2nd/10_Wiki/Topics/Coding/Android_Notification_Patterns.md

id, title, category, status, source_trust_level, verification_status, created_at, updated_at, tags, tech_stack, applied_in, aliases

id	title	category	status	source_trust_level	verification_status	created_at	updated_at	tags	tech_stack	applied_in	aliases
android-notification-patterns	Android Notification — 채널 / 권한 / 스타일	Coding	draft	B	conceptual	2026-05-09	2026-05-09	android notification fcm vibe-coding	language applicable_to Kotlin / Android Android		NotificationChannel FCM push BigText MessagingStyle POST_NOTIFICATIONS

Android Notification

Android 8+ = NotificationChannel 필수. Android 13+ = POST_NOTIFICATIONS 권한. Style (BigText/Inbox/Messaging) 으로 풍부. FCM 으로 push.

📖 핵심 개념

• Channel: 카테고리 (chat / promo / system). 사용자가 채널별 설정.
• Importance: HIGH (heads-up), DEFAULT, LOW, MIN.
• Style: 단순 / BigText / BigPicture / Messaging / Media.
• Action: 인라인 버튼 + 답장 입력.

💻 코드 패턴

Channel 생성 (앱 시작)

class App : Application() {
    override fun onCreate() {
        super.onCreate()
        val nm = getSystemService<NotificationManager>()!!
        nm.createNotificationChannels(listOf(
            NotificationChannel("chat", "Chat", NotificationManager.IMPORTANCE_HIGH).apply {
                description = "New messages"
                enableVibration(true)
                setSound(soundUri, audioAttrs)
            },
            NotificationChannel("promo", "Promotions", NotificationManager.IMPORTANCE_LOW),
        ))
    }
}

권한 (13+)

private val launcher = registerForActivityResult(ActivityResultContracts.RequestPermission()) { granted -> }

if (Build.VERSION.SDK_INT >= 33 &&
    ContextCompat.checkSelfPermission(this, Manifest.permission.POST_NOTIFICATIONS) != PackageManager.PERMISSION_GRANTED) {
    launcher.launch(Manifest.permission.POST_NOTIFICATIONS)
}

<uses-permission android:name="android.permission.POST_NOTIFICATIONS" />

단순 notification

val pi = PendingIntent.getActivity(ctx, 0,
    Intent(ctx, MainActivity::class.java), PendingIntent.FLAG_IMMUTABLE)

val notif = NotificationCompat.Builder(ctx, "chat")
    .setSmallIcon(R.drawable.ic_chat)
    .setContentTitle("Alice")
    .setContentText("Hi there")
    .setContentIntent(pi)
    .setAutoCancel(true)
    .build()

NotificationManagerCompat.from(ctx).notify(notifId, notif)

BigText (긴 본문)

.setStyle(NotificationCompat.BigTextStyle().bigText(longBody))

MessagingStyle (chat)

val you = Person.Builder().setName("You").build()
val alice = Person.Builder().setName("Alice").setIcon(...).build()

val style = NotificationCompat.MessagingStyle(you)
    .setConversationTitle("Alice")
    .addMessage("Hi", System.currentTimeMillis() - 60_000, alice)
    .addMessage("Hello", System.currentTimeMillis(), you)

builder.setStyle(style)

Action + RemoteInput (답장)

val replyKey = "key_reply"
val remoteInput = RemoteInput.Builder(replyKey).setLabel("Reply").build()
val replyPI = PendingIntent.getBroadcast(ctx, 0,
    Intent(ctx, ReplyReceiver::class.java).putExtra("convId", convId),
    PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_MUTABLE)

val replyAction = NotificationCompat.Action.Builder(R.drawable.ic_reply, "Reply", replyPI)
    .addRemoteInput(remoteInput)
    .setSemanticAction(NotificationCompat.Action.SEMANTIC_ACTION_REPLY)
    .build()

builder.addAction(replyAction)

class ReplyReceiver : BroadcastReceiver() {
    override fun onReceive(context: Context, intent: Intent) {
        val text = RemoteInput.getResultsFromIntent(intent)?.getCharSequence("key_reply").toString()
        // send + update notification
    }
}

FCM (push)

class MyFcmService : FirebaseMessagingService() {
    override fun onMessageReceived(msg: RemoteMessage) {
        val data = msg.data
        showNotification(data["title"] ?: "", data["body"] ?: "")
    }

    override fun onNewToken(token: String) {
        // 서버에 등록
    }
}

<service android:name=".MyFcmService" android:exported="false">
    <intent-filter>
        <action android:name="com.google.firebase.MESSAGING_EVENT" />
    </intent-filter>
</service>

Group + summary

val groupKey = "messages-group"

val notif1 = NotificationCompat.Builder(ctx, "chat").setGroup(groupKey).build()
val notif2 = NotificationCompat.Builder(ctx, "chat").setGroup(groupKey).build()
val summary = NotificationCompat.Builder(ctx, "chat")
    .setGroup(groupKey).setGroupSummary(true)
    .setSmallIcon(R.drawable.ic_chat)
    .setContentTitle("3 new messages")
    .build()

Heads-up (떠 있는 알림)

NotificationChannel(..., IMPORTANCE_HIGH) // 채널이 HIGH
.setPriority(NotificationCompat.PRIORITY_HIGH)
.setCategory(NotificationCompat.CATEGORY_MESSAGE)
.setFullScreenIntent(pi, true) // 전화 같은 거 (lock screen 도)

Image / Avatar

.setLargeIcon(bitmap)
.setStyle(NotificationCompat.BigPictureStyle().bigPicture(bigBitmap))

🤔 의사결정 기준

종류	채널 / 스타일
채팅	HIGH + MessagingStyle + reply action
시스템 (sync 완료)	LOW + 단순
마케팅 / promo	LOW + dismissable
진행 중 (다운로드)	LOW + progress
알람 / 콜	HIGH + fullScreenIntent

❌ 안티패턴

• Channel 안 만들고 notify: 8+ 에서 안 보임.
• 권한 미요청 (13+): silently 차단.
• 모든 채널 HIGH: 사용자 끄기. 적절히.
• PendingIntent FLAG_IMMUTABLE 누락 (12+): SecurityException.
• Group summary 누락 + 많은 알림: 사용자 화남.
• Image inline base64 큼: 메모리.
• setOngoing(true) 잘못 쓰면 dismiss 못 함.
• Channel 삭제 + 재생성: 사용자 설정 잃음.

🤖 LLM 활용 힌트

• Channel + 권한 (13+) + Style + Action 4종.
• FCM + onMessageReceived → showNotification.
• Group key + summary.

🔗 관련 문서

• Android_Foreground_Service_Patterns
• iOS_Push_Notifications
• Native_Battery_Network_Profiling