Generate Android Notifications with Code

This skill builds rich, interactive, platform-optimized Android notifications using NotificationCompat.Builder and notification channels. Every notification flow starts with a channel (required on API 26+) configured with an ID, name, importance level, description, lights, and vibration pattern, before any basic notification (small icon, title, content, priority, auto-cancel) is shown. It covers advanced expandable styles - BigTextStyle for long-form content with a summary, and BigPictureStyle for image-led notifications with a large icon - plus interactive notifications with accept and reject actions wired to a BroadcastReceiver via PendingIntent.

Use it when building Android notifications that need to be rich (expandable text or images), interactive (in-notification actions), or grouped and progress-tracked, not a bare single-line alert. It is not a shortcut around channel setup: channels must exist before any notification post on API 26+, and every PendingIntent should carry FLAG_IMMUTABLE on API 23+ for security.

Given a notification's content and desired behavior, it produces: progress notifications (a determinate variant with setProgress(maxProgress, progress, false) and an ongoing flag, and an indeterminate variant with setProgress(0, 0, true)) and grouped notifications (individual messages tagged with a shared group key via setGroup, plus a summary notification using InboxStyle with a line count and setGroupSummary(true)). Interactive notifications wire accept and reject PendingIntents to a BroadcastReceiver with distinct action strings and request codes, each rendered as an addAction button on the notification.

fun createActionNotification(title: String, content: String) {
    val acceptIntent = Intent(context, NotificationReceiver::class.java).apply {
        action = "ACTION_ACCEPT"
    }
    val acceptPendingIntent = PendingIntent.getBroadcast(
        context, 0, acceptIntent, 
        PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_IMMUTABLE
    )
    
    val rejectIntent = Intent(context, NotificationReceiver::class.java).apply {
        action = "ACTION_REJECT"
    }
    val rejectPendingIntent = PendingIntent.getBroadcast(
        context, 1, rejectIntent,
        PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_IMMUTABLE
    )
    
    val notification = NotificationCompat.Builder(context, CHANNEL_ID)
        .setSmallIcon(R.drawable.ic_notification)
        .setContentTitle(title)
        .setContentText(content)
        .addAction(R.drawable.ic_check, "Accept", acceptPendingIntent)
        .addAction(R.drawable.ic_close, "Reject", rejectPendingIntent)
        .setAutoCancel(true)
        .build()
        
    NotificationManagerCompat.from(context).notify(NOTIFICATION_ID, notification)
}

Integrates with Android's NotificationManager and NotificationManagerCompat, PendingIntent-based deep-linking back into the app, and large-icon bitmap handling optimized for performance - scaling any bitmap wider or taller than 256px down to 256x256 before attaching it as a large icon.

Android developers who need production-grade notification UX, not just a basic toast-style alert - following channel-management guidance (create channels at app init, use descriptive names, set HIGH importance for urgent channels and DEFAULT for routine ones, group related channels), UX guidelines (meaningful content previews, priority levels that respect user attention, proper deep-linking, dismiss-pattern support, cross-version testing, accessibility-friendly content descriptions), and security practices (no sensitive data in lock-screen previews, VISIBILITY_PRIVATE for sensitive content, validating all data before display).