本编文章针对AndroidO 8.0代码讲述。此版本的SystemUI和Notification较之前版本有一些改动。
本编文章讲述展示过程: System Notification –> SystemUI –> Display Notifications。
第一编文章《Android O 8.0 Notification 源码分析（一）》讲述生成过程：
App create Notification —-> System’s NotificationManagerService。
此便文章的目的为方便自己回忆和给需要的同学参考下。
还是先把整体流程图贴出来：
咱们直接从StatusBar的start()方法开始，到底SystemUI怎么重启的流程，咱们下回分解。
步骤1，2，3，4，5，5，6，7，8，10，11，13：为SystemUI的Statusbar,Navigationbar,Notificationpanel自定义控件的初始化。
步骤15：初始化NotificationListenerWithPlugins，并且注册：
public class NotificationListenerWithPlugins extends NotificationListenerService implements
PluginListener<NotificationListenerController> {
//下面只列出了类中方法名，具体实现自己翻代码。
registerAsSystemService();
unregisterAsSystemService();
getActiveNotifications();
getCurrentRanking();
...
}下面在start()方法注册service：
// Set up the initial notification state.
try {
mNotificationListener.registerAsSystemService(mContext,
new ComponentName(mContext.getPackageName(), getClass().getCanonicalName()),
UserHandle.USER_ALL);
} catch (RemoteException e) {
Log.e(TAG, "Unable to register notification listener", e);
}
下面代码为在destroy()方法中注销service：
public void destroy() {
// Begin old BaseStatusBar.destroy().
mContext.unregisterReceiver(mBaseBroadcastReceiver);
try {
mNotificationListener.unregisterAsSystemService();
} catch (RemoteException e) {
// Ignore.
}
}步骤9，12，14，16，18：为listener的回调方法会调用
步骤17，19 StatusBar的addNotification(),updateNotification()方法；
public void addNotification(StatusBarNotification notification, RankingMap ranking)
throws InflationException {
String key = notification.getKey();
if (DEBUG) Log.d(TAG, "addNotification key=" + key);
mNotificationData.updateRanking(ranking);
Entry shadeEntry = createNotificationViews(notification);
...
//提示方式
}步骤20，21:
protected NotificationData.Entry createNotificationViews(StatusBarNotification sbn)
throws InflationException {
NotificationData.Entry entry = new NotificationData.Entry(sbn);
Dependency.get(LeakDetector.class).trackInstance(entry);
entry.createIcons(mContext, sbn);
// Construct the expanded view.
inflateViews(entry, mStackScroller);
return entry;
}
protected void inflateViews(Entry entry, ViewGroup parent) {
PackageManager pmUser = getPackageManagerForUser(mContext,
entry.notification.getUser().getIdentifier());
final StatusBarNotification sbn = entry.notification;
if (entry.row != null) {
entry.reset();
updateNotification(entry, pmUser, sbn, entry.row);
} else {
new RowInflaterTask().inflate(mContext, parent, entry,
row -> {
bindRow(entry, pmUser, sbn, row);
updateNotification(entry, pmUser, sbn, row);
});
}
}步骤22:使用RowInflaterTask的inflate方法：
public void inflate(Context context, ViewGroup parent, NotificationData.Entry entry,
RowInflationFinishedListener listener) {
mListener = listener;
AsyncLayoutInflater inflater = new AsyncLayoutInflater(context);
mEntry = entry;
entry.setInflationTask(this);
inflater.inflate(R.layout.status_bar_notification_row, parent, this);
}步骤26，27: view加载完后的回调；
private void updateNotification(Entry entry, PackageManager pmUser,
StatusBarNotification sbn, ExpandableNotificationRow row) {
...
row.updateNotification(entry);
}步骤28:调用ExpandableNotificationRow的方法；
public void updateNotification(NotificationData.Entry entry) {
mEntry = entry;
mStatusBarNotification = entry.notification;
mNotificationInflater.inflateNotificationViews();
}步骤29:调用NotificationInflater的方法；
@VisibleForTesting
void inflateNotificationViews(int reInflateFlags) {
if (mRow.isRemoved()) {
// We don't want to reinflate anything for removed notifications. Otherwise views might
// be readded to the stack, leading to leaks. This may happen with low-priority groups
// where the removal of already removed children can lead to a reinflation.
return;
}
StatusBarNotification sbn = mRow.getEntry().notification;
new AsyncInflationTask(sbn, reInflateFlags, mRow, mIsLowPriority,
mIsChildInGroup, mUsesIncreasedHeight, mUsesIncreasedHeadsUpHeight, mRedactAmbient,
mCallback, mRemoteViewClickHandler).execute();
}
步骤30，调用NotificationInflater.AsyncInflationTask的方法；
@Override
protected InflationProgress doInBackground(Void... params) {
try {
final Notification.Builder recoveredBuilder
= Notification.Builder.recoverBuilder(mContext,
mSbn.getNotification());
Context packageContext = mSbn.getPackageContext(mContext);
Notification notification = mSbn.getNotification();
if (mIsLowPriority) {
int backgroundColor = mContext.getColor(
R.color.notification_material_background_low_priority_color);
recoveredBuilder.setBackgroundColorHint(backgroundColor);
}
if (notification.isMediaNotification()) {
MediaNotificationProcessor processor = new MediaNotificationProcessor(mContext,
packageContext);
processor.setIsLowPriority(mIsLowPriority);
processor.processNotification(notification, recoveredBuilder);
}
return createRemoteViews(mReInflateFlags,
recoveredBuilder, mIsLowPriority, mIsChildInGroup,
mUsesIncreasedHeight, mUsesIncreasedHeadsUpHeight, mRedactAmbient,
packageContext);
} catch (Exception e) {
mError = e;
return null;
}
}
@Override
protected void onPostExecute(InflationProgress result) {
if (mError == null) {
mCancellationSignal = apply(result, mReInflateFlags, mRow, mRedactAmbient,
mRemoteViewClickHandler, this);
} else {
handleError(mError);
}
}
步骤32-38：生成RemoteView；
private static InflationProgress createRemoteViews(int reInflateFlags,
Notification.Builder builder, boolean isLowPriority, boolean isChildInGroup,
boolean usesIncreasedHeight, boolean usesIncreasedHeadsUpHeight, boolean redactAmbient,
Context packageContext) {
InflationProgress result = new InflationProgress();
isLowPriority = isLowPriority && !isChildInGroup;
if ((reInflateFlags & FLAG_REINFLATE_CONTENT_VIEW) != 0) {
result.newContentView = createContentView(builder, isLowPriority, usesIncreasedHeight);
}
if ((reInflateFlags & FLAG_REINFLATE_EXPANDED_VIEW) != 0) {
result.newExpandedView = createExpandedView(builder, isLowPriority);
}
if ((reInflateFlags & FLAG_REINFLATE_HEADS_UP_VIEW) != 0) {
result.newHeadsUpView = builder.createHeadsUpContentView(usesIncreasedHeadsUpHeight);
}
if ((reInflateFlags & FLAG_REINFLATE_PUBLIC_VIEW) != 0) {
result.newPublicView = builder.makePublicContentView();
}
if ((reInflateFlags & FLAG_REINFLATE_AMBIENT_VIEW) != 0) {
result.newAmbientView = redactAmbient ? builder.makePublicAmbientNotification()
: builder.makeAmbientNotification();
}
result.packageContext = packageContext;
return result;
}还有apply的方法：
public static CancellationSignal apply(InflationProgress result, int reInflateFlags,
ExpandableNotificationRow row, boolean redactAmbient,
RemoteViews.OnClickHandler remoteViewClickHandler,
@Nullable InflationCallback callback) {
NotificationData.Entry entry = row.getEntry();
NotificationContentView privateLayout = row.getPrivateLayout();
NotificationContentView publicLayout = row.getPublicLayout();
final HashMap<Integer, CancellationSignal> runningInflations = new HashMap<>();
int flag = FLAG_REINFLATE_CONTENT_VIEW;
if ((reInflateFlags & flag) != 0) {
boolean isNewView = !canReapplyRemoteView(result.newContentView, entry.cachedContentView);
ApplyCallback applyCallback = new ApplyCallback() {
@Override
public void setResultView(View v) {
result.inflatedContentView = v;
}
@Override
public RemoteViews getRemoteView() {
return result.newContentView;
}
};
applyRemoteView(result, reInflateFlags, flag, row, redactAmbient,
isNewView, remoteViewClickHandler, callback, entry, privateLayout,
privateLayout.getContractedChild(), privateLayout.getVisibleWrapper(
NotificationContentView.VISIBLE_TYPE_CONTRACTED),
runningInflations, applyCallback);
}
flag = FLAG_REINFLATE_EXPANDED_VIEW;
if ((reInflateFlags & flag) != 0) {
if (result.newExpandedView != null) {
boolean isNewView = !canReapplyRemoteView(result.newExpandedView,
entry.cachedBigContentView);
ApplyCallback applyCallback = new ApplyCallback() {
@Override
public void setResultView(View v) {
result.inflatedExpandedView = v;
}
@Override
public RemoteViews getRemoteView() {
return result.newExpandedView;
}
};
applyRemoteView(result, reInflateFlags, flag, row,
redactAmbient, isNewView, remoteViewClickHandler, callback, entry,
privateLayout, privateLayout.getExpandedChild(),
privateLayout.getVisibleWrapper(
NotificationContentView.VISIBLE_TYPE_EXPANDED), runningInflations,
applyCallback);
}
}
flag = FLAG_REINFLATE_HEADS_UP_VIEW;
if ((reInflateFlags & flag) != 0) {
if (result.newHeadsUpView != null) {
boolean isNewView = !canReapplyRemoteView(result.newHeadsUpView,
entry.cachedHeadsUpContentView);
ApplyCallback applyCallback = new ApplyCallback() {
@Override
public void setResultView(View v) {
result.inflatedHeadsUpView = v;
}
@Override
public RemoteViews getRemoteView() {
return result.newHeadsUpView;
}
};
applyRemoteView(result, reInflateFlags, flag, row,
redactAmbient, isNewView, remoteViewClickHandler, callback, entry,
privateLayout, privateLayout.getHeadsUpChild(),
privateLayout.getVisibleWrapper(
NotificationContentView.VISIBLE_TYPE_HEADSUP), runningInflations,
applyCallback);
}
}
flag = FLAG_REINFLATE_PUBLIC_VIEW;
if ((reInflateFlags & flag) != 0) {
boolean isNewView = !canReapplyRemoteView(result.newPublicView,
entry.cachedPublicContentView);
ApplyCallback applyCallback = new ApplyCallback() {
@Override
public void setResultView(View v) {
result.inflatedPublicView = v;
}
@Override
public RemoteViews getRemoteView() {
return result.newPublicView;
}
};
applyRemoteView(result, reInflateFlags, flag, row,
redactAmbient, isNewView, remoteViewClickHandler, callback, entry,
publicLayout, publicLayout.getContractedChild(),
publicLayout.getVisibleWrapper(NotificationContentView.VISIBLE_TYPE_CONTRACTED),
runningInflations, applyCallback);
}
flag = FLAG_REINFLATE_AMBIENT_VIEW;
if ((reInflateFlags & flag) != 0) {
NotificationContentView newParent = redactAmbient ? publicLayout : privateLayout;
boolean isNewView = !canReapplyAmbient(row, redactAmbient) ||
!canReapplyRemoteView(result.newAmbientView, entry.cachedAmbientContentView);
ApplyCallback applyCallback = new ApplyCallback() {
@Override
public void setResultView(View v) {
result.inflatedAmbientView = v;
}
@Override
public RemoteViews getRemoteView() {
return result.newAmbientView;
}
};
applyRemoteView(result, reInflateFlags, flag, row,
redactAmbient, isNewView, remoteViewClickHandler, callback, entry,
newParent, newParent.getAmbientChild(), newParent.getVisibleWrapper(
NotificationContentView.VISIBLE_TYPE_AMBIENT), runningInflations,
applyCallback);
}
// Let's try to finish, maybe nobody is even inflating anything
finishIfDone(result, reInflateFlags, runningInflations, callback, row,
redactAmbient);
CancellationSignal cancellationSignal = new CancellationSignal();
cancellationSignal.setOnCancelListener(
() -> runningInflations.values().forEach(CancellationSignal::cancel));
return cancellationSignal;
}好了，以上为大部分流程。有不对的地方欢迎指正，谢谢。拜拜
上编文章讲述了Notificaion从Apps端发送到系统中的流程。
《Android O 8.0 Notification 源码分析（一）》
