Use top-level function instead of object class.

[satorufujiwara]

Issue

• No issue.

Overview (Required)

• Use top-level function instead of object class.

Like #556, there is room for discussion for this. I prefer top-level function to (companion) object object class. This opinion is based on Kotlin in Action(chapter 4.4.2).

The detailed explanation is in the following blog(in Japanese). http://hydrakecat.hatenablog.jp/entry/2017/12/02/companion_object_vs._top-level

Changes

These are decompiled java code.

Before

public final class NotificationHelper {
   public static final NotificationHelper INSTANCE;

   public final void initNotificationChannel(@NotNull Context context) {
      Intrinsics.checkParameterIsNotNull(context, "context");
      if(VERSION.SDK_INT >= 26) {
         Object[] $receiver$iv = (Object[])NotificationHelper.ChannelType.values();
         int var3 = $receiver$iv.length;

         for(int var4 = 0; var4 < var3; ++var4) {
            Object element$iv = $receiver$iv[var4];
            NotificationHelper.ChannelType it = (NotificationHelper.ChannelType)element$iv;
            INSTANCE.createNotificationChannel(context, it);
         }
      }

   }

   @RequiresApi(26)
   private final void createNotificationChannel(Context context, NotificationHelper.ChannelType channelType) {
      Object var10000 = context.getSystemService("notification");
      if(var10000 == null) {
         throw new TypeCastException("null cannot be cast to non-null type android.app.NotificationManager");
      } else {
         NotificationManager manager = (NotificationManager)var10000;
         String channelName = context.getString(channelType.getNameRes());
         NotificationChannel channel = new NotificationChannel(channelType.getId(), (CharSequence)channelName, channelType.getImportance());
         manager.createNotificationChannel(channel);
      }
   }

   public final void showNotification(@NotNull Context context, @NotNull NotificationContent content) {
      Intrinsics.checkParameterIsNotNull(context, "context");
      Intrinsics.checkParameterIsNotNull(content, "content");
      Notification notification = (new Builder(context, content.getChannelType().getId())).setContentTitle((CharSequence)content.getTitle()).setContentText((CharSequence)content.getText()).setFullScreenIntent(content.createPendingContentIntent(context), true).setAutoCancel(true).setColor(ContextCompat.getColor(context, 2131099750)).setSmallIcon(2131230882).build();
      NotificationManagerCompat manager = NotificationManagerCompat.from(context);
      manager.notify(content.getText().hashCode(), notification);
   }

   static {
      NotificationHelper var0 = new NotificationHelper();
      INSTANCE = var0;
   }

   public static enum ChannelType {
      FAVORITE_SESSION_START;

      @NotNull
      private final String id;
      private final int nameRes;
      private final int importance;

      @NotNull
      public final String getId() {
         return this.id;
      }

      public final int getNameRes() {
         return this.nameRes;
      }

      public final int getImportance() {
         return this.importance;
      }

      protected ChannelType(@NotNull String id, @StringRes int nameRes, int importance) {
         Intrinsics.checkParameterIsNotNull(id, "id");
         super($enum_name_or_ordinal$0, $enum_name_or_ordinal$1);
         this.id = id;
         this.nameRes = nameRes;
         this.importance = importance;
      }
   }
}

• NotificationHelper is singleton.

After

public final class NotificationHelperKt {
   public static final void initNotificationChannel(@NotNull Context $receiver) {
      Intrinsics.checkParameterIsNotNull($receiver, "$receiver");
      if(VERSION.SDK_INT >= 26) {
         Object[] $receiver$iv = (Object[])NotificationChannelType.values();
         int var2 = $receiver$iv.length;

         for(int var3 = 0; var3 < var2; ++var3) {
            Object element$iv = $receiver$iv[var3];
            NotificationChannelType p1 = (NotificationChannelType)element$iv;
            createNotificationChannel($receiver, p1);
         }
      }

   }

   @RequiresApi(26)
   private static final void createNotificationChannel(@NotNull Context $receiver, NotificationChannelType channelType) {
      Object var10000 = $receiver.getSystemService("notification");
      if(var10000 == null) {
         throw new TypeCastException("null cannot be cast to non-null type android.app.NotificationManager");
      } else {
         ((NotificationManager)var10000).createNotificationChannel(new NotificationChannel(channelType.getId(), (CharSequence)$receiver.getString(channelType.getNameRes()), channelType.getImportance()));
      }
   }

   public static final void showNotification(@NotNull Context $receiver, @NotNull NotificationContent content) {
      Intrinsics.checkParameterIsNotNull($receiver, "$receiver");
      Intrinsics.checkParameterIsNotNull(content, "content");
      NotificationManagerCompat.from($receiver).notify(content.getText().hashCode(), (new Builder($receiver, content.getChannelType().getId())).setContentTitle((CharSequence)content.getTitle()).setContentText((CharSequence)content.getText()).setFullScreenIntent(content.createPendingContentIntent($receiver), true).setAutoCancel(true).setColor(ContextCompat.getColor($receiver, 2131099750)).setSmallIcon(2131230882).build());
   }
}

public enum NotificationChannelType {
   FAVORITE_SESSION_START;

   @NotNull
   private final String id;
   private final int nameRes;
   private final int importance;

   @NotNull
   public final String getId() {
      return this.id;
   }

   public final int getNameRes() {
      return this.nameRes;
   }

   public final int getImportance() {
      return this.importance;
   }

   protected NotificationChannelType(@NotNull String id, @StringRes int nameRes, int importance) {
      Intrinsics.checkParameterIsNotNull(id, "id");
      super($enum_name_or_ordinal$0, $enum_name_or_ordinal$1);
      this.id = id;
      this.nameRes = nameRes;
      this.importance = importance;
   }
}

Other change.

• context parameter of BroadcastReceiver::onReceive is changed to Non-Null.

This is because it is assumed that it will not become Non-Null. Even if it falls to Null, it falls before the calling context (falls by Intrinsics.checkParameterIsNotNull(context, "context");), so you can quickly find a bug. I guess that this also is certainly described in Kotlin in Action.

Links

• http://hydrakecat.hatenablog.jp/entry/2017/12/02/companion_object_vs._top-level

Screenshot

Nothing has changed. And this changes is hard to test 🙏 .

[takahirom]

👀

[takahirom]

🆒

[takahirom]

I learned a lot! Thanks 👍