Link priority setting to message channel setting on Oreo+

When using notification channels, us setting priority actually has
no effect. So instead of having a non-functional setting, we've
routed the notification priority setting to go to the system
notification channel settings page for our Messages channel.

src/org/thoughtcrime/securesms/notifications/MultipleRecipientNotificationBuilder.java

@@ -30,8 +30,11 @@ public class MultipleRecipientNotificationBuilder extends AbstractNotificationBu
     setContentTitle(context.getString(R.string.app_name));
     setContentIntent(PendingIntent.getActivity(context, 0, new Intent(context, ConversationListActivity.class), 0));
     setCategory(NotificationCompat.CATEGORY_MESSAGE);
-    setPriority(TextSecurePreferences.getNotificationPriority(context));
     setGroupSummary(true);
+
+    if (!NotificationChannels.supported()) {
+      setPriority(TextSecurePreferences.getNotificationPriority(context));
+    }
   }
 
   public void setMessageCount(int messageCount, int threadCount) {

src/org/thoughtcrime/securesms/notifications/NotificationChannels.java

@@ -26,7 +26,7 @@ public class NotificationChannels {
    * ignored for API < 26.
    */
   public static void create(@NonNull Context context) {
-    if (Build.VERSION.SDK_INT < 26) {
+    if (!supported()) {
       return;
     }
 
@@ -47,4 +47,8 @@ public class NotificationChannels {
       notificationManager.deleteNotificationChannel(APP_UPDATES);
     }
   }
+
+  public static boolean supported() {
+    return Build.VERSION.SDK_INT >= 26;
+  }
 }

src/org/thoughtcrime/securesms/notifications/PendingMessageNotificationBuilder.java

@@ -21,7 +21,6 @@ public class PendingMessageNotificationBuilder extends AbstractNotificationBuild
 
     setSmallIcon(R.drawable.icon_notification);
     setColor(context.getResources().getColor(R.color.textsecure_primary));
-    setPriority(TextSecurePreferences.getNotificationPriority(context));
     setCategory(NotificationCompat.CATEGORY_MESSAGE);
 
     setContentTitle(context.getString(R.string.MessageNotifier_pending_signal_messages));
@@ -31,5 +30,9 @@ public class PendingMessageNotificationBuilder extends AbstractNotificationBuild
     setContentIntent(PendingIntent.getActivity(context, 0, intent, 0));
     setAutoCancel(true);
     setAlarms(null, RecipientDatabase.VibrateState.DEFAULT);
+
+    if (!NotificationChannels.supported()) {
+      setPriority(TextSecurePreferences.getNotificationPriority(context));
+    }
   }
 }

src/org/thoughtcrime/securesms/notifications/SingleRecipientNotificationBuilder.java

@@ -52,8 +52,11 @@ public class SingleRecipientNotificationBuilder extends AbstractNotificationBuil
 
     setSmallIcon(R.drawable.icon_notification);
     setColor(context.getResources().getColor(R.color.textsecure_primary));
-    setPriority(TextSecurePreferences.getNotificationPriority(context));
     setCategory(NotificationCompat.CATEGORY_MESSAGE);
+
+    if (!NotificationChannels.supported()) {
+      setPriority(TextSecurePreferences.getNotificationPriority(context));
+    }
   }
 
   public void setThread(@NonNull Recipient recipient) {

src/org/thoughtcrime/securesms/preferences/NotificationsPreferenceFragment.java

@@ -18,6 +18,8 @@ import org.thoughtcrime.securesms.ApplicationPreferencesActivity;
 import org.thoughtcrime.securesms.R;
 import org.thoughtcrime.securesms.components.SwitchPreferenceCompat;
 import org.thoughtcrime.securesms.notifications.MessageNotifier;
+import org.thoughtcrime.securesms.notifications.NotificationChannels;
+import org.thoughtcrime.securesms.preferences.widgets.SignalListPreference;
 import org.thoughtcrime.securesms.preferences.widgets.SignalPreference;
 import org.thoughtcrime.securesms.util.TextSecurePreferences;
 import org.w3c.dom.Text;
@@ -84,7 +86,21 @@ public class NotificationsPreferenceFragment extends ListSummaryPreferenceFragme
     initializeListSummary((ListPreference) findPreference(TextSecurePreferences.LED_BLINK_PREF));
     initializeListSummary((ListPreference) findPreference(TextSecurePreferences.REPEAT_ALERTS_PREF));
     initializeListSummary((ListPreference) findPreference(TextSecurePreferences.NOTIFICATION_PRIVACY_PREF));
+
+    if (NotificationChannels.supported()) {
+      ((SignalListPreference) this.findPreference(TextSecurePreferences.NOTIFICATION_PRIORITY_PREF)).disableDialog();
+
+      this.findPreference(TextSecurePreferences.NOTIFICATION_PRIORITY_PREF)
+          .setOnPreferenceClickListener(preference -> {
+            Intent intent = new Intent(Settings.ACTION_CHANNEL_NOTIFICATION_SETTINGS);
+            intent.putExtra(Settings.EXTRA_CHANNEL_ID, NotificationChannels.MESSAGES);
+            intent.putExtra(Settings.EXTRA_APP_PACKAGE, getContext().getPackageName());
+            startActivity(intent);
+            return true;
+          });
+    } else {
       initializeListSummary((ListPreference) findPreference(TextSecurePreferences.NOTIFICATION_PRIORITY_PREF));
+    }
 
     initializeRingtoneSummary(findPreference(TextSecurePreferences.RINGTONE_PREF));
     initializeCallRingtoneSummary(findPreference(TextSecurePreferences.CALL_RINGTONE_PREF));

src/org/thoughtcrime/securesms/preferences/widgets/SignalListPreference.java

@@ -18,6 +18,7 @@ public class SignalListPreference extends ListPreference {
 
   private TextView     rightSummary;
   private CharSequence summary;
+  private boolean      dialogDisabled;
 
   @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
   public SignalListPreference(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
@@ -63,4 +64,15 @@ public class SignalListPreference extends ListPreference {
       this.rightSummary.setText(summary);
     }
   }
+
+  public void disableDialog() {
+    dialogDisabled = true;
+  }
+
+  @Override
+  protected void onClick() {
+    if (!dialogDisabled) {
+      super.onClick();
+    }
+  }
 }