Fix check wether the app's notifications are disabled via system settings

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Rename a few methods

app/src/main/java/org/schabi/newpipe/local/feed/notifications/NotificationHelper.kt

@@ -101,39 +101,57 @@ class NotificationHelper(val context: Context) {
 
     companion object {
         /**
-         * Check whether notifications are not disabled by user via system settings.
+         * Check whether notifications are enabled on the device.
+         * Users can disable them via the system settings for a single app.
+         * If this is the case, the app cannot create any notifications
+         * and display them to the user.
+         * <br>
+         * On Android 26 and above, notification channels are used by NewPipe.
+         * These can be configured by the user, too.
+         * The notification channel for new streams is also checked by this method.
          *
          * @param context Context
-         * @return true if notifications are allowed, false otherwise
+         * @return <code>true</code> if notifications are allowed and can be displayed;
+         * <code>false</code> otherwise
          */
-        fun isNotificationsEnabledNative(context: Context): Boolean {
+        fun areNotificationsEnabledOnDevice(context: Context): Boolean {
             return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                 val channelId = context.getString(R.string.streams_notification_channel_id)
                 val manager = context.getSystemService(
                     Context.NOTIFICATION_SERVICE
                 ) as NotificationManager
+                val enabled = manager.areNotificationsEnabled()
                 val channel = manager.getNotificationChannel(channelId)
-                channel != null && channel.importance != NotificationManager.IMPORTANCE_NONE
+                val importance = channel?.importance
+                enabled && channel != null && importance != NotificationManager.IMPORTANCE_NONE
             } else {
                 NotificationManagerCompat.from(context).areNotificationsEnabled()
             }
         }
 
         @JvmStatic
+        /**
+         * Whether the user enabled the notifications for new streams in the app settings.
+         */
         fun areNewStreamsNotificationsEnabled(context: Context): Boolean {
             return (
                 PreferenceManager.getDefaultSharedPreferences(context)
                     .getBoolean(context.getString(R.string.enable_streams_notifications), false) &&
-                    isNotificationsEnabledNative(context)
+                    areNotificationsEnabledOnDevice(context)
                 )
         }
 
-        fun openNativeSettingsScreen(context: Context) {
+        /**
+         * Open the system's notification settings for NewPipe on Android O (API 26) and later.
+         * Open the system's app settings for NewPipe on previous Android versions.
+         */
+        fun openNewPipeSystemNotificationSettings(context: Context) {
             if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                 val channelId = context.getString(R.string.streams_notification_channel_id)
                 val intent = Intent(Settings.ACTION_CHANNEL_NOTIFICATION_SETTINGS)
                     .putExtra(Settings.EXTRA_APP_PACKAGE, context.packageName)
                     .putExtra(Settings.EXTRA_CHANNEL_ID, channelId)
+                    .addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
                 context.startActivity(intent)
             } else {
                 val intent = Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS)

app/src/main/java/org/schabi/newpipe/local/feed/notifications/NotificationWorker.kt

@@ -75,7 +75,7 @@ class NotificationWorker(
                 .getBoolean(
                     context.getString(R.string.enable_streams_notifications),
                     false
-                ) && NotificationHelper.isNotificationsEnabledNative(context)
+                ) && NotificationHelper.areNotificationsEnabledOnDevice(context)
         }
 
         fun schedule(context: Context, options: ScheduleOptions, force: Boolean = false) {

app/src/main/java/org/schabi/newpipe/settings/NotificationsSettingsFragment.kt

@@ -47,7 +47,7 @@ class NotificationsSettingsFragment : BasePreferenceFragment(), OnSharedPreferen
 
     override fun onResume() {
         super.onResume()
-        val enabled = NotificationHelper.isNotificationsEnabledNative(requireContext())
+        val enabled = NotificationHelper.areNotificationsEnabledOnDevice(requireContext())
         preferenceScreen.isEnabled = enabled
         if (!enabled) {
             if (notificationWarningSnackbar == null) {
@@ -56,8 +56,8 @@ class NotificationsSettingsFragment : BasePreferenceFragment(), OnSharedPreferen
                     R.string.notifications_disabled,
                     Snackbar.LENGTH_INDEFINITE
                 ).apply {
-                    setAction(R.string.settings) { v ->
+                    setAction(R.string.settings) {
-                        NotificationHelper.openNativeSettingsScreen(v.context)
+                        activity?.let { NotificationHelper.openNewPipeSystemNotificationSettings(it) }
                     }
                     setActionTextColor(Color.YELLOW)
                     addCallback(object : Snackbar.Callback() {

app/src/main/java/org/schabi/newpipe/util/NavigationHelper.java

@@ -1,5 +1,7 @@
 package org.schabi.newpipe.util;
 
+import static org.schabi.newpipe.util.external_communication.ShareUtils.installApp;
+
 import android.annotation.SuppressLint;
 import android.app.Activity;
 import android.content.Context;
@@ -18,6 +20,8 @@ import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentManager;
 import androidx.fragment.app.FragmentTransaction;
 
+import com.jakewharton.processphoenix.ProcessPhoenix;
+
 import org.schabi.newpipe.MainActivity;
 import org.schabi.newpipe.NewPipeDatabase;
 import org.schabi.newpipe.R;
@@ -57,10 +61,6 @@ import org.schabi.newpipe.util.external_communication.ShareUtils;
 
 import java.util.ArrayList;
 
-import static org.schabi.newpipe.util.external_communication.ShareUtils.installApp;
-
-import com.jakewharton.processphoenix.ProcessPhoenix;
-
 public final class NavigationHelper {
     public static final String MAIN_FRAGMENT_TAG = "main_fragment_tag";
     public static final String SEARCH_FRAGMENT_TAG = "search_fragment_tag";