基于 Launcher3 2c34cba ### 概述找到LauncherModel中监听应用安装的回调，在PackageUpdateTask中通过ItemInstallQueue发送一条添加应用图标的任务，桌面在onResume后会执行图标添加 ### 代码修改位置找到com.android.launcher3.model.PackageUpdatedTask这个类，在execute方法中最后面部分进行修改修改前 ```kotlin if (mOp == OP_ADD) { // Load widgets for the new package. Changes due to app updates are handled through // AppWidgetHost events, this is just to initialize the long-press options. for (int i = 0; i < N; i++) { dataModel.widgetsModel.update(app, new PackageUserKey(packages[i], mUser)); } bindUpdatedWidgets(dataModel); } ``` 修改后 ```kotlin if (mOp == OP_ADD) { for (String pkg : mPackages) { //将新安装的应用包名和当前user发送给ItemInstallQueue待添加 ItemInstallQueue.INSTANCE.get(context).queueItem(pkg，mUser); } // Load widgets for the new package. Changes due to app updates are handled through // AppWidgetHost events, this is just to initialize the long-press options. for (int i = 0; i < N; i++) { dataModel.widgetsModel.update(app, new PackageUserKey(packages[i], mUser)); } bindUpdatedWidgets(dataModel); } ``` ### 简易流程 ```mermaid graph TB LauncherModel.onPackageAdded-->PackageUpdateTask.execute-->ItemInstallQueue.queueItem-->LauncherModel.addAndBindAddedWorkspaceItems-->AddWorkspaceItemTask.execute-->Launcher.bindAppsAdded ``` ### 逻辑分析在LauncherAppState的构造方法中，LauncherModel被注册到了LauncherApps中，LauncherApps是一个系统服务，可以用来查询和监听系统内应用的安装卸载等变化。 LauncherModel类继承了LauncherApps.Callback并实现了其回调方法。所以当有新应用安装成功后，会回调此方法，在此方法内创建了一个op为OP_ADD的PackageUpdatedTask给线程池执行 ```kotlin @Override public void onPackageAdded(@NonNull final String packageName, @NonNullfinal UserHandle user) { int op = PackageUpdatedTask.OP_ADD; enqueueModelUpdateTask(new PackageUpdatedTask(op, user, packageName)); } ``` 给PackageUpdatedTask一些参数赋值 ```kotlin public void enqueueModelUpdateTask(@NonNull final ModelUpdateTask task){ if (mModelDestroyed) { return; } task.init(mApp, this, mBgDataModel, mBgAllAppsList, MAIN_EXECUTOR); MODEL_EXECUTOR.execute(task); } ``` 在MODEL_EXECUTOR.execute(task)后这个PackageUpdatedTask的execute方法会被执行，在这个方法的末尾刚好有一个mOp == OP_ADD的判断，在这个判断里面我们添加一段代码，将新安装应用的包名和user添加到ItemInstallQueue的集合中 ```kotlin if (mOp == OP_ADD) { for (String pkg : mPackages) { //新安装的应用添加到队列中，在桌面回到前台后，自动将图标显示到桌面 ItemInstallQueue.INSTANCE.get(context).queueItem(pkg,mUser); } // Load widgets for the new package. Changes due to app updates are handled through // AppWidgetHost events, this is just to initialize the long-press options. for (int i = 0; i < N; i++) { dataModel.widgetsModel.update(app, new PackageUserKey(packages[i], mUser)); } bindUpdatedWidgets(dataModel); } ``` ItemInstallQueue这个类的作用是处理将要向workspace插入的item，item包括shortcut或者widget 将包名和userHandle封装成一个PendingInstallShortcutInfo，然后存入到集合中待执行 ```kotlin public void queueItem(String packageName, UserHandle userHandle) { queuePendingShortcutInfo(new PendingInstallShortcutInfo(packageName, userHandle)); } ``` info.getItemInfo会根据创建PendingInstallShortcutInfo时的包名和类型来创建一个WorkspaceItemInfo。这里执行时会打印stackTrace，应该是原开发者想看一些堆栈信息留下的当PendingInstallShortcutInfo被添加到集合后并不一定会立即执行，通常情况是桌面处于可见情况时才会执行队列里的任务，Launcher通过调用ItemInstallQueue的pauseModelPush和resumeModelPush方法来修改mInstallQueueDisabledFlags，以此来控制集合内的任务是否执行 ```kotlin private void queuePendingShortcutInfo(PendingInstallShortcutInfo info) { final Exception stackTrace = new Exception(); // Queue the item up for adding if launcher has not loaded properly yet MODEL_EXECUTOR.post(() -> { Pair itemInfo = info.getItemInfo(mContext); if (TestProtocol.sDebugTracing) { Log.d(TestProtocol.MISSING_PROMISE_ICON, LOG + " queuePendingShortcutInfo" + ", itemInfo=" + itemInfo); } if (itemInfo == null) { FileLog.d(LOG, "Adding PendingInstallShortcutInfo with no attached info to queue.", stackTrace); } else { FileLog.d(LOG, "Adding PendingInstallShortcutInfo to queue. Attached info: " + itemInfo.first, stackTrace); } addToQueue(info); }); flushInstallQueue(); } ``` ```kotlin public Pair getItemInfo(Context context) { switch (itemType) { case ITEM_TYPE_APPLICATION: { String packageName = intent.getPackage(); List laiList = context.getSystemService(LauncherApps.class) .getActivityList(packageName, user); final WorkspaceItemInfo si = new WorkspaceItemInfo(); si.user = user; si.itemType = ITEM_TYPE_APPLICATION; LauncherActivityInfo lai; boolean usePackageIcon = laiList.isEmpty(); if (usePackageIcon) { lai = null; si.intent = makeLaunchIntent(new ComponentName(packageName, "")) .setPackage(packageName); si.status |= WorkspaceItemInfo.FLAG_AUTOINSTALL_ICON; } else { lai = laiList.get(0); si.intent = makeLaunchIntent(lai); } LauncherAppState.getInstance(context).getIconCache() .getTitleAndIcon(si, () -> lai, usePackageIcon, false); return Pair.create(si, null); } case ITEM_TYPE_DEEP_SHORTCUT: { //此处代码省略.... } case ITEM_TYPE_APPWIDGET: { //此处代码省略.... } } return null; } ``` 而执行任务的方法就是flushInstallQueue和flushQueueInBackground，在flushQueueInBackground中将任务转换成一个集合交给LauncherModel，然后清空队列和本地存储 ```kotlin private void flushInstallQueue() { if (mInstallQueueDisabledFlags != 0) { return; } MODEL_EXECUTOR.post(this::flushQueueInBackground); } @WorkerThread private void flushQueueInBackground() { Launcher launcher = Launcher.ACTIVITY_TRACKER.getCreatedActivity(); if (launcher == null) { // Launcher not loaded if (TestProtocol.sDebugTracing) { Log.d(TestProtocol.MISSING_PROMISE_ICON, LOG + " flushQueueInBackground launcher not loaded"); } return; } ensureQueueLoaded(); if (mItems.isEmpty()) { if (TestProtocol.sDebugTracing) { Log.d(TestProtocol.MISSING_PROMISE_ICON, LOG + " flushQueueInBackground no items to load"); } return; } List> installQueue = mItems.stream() .map(info -> info.getItemInfo(mContext)) .collect(Collectors.toList()); // Add the items and clear queue if (!installQueue.isEmpty()) { if (TestProtocol.sDebugTracing) { Log.d(TestProtocol.MISSING_PROMISE_ICON, LOG + " flushQueueInBackground launcher addAndBindAddedWorkspaceItems"); } // add log launcher.getModel().addAndBindAddedWorkspaceItems(installQueue); } mItems.clear(); mStorage.getFile(mContext).delete(); } ``` 回到LauncherModel中，创建了一个AddWorkspaceItemsTask任务交给队列执行，直接看它的execute方法这里主要是4件事，先对要添加的item进行最终筛查，之后给通过筛查的item在桌面找一个合适的添加位置，然后保存到数据库，最后通知桌面进行更新 ```kotlin @Override public void execute(@NonNull final LauncherAppState app, @NonNull finaBgDataModel dataModel, @NonNull final AllAppsList apps) { if (mItemList.isEmpty()) { return; } final ArrayList addedItemsFinal = new ArrayList<>(); final IntArray addedWorkspaceScreensFinal = new IntArray(); synchronized (dataModel) { IntArray workspaceScreens = dataModel.collectWorkspaceScreens(); List filteredItems = new ArrayList<>(); for (Pair entry : mItemList) { ItemInfo item = entry.first; //这个判断只是为了加快轮询速度，对于图标已存在或者是系统应用的item直接跳过 if (item.itemType == LauncherSettings.Favorites.ITEM_TYPE_APPLICATION || item.itemType == LauncherSettings.Favorites.ITEM_TYPE_SHORTCUT) { //此处代码省略... } if (item.itemType == LauncherSettings.Favorites.ITEM_TYPE_APPLICATION) { if (item instanceof WorkspaceItemFactory) { item = ((WorkspaceItemFactory) item).makeWorkspaceItem(app.getContext()); } } if (item != null) { filteredItems.add(item); } } InstallSessionHelper packageInstaller = InstallSessionHelper.INSTANCE.get(app.getContext()); LauncherApps launcherApps = app.getContext().getSystemService(LauncherApps.class); for (ItemInfo item : filteredItems) { //mItemSpaceFinder给item找一个合适位置 // Find appropriate space for the item. int[] coords = mItemSpaceFinder.findSpaceForItem(app, dataModel, workspaceScreens, addedWorkspaceScreensFinal, item.spanX, item.spanY); int screenId = coords[0]; ItemInfo itemInfo; if (item instanceof WorkspaceItemInfo || item instanceof FolderInfo || item instanceof LauncherAppWidgetInfo) { itemInfo = item; } else if (item instanceof WorkspaceItemFactory) { itemInfo = ((WorkspaceItemFactory) item).makeWorkspaceItem(app.getContext()); } else { throw new RuntimeException("Unexpected info type"); } if (item instanceof WorkspaceItemInfo && ((WorkspaceItemInfo) item).isPromise()) { //这里一大段都是处理PromiseApp的，省略代码... } // Add the shortcut to the db getModelWriter().addItemToDatabase(itemInfo, LauncherSettings.Favorites.CONTAINER_DESKTOP, screenId, coords[1], coords[2]); // Save the WorkspaceItemInfo for binding in the workspace addedItemsFinal.add(itemInfo); // log bitmap and label FileLog.d(LOG, "Adding item info to workspace: " + itemInfo); } } if (!addedItemsFinal.isEmpty()) { scheduleCallbackTask(new CallbackTask() { @Override public void execute(@NonNull Callbacks callbacks) { final ArrayList addAnimated = new ArrayList<>(); final ArrayList addNotAnimated = new ArrayList<>(); if (!addedItemsFinal.isEmpty()) { ItemInfo info = addedItemsFinal.get(addedItemsFinal.size() - 1); int lastScreenId = info.screenId; for (ItemInfo i : addedItemsFinal) { if (i.screenId == lastScreenId) { addAnimated.add(i); } else { addNotAnimated.add(i); } } } callbacks.bindAppsAdded(addedWorkspaceScreensFinal, addNotAnimated, addAnimated); } }); } } ```