本文主要分享 SystemUI Notification 具体如何呈现的？基于 AOSP 9.0 分析。
概述
在《Android 9.0 SystemUI 主要视图 SystemBars》知道通知在折叠时状态栏、下拉状态栏、锁屏都有通知，其中锁屏和下拉状态栏是一个布局，折叠状态栏 是在 CollapsedStatusBarFragment，status_bar.xml，PhoneStatusBarView，锁屏是 NotificationStackScrollLayout，@+id/notification_stack_scroller，先来看看锁屏的通知，NotificationStackScrollLayout 是 ViewGroup，如果来了条通知，肯定是有地方进行 addView，我们就沿着这个思路去 AOSP 寻找答案。
序列图
序列图为来通知到 SystemUI 锁屏通知呈现整个流程。
锁屏通知
NotificationStackScrollLayout#addContainerView
锁屏是 NotificationStackScrollLayout，直接找 NotificationStackScrollLayout，看到有个 addContainerView方法，一看，果然是目标 addView：
@Override
public void addContainerView(View v) {
addView(v);
}
反查，看到 addContainerView 被 NotificationViewHierarchyManager#updateNotificationViews 方法调用了。
NotificationViewHierarchyManager#updateNotificationViews
public void updateNotificationViews() {
ArrayList<NotificationData.Entry> activeNotifications = mEntryManager.getNotificationData()
.getActiveNotifications();
ArrayList<ExpandableNotificationRow> toShow = new ArrayList<>(activeNotifications.size());
//省略其他代码
for (int i = 0; i < toShow.size(); i++) {
View v = toShow.get(i);
if (v.getParent() == null) {
mVisualStabilityManager.notifyViewAddition(v);
mListContainer.addContainerView(v);
}
}
//省略其他代码
}
这里 mListContainer 是 NotificationListContainer，NotificationStackScrollLayout#addContainerView 进行了重写。
反查， NotificationViewHierarchyManager#updateNotificationViews 被 StatusBar#updateNotificationViews 方法调用了。
StatusBar#updateNotificationViews
@Override
public void updateNotificationViews() {
//省略其他代码
mViewHierarchyManager.updateNotificationViews();
//省略其他代码
//这里和折叠状态栏相关
mNotificationIconAreaController.updateNotificationIcons();
}
StatusBar#updateNotificationViews 被 NotificationEntryManager#updateNotifications 调用了。
NotificationEntryManager#updateNotifications
public void updateNotifications() {
mNotificationData.filterAndSort();
mPresenter.updateNotificationViews();
}
presenter 是 NotificationPresenter 对象，从 StatusBar#makeStatusBarView 传过来了，继续看 NotificationEntryManager#updateNotifications 哪里被调用了，是 NotificationEntryManager#addNotificationViews。
NotificationEntryManager#addNotificationViews
protected void addNotificationViews(NotificationData.Entry entry) {
if (entry == null) {
return;
}
// Add the expanded view and icon.
mNotificationData.add(entry);
tagForeground(entry.notification);
updateNotifications();
}
//NotificationEntryManager#addNotificationViews 由 addEntry 调用了
private void addEntry(NotificationData.Entry shadeEntry) {
boolean isHeadsUped = shouldPeek(shadeEntry);
if (isHeadsUped) {
mHeadsUpManager.showNotification(shadeEntry);
// Mark as seen immediately
setNotificationShown(shadeEntry.notification);
}
addNotificationViews(shadeEntry);
mCallback.onNotificationAdded(shadeEntry);
}
NotificationEntryManager#addEntry 由 NotificationEntryManager#onAsyncInflationFinished 调用了。
NotificationEntryManager#onAsyncInflationFinished
@Override
public void onAsyncInflationFinished(NotificationData.Entry entry) {
mPendingNotifications.remove(entry.key);
// If there was an async task started after the removal, we don't want to add it back to
// the list, otherwise we might get leaks.
boolean isNew = mNotificationData.get(entry.key) == null;
if (isNew && !entry.row.isRemoved()) {
addEntry(entry);
} else if (!isNew && entry.row.hasLowPriorityStateUpdated()) {
mVisualStabilityManager.onLowPriorityUpdated(entry);
mPresenter.updateNotificationViews();
}
entry.row.setLowPriorityStateUpdated(false);
}
问题来了，NotificationEntryManager#onAsyncInflationFinished 哪里被调到了，似乎断掉了，是怎么和来通知关联起来的？这得需要看看通知的流程。
通知流程
这部分分析按照正常的调用顺序来分析。
NotificationManager#notify
NotificationManager 调用 notify 方法发送 notification，最后调用到 notifyAsUser() 方法：
@UnsupportedAppUsage
public void notifyAsUser(String tag, int id, Notification notification, UserHandle user)
{
INotificationManager service = getService();
String pkg = mContext.getPackageName();
// Fix the notification as best we can.
Notification.addFieldsFromContext(mContext, notification);
if (notification.sound != null) {
notification.sound = notification.sound.getCanonicalUri();
if (StrictMode.vmFileUriExposureEnabled()) {
notification.sound.checkFileUriExposed("Notification.sound");
}
}
fixLegacySmallIcon(notification, pkg);
if (mContext.getApplicationInfo().targetSdkVersion > Build.VERSION_CODES.LOLLIPOP_MR1) {
if (notification.getSmallIcon() == null) {
throw new IllegalArgumentException("Invalid notification (no valid small icon): "
+ notification);
}
}
if (localLOGV) Log.v(TAG, pkg + ": notify(" + id + ", " + notification + ")");
notification.reduceImageSizes(mContext);
ActivityManager am = (ActivityManager) mContext.getSystemService(Context.ACTIVITY_SERVICE);
boolean isLowRam = am.isLowRamDevice();
final Notification copy = Builder.maybeCloneStrippedForDelivery(notification, isLowRam,
mContext);
try {
service.enqueueNotificationWithTag(pkg, mContext.getOpPackageName(), tag, id,
copy, user.getIdentifier());
} catch (RemoteException e) {
throw e.rethrowFromSystemServer();
}
}
这里 service 是 INotificationManager，对应的是 NotificationManagerService，看 NotificationManagerService#enqueueNotificationWithTag，又调用了 NotificationManagerService#enqueueNotificationInternal。
NotificationManagerService#enqueueNotificationInternal
void enqueueNotificationInternal(final String pkg, final String opPkg, final int callingUid,
final int callingPid, final String tag, final int id, final Notification notification,
int incomingUserId) {
//省略其他代码
final NotificationRecord r = new NotificationRecord(getContext(), n, channel);
r.setIsAppImportanceLocked(mRankingHelper.getIsAppImportanceLocked(pkg, callingUid));
//省略其他代码
mHandler.post(new EnqueueNotificationRunnable(userId, r));
}
EnqueueNotificationRunnable#run
protected class EnqueueNotificationRunnable implements Runnable {
private final NotificationRecord r;
private final int userId;
EnqueueNotificationRunnable(int userId, NotificationRecord r) {
this.userId = userId;
this.r = r;
};
@Override
public void run() {
synchronized (mNotificationLock) {
// 省略其他代码
if (mAssistants.isEnabled()) {
mAssistants.onNotificationEnqueued(r);
mHandler.postDelayed(new PostNotificationRunnable(r.getKey()),
DELAY_FOR_ASSISTANT_TIME);
} else {
mHandler.post(new PostNotificationRunnable(r.getKey()));
}
}
}
}
PostNotificationRunnable#run
protected class PostNotificationRunnable implements Runnable {
private final String key;
PostNotificationRunnable(String key) {
this.key = key;
}
@Override
public void run() {
synchronized (mNotificationLock) {
try {
// 省略其他代码
if (notification.getSmallIcon() != null) {
StatusBarNotification oldSbn = (old != null) ? old.sbn : null;
mListeners.notifyPostedLocked(r, old);
if (oldSbn == null || !Objects.equals(oldSbn.getGroup(), n.getGroup())) {
mHandler.post(new Runnable() {
@Override
public void run() {
mGroupHelper.onNotificationPosted(
n, hasAutoGroupSummaryLocked(n));
}
});
}
} // 省略其他代码
} finally {
// 省略其他代码
}
}
}
}
mListeners 是 NotificationListeners，调用 NotificationManagerService#notifyPostedLocked。
NotificationManagerService#notifyPostedLocked
@GuardedBy("mNotificationLock")
public void notifyPostedLocked(NotificationRecord r, NotificationRecord old) {
notifyPostedLocked(r, old, true);
}
@GuardedBy("mNotificationLock")
private void notifyPostedLocked(NotificationRecord r, NotificationRecord old,
boolean notifyAllListeners) {
// Lazily initialized snapshots of the notification.
StatusBarNotification sbn = r.sbn;
StatusBarNotification oldSbn = (old != null) ? old.sbn : null;
TrimCache trimCache = new TrimCache(sbn);
for (final ManagedServiceInfo info : getServices()) {
//省略其他代码
final NotificationRankingUpdate update = makeRankingUpdateLocked(info);
// This notification became invisible -> remove the old one.
if (oldSbnVisible && !sbnVisible) {
final StatusBarNotification oldSbnLightClone = oldSbn.cloneLight();
mHandler.post(new Runnable() {
@Override
public void run() {
notifyRemoved(
info, oldSbnLightClone, update, null, REASON_USER_STOPPED);
}
});
continue;
}
// Grant access before listener is notified
final int targetUserId = (info.userid == UserHandle.USER_ALL)
? UserHandle.USER_SYSTEM : info.userid;
updateUriPermissions(r, old, info.component.getPackageName(), targetUserId);
final StatusBarNotification sbnToPost = trimCache.ForListener(info);
mHandler.post(new Runnable() {
@Override
public void run() {
//调用NotificationManagerService#notifyPosted
notifyPosted(info, sbnToPost, update);
}
});
}
}
private void notifyPosted(final ManagedServiceInfo info,
final StatusBarNotification sbn, NotificationRankingUpdate rankingUpdate) {
final INotificationListener listener = (INotificationListener) info.service;
StatusBarNotificationHolder sbnHolder = new StatusBarNotificationHolder(sbn);
try {
listener.onNotificationPosted(sbnHolder, rankingUpdate);
} catch (RemoteException ex) {
Log.e(TAG, "unable to notify listener (posted): " + listener, ex);
}
}
这里 service 是 INotificationListener，对应的是 NotificationListenerWrapper，看 NotificationListenerWrapper#onNotificationPosted。
NotificationListenerWrapper#onNotificationPosted
protected class NotificationListenerWrapper extends INotificationListener.Stub {
@Override
public void onNotificationPosted(IStatusBarNotificationHolder sbnHolder,
NotificationRankingUpdate update) {
StatusBarNotification sbn;
try {
sbn = sbnHolder.get();
} catch (RemoteException e) {
Log.w(TAG, "onNotificationPosted: Error receiving StatusBarNotification", e);
return;
}
try {
// convert icon metadata to legacy format for older clients
createLegacyIconExtras(sbn.getNotification());
maybePopulateRemoteViews(sbn.getNotification());
maybePopulatePeople(sbn.getNotification());
} catch (IllegalArgumentException e) {
// warn and drop corrupt notification
Log.w(TAG, "onNotificationPosted: can't rebuild notification from " +
sbn.getPackageName());
sbn = null;
}
// protect subclass from concurrent modifications of (@link mNotificationKeys}.
synchronized (mLock) {
applyUpdateLocked(update);
if (sbn != null) {
SomeArgs args = SomeArgs.obtain();
args.arg1 = sbn;
args.arg2 = mRankingMap;
mHandler.obtainMessage(MyHandler.MSG_ON_NOTIFICATION_POSTED,
args).sendToTarget();
} else {
// still pass along the ranking map, it may contain other information
mHandler.obtainMessage(MyHandler.MSG_ON_NOTIFICATION_RANKING_UPDATE,
mRankingMap).sendToTarget();
}
}
}
}
看 MyHandler 处理中的 MSG_ON_NOTIFICATION_POSTED。
MyHandler#handleMessage
private final class MyHandler extends Handler {
public static final int MSG_ON_NOTIFICATION_POSTED = 1;
public static final int MSG_ON_NOTIFICATION_REMOVED = 2;
public static final int MSG_ON_LISTENER_CONNECTED = 3;
public static final int MSG_ON_NOTIFICATION_RANKING_UPDATE = 4;
public static final int MSG_ON_LISTENER_HINTS_CHANGED = 5;
public static final int MSG_ON_INTERRUPTION_FILTER_CHANGED = 6;
public static final int MSG_ON_NOTIFICATION_CHANNEL_MODIFIED = 7;
public static final int MSG_ON_NOTIFICATION_CHANNEL_GROUP_MODIFIED = 8;
public MyHandler(Looper looper) {
super(looper, null, false);
}
@Override
public void handleMessage(Message msg) {
if (!isConnected) {
return;
}
switch (msg.what) {
case MSG_ON_NOTIFICATION_POSTED: {
SomeArgs args = (SomeArgs) msg.obj;
StatusBarNotification sbn = (StatusBarNotification) args.arg1;
RankingMap rankingMap = (RankingMap) args.arg2;
args.recycle();
onNotificationPosted(sbn, rankingMap);
} break;
//省略其他代码
}
}
}
NotificationListenerService#onNotificationPosted
public void onNotificationPosted(StatusBarNotification sbn, RankingMap rankingMap) {
onNotificationPosted(sbn);
}
NotificationListenerService 是抽象类，NotificationListenerService#onNotificationPosted 在 NotificationListener##onNotificationPosted 有重写。
NotificationListener#onNotificationPosted
@Override
public void onNotificationPosted(final StatusBarNotification sbn,
final RankingMap rankingMap) {
if (DEBUG) Log.d(TAG, "onNotificationPosted: " + sbn);
if (sbn != null && !onPluginNotificationPosted(sbn, rankingMap)) {
mPresenter.getHandler().post(() -> {
//省略其他代码
if (isUpdate) {
mEntryManager.updateNotification(sbn, rankingMap);
} else {
mEntryManager.addNotification(sbn, rankingMap);
}
});
}
}
调用了 NotificationEntryManager#addNotification。
NotificationEntryManager#addNotification
@Override
public void addNotification(StatusBarNotification notification,
NotificationListenerService.RankingMap ranking) {
try {
addNotificationInternal(notification, ranking);
} catch (InflationException e) {
handleInflationException(notification, e);
}
}
private void addNotificationInternal(StatusBarNotification notification,
NotificationListenerService.RankingMap ranking) throws InflationException {
String key = notification.getKey();
if (DEBUG) Log.d(TAG, "addNotification key=" + key);
mNotificationData.updateRanking(ranking);
//继续看 createNotificationViews
NotificationData.Entry shadeEntry = createNotificationViews(notification);
//省略其他代码
}
protected NotificationData.Entry createNotificationViews(StatusBarNotification sbn)
throws InflationException {
if (DEBUG) {
Log.d(TAG, "createNotificationViews(notification=" + sbn);
}
NotificationData.Entry entry = new NotificationData.Entry(sbn);
Dependency.get(LeakDetector.class).trackInstance(entry);
entry.createIcons(mContext, sbn);
// Construct the expanded view.
inflateViews(entry, mListContainer.getViewParentForNotification(entry));
return entry;
}
从 NotificationEntryManager#addNotification 到 NotificationEntryManager#addNotificationInternal 再到 NotificationEntryManager#inflateViews 方法。
NotificationEntryManager#inflateViews
private void inflateViews(NotificationData.Entry entry, ViewGroup parent) {
PackageManager pmUser = StatusBar.getPackageManagerForUser(mContext,
entry.notification.getUser().getIdentifier());
final StatusBarNotification sbn = entry.notification;
if (entry.row != null) {
entry.reset();
updateNotification(entry, pmUser, sbn, entry.row);
} else {
//来通知会走到这里
new RowInflaterTask().inflate(mContext, parent, entry,
row -> {
bindRow(entry, pmUser, sbn, row);
updateNotification(entry, pmUser, sbn, row);
});
}
}
RowInflaterTask#inflate
public void inflate(Context context, ViewGroup parent, NotificationData.Entry entry,
RowInflationFinishedListener listener) {
if (TRACE_ORIGIN) {
mInflateOrigin = new Throwable("inflate requested here");
}
mListener = listener;
AsyncLayoutInflater inflater = new AsyncLayoutInflater(context);
mEntry = entry;
entry.setInflationTask(this);
//这里是Notification布局文件
inflater.inflate(R.layout.status_bar_notification_row, parent, this);
}
再看 RowInflaterTask#onInflateFinished：
@Override
public void onInflateFinished(View view, int resid, ViewGroup parent) {
if (!mCancelled) {
try {
mEntry.onInflationTaskFinished();
//1. 调 RowInflationFinishedListener#onInflationFinished
mListener.onInflationFinished((ExpandableNotificationRow) view);
} catch (Throwable t) {
if (mInflateOrigin != null) {
Log.e(TAG, "Error in inflation finished listener: " + t, mInflateOrigin);
t.addSuppressed(mInflateOrigin);
}
throw t;
}
}
}
public interface RowInflationFinishedListener {
//2. 在 NotificationEntryManager#row 实现
void onInflationFinished(ExpandableNotificationRow row);
}
看 NotificationEntryManager#row 会调用 bindRow 和 updateNotification，看 updateNotification方法最终会调用 ExpandableNotificationRow#updateNotification。
ExpandableNotificationRow#updateNotification
public void updateNotification(NotificationData.Entry entry) {
mEntry = entry;
mStatusBarNotification = entry.notification;
mNotificationInflater.inflateNotificationViews();
cacheIsSystemNotification();
}
继续跟，到 NotificationInflater#inflateNotificationViews。
NotificationInflater#inflateNotificationViews
@VisibleForTesting
void inflateNotificationViews(int reInflateFlags) {
if (mRow.isRemoved()) {
return;
}
StatusBarNotification sbn = mRow.getEntry().notification;
AsyncInflationTask task = new AsyncInflationTask(sbn, reInflateFlags, mRow,
mIsLowPriority,
mIsChildInGroup, mUsesIncreasedHeight, mUsesIncreasedHeadsUpHeight, mRedactAmbient,
mCallback, mRemoteViewClickHandler);
if (mCallback != null && mCallback.doInflateSynchronous()) {
task.onPostExecute(task.doInBackground());
} else {
task.execute();
}
}
看 AsyncInflationTask 执行的结果：
public static class AsyncInflationTask extends AsyncTask<Void, Void, InflationProgress>
implements InflationCallback, InflationTask {
//省略其他代码
@Override
protected InflationProgress doInBackground(Void... params) {
//省略其他代码
}
@Override
protected void onPostExecute(InflationProgress result) {
if (mError == null) {
mCancellationSignal = apply(result, mReInflateFlags, mRow, mRedactAmbient,
mRemoteViewClickHandler, this);
} else {
handleError(mError);
}
}
}
调用 NotificationInflater#apply，最终会到 NotificationInflater#applyRemoteView
@VisibleForTesting
static void applyRemoteView(final InflationProgress result,
final int reInflateFlags, int inflationId,
final ExpandableNotificationRow row,
final boolean redactAmbient, boolean isNewView,
RemoteViews.OnClickHandler remoteViewClickHandler,
@Nullable final InflationCallback callback, NotificationData.Entry entry,
NotificationContentView parentLayout, View existingView,
NotificationViewWrapper existingWrapper,
final HashMap<Integer, CancellationSignal> runningInflations,
ApplyCallback applyCallback) {
RemoteViews newContentView = applyCallback.getRemoteView();
//省略其他代码
RemoteViews.OnViewAppliedListener listener
= new RemoteViews.OnViewAppliedListener() {
@Override
public void onViewApplied(View v) {
if (isNewView) {
v.setIsRootNamespace(true);
applyCallback.setResultView(v);
} else if (existingWrapper != null) {
existingWrapper.onReinflated();
}
runningInflations.remove(inflationId);
finishIfDone(result, reInflateFlags, runningInflations, callback, row,
redactAmbient);
}
//
};
CancellationSignal cancellationSignal;
if (isNewView) {
//调用RemoteViews#applyAsync，最终回调了上面的onViewApplied方法。
cancellationSignal = newContentView.applyAsync(
result.packageContext,
parentLayout,
EXECUTOR,
listener,
remoteViewClickHandler);
}//省略其他代码
runningInflations.put(inflationId, cancellationSignal);
}
继续看 NotificationInflater#finishIfDone，这个方法看到最后的endListener.onAsyncInflationFinished(row.getEntry()); 实现方法在 NotificationEntryManager#onAsyncInflationFinished。
NotificationEntryManager#onAsyncInflationFinished
@Override
public void onAsyncInflationFinished(NotificationData.Entry entry) {
mPendingNotifications.remove(entry.key);
// If there was an async task started after the removal, we don't want to add it back to
// the list, otherwise we might get leaks.
boolean isNew = mNotificationData.get(entry.key) == null;
if (isNew && !entry.row.isRemoved()) {
addEntry(entry);
} else if (!isNew && entry.row.hasLowPriorityStateUpdated()) {
mVisualStabilityManager.onLowPriorityUpdated(entry);
mPresenter.updateNotificationViews();
}
entry.row.setLowPriorityStateUpdated(false);
}
这里的 addEntry 方法调用了addNotificationViews，好了，终于和 SystemUI 的通知关联起来了，这样，锁屏来通知分析结束。
折叠状态栏通知
有了以上锁屏通知分析，再来分析折叠状态栏通知就简单很多了，先看来折叠状态栏初始化部分。
status_bar.xml
折叠状态栏对应的布局文件是 status_bar.xml：
<com.android.systemui.statusbar.AlphaOptimizedFrameLayout
android:id="@+id/notification_icon_area"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="horizontal"
android:clipChildren="false"/>
如果来通知，就在 notification_icon_area 进行 addView 填充。再看看代码初始化。
StatusBar#makeStatusBarView
//NotificationIconAreaController 初始化
mNotificationIconAreaController = SystemUIFactory.getInstance()
.createNotificationIconAreaController(context, this);
inflateShelf();
mNotificationIconAreaController.setupShelf(mNotificationShelf);
mStackScroller.setIconAreaController(mNotificationIconAreaController);
Dependency.get(DarkIconDispatcher.class).addDarkReceiver(mNotificationIconAreaController);
FragmentHostManager.get(mStatusBarWindow)
.addTagListener(CollapsedStatusBarFragment.TAG, (tag, fragment) -> {
CollapsedStatusBarFragment statusBarFragment =
(CollapsedStatusBarFragment) fragment;
statusBarFragment.initNotificationIconArea(mNotificationIconAreaController);
//省略其他代码
}).getFragmentManager()
.beginTransaction()
.replace(R.id.status_bar_container, new CollapsedStatusBarFragment(),
CollapsedStatusBarFragment.TAG)
.commit();
CollapsedStatusBarFragment#initNotificationIconArea
public void initNotificationIconArea(NotificationIconAreaController
notificationIconAreaController) {
ViewGroup notificationIconArea = mStatusBar.findViewById(R.id.notification_icon_area);
mNotificationIconAreaInner =
notificationIconAreaController.getNotificationInnerAreaView();
if (mNotificationIconAreaInner.getParent() != null) {
((ViewGroup) mNotificationIconAreaInner.getParent())
.removeView(mNotificationIconAreaInner);
}
notificationIconArea.addView(mNotificationIconAreaInner);
// Default to showing until we know otherwise.
showNotificationIconArea(false);
}
看到这里的notificationIconArea.addView(mNotificationIconAreaInner); ，notificationIconArea 被 mNotificationIconAreaInner 填充，因此我们要重点关注 NotificationIconAreaController 什么时候被填充。
有以上锁屏通知分析知道有通知来最后会调用 StatusBar#updateNotificationViews。
StatusBar#updateNotificationViews
@Override
public void updateNotificationViews() {
// 省略其他代码
mNotificationIconAreaController.updateNotificationIcons();
}
调用 NotificationIconAreaController#updateNotificationIcons。
NotificationIconAreaController#updateNotificationIcons
public void updateNotificationIcons() {
updateStatusBarIcons();
updateShelfIcons();
updateHasShelfIconsWhenFullyDark();
applyNotificationIconsTint();
}
public void updateStatusBarIcons() {
updateIconsForLayout(entry -> entry.icon, mNotificationIcons,
false /* showAmbient */, true /* hideDismissed */, true /* hideRepliedMessages */);
}
private void updateIconsForLayout(Function<NotificationData.Entry, StatusBarIconView> function,
NotificationIconContainer hostLayout, boolean showAmbient, boolean hideDismissed,
boolean hideRepliedMessages) {
ArrayList<StatusBarIconView> toShow = new ArrayList<>(
mNotificationScrollLayout.getChildCount());
//省略其他代码
final FrameLayout.LayoutParams params = generateIconLayoutParams();
for (int i = 0; i < toShow.size(); i++) {
StatusBarIconView v = toShow.get(i);
// The view might still be transiently added if it was just removed and added again
hostLayout.removeTransientView(v);
if (v.getParent() == null) {
if (hideDismissed) {
v.setOnDismissListener(mUpdateStatusBarIcons);
}
hostLayout.addView(v, i, params);
}
}
hostLayout.setChangingViewPositions(true);
// Re-sort notification icons
final int childCount = hostLayout.getChildCount();
for (int i = 0; i < childCount; i++) {
View actual = hostLayout.getChildAt(i);
StatusBarIconView expected = toShow.get(i);
if (actual == expected) {
continue;
}
hostLayout.removeView(expected);
hostLayout.addView(expected, i);
}
hostLayout.setChangingViewPositions(false);
hostLayout.setReplacingIcons(null);
}
OK，折叠状态栏通知分析结束。
结语
本篇梳理了 SystemUI Notification 大致流程，分为锁屏的通知和状态栏通知，代码很多，细节没有去纠结，省略了很多代码，有兴趣，可以自己去 AOSP 查看。