EventsFlow

app/build.gradle

@@ -22,7 +22,7 @@ android {
     compileSdkVersion 30
 
     defaultConfig {
-        applicationId "com.example.recyclersample"
+        applicationId "io.heckel.ntfy"
         minSdkVersion 21
         targetSdkVersion 30
         versionCode 1
@@ -45,7 +45,6 @@ android {
     kotlinOptions {
         jvmTarget = JavaVersion.VERSION_1_8.toString()
     }
-
 }
 
 dependencies {
@@ -54,6 +53,7 @@ dependencies {
     implementation "androidx.core:core-ktx:$rootProject.coreKtxVersion"
     implementation "androidx.constraintlayout:constraintlayout:$rootProject.constraintLayoutVersion"
     implementation "androidx.activity:activity-ktx:$rootProject.activityVersion"
+    implementation 'com.google.code.gson:gson:2.8.8'
 
     // RecyclerView
     implementation "androidx.recyclerview:recyclerview:$rootProject.recyclerViewVersion"

app/src/main/AndroidManifest.xml

@@ -16,7 +16,7 @@
 -->
 
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
-    package="com.heckel.ntfy">
+    package="io.heckel.ntfy">
 
     <uses-permission android:name="android.permission.INTERNET"/>
 

app/src/main/java/io/heckel/ntfy/add/AddTopicActivity.kt

@@ -21,7 +21,7 @@ import android.content.Intent
 import android.os.Bundle
 import android.widget.Button
 import androidx.appcompat.app.AppCompatActivity
-import com.heckel.ntfy.R
+import io.heckel.ntfy.R
 import com.google.android.material.textfield.TextInputEditText
 
 const val TOPIC_URL = "url"

app/src/main/java/io/heckel/ntfy/data/NtfyApi.kt

@@ -0,0 +1,64 @@
+package io.heckel.ntfy.data
+
+import android.content.Context
+import com.google.gson.GsonBuilder
+import com.google.gson.JsonObject
+import com.google.gson.JsonSyntaxException
+import kotlinx.coroutines.*
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.flow
+import java.io.IOException
+import java.net.HttpURLConnection
+import java.net.URL
+
+class NtfyApi(context: Context) {
+    private val gson = GsonBuilder().create()
+
+    private suspend fun getStreamConnection(url: String): HttpURLConnection =
+        withContext(Dispatchers.IO) {
+            return@withContext (URL(url).openConnection() as HttpURLConnection).also {
+                it.setRequestProperty("Accept", "text/event-stream")
+                it.doInput = true
+            }
+        }
+
+    data class Event(val name: String = "", val data: JsonObject = JsonObject())
+
+    fun getEventsFlow(): Flow<Event> = flow {
+        coroutineScope {
+            val conn = getStreamConnection("https://ntfy.sh/_phil")
+            val input = conn.inputStream.bufferedReader()
+            try {
+                conn.connect()
+                var event = Event()
+                while (isActive) {
+                    val line = input.readLine()
+                    println("PHIL: " + line)
+                    when {
+                        line.startsWith("event:") -> {
+                            event = event.copy(name = line.substring(6).trim())
+                        }
+                        line.startsWith("data:") -> {
+                            val data = line.substring(5).trim()
+                            try {
+                                event = event.copy(data = gson.fromJson(data, JsonObject::class.java))
+                            } catch (e: JsonSyntaxException) {
+                                // Nothing
+                            }
+                        }
+                        line.isEmpty() -> {
+                            emit(event)
+                            event = Event()
+                        }
+                    }
+                }
+            } catch (e: IOException) {
+                println("PHIL: " + e.message)
+                this.cancel(CancellationException("Network Problem", e))
+            } finally {
+                conn.disconnect()
+                input.close()
+            }
+        }
+    }
+}

app/src/main/java/io/heckel/ntfy/detail/TopicDetailActivity.kt

@@ -21,7 +21,7 @@ import android.widget.Button
 import android.widget.TextView
 import androidx.activity.viewModels
 import androidx.appcompat.app.AppCompatActivity
-import com.heckel.ntfy.R
+import io.heckel.ntfy.R
 import io.heckel.ntfy.list.TOPIC_ID
 
 class TopicDetailActivity : AppCompatActivity() {

app/src/main/java/io/heckel/ntfy/list/TopicsAdapter.kt

@@ -19,12 +19,11 @@ package io.heckel.ntfy.list
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
-import android.widget.ImageView
 import android.widget.TextView
 import androidx.recyclerview.widget.DiffUtil
 import androidx.recyclerview.widget.ListAdapter
 import androidx.recyclerview.widget.RecyclerView
-import com.heckel.ntfy.R
+import io.heckel.ntfy.R
 import io.heckel.ntfy.data.Topic
 
 class TopicsAdapter(private val onClick: (Topic) -> Unit) :

app/src/main/java/io/heckel/ntfy/list/TopicsListActivity.kt

@@ -22,16 +22,24 @@ import android.os.Bundle
 import android.view.View
 import androidx.activity.viewModels
 import androidx.appcompat.app.AppCompatActivity
+import androidx.lifecycle.Observer
+import androidx.lifecycle.asLiveData
+import androidx.lifecycle.lifecycleScope
 import androidx.recyclerview.widget.RecyclerView
-import com.heckel.ntfy.R
+import io.heckel.ntfy.R
 import io.heckel.ntfy.add.AddTopicActivity
 import io.heckel.ntfy.add.TOPIC_URL
+import io.heckel.ntfy.data.NtfyApi
 import io.heckel.ntfy.data.Topic
 import io.heckel.ntfy.detail.TopicDetailActivity
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
 
 const val TOPIC_ID = "topic id"
 
 class TopicsListActivity : AppCompatActivity() {
+    private val api = NtfyApi(this)
     private val newTopicActivityRequestCode = 1
     private val topicsListViewModel by viewModels<TopicsListViewModel> {
         TopicsListViewModelFactory(this)
@@ -55,6 +63,19 @@ class TopicsListActivity : AppCompatActivity() {
         fab.setOnClickListener {
             fabOnClick()
         }
+
+        val self = this
+        api.getEventsFlow().asLiveData(Dispatchers.IO).observe(this, Observer { event ->
+            // Get the Activity's lifecycleScope and launch
+            this.lifecycleScope.launch(Dispatchers.Main) {
+                // run the code again in IO context
+                withContext(Dispatchers.IO) {
+                    println(event.data)
+                    //Toast.makeText(self, event.data, Toast.LENGTH_SHORT)
+                }
+            }
+        }
+        )
     }
 
     /* Opens TopicDetailActivity when RecyclerView item is clicked. */