView(this, appWidgetId, appWidgetInfo);        item.hostView.setAppWidget(appWidgetId, appWidgetInfo);        item.hostView.setTag(item);        workspace.addInScreen(item.hostView, item.container, item.screen, item.cellX,                item.cellY, item.spanX, item.spanY, false);        addWidgetToAutoAdvanceIfNeeded(item.hostView, appWidgetInfo);        workspace.requestLayout();        ......    }

先获取到AppWidget的相关信息之后，调用Workspace.addInScreen()添加到Workspace。AppWidget是Android系统的一大特色，可

以在桌面上快捷的获取实时信息和对一些指定应用进行控制。AppWidget是需要自动更新的（如果应用中设置了更新），因此除了

将其添加到桌面我们需要更具需要设置自动更新。进而调用addWidgetToAutoAdvanceifNeeded()来实现此功能，关于如何实现自动

更新AppWidget的话题，本文暂不做分析。bindAppWidgets()一共被调用两次，这样做的目的是增加流畅感，第一次调用的时候为

当前显示的分屏添加AppWidget，第二次调用的时候为其他未显示的分屏添加AppWidget。这样就给用户带来了一种流畅的用户体验。

Step5:调用Callbacks.finishBindingItems()

通过上面的操作，所有item就已经悉数被添加到Workspace当中，此时调用finishBindingItems()通知Launcher添加完毕。

     /**     * Callback saying that there aren't any more items to bind.     *     * Implementation of the method from LauncherModel.Callbacks.     */    public void finishBindingItems() {        setLoadOnResume();        ......        mWorkspaceLoading = false;        // If we received the result of any pending adds while the loader was running (e.g. the        // widget configuration forced an orientation change), process them now.        for (int i = 0; i < sPendingAddList.size(); i++) {            completeAdd(sPendingAddList.get(i));        }        sPendingAddList.clear();        ......        mWorkspace.post(mBuildLayersRunnable);    }

当Workspace正在加载的时候，有一些操作发生却还未执行，在finishBindingItems()中来执行这些操作，调用completeAdd()来完成

还未来得及完成的操作。紧接着又向Workspace的消息队列里加入了mBuildLayersRunnable，mBuildLayersRunnable是Runnable的

一个实例，它的功能就是迫使每个View都完成渲染的工作，即及时的现实到桌面中现好了所有需要的内容了。那下一步就是需要向

All Apps页中加载内容了。

二、AllApps的内容加载

回到mLoaderTask.run()方法中，当bindWorkspace()执行结束之后，并通过waitForIdle()确认加载完成之后，就会调用

loadAndBindAllApps()来为AllApps页面加载内容。

private void loadAndBindAllApps() {            ......            if (!mAllAppsLoaded) {                //批量加载app和widget信息                loadAllAppsByBatch();                ......            } else {                //无需重复加载，直接绑定                onlyBindAllApps();            }        }

AllApps中的加载过程和Workspace中的加载过程大致是相同的，只是All Apps的加载和绑定过程被放到同一个方法loadAllAppsByBatch()中执行：

       /**        *批量的向加载内容        */        private void loadAllAppsByBatch() {            ......            //设置Intent的action为ACTION_MAIN，category为CATEGORY_LAUNCHER            //这样就筛选出桌面上显示的启动项了。            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();                    ......                    //查询所有应该在桌面上显示的app                    apps = packageManager.queryIntentActivities(mainIntent, 0);                    ......                                        N = apps.size();                    ......                    if (mBatchSize == 0) {                        //mBatchSize==0表示一次性加载所有的应用                        batchSize = N;                    } else {                        batchSize = mBatchSize;                    }                    ......                    //将获取到的app的信息按名字进行排序                    Collections.sort(apps,                            new LauncherModel.ShortcutNameComparator(packageManager, mLabelCache));                    ......                }                ......                startIndex = i;                //添加一批应用信息到mAllAppsList，每一批添加N个                for (int j=0; i<N && j<batchSize; j++) {                    // This builds the icon bitmaps.                    mAllAppsList.add(new ApplicationInfo(packageManager, apps.get(i),                            mIconCache, mLabelCache));                    i++;                }                //i < batchSize表示添加的是第一批信息                final boolean first = i <= batchSize;                final Callbacks callbacks = tryGetCallbacks(oldCallbacks);                final ArrayList<ApplicationInfo> added = mAllAppsList.added;                //每添加完一批之后，将added重新清空                mAllAppsList.added = new ArrayList<ApplicationInfo>();                mHandler.post(new Runnable() {                    public void run() {                        ......                        //Launcher实现了Callbacks接口，将获取到的数据回调给Launcher                        if (callbacks != null) {                            if (first) {                                callbacks.bindAllApplications(added);                            } else {                                callbacks.bindAppsAdded(added);                            }                            ......                        } else {                           ......                        }                    }                });                ......            }            ......        }

过程还是挺简单的，首先当然是查询所有的App了，通过向PackagedManager发送指定的Intent就能够获得安装好的应用的信息。查

询完毕之后，将数据封装到ArrayList<ApplicationInfo>对象中，然后通过Callbacks.bindAllApplication()或Callbacks.bindAppsAdded()

将数据传给Launcher。Launcher中的操作也比加载Workspace时简单多，毕竟这里只需要加载Icon。

   /**     * Add the icons for all apps.     *     * Implementation of the method from LauncherModel.Callbacks.     */    public void bindAllApplications(final ArrayList<ApplicationInfo> apps) {        ......        // We just post the call to setApps so the user sees the progress bar        // disappear-- otherwise, it just looks like the progress bar froze        // which doesn't look great        mAppsCustomizeTabHost.post(new Runnable() {            public void run() {                if (mAppsCustomizeContent != null) {                    mAppsCustomizeContent.setApps(apps);                }            }        });    }

    /**     * A package was installed.     *     * Implementation of the method from LauncherModel.Callbacks.     */    public void bindAppsAdded(ArrayList<ApplicationInfo> apps) {        setLoadOnResume();        ......        if (mAppsCustomizeContent != null) {            mAppsCustomizeContent.addApps(apps);        }    }

这样All Apps页面的加载也完成了。

到这一步，Launcher内容的加载过程也就完成了。