Singleton repository class

app/src/main/java/io/heckel/ntfy/MainActivity.kt

@@ -41,7 +41,7 @@ const val TOPIC_URL = "url"
 class MainActivity : AppCompatActivity() {
     private val newTopicActivityRequestCode = 1
     private val topicsViewModel by viewModels<TopicsViewModel> {
-        TopicsViewModelFactory(this)
+        TopicsViewModelFactory()
     }
 
     override fun onCreate(savedInstanceState: Bundle?) {

app/src/main/java/io/heckel/ntfy/TopicsViewModel.kt

@@ -1,116 +1,46 @@
-/*
+package io.heckel.ntfy
- * Copyright (C) 2020 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
 
-package io.heckel.ntfy.list
+import androidx.lifecycle.LiveData
-
+import androidx.lifecycle.ViewModel
-import android.content.Context
+import androidx.lifecycle.ViewModelProvider
-import androidx.lifecycle.*
+import androidx.lifecycle.viewModelScope
-import com.google.gson.GsonBuilder
+import io.heckel.ntfy.data.TopicsRepository
-import com.google.gson.JsonObject
-import com.google.gson.JsonSyntaxException
-import io.heckel.ntfy.data.DataSource
 import io.heckel.ntfy.data.Topic
 import kotlinx.coroutines.*
-import kotlinx.coroutines.flow.Flow
+import kotlin.collections.List
-import kotlinx.coroutines.flow.flow
-import java.io.IOException
-import java.net.HttpURLConnection
-import java.net.URL
 
 data class Notification(val topic: String, val message: String)
 typealias NotificationListener = (notification: Notification) -> Unit
 
-class TopicsViewModel(val datasource: DataSource) : ViewModel() {
+class TopicsViewModel(private val repository: TopicsRepository) : ViewModel() {
-    private val gson = GsonBuilder().create()
-    private val jobs = mutableMapOf<Long, Job>()
-    private var notificationListener: NotificationListener? = null;
-
     fun add(topic: Topic) {
-        println("Adding topic $topic $this")
+        repository.add(topic, viewModelScope)
-        datasource.add(topic)
-        jobs[topic.id] = subscribeTopic(topic.url)
     }
 
     fun get(id: Long) : Topic? {
-        return datasource.get(id)
+        return repository.get(id)
     }
 
     fun list(): LiveData<List<Topic>> {
-        return datasource.list()
+        return repository.list()
     }
 
     fun remove(topic: Topic) {
-        println("Removing topic $topic $this")
+        repository.remove(topic)
-        jobs[topic.id]?.cancel()
-        println("${jobs[topic.id]}")
-
-        jobs.remove(topic.id)?.cancel() // Cancel and remove
-        println("${jobs[topic.id]}")
-        datasource.remove(topic)
     }
 
     fun setNotificationListener(listener: NotificationListener) {
-        notificationListener = listener
+        repository.setNotificationListener(listener)
-    }
-
-    private fun subscribeTopic(url: String): Job {
-        return viewModelScope.launch(Dispatchers.IO) {
-            while (isActive) {
-                openURL(this, url)
-                delay(5000) // TODO exponential back-off
-            }
-        }
-    }
-
-    private fun openURL(scope: CoroutineScope, url: String) {
-        println("Connecting to $url ...")
-        val conn = (URL(url).openConnection() as HttpURLConnection).also {
-            it.doInput = true
-        }
-        try {
-            val input = conn.inputStream.bufferedReader()
-            while (scope.isActive) {
-                val line = input.readLine() ?: break // Exit if null
-                try {
-                    val json = gson.fromJson(line, JsonObject::class.java) ?: break // Exit if null
-                    if (!json.isJsonNull && json.has("message")) {
-                        val message = json.get("message").asString
-                        notificationListener?.let { it(Notification(url, message)) }
-                    }
-                } catch (e: JsonSyntaxException) {
-                    // Ignore invalid JSON
-                }
-            }
-        } catch (e: IOException) {
-            println("PHIL: " + e.message)
-        } finally {
-            conn.disconnect()
-        }
-        println("Connection terminated: $url")
     }
 }
 
-class TopicsViewModelFactory(private val context: Context) : ViewModelProvider.Factory {
+class TopicsViewModelFactory() : ViewModelProvider.Factory {
-    override fun <T : ViewModel> create(modelClass: Class<T>): T {
+    @Suppress("UNCHECKED_CAST")
-        if (modelClass.isAssignableFrom(TopicsViewModel::class.java)) {
+    override fun <T : ViewModel?> create(modelClass: Class<T>) =
-            @Suppress("UNCHECKED_CAST")
+        with(modelClass){
-            return TopicsViewModel(
+            when {
-                datasource = DataSource.getDataSource(context.resources)
+                isAssignableFrom(TopicsViewModel::class.java) -> TopicsViewModel(TopicsRepository.getInstance()) as T
-            ) as T
+                else -> throw IllegalArgumentException("Unknown viewModel class $modelClass")
+            }
         }
-        throw IllegalArgumentException("Unknown ViewModel class")
-    }
 }

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

@@ -1,72 +0,0 @@
-/*
- * Copyright (C) 2020 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package io.heckel.ntfy.data
-
-import android.content.res.Resources
-import androidx.lifecycle.LiveData
-import androidx.lifecycle.MutableLiveData
-
-/* Handles operations on topicsLiveData and holds details about it. */
-class DataSource(resources: Resources) {
-    private val topicsLiveData: MutableLiveData<List<Topic>> = MutableLiveData(mutableListOf())
-
-    /* Adds topic to liveData and posts value. */
-    fun add(topic: Topic) {
-        val currentList = topicsLiveData.value
-        if (currentList == null) {
-            topicsLiveData.postValue(listOf(topic))
-        } else {
-            val updatedList = currentList.toMutableList()
-            updatedList.add(0, topic)
-            topicsLiveData.postValue(updatedList)
-        }
-    }
-
-    /* Removes topic from liveData and posts value. */
-    fun remove(topic: Topic) {
-        val currentList = topicsLiveData.value
-        if (currentList != null) {
-            val updatedList = currentList.toMutableList()
-            updatedList.remove(topic)
-            topicsLiveData.postValue(updatedList)
-        }
-    }
-
-    /* Returns topic given an ID. */
-    fun get(id: Long): Topic? {
-        topicsLiveData.value?.let { topics ->
-            return topics.firstOrNull{ it.id == id}
-        }
-        return null
-    }
-
-    fun list(): LiveData<List<Topic>> {
-        return topicsLiveData
-    }
-
-    companion object {
-        private var instance: DataSource? = null
-
-        fun getDataSource(resources: Resources): DataSource {
-            return synchronized(DataSource::class) {
-                val newInstance = instance ?: DataSource(resources)
-                instance = newInstance
-                newInstance
-            }
-        }
-    }
-}

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

@@ -0,0 +1,109 @@
+package io.heckel.ntfy.data
+
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.MutableLiveData
+import com.google.gson.GsonBuilder
+import com.google.gson.JsonObject
+import com.google.gson.JsonSyntaxException
+import io.heckel.ntfy.Notification
+import io.heckel.ntfy.NotificationListener
+import kotlinx.coroutines.*
+import java.io.IOException
+import java.net.HttpURLConnection
+import java.net.URL
+
+/* Handles operations on topicsLiveData and holds details about it. */
+class TopicsRepository {
+    private val topics: MutableLiveData<List<Topic>> = MutableLiveData(mutableListOf())
+    private val jobs = mutableMapOf<Long, Job>()
+    private val gson = GsonBuilder().create()
+    private var notificationListener: NotificationListener? = null;
+
+    /* Adds topic to liveData and posts value. */
+    fun add(topic: Topic, scope: CoroutineScope) {
+        val currentList = topics.value
+        if (currentList == null) {
+            topics.postValue(listOf(topic))
+        } else {
+            val updatedList = currentList.toMutableList()
+            updatedList.add(0, topic)
+            topics.postValue(updatedList)
+        }
+        jobs[topic.id] = subscribeTopic(topic, scope)
+    }
+
+    /* Removes topic from liveData and posts value. */
+    fun remove(topic: Topic) {
+        val currentList = topics.value
+        if (currentList != null) {
+            val updatedList = currentList.toMutableList()
+            updatedList.remove(topic)
+            topics.postValue(updatedList)
+        }
+        jobs.remove(topic.id)?.cancel() // Cancel and remove
+    }
+
+    /* Returns topic given an ID. */
+    fun get(id: Long): Topic? {
+        topics.value?.let { topics ->
+            return topics.firstOrNull{ it.id == id}
+        }
+        return null
+    }
+
+    fun list(): LiveData<List<Topic>> {
+        return topics
+    }
+
+    fun setNotificationListener(listener: NotificationListener) {
+        notificationListener = listener
+    }
+
+    private fun subscribeTopic(topic: Topic, scope: CoroutineScope): Job {
+        return scope.launch(Dispatchers.IO) {
+            while (isActive) {
+                openURL(this, topic.url, topic.url) // TODO
+                delay(5000) // TODO exponential back-off
+            }
+        }
+    }
+
+    private fun openURL(scope: CoroutineScope, topic: String, url: String) {
+        println("Connecting to $url ...")
+        val conn = (URL(url).openConnection() as HttpURLConnection).also {
+            it.doInput = true
+        }
+        try {
+            val input = conn.inputStream.bufferedReader()
+            while (scope.isActive) {
+                val line = input.readLine() ?: break // Exit if null
+                try {
+                    val json = gson.fromJson(line, JsonObject::class.java) ?: break // Exit if null
+                    if (!json.isJsonNull && json.has("message")) {
+                        val message = json.get("message").asString
+                        notificationListener?.let { it(Notification(url, message)) }
+                    }
+                } catch (e: JsonSyntaxException) {
+                    // Ignore invalid JSON
+                }
+            }
+        } catch (e: IOException) {
+            println("PHIL: " + e.message)
+        } finally {
+            conn.disconnect()
+        }
+        println("Connection terminated: $url")
+    }
+
+    companion object {
+        private var instance: TopicsRepository? = null
+
+        fun getInstance(): TopicsRepository {
+            return synchronized(TopicsRepository::class) {
+                val newInstance = instance ?: TopicsRepository()
+                instance = newInstance
+                newInstance
+            }
+        }
+    }
+}

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

@@ -23,12 +23,12 @@ import androidx.activity.viewModels
 import androidx.appcompat.app.AppCompatActivity
 import io.heckel.ntfy.R
 import io.heckel.ntfy.TOPIC_ID
-import io.heckel.ntfy.list.TopicsViewModel
+import io.heckel.ntfy.TopicsViewModel
-import io.heckel.ntfy.list.TopicsViewModelFactory
+import io.heckel.ntfy.TopicsViewModelFactory
 
 class DetailActivity : AppCompatActivity() {
     private val topicsViewModel by viewModels<TopicsViewModel> {
-        TopicsViewModelFactory(this)
+        TopicsViewModelFactory()
     }
 
     override fun onCreate(savedInstanceState: Bundle?) {