Android O 8.0 Notification 源码分析（二）

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）》