Pushmanager is a small wrapper for FCM (Firebase Cloud Messageing) and your app needs just a few methods to interact with it.
Add google-services as dependency to your project build.gradle
buildscript {
    ...
    dependencies {
        ...
        classpath "com.google.gms:google-services:4.3.5"
        ...
    }
}and add jitpackto your repositories
allprojects {
    repositories {
        ...
        maven { url "https://jitpack.io" }
    }
    ...
}Add this dependency to your app build.gradle and apply the plugin at the bottom:
implementation 'com.github.grumpyshoe:android-module-pushmanager:1.3.1'...
apply plugin: 'com.google.gms.google-services'Get instance of PushManager:
val pushmanager: PushManager = PushManagerImpl  Put your google-services.json to the app-root folder.
Create a class extending PushmanagerMessagingService and implement handleNotificationPayload. Here you can decide if a notification should be silent handled or shown to the user according to it's reason.
class MyService : PushmanagerMessagingService() {
    override fun handleNotificationPayload(context:Context, remoteMessageData: RemoteMessageData): NotificationData? {
      Log.d("PushManager", "handlePayload - ${remoteMessageData.title} - ${remoteMessageData.body}" )
      // create pending intent (example)
      val notificationIntent = Intent(context, SomeActivity::class.java)
      notificationIntent.putExtra("info", "Some information for pending intent")
      notificationIntent.flags = Intent.FLAG_ACTIVITY_CLEAR_TOP or Intent.FLAG_ACTIVITY_SINGLE_TOP
      val contentIntent = PendingIntent.getActivity(context, 0, notificationIntent, PendingIntent.FLAG_UPDATE_CURRENT)
      // create notification (example)
      return NotificationData(
            context = context,
            title = remoteMessageData.title ?: "Default Title",
            message = remoteMessageData.body ?: "Default Message",
            channelId = "channel_global_notifications",             // needed SDK >= Android O
            autoCancel = true,
            pendingIntent = contentIntent)
    }
}Add your implementation to you Manifest.xml
<application ... >
       <service
           android:name=".MyService">
           <intent-filter>
               <action android:name="com.google.firebase.MESSAGING_EVENT"/>
           </intent-filter>
       </service>
       ...
</application>
Call the method register in your onCreate to register to FCM. Notice that register is a coroutine so you have to use something like GlobalScope.launch to run this function.
pushmanager.register(
      context = this,
      onTokenReceived = { token ->
          Log.d("PushManager", "token received: $token")
      },
      onFailure = { exception ->
          Log.d("PushManager", " error during registration: ${exception?.message}")
      })To unregister from FCM you need to register first. Notice that unregister is a coroutine so you have to use something like GlobalScope.launch to run this function.
pushmanager.unregister(context)To subscribe to a topic just call  subscriptToTopic:
pushmanager.subscriptToTopic(
      topic = "wurst",
      onSuccess = {
          Log.d("PushManager", "successfully subscribed")
      },
      onFailure = { exception ->
          Log.d("PushManager", " error while subscribing: ${exception?.message}")
      })
To unsubscribe from a topic call  unsubscriptFromTopic:
pushmanager.unsubscriptFromTopic(
      topic = "wurst",
      onSuccess = {
          Log.d("PushManager", "successfully unsubscribed")
      },
      onFailure = { exception ->
          Log.d("PushManager", "error while unsubscribing: ${exception?.message}")
      })
| Package | Version | 
|---|---|
| com.google.firebase:firebase-core | 17.2.0 | 
| com.google.firebase:firebase-iid | 20.0.0 | 
| com.google.firebase:firebase-messaging | 20.0.0 | 
To run the sample App, just replace the application_id at the project build.gradle with someone according to your firebase project and add your google-services.json to to app root folder.
See Troubleshooting at github wiki.
Please submit an issue on GitHub.
See CHANGELOG for morre information.
This project is licensed under the terms of the MIT license. See the LICENSE file.
Android Studio 4.1.2
Build #AI-201.8743.12.41.7042882, built on December 20, 2020
Runtime version: 1.8.0_242-release-1644-b3-6915495 x86_64
VM: OpenJDK 64-Bit Server VM by JetBrains s.r.o
macOS 10.15.5