Added NotificationChannelManager to support notifications on Android 8.0 | Close #121.

Author: DenBond7

FlowCrypt/src/main/java/com/flowcrypt/email/FlowCryptApplication.java

@@ -11,6 +11,7 @@
 import android.support.v4.app.FragmentManager;
 import android.support.v7.preference.PreferenceManager;
 
+import com.flowcrypt.email.ui.NotificationChannelManager;
 import com.flowcrypt.email.util.SharedPreferencesHelper;
 import com.squareup.leakcanary.LeakCanary;
 
@@ -65,6 +66,8 @@ public class FlowCryptApplication extends Application {
     @Override
     public void onCreate() {
         super.onCreate();
+        NotificationChannelManager.registerNotificationChannels(this);
+
         intiLeakCanary();
         FragmentManager.enableDebugLogging(BuildConfig.DEBUG);
     }

FlowCrypt/src/main/java/com/flowcrypt/email/service/attachment/AttachmentNotificationManager.java

@@ -18,6 +18,7 @@
 
 import com.flowcrypt.email.R;
 import com.flowcrypt.email.api.email.model.AttachmentInfo;
+import com.flowcrypt.email.ui.NotificationChannelManager;
 
 /**
  * This manager is responsible for displaying attachment notifications.
@@ -45,7 +46,8 @@ public AttachmentNotificationManager(Context context) {
      * @param attachmentInfo {@link AttachmentInfo} object which contains a detail information about an attachment.
      */
     public void attachmentAddedToLoadQueue(Context context, int startId, AttachmentInfo attachmentInfo) {
-        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(context)
+        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(context,
+                NotificationChannelManager.CHANNEL_ID_ATTACHMENTS)
                 .setWhen(startId)
                 .setShowWhen(false)
                 .setProgress(0, 0, true)
@@ -72,7 +74,8 @@ public void attachmentAddedToLoadQueue(Context context, int startId, AttachmentI
      */
     public void updateLoadingProgress(Context context, int startId, AttachmentInfo attachmentInfo,
                                       int progress, long timeLeftInMillisecond) {
-        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(context)
+        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(context,
+                NotificationChannelManager.CHANNEL_ID_ATTACHMENTS)
                 .setProgress(MAX_FILE_SIZE_IN_PERCENTAGE, progress, timeLeftInMillisecond == 0)
                 .setWhen(startId)
                 .setShowWhen(false)
@@ -103,7 +106,8 @@ public void downloadComplete(Context context, int startId, AttachmentInfo attach
 
         PendingIntent pendingIntentOpenFile = PendingIntent.getActivity(context, 0, intentOpenFile, 0);
 
-        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(context)
+        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(context,
+                NotificationChannelManager.CHANNEL_ID_ATTACHMENTS)
                 .setProgress(0, 0, false)
                 .setAutoCancel(true)
                 .setOngoing(false)
@@ -128,7 +132,8 @@ public void downloadComplete(Context context, int startId, AttachmentInfo attach
      * @param e              The {@link Exception} which contains a detail information about happened error..
      */
     public void errorHappened(Context context, int startId, AttachmentInfo attachmentInfo, Exception e) {
-        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(context)
+        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(context,
+                NotificationChannelManager.CHANNEL_ID_ATTACHMENTS)
                 .setProgress(0, 0, false)
                 .setAutoCancel(true)
                 .setOngoing(false)

FlowCrypt/src/main/java/com/flowcrypt/email/ui/NotificationChannelManager.java

@@ -0,0 +1,65 @@
+/*
+ * Business Source License 1.0 © 2017 FlowCrypt Limited ([email protected]).
+ * Use limitations apply. See https://github.com/FlowCrypt/flowcrypt-android/blob/master/LICENSE
+ * Contributors: DenBond7
+ */
+
+package com.flowcrypt.email.ui;
+
+import android.app.NotificationChannel;
+import android.app.NotificationManager;
+import android.content.Context;
+import android.os.Build;
+import android.support.annotation.RequiresApi;
+
+import com.flowcrypt.email.R;
+
+/**
+ * This manager does job of register {@link NotificationChannel} of the app. The {@link NotificationChannel} was
+ * added in the {@link Build.VERSION_CODES#O} and doesn't work on previous Android versions.
+ *
+ * @author Denis Bondarenko
+ *         Date: 17.10.2017
+ *         Time: 12:12
+ *         E-mail: [email protected]
+ */
+
+public class NotificationChannelManager {
+    public static final String CHANNEL_ID_ATTACHMENTS = "Attachments";
+
+    /**
+     * Register {@link NotificationChannel}(s) of the app in the system.
+     *
+     * @param context Interface to global information about an application environment.
+     */
+    public static void registerNotificationChannels(Context context) {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            NotificationManager notificationManager =
+                    (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
+
+            if (notificationManager != null) {
+                notificationManager.createNotificationChannel(generateAttachmentsNotificationChannel(context));
+            }
+        }
+    }
+
+    /**
+     * Generate attachments notification channel.
+     *
+     * @param context Interface to global information about an application environment.
+     * @return Generated {@link NotificationChannel}
+     */
+    @RequiresApi(api = Build.VERSION_CODES.O)
+    private static NotificationChannel generateAttachmentsNotificationChannel(Context context) {
+        CharSequence name = context.getString(R.string.attachments);
+        String description = context.getString(R.string.download_attachments_notification_channel);
+        int importance = NotificationManager.IMPORTANCE_DEFAULT;
+
+        NotificationChannel notificationChannel = new NotificationChannel(CHANNEL_ID_ATTACHMENTS, name, importance);
+        notificationChannel.setDescription(description);
+        notificationChannel.enableLights(false);
+        notificationChannel.enableVibration(false);
+
+        return notificationChannel;
+    }
+}

FlowCrypt/src/main/res/values/strings.xml

@@ -199,4 +199,6 @@
     <string name="experimental">Experimental</string>
     <string name="experimental_settings">Experimental Settings</string>
     <string name="simulate_app_crash">Simulate app crash</string>
+    <string name="attachments">Attachments</string>
+    <string name="download_attachments_notification_channel">The download attachments notification channel</string>
 </resources>