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
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
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
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
@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
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
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
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
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, Object> 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();
}
public Pair<ItemInfo, Object> getItemInfo(Context context) {
switch (itemType) {
case ITEM_TYPE_APPLICATION: {
String packageName = intent.getPackage();
List<LauncherActivityInfo> 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
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<Pair<ItemInfo, Object>> 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
@Override
public void execute(@NonNull final LauncherAppState app, @NonNull finaBgDataModel dataModel,
@NonNull final AllAppsList apps) {
if (mItemList.isEmpty()) {
return;
}
final ArrayList<ItemInfo> addedItemsFinal = new ArrayList<>();
final IntArray addedWorkspaceScreensFinal = new IntArray();
synchronized (dataModel) {
IntArray workspaceScreens = dataModel.collectWorkspaceScreens();
List<ItemInfo> filteredItems = new ArrayList<>();
for (Pair<ItemInfo, Object> 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<ItemInfo> addAnimated = new ArrayList<>();
final ArrayList<ItemInfo> 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);
}
});
}
}