Fix: Notification doesn't work with target SDK 27+ Etar-Group#372

src/com/android/calendar/alerts/AlertReceiver.java

@@ -59,6 +59,8 @@
 
 import ws.xsoh.etar.R;
 
+import static com.android.calendar.alerts.AlertService.ALERT_CHANNEL_ID;
+
 /**
  * Receives android.intent.action.EVENT_REMINDER intents and handles
  * event reminders.  The intent URI specifies an alert id in the
@@ -258,6 +260,12 @@ private static Notification buildBasicNotification(Notification.Builder notifica
         notificationBuilder.setSmallIcon(R.drawable.stat_notify_calendar);
         notificationBuilder.setContentIntent(clickIntent);
         notificationBuilder.setDeleteIntent(deleteIntent);
+
+        // Add setting channel ID for Oreo or later
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            notificationBuilder.setChannelId(ALERT_CHANNEL_ID);
+        }
+
         if (doPopup) {
             notificationBuilder.setFullScreenIntent(createAlertActivityIntent(context), true);
         }
@@ -319,7 +327,7 @@ private static Notification buildBasicNotification(Notification.Builder notifica
                         resources.getString(R.string.snooze_label), snoozeIntent);
                 numActions++;
             }
-            return notificationBuilder.getNotification();
+            return notificationBuilder.build();
 
         } else {
             // Old-style notification (pre-JB).  Use custom view with buttons to provide

src/com/android/calendar/alerts/AlertService.java

@@ -17,7 +17,9 @@
 package com.android.calendar.alerts;
 
 import android.Manifest;
+import android.annotation.TargetApi;
 import android.app.Notification;
+import android.app.NotificationChannel;
 import android.app.NotificationManager;
 import android.app.Service;
 import android.content.ContentResolver;
@@ -61,6 +63,9 @@
  * This service is used to handle calendar event reminders.
  */
 public class AlertService extends Service {
+
+    public static final String ALERT_CHANNEL_ID = "alert_channel_01";// The id of the channel.
+
     // Hard limit to the number of notifications displayed.
     public static final int MAX_NOTIFICATIONS = 20;
     static final boolean DEBUG = true;
@@ -149,6 +154,13 @@ static boolean updateAlertNotification(Context context) {
         ContentResolver cr = context.getContentResolver();
         NotificationMgr nm = new NotificationMgrWrapper(
                 (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE));
+
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            String appName = context.getString(R.string.standalone_app_label);
+            NotificationChannel channel  = new NotificationChannel(ALERT_CHANNEL_ID, appName, NotificationManager.IMPORTANCE_HIGH);
+            nm.createNotificationChannel(channel);
+        }
+
         final long currentTime = System.currentTimeMillis();
         SharedPreferences prefs = GeneralPreferences.getSharedPreferences(context);
 
@@ -1047,6 +1059,12 @@ public void cancel(int id) {
             mNm.cancel(id);
         }
 
+        @TargetApi(Build.VERSION_CODES.O)
+        @Override
+        public void createNotificationChannel(NotificationChannel channel) {
+            mNm.createNotificationChannel(channel);
+        }
+
         @Override
         public void notify(int id, NotificationWrapper nw) {
             mNm.notify(id, nw.mNotification);

src/com/android/calendar/alerts/NotificationMgr.java

@@ -16,11 +16,14 @@
 
 package com.android.calendar.alerts;
 
+import android.app.NotificationChannel;
+
 import com.android.calendar.alerts.AlertService.NotificationWrapper;
 
 public abstract class NotificationMgr {
     public abstract void notify(int id, NotificationWrapper notification);
     public abstract void cancel(int id);
+    public abstract void createNotificationChannel(NotificationChannel channel);
 
     /**
      * Don't actually use the notification framework's cancelAll since the SyncAdapter