Combine view models

app/src/main/AndroidManifest.xml

@@ -27,7 +27,7 @@
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/AppTheme">
-        <activity android:name="io.heckel.ntfy.list.TopicsListActivity">
+        <activity android:name="io.heckel.ntfy.MainActivity">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.LAUNCHER" />

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

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package io.heckel.ntfy.list
+package io.heckel.ntfy
 
 import android.app.Activity
 import android.app.NotificationChannel
@@ -33,13 +33,14 @@ import androidx.recyclerview.widget.RecyclerView
 import com.google.gson.GsonBuilder
 import com.google.gson.JsonObject
 import com.google.gson.JsonSyntaxException
-import io.heckel.ntfy.R
 import io.heckel.ntfy.add.AddTopicActivity
 import io.heckel.ntfy.add.TOPIC_URL
 import io.heckel.ntfy.data.Topic
 import io.heckel.ntfy.detail.TopicDetailActivity
+import io.heckel.ntfy.list.TopicsAdapter
+import io.heckel.ntfy.list.TopicsViewModelFactory
+import io.heckel.ntfy.list.TopicsViewModel
 import kotlinx.coroutines.*
-import java.io.BufferedReader
 import java.io.IOException
 import java.net.HttpURLConnection
 import java.net.URL
@@ -47,12 +48,12 @@ import kotlin.random.Random
 
 const val TOPIC_ID = "topic id"
 
-class TopicsListActivity : AppCompatActivity() {
+class MainActivity : AppCompatActivity() {
     private val gson = GsonBuilder().create()
     private val jobs = mutableMapOf<Long, Job>()
     private val newTopicActivityRequestCode = 1
-    private val topicsListViewModel by viewModels<TopicsListViewModel> {
+    private val topicsListViewModel by viewModels<TopicsViewModel> {
-        TopicsListViewModelFactory(this)
+        TopicsViewModelFactory(this)
     }
 
     override fun onCreate(savedInstanceState: Bundle?) {

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

@@ -23,19 +23,27 @@ import androidx.lifecycle.ViewModelProvider
 import io.heckel.ntfy.data.DataSource
 import io.heckel.ntfy.data.Topic
 
-class TopicsListViewModel(val dataSource: DataSource) : ViewModel() {
+class TopicsViewModel(val dataSource: DataSource) : ViewModel() {
     val topics: LiveData<List<Topic>> = dataSource.getTopicList()
 
     fun add(topic: Topic) {
-        dataSource.addTopic(topic)
+        dataSource.add(topic)
+    }
+
+    fun get(id: Long) : Topic? {
+        return dataSource.get(id)
+    }
+
+    fun remove(topic: Topic) {
+        dataSource.remove(topic)
     }
 }
 
-class TopicsListViewModelFactory(private val context: Context) : ViewModelProvider.Factory {
+class TopicsViewModelFactory(private val context: Context) : ViewModelProvider.Factory {
     override fun <T : ViewModel> create(modelClass: Class<T>): T {
-        if (modelClass.isAssignableFrom(TopicsListViewModel::class.java)) {
+        if (modelClass.isAssignableFrom(TopicsViewModel::class.java)) {
             @Suppress("UNCHECKED_CAST")
-            return TopicsListViewModel(
+            return TopicsViewModel(
                 dataSource = DataSource.getDataSource(context.resources)
             ) as T
         }

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

@@ -25,7 +25,7 @@ class DataSource(resources: Resources) {
     private val topicsLiveData: MutableLiveData<List<Topic>> = MutableLiveData(mutableListOf())
 
     /* Adds topic to liveData and posts value. */
-    fun addTopic(topic: Topic) {
+    fun add(topic: Topic) {
         val currentList = topicsLiveData.value
         if (currentList == null) {
             topicsLiveData.postValue(listOf(topic))
@@ -37,7 +37,7 @@ class DataSource(resources: Resources) {
     }
 
     /* Removes topic from liveData and posts value. */
-    fun removeTopic(topic: Topic) {
+    fun remove(topic: Topic) {
         val currentList = topicsLiveData.value
         if (currentList != null) {
             val updatedList = currentList.toMutableList()
@@ -47,7 +47,7 @@ class DataSource(resources: Resources) {
     }
 
     /* Returns topic given an ID. */
-    fun getTopicForId(id: Long): Topic? {
+    fun get(id: Long): Topic? {
         topicsLiveData.value?.let { topics ->
             return topics.firstOrNull{ it.id == id}
         }
@@ -59,12 +59,12 @@ class DataSource(resources: Resources) {
     }
 
     companion object {
-        private var INSTANCE: DataSource? = null
+        private var instance: DataSource? = null
 
         fun getDataSource(resources: Resources): DataSource {
             return synchronized(DataSource::class) {
-                val newInstance = INSTANCE ?: DataSource(resources)
+                val newInstance = instance ?: DataSource(resources)
-                INSTANCE = newInstance
+                instance = newInstance
                 newInstance
             }
         }

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

@@ -22,11 +22,13 @@ import android.widget.TextView
 import androidx.activity.viewModels
 import androidx.appcompat.app.AppCompatActivity
 import io.heckel.ntfy.R
-import io.heckel.ntfy.list.TOPIC_ID
+import io.heckel.ntfy.TOPIC_ID
+import io.heckel.ntfy.list.TopicsViewModel
+import io.heckel.ntfy.list.TopicsViewModelFactory
 
 class TopicDetailActivity : AppCompatActivity() {
-    private val topicDetailViewModel by viewModels<TopicDetailViewModel> {
+    private val topicDetailViewModel by viewModels<TopicsViewModel> {
-        TopicDetailViewModelFactory(this)
+        TopicsViewModelFactory(this)
     }
 
     override fun onCreate(savedInstanceState: Bundle?) {
@@ -47,12 +49,12 @@ class TopicDetailActivity : AppCompatActivity() {
         /* If currentTopicId is not null, get corresponding topic and set name, image and
         description */
         currentTopicId?.let {
-            val currentTopic = topicDetailViewModel.getTopicForId(it)
+            val currentTopic = topicDetailViewModel.get(it)
             topicUrl.text = currentTopic?.url
 
             removeTopicButton.setOnClickListener {
                 if (currentTopic != null) {
-                    topicDetailViewModel.removeTopic(currentTopic)
+                    topicDetailViewModel.remove(currentTopic)
                 }
                 finish()
             }

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

@@ -1,49 +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.detail
-
-import android.content.Context
-import androidx.lifecycle.ViewModel
-import androidx.lifecycle.ViewModelProvider
-import io.heckel.ntfy.data.DataSource
-import io.heckel.ntfy.data.Topic
-
-class TopicDetailViewModel(private val datasource: DataSource) : ViewModel() {
-
-    /* Queries datasource to returns a topic that corresponds to an id. */
-    fun getTopicForId(id: Long) : Topic? {
-        return datasource.getTopicForId(id)
-    }
-
-    /* Queries datasource to remove a topic. */
-    fun removeTopic(topic: Topic) {
-        datasource.removeTopic(topic)
-    }
-}
-
-class TopicDetailViewModelFactory(private val context: Context) : ViewModelProvider.Factory {
-
-    override fun <T : ViewModel> create(modelClass: Class<T>): T {
-        if (modelClass.isAssignableFrom(TopicDetailViewModel::class.java)) {
-            @Suppress("UNCHECKED_CAST")
-            return TopicDetailViewModel(
-                datasource = DataSource.getDataSource(context.resources)
-            ) as T
-        }
-        throw IllegalArgumentException("Unknown ViewModel class")
-    }
-}