android6.0锁屏界面接收新通知处理流程

灭屏状态下，接收新信息，屏幕会半亮显示通知流程：

1,应用构造notification后，传给NotificationManager，而后进入NotificationManagerService处理。

NotificationManager nm = (NotificationManager)context.getSystemService(Context.NOTIFICATION_SERVICE);

nm.notify(NOTIFICATION_ID, notification)

frameworks\base\core\java\android\app\NotificationManager.java

public void notify(int id, Notification notification)
{
notify(null, id, notification);
}

public void notify(String tag, int id, Notification notification)
{
……

　　　　 Notification stripped = notification.clone();
Builder.stripForDelivery(stripped);
try {
service.enqueueNotificationWithTag(pkg, mContext.getOpPackageName(), tag, id,
stripped, idOut, UserHandle.myUserId());
if (id != idOut[0]) {
Log.w(TAG, "notify: id corrupted: sent " + id + ", got back " + idOut[0]);
}
} catch (RemoteException e) {
}
}

frameworks\base\services\core\java\com\android\server\notification\NotificationManagerService.java

public void enqueueNotificationWithTag(String pkg, String opPkg, String tag, int id,
Notification notification, int[] idOut, int userId) throws RemoteException {
enqueueNotificationInternal(pkg, opPkg, Binder.getCallingUid(),
Binder.getCallingPid(), tag, id, notification, idOut, userId);
}

同一个包名的通知超过50条不会继续处理。

if (count >= MAX_PACKAGE_NOTIFICATIONS) {
Slog.e(TAG, "Package has already posted " + count
+ " notifications. Not showing more. package=" + pkg);
return;
}

private void buzzBeepBlinkLocked(NotificationRecord record) {
……
……
// light
// release the light
boolean wasShowLights = mLights.remove(record.getKey());
if ((notification.flags & Notification.FLAG_SHOW_LIGHTS) != 0 && aboveThreshold) {
mLights.add(record.getKey());
updateLightsLocked();
if (mUseAttentionLight) {
mAttentionLight.pulse();
}
blink = true;
} else if (wasShowLights) {
updateLightsLocked();
}
if (buzz || beep || blink) {
EventLogTags.writeNotificationAlert(record.getKey(),
buzz ? 1 : 0, beep ? 1 : 0, blink ? 1 : 0);
mHandler.post(mBuzzBeepBlinked);
}

}

屏幕半亮闪烁需要判断 (notification.flags & Notification.FLAG_SHOW_LIGHTS) != 0

所以在应用构建notification时可以通过给flag赋值来控制是否要屏幕半亮闪烁。

先读取设置数据库中的NOTIFICATION_LIGHT_PULSE来判断是否闪烁，如果mNotificationPulseEnabled为true，则先闪烁一次（Light.LIGHT_FLASH_TIMED =1）。

Settings.System.getInt(resolver, Settings.System.NOTIFICATION_LIGHT_PULSE, 0)
if (mNotificationPulseEnabled) {
// pulse repeatedly
mNotificationLight.setFlashing(ledARGB, Light.LIGHT_FLASH_TIMED, //Light.LIGHT_FLASH_TIMED =1
ledOnMS, ledOffMS);
}
// let SystemUI make an independent decision //进入SystemUI处理
mStatusBar.notificationLightPulse(ledARGB, ledOnMS, ledOffMS);

2,然后进入SystemUi继续处理。
SystemUI中最终处理在DozeService中，也有一个开关判断，是否要闪烁。
if (!mDozeParameters.getPulseOnNotifications()) return;//getPulseOnNotifications默认为true

DozeService.java中调用private void requestPulse(final int reason)执行点亮屏幕。

private void requestPulse(final int reason, boolean performedProxCheck) {
if (mHost != null && mDreaming && !mPulsing) {
// Let the host know we want to pulse.  Wait for it to be ready, then
// turn the screen on.  When finished, turn the screen off again.
// Here we need a wakelock to stay awake until the pulse is finished.
mWakeLock.acquire();
mPulsing = true;
if (!mDozeParameters.getProxCheckBeforePulse()) {//这里先判断是否要先执行ProxCheck, proxCheck会检查手机sensor是否正常，如果不正常就退出，不执行点亮屏幕
// skip proximity check
continuePulsing(reason);
return;
}
final long start = SystemClock.uptimeMillis();
if (performedProxCheck) {
// the caller already performed a successful proximity check; we'll only do one to
// capture statistics, continue pulsing immediately.
continuePulsing(reason);
}
// perform a proximity check
new ProximityCheck() {
@Override
public void onProximityResult(int result) {
……
……
}
}.check();
}
}

private abstract class ProximityCheck implements SensorEventListener, Runnable {
……
……
public void check() {
if (mFinished || mRegistered) return;
final Sensor sensor = mSensorManager.getDefaultSensor(Sensor.TYPE_PROXIMITY);
if (sensor == null) {//手机sensor无效，直接退出程序。
if (DEBUG) Log.d(mTag, "No sensor found");
finishWithResult(RESULT_UNKNOWN);
return;
}
// the pickup sensor interferes with the prox event, disable it until we have a result
mPickupSensor.setDisabled(true);

mMaxRange = sensor.getMaximumRange();
mSensorManager.registerListener(this, sensor, SensorManager.SENSOR_DELAY_NORMAL, 0,
mHandler);
mHandler.postDelayed(this, TIMEOUT_DELAY_MS);
mRegistered = true;
}

……
……
}

----------------------------------------------------------------------------------------------------

3,SystemUI下拉展开布局中显示通知处理流程：

BaseStatusBar中通过mNotificationListener监听通知更新，获取通知

private final NotificationListenerService mNotificationListener =
new NotificationListenerService() {

public void onListenerConnected() {
if (DEBUG) Log.d(TAG, "onListenerConnected");
final StatusBarNotification[] notifications = getActiveNotifications();//获取当前所有通知集合
final RankingMap currentRanking = getCurrentRanking();
mHandler.post(new Runnable() {
@Override
public void run() {
for (StatusBarNotification sbn : notifications) {
addNotification(sbn, currentRanking, null /* oldEntry */);
}
}
});
}
……
}

NotificationListenerService获取通知

　　public StatusBarNotification[] getActiveNotifications() {
return getActiveNotifications(null, TRIM_FULL);
}

public StatusBarNotification[] getActiveNotifications(String[] keys, int trim) {
if (!isBound())
return null;
try {
//这里通过Binder调用NotificationManagerService调用getActiveNotificationsFromListener获取通知
ParceledListSlice<StatusBarNotification> parceledList = getNotificationInterface().getActiveNotificationsFromListener(mWrapper, keys, trim);
List<StatusBarNotification> list = parceledList.getList();
…………
return list.toArray(new StatusBarNotification[list.size()]);
} catch (android.os.RemoteException ex) {
Log.v(TAG, "Unable to contact notification manager", ex);
}
return null;
}

//获取INotificationManager的实例，也就是NotificationManagerService中的mService
private final INotificationManager getNotificationInterface() {
if (mNoMan == null) {
mNoMan = INotificationManager.Stub.asInterface(
ServiceManager.getService(Context.NOTIFICATION_SERVICE));
}
return mNoMan;
}
NotificationManagerService中对Context.NOTIFICATION_SERVICE的映射

public class NotificationManagerService extends SystemService
public void onStart() {
……
publishBinderService(Context.NOTIFICATION_SERVICE, mService);//SystemService中定义的方法 publishBinderService(..)
……
}

通过上述流程已经获取通知数据，将数据显示在SystemUI中在PhoneStatusBar中处理

　　//重载父类BaseStatusBar中的方法，mNotificationListener中会直接调用这里添加通知
public void addNotification(StatusBarNotification notification, RankingMap ranking, Entry oldEntry) {
if (DEBUG) Log.d(TAG, "addNotification key=" + notification.getKey());

Entry shadeEntry = createNotificationViews(notification);
if (shadeEntry == null) {
return;
}
……
addNotificationViews(shadeEntry, ranking);//
// Recalculate the position of the sliding windows and the titles.
setAreThereNotifications();
}

　　protected void addNotificationViews(Entry entry, RankingMap ranking) {
if (entry == null) {
return;
}
// Add the expanded view and icon.
mNotificationData.add(entry, ranking);//
        updateNotifications(); //此方法会将新通知添加到SystemUI布局中显示
}